EP2816094B1 - Method for producing gasoline with low sulphur and mercaptan content - Google Patents

Method for producing gasoline with low sulphur and mercaptan content Download PDF

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Publication number
EP2816094B1
EP2816094B1 EP14305833.7A EP14305833A EP2816094B1 EP 2816094 B1 EP2816094 B1 EP 2816094B1 EP 14305833 A EP14305833 A EP 14305833A EP 2816094 B1 EP2816094 B1 EP 2816094B1
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Prior art keywords
gasoline
catalyst
weight
cut
range
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EP14305833.7A
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German (de)
French (fr)
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EP2816094A1 (en
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Julien Gornay
Philibert Leflaive
Annick Pucci
Olivier TOUZALIN
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IFP Energies Nouvelles IFPEN
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IFP Energies Nouvelles IFPEN
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Priority claimed from FR1355749A external-priority patent/FR3007416B1/en
Priority claimed from FR1453795A external-priority patent/FR3020376B1/en
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
    • C10G45/02—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
    • C10G45/04—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used
    • C10G45/06—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing nickel or cobalt metal, or compounds thereof
    • C10G45/08—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing nickel or cobalt metal, or compounds thereof in combination with chromium, molybdenum, or tungsten metals, or compounds thereof
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
    • C10G45/02—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
    • C10G45/04—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
    • C10G45/02—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
    • C10G45/04—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used
    • C10G45/12—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing crystalline alumino-silicates, e.g. molecular sieves
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
    • C10G65/02—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only
    • C10G65/04—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only including only refining steps
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
    • C10G65/02—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only
    • C10G65/04—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only including only refining steps
    • C10G65/06—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only including only refining steps at least one step being a selective hydrogenation of the diolefins
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
    • C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/10—Feedstock materials
    • C10G2300/1037—Hydrocarbon fractions
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/20—Characteristics of the feedstock or the products
    • C10G2300/201—Impurities
    • C10G2300/202—Heteroatoms content, i.e. S, N, O, P
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/40—Characteristics of the process deviating from typical ways of processing
    • C10G2300/405—Limiting CO, NOx or SOx emissions
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/70—Catalyst aspects
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/80—Additives
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
    • C10G2400/02—Gasoline

Definitions

  • the present invention relates to a process for producing gasoline with a low sulfur and mercaptan content.
  • the residual sulfur compounds generally present in the desulfurized gasoline can be separated into two distinct families: the unconverted sulfur compounds present in the feed on the one hand, and the sulfur compounds formed in the reactor by so-called recombination side reactions.
  • the majority compounds are the mercaptans resulting from the addition of H 2 S formed in the reactor on the mono-olefins present in the feed.
  • the mercaptans of chemical formula R-SH, where R is an alkyl group are also called recombinant mercaptans and generally represent between 20% and 80% by weight of the residual sulfur in the desulfurized gasolines.
  • An object of the present invention is to provide a process for the treatment of a gasoline containing sulfur, part of which is in the form of mercaptans, which makes it possible to reduce the mercaptan content of said hydrocarbon fraction while minimizing the loss of octane and the consumption of reagents such as hydrogen or extraction solvents.
  • step c) of demercaptization which can also be described as a non-desulfurizing softening step, makes it possible to produce a gasoline having a low mercaptan content specification without requiring a severe and costly hydrodesulfurization finishing step.
  • step a Another advantage of the process according to the invention comes from the fact that it makes it possible to achieve a very low content of mercaptans (eg less than 10 ppm by weight) in the final desulfurized gasoline with operating conditions for the hydrodesulfurization step. (step a) much less severe (for example significant reduction in temperature and / or operating pressure), which has the effect of limiting the loss of octane, of increasing the lifetime of the catalyst of the hydrodesulfurization step and also reduce energy consumption.
  • step a much less severe (for example significant reduction in temperature and / or operating pressure), which has the effect of limiting the loss of octane, of increasing the lifetime of the catalyst of the hydrodesulfurization step and also reduce energy consumption.
  • the group VIII metal is nickel and the group VIB metal is molybdenum.
  • the method according to the invention may include a step in which the effluent from step b) is mixed with a hydrocarbon cut chosen from an LPG cut (liquefied petroleum gas), a gasoline cut resulting from a distillation crude oil, a pyrolysis unit, a coking unit, a hydrocracking unit, an oligomerization unit and a C4 olefinic cut, and the mixture is treated in step c ).
  • a hydrocarbon cut chosen from an LPG cut (liquefied petroleum gas), a gasoline cut resulting from a distillation crude oil, a pyrolysis unit, a coking unit, a hydrocracking unit, an oligomerization unit and a C4 olefinic cut, and the mixture is treated in step c ).
  • the effluent from step c) is fractionated so as to separate an unreacted C4 olefinic cut and said unreacted C4 olefinic cut is recycled to the reactor of step c).
  • the effluent from step b) is mixed with an olefinic cut at C4 in order to promote the reaction for adding mercaptans to olefins in the softening reactor.
  • the effluent from step c) of softening is fractionated so as to separate a cut containing C4 olefins which have not reacted and said olefinic cut into C4 is recycled in the softening reactor.
  • step a) a gasoline distillation step is carried out so as to split said gasoline into at least two light and heavy gasoline cuts and the heavy gasoline cut is treated in steps a), b) and c ).
  • the effluent from step b) is mixed with the light gasoline cut from the distillation so as to produce a mixture and said mixture is treated in step c).
  • step a) a step of distilling the gasoline so as to fractionate said gasoline in at at least two light and heavy petrol cuts, the heavy petrol cut is treated in step a), the light petrol cut is mixed with the effluent from step a) so as to produce a mixture and said mixture is treated in steps b) and c).
  • the mixture with the light gasoline cuts contains up to 50% volume of the light gasoline cut.
  • a gasoline distillation step is carried out so as to split said gasoline into at least three light, intermediate and heavy gasoline cuts respectively and then the gasoline cut is processed intermediate in step a) then step b) and step c).
  • the heavy gasoline fraction resulting from the distillation is advantageously treated in a hydrodesulfurization step in a dedicated unit and then subjected to a step of softening in mercaptans after elimination of the H 2 S.
  • the step softening of the desulfurized heavy petrol cut can be carried out either in a dedicated reactor or in the same softening reactor as that which processes the intermediate petrol cut (the intermediate and heavy cuts are treated as a mixture in a softening reactor) .
  • step a) and before any possible distillation step it is also possible, before step a) and before any possible distillation step, to bring the gasoline into contact with hydrogen and a selective hydrogenation catalyst to selectively hydrogenate the diolefins contained in said gasoline into olefins.
  • This step of selective hydrogenation of diolefins can be carried out in a catalytic distillation column equipped with a section comprising a selective hydrogenation catalyst.
  • steps a) and / or c) can be implemented in reactors which are catalytic columns including at least one catalytic bed, in which both the reaction are carried out catalytic and the separation of gasoline into at least two cuts (or fraction).
  • step a) is carried out in a catalytic column
  • the sections coming from the catalytic column are sent to step b) and c) separately or as a mixture in order to lower the mercaptans content.
  • step a) is carried out in a catalytic column, only the light cut, drawn off at the head of the catalytic column which concentrates the mercaptans, is sent to steps b) and c).
  • the method further comprises a step d) in which the effluent from step c) is sent to a fractionation column and a gasoline cut with a low mercaptan content is separated at the top of the fractionation column and a section of hydrocarbons containing thioether compounds at the bottom of the fractionation column.
  • Steps c) and d) are advantageously carried out concomitantly in a catalytic distillation column comprising a catalyst bed from step c).
  • the catalyst of step a) contains at least one group VIB metal and / or at least one group VIII metal on a support having a specific surface of less than 250 m 2 / g, in which the metal content of group VIII expressed as oxide is between 0.5 and 15% by weight and the metal content of group VIB, expressed as oxide, is between 1.5 and 60% by weight relative to the weight of catalyst.
  • the catalyst of step a) comprises cobalt and molybdenum and the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface of the catalyst, is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 .
  • step c) is carried out in the absence of supply of hydrogen.
  • the invention relates to a process for the treatment of gasolines comprising all types of chemical families and in particular diolefins, mono-olefins, and sulfur-containing compounds.
  • the present invention finds its application particularly in the conversion of conversion essences, and in particular essences from catalytic cracking, catalytic cracking in a fluid bed (FCC), a coking process, a visbreaking process, or a pyrolysis process.
  • FCC fluid bed
  • gasolines from catalytic cracking units (FCC) contain, on average, between 0.5% and 5% by weight of diolefins, between 20% and 50% by weight of mono-olefins, between 10 ppm and 0, 5% sulfur weight
  • the gasoline treated generally has a boiling point of less than 350 ° C, preferably less than 300 ° C and very preferably less than 220 ° C.
  • the fillers for which the process according to the invention applies have a boiling temperature of between 0 ° C and 280 ° C, preferably between 30 ° C and 250 ° C.
  • the fillers can also contain hydrocarbons with 3 or 4 carbon atoms.
  • the hydrodesulfurization step is implemented to reduce the sulfur content of the gasoline to be treated by converting the sulfur compounds to H 2 S which is then eliminated in step b). Its implementation is particularly necessary when the feed to be desulfurized contains more than 100 ppm by weight of sulfur and more generally more than 50 ppm by weight of sulfur.
  • the hydrodesulfurization step consists in bringing the gasoline to be treated into contact with hydrogen, in one or more hydrodesulfurization reactors, containing one or more catalysts suitable for carrying out the hydrodesulfurization.
  • step a) is implemented with the aim of carrying out hydrodesulfurization selectively, that is to say with a hydrogenation rate of the mono-olefins lower than 80%, preferably less than 70% and very preferably less than 60%.
  • the operating pressure of this step is generally between 0.5 MPa and 5 MPa and preferably between 1 MPa and 3 MPa.
  • the temperature is generally between 200 ° C and 400 ° C and preferably between 220 ° C and 380 ° C.
  • the average operating temperature of each reactor is generally at least 5 ° C. higher, preferably at least 10 ° C. and very preferably at least 30 ° C. at the operating temperature of the reactor which precedes it.
  • the amount of catalyst used in each reactor is generally such that the ratio between the flow rate of gasoline to be treated expressed in m 3 per hour at standard conditions, per m 3 of catalyst (also called space speed) is between 0.5 h -1 and 20 h -1 and preferably between 1 h -1 and 15 h -1 .
  • the hydrodesulfurization reactor is operated with a space speed of between 2 h -1 and 8 h -1 .
  • the hydrogen flow rate is generally such that the ratio between the hydrogen flow rate expressed in normal m 3 per hour (Nm 3 / h) and the feed flow rate to be treated expressed in m 3 per hour at standard conditions is between 50 Nm 3 / m 3 and 1000 Nm 3 / m 3 , preferably between 70 Nm 3 / m 3 and 800 Nm 3 / m 3 .
  • the desulfurization rate which depends on the sulfur content of the feed to be treated, is generally greater than 50% and preferably greater than 70% so that the product resulting from stage a) contains less than 100 ppm by weight of sulfur and preferably less than 50 ppm by weight of sulfur.
  • the process comprises a succession of hydrodesulfurization steps, such that the activity of the catalyst of a step n + 1 is between 1% and 90% of the activity of the stage n catalyst, as taught in the document EP 1612255 .
  • Any catalyst known to a person skilled in the art capable of promoting reactions for converting organic sulfur into H 2 S in the presence of hydrogen can be used within the framework of the invention.
  • the hydrodesulfurization catalyst of step a) generally contains at least one metal from group VIB and / or at least one metal from group VIII on a support (groups VIB and VIII according to the CAS classification correspond respectively to the metals groups 6 and groups 8 to 10 of the new IUPAC classification according to CRC Handbook of Chemistry and Physics, CRC press editor, editor-in-chief DR Lide, 81st edition, 2000-2001 ).
  • group VIB metal is preferably molybdenum or tungsten and the group VIII metal is preferably chosen from nickel or cobalt.
  • the catalyst of step a) comprises cobalt and molybdenum.
  • the content of group VIII metal expressed as oxide is generally between 0.5% and 15% by weight, preferably between 1% and 10% by weight relative to the total weight of the catalyst.
  • the metal content of group VIb is generally between 1.5% and 60% by weight, preferably between 3% and 50% by weight relative to the total weight of the catalyst.
  • the catalyst support is usually a porous solid, such as for example an alumina, a silica-alumina, magnesia, silica or titanium oxide, alone or as a mixture.
  • the support consists essentially of transition alumina, that is to say that it comprises at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight , or even at least 90% by weight of transition alumina relative to the total weight of the support. It can optionally consist only of a transition alumina.
  • the hydrodesulfurization catalyst preferably has a specific surface of less than 250 m 2 / g, more preferably less than 230 m 2 / g, and very preferably less than 190 m 2 / g.
  • a catalyst comprising molybdenum alone or in admixture with nickel or cobalt and in which the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface of the catalyst is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 .
  • a catalyst is chosen comprising cobalt and molybdenum, the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface area of the catalyst, is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 .
  • the hydrodesulfurization catalyst before sulfiding, has an average pore diameter greater than 20 nm, preferably greater than 25 nm, or even 30 nm and often between 20 and 140 nm, preferably between 20 and 100 nm, and very preferably between 25 and 80 nm.
  • the pore diameter is measured by mercury porosimetry according to standard ASTM D4284-92 with a wetting angle of 140 °.
  • the deposition of metals on the support is obtained for all methods known to those skilled in the art, such as, for example, dry impregnation, by excess of a solution containing the metal precursors. Said solution is chosen so as to be able to dissolve the metal precursors in the desired concentrations.
  • the molybdenum precursor can be molybdenum oxide, ammonium heptamolybdate.
  • cobalt mention may, for example, be made of cobalt nitrate, cobalt hydroxide, cobalt carbonate.
  • the precursors are generally dissolved in a medium allowing their solubilization in the desired concentrations. This can therefore be, depending on the case, carried out in an aqueous medium and / or in an organic medium.
  • the catalyst After introduction of the metal or metals and optionally shaping of the catalyst, the catalyst is in a first activated stage.
  • This activation can correspond either to a calcination (oxidation) then to a reduction, or to a direct reduction, or to a calcination only.
  • the calcination step is generally carried out at temperatures ranging from 100 ° C to 600 ° C and preferably between 200 ° C and 450 ° C, under an air flow.
  • the reduction step is carried out under conditions which make it possible to convert at least part of the oxidized forms of the base metal to metal. Generally, it consists in treating the catalyst under a stream of hydrogen at a temperature preferably at least equal to 300 ° C.
  • the catalyst is preferably used at least in part in its sulfurized form.
  • the introduction of sulfur can occur before or after any activation step, that is to say calcination or reduction.
  • no oxidation step of the catalyst is carried out when the sulfur or a sulfur-containing compound has been introduced onto the catalyst.
  • the sulfur or a sulfur-containing compound can be introduced ex situ, that is to say outside the reactor where the process according to the invention is carried out, or in situ, that is to say in the reactor used for the method according to the invention.
  • the catalyst is preferably sulfurized by passing a charge containing at least one sulfur compound, which once decomposed leads to the fixing of sulfur on the catalyst.
  • This charge can be gaseous or liquid, for example hydrogen containing H 2 S, or a liquid containing at least one sulfur-containing compound.
  • the sulfur-containing compound is added to the catalyst ex situ.
  • a sulfur-containing compound can be introduced onto the catalyst in the optional presence of another compound.
  • the catalyst is then dried, then transferred to the reactor used to carry out the process according to the invention. In this reactor, the catalyst is then treated under hydrogen in order to transform at least part of the main metal into sulphide.
  • a procedure which is particularly suitable for the sulfurization of the catalyst is that described in the documents. FR 2 708 596 and FR 2 708 597 .
  • step a) is carried out in a catalytic distillation column provided with a section comprising a hydrodesulfurization catalyst, in which both the catalytic hydrodesulfurization reaction and the separation are carried out gasoline in at least two cuts (or fractions).
  • the catalytic distillation column comprises two beds of hydrodesulfurization catalyst and the charge is sent to the column between the two catalyst beds.
  • This step is implemented in order to separate the excess hydrogen as well as the H 2 S formed during step a) from the effluent from step a). Any method known to a person skilled in the art can be envisaged.
  • the effluent is cooled to a temperature generally below 80 ° C and preferably below 60 ° C in order to condense the hydrocarbons.
  • the gas and liquid phases are then separated in a separation flask.
  • the liquid fraction which contains the desulfurized gasoline as well as a fraction of the dissolved H 2 S is sent to a stabilization column or debutanizer. This column separates a head section essentially consisting of residual H 2 S and of hydrocarbon compounds having a boiling temperature lower than or equal to that of butane and a bottom section stripped of H 2 S, called stabilized gasoline, containing compounds having a boiling point higher than that of butane.
  • the liquid fraction which contains the desulfurized gasoline as well as a fraction of the dissolved H 2 S is sent to a stripping section, while the gaseous fraction constituted mainly hydrogen and H 2 S is sent to a purification section.
  • the stripping can be carried out by heating the hydrocarbon fraction alone or with an injection of hydrogen or water vapor, in a distillation column in order to extract, at the top, the light compounds which have been entrained by dissolution in the liquid fraction. as well as the residual dissolved H 2 S.
  • the temperature of the stripped gasoline recovered at the bottom of the column is generally between 120 ° C and 250 ° C.
  • Step b) is preferably implemented so that the sulfur in the form of H 2 S remaining in the desulfurized gasoline, before the demercaptization (softening) step c) represents less than 30%, preferably less than 20% and more preferably less than 10% of the total sulfur present in the treated hydrocarbon fraction.
  • This step consists in transforming the sulfur compounds of the mercaptan family into heavier sulfur compounds of the thioether type.
  • These mercaptans are essentially recombinant mercaptans resulting from the reaction of the H 2 S formed in step a) with the olefins of gasoline.
  • the transformation reaction involved in this step c) consists in reacting the mercaptans on the olefins to form heavier sulfur compounds of the thioether type. It should be noted that this step is to be distinguished from a "conventional" hydrodesulfurization step which aims to transform, in the presence of hydrogen, the sulfur-containing compounds into H 2 S.
  • This step also makes it possible to convert the residual H 2 S, which would not have been completely eliminated during step b), into thioether by reaction with the olefins present in the feed.
  • the demercaptization (or softening) reaction is carried out on a catalyst comprising at least one sulfide of a metal chosen from group VIB, group VIII, copper and lead, deposited on a porous support capable of transforming the sulfur compounds of the mercaptan family, by reaction with petroleum olefins to sulfur compounds of the thioether type.
  • the catalyst comprises at least one element from group VIII (groups 8, 9 and 10 of the new periodic classification Handbook of Chemistry and Physics, 76th edition, 1995-1996 ), at least one element from group VIB (group 6 of the new periodic classification) Handbook of Chemistry and Physics, 76th edition, 1995-1996 ) and a support.
  • the element of group VIII is preferably chosen from nickel and cobalt and in particular nickel.
  • the element of group VIB is preferably chosen from molybdenum and tungsten and very preferably molybdenum.
  • the catalyst support of step c) is preferably chosen from alumina, nickel aluminate, silica, silicon carbide, or a mixture of these oxides.
  • Alumina is preferably used, and even more preferably alumina is used. pure.
  • a support is used which has a total pore volume measured by mercury porosimetry of between 0.4 and 1.4 cm 3 / g and preferably between 0.5 and 1.3 cm 3 / g.
  • the specific surface of the support is preferably between 70 m 2 / g and 350 m 2 / g.
  • the support is a cubic gamma alumina or a delta alumina.
  • a very preferred embodiment of the invention corresponds to the use for step c) of a catalyst containing a content by weight relative to the total weight of nickel oxide catalyst (in NiO form) between 4 and 12%, a content by weight relative to the total weight of molybdenum oxide catalyst (in MoO 3 form) of between 6% and 18%, a nickel / molybdenum molar ratio of between 1 and 2.5, the metals being deposited on a support consisting solely of gamma alumina with a specific surface of between 180 m 2 / g and 270 m 2 / g and the sulfurization rate of the metals constituting the catalyst being greater than 80%.
  • the catalyst for step c) can be prepared using any technique known to those skilled in the art, and in particular by impregnating the metals on the selected support.
  • the latter After introduction of the metals, and possibly shaping of the catalyst, the latter undergoes an activation treatment.
  • This treatment generally aims to transform the molecular precursors of the elements in the oxide phase. In this case it is an oxidizing treatment but a simple drying of the catalyst can also be carried out.
  • an oxidizing treatment also called calcination, it is generally carried out in air or under dilute oxygen, and the treatment temperature is generally between 200 ° C and 550 ° C, preferably between 300 ° C and 500 ° C.
  • the metals deposited on the support are in the form of oxide.
  • the metals are mainly found in the form of MoO 3 and NiO.
  • the sulfurization is preferably carried out in a sulforeductive medium, that is to say in the presence of H 2 S and of hydrogen, in order to transform the metal oxides into sulphides such as for example, MoS 2 and Ni 3 S 2 .
  • Sulfurization is carried out by injecting a flux containing H 2 S and hydrogen onto the catalyst, or else a sulfur-containing compound capable of decomposing into H 2 S in the presence of the catalyst and hydrogen.
  • Polysulfides such as dimethyldisulfide (DMDS) are precursors of H 2 S commonly used to sulfurize catalysts.
  • the temperature is adjusted so that the H 2 S reacts with the metal oxides to form metal sulfides.
  • This sulfurization can be carried out in situ or ex situ (inside or outside the reactor) of the demercaptization reactor, at a temperature between 200 ° C and 600 ° C and more preferably between 300 ° C and 500 ° C.
  • Step c) of softening in mercaptans consists in bringing the desulphurized gasoline and freed of at least part of the H 2 S into contact with the catalyst in sulphide form.
  • the demercaptization reactions according to the invention are characterized by a reaction of the mercaptans on the olefins via a direct addition on the double bond to produce compounds of the thioether type, of formula R1-S-R2 with R1 and R2 being alkyl radicals, whose boiling point is higher than that of the starting mercaptans.
  • This softening step can be carried out in the absence (without addition or addition of hydrogen) or in the presence of hydrogen supplied to the reactor. Preferably, it is carried out in the absence of hydrogen supply. When hydrogen is used, this is injected with the charge so as to maintain a hydrogenating surface state of the catalyst suitable for high conversions to demercaptization.
  • step c) operates with a H 2 / feed ratio of between 0 and 10 Nm 3 of hydrogen per m 3 of feed, very preferably between 0 and 5 Nm 3 of hydrogen per m 3 of feed, and even more preferably between 0 and 2 Nm 3 of hydrogen per m 3 of feed.
  • the entire charge is generally injected at the inlet of the reactor. However, it may be advantageous in certain cases to inject a fraction or all of the charge between two consecutive catalytic beds placed in the reactor.
  • the gasoline to be treated is brought into contact with the catalyst at a temperature between 30 ° C and 250 ° C, and preferably between 60 ° C and 220 ° C, and even more preferably between 90 ° C and 200 ° C, with a liquid space speed (LHSV) of between 0.5 h -1 and 10 h -1 , the unit of the liquid space speed being the liter of feed per liter of catalyst and per hour (l / lh).
  • the pressure is between 0.2 MPa and 5 MPa, preferably between 0.5 and 2 MPa and even more preferably between 0.6 and 1 MPa.
  • the mercaptans which combine with the olefins of the feed to form thioether compounds have a carbon number typically between 5 and 12 and are more generally branched.
  • the mercaptans which may be contained in the feed of step c) are 2-methylhexan-2-thiol, 4-methylheptan-4-thiol, 2-ethyl-hexan-3-thiol or 2,2,4-trimethylpentan-4-thiol.
  • the hydrocarbon fraction treated under the conditions set out above therefore has a reduced mercaptan content (the latter have been converted to thioether compounds).
  • the gasoline produced at the end of step c) contains less than 20 ppm by weight of mercaptans, and preferably less than 10 ppm by weight, and even more preferably less than 5 ppm by weight.
  • the olefins are not or very little hydrogenated, which makes it possible to maintain a good octane number of the effluent at the outlet of the step vs).
  • the rate of hydrogenation of olefins is generally less than 2%.
  • step c) the gasoline treated under the conditions set out above therefore has a reduced content of mercaptans. Indeed the latter were converted into compounds of the thioether type whose molecular point is higher than the starting mercaptans.
  • a fractionation step (step d) of the gasoline softened into mercaptans is carried out into at least one light cut and one heavy cut of hydrocarbons.
  • This fractionation step is carried out under conditions such that the sulfur-containing compounds of the thioether type formed in step c) and optionally the heaviest and most refractory residual mercaptans which have not reacted during step c) concentrate in heavy cutting of hydrocarbons.
  • the fractionation step is carried out in such a way that the light cutting of hydrocarbons with a low sulfur content, in particular mercaptans and sulphide compounds, has a final boiling temperature of between 130 and 160 ° C. .
  • the cutting point ie the final boiling temperature of the light cut of hydrocarbons
  • the light petrol cut has a mercaptan content of less than 10 ppm by weight, preferably less than 5 ppm by weight and more preferably less than 1 ppm by weight and a total sulfur content of less than 50 ppm by weight, preferably less than 20 ppm by weight and more preferably less than 10 ppm by weight.
  • the light cut of hydrocarbons with low sulfur and mercaptan content is advantageously sent to the petrol pool of the refinery.
  • hydrodesulfurization which applies more severe hydrotreatment conditions (higher temperature, higher quantity of hydrogen used) or is alternatively sent to the diesel pool of the refinery.
  • step c) and the fractionation (step d) can be carried out simultaneously by means of a catalytic column equipped with a catalytic bed containing the softening catalyst.
  • the catalytic distillation column has two softening catalyst beds and the charge is sent to the column between the two catalyst beds.
  • step c) of catalytic softening can be implemented directly in series with step b) of separation.
  • step b) of separation is carried out at a temperature compatible with the operating temperature of step c) of catalytic softening
  • the effluent from step b) is sent directly in step c). It can also be envisaged to adjust the temperature between steps b) and c) by means of heat exchange devices.
  • a mixture of the gasoline obtained from step b) is mixed with an LPG cut (liquefied petroleum gas) or another gasoline cut containing sulfur.
  • LPG cut liquefied petroleum gas
  • another gasoline cut containing sulfur such as, for example, petroleum distillation essences, essences resulting from any cracking process such as essences resulting from pyrolysis, coking or hydrocracker processes, or a essence originating from an oligomerization unit and then the mixture is treated in step c).
  • LPG cut liquefied petroleum gas
  • another gasoline cut containing sulfur such as, for example, petroleum distillation essences, essences resulting from any cracking process such as essences resulting from pyrolysis, coking or hydrocracker processes, or a essence originating from an oligomerization unit.
  • step c) softening the essence from step b) mixed with a cut C4 olefinic hydrocarbons to promote the catalytic reaction of addition of mercaptans (recombination) with olefins.
  • a step of distilling the gasoline to be treated is carried out in order to separate two cuts (or fractions), namely a light cut and a heavy cut, and the heavy cut is treated according to the process of the invention.
  • the heavy cut is treated by hydrodesulfurization (step a), then the H 2 S formed present in the heavy hydrodesulfurized cut (step b) is separated, then the light cut (after the distillation) with the heavy cut from step b) and finally the mixture is treated in step c).
  • a light cut is mixed with the heavy hydrodesulfurized cut from step a), the mixture thus obtained is treated in step b) and c) .
  • This third variant has the advantage of not hydrotreating the light cut which is rich in olefins and generally poor in sulfur, which makes it possible to limit the loss of octane by hydrogenation of the olefins.
  • the charge treated in step c) consists of the entire desulfurized heavy cut and a portion of between 0 and 50% volume of the light cut.
  • the light cut has a boiling temperature range of less than 100 ° C. and the heavy cut has a temperature range of more than 65 ° C.
  • a distillation of the gasoline is carried out in two cuts: a first light cut and a first heavy cut of hydrocarbons.
  • the first light cut has a boiling temperature between the initial boiling temperature of the gasoline to be treated and a final boiling temperature between 140 ° C and 160 ° C.
  • the first light cut of hydrocarbons is then treated by hydrodesulfurization (step a), then the H 2 S formed is separated from the hydrodesulfurized effluent (step b), the hydrodesulfurized effluent is softened in mercaptans (step c) and splits the softened effluent into mercaptans (step d) so as to produce a second light gasoline cut (the boiling temperature of which is between the initial boiling temperature of the gasoline to be treated and a lower final boiling temperature or equal to 140 ° C.) with a low content of mercaptans and thioethers and a second heavy cut of hydrocarbons containing thioethers and unconverted mercaptans.
  • the first and second heavy cuts of hydrocarbons can be mixed and treated by hydrodesulfurization in a dedicated unit.
  • a distillation of the gasoline is carried out in three light, intermediate and heavy cuts of hydrocarbons using one or more columns to be distilled.
  • the light cut of hydrocarbons preferably has a boiling temperature between the initial boiling temperature of the gasoline to be treated and a final boiling temperature between 50 ° C and 90 ° C.
  • Such a light cut of hydrocarbons generally contains little sulfur and therefore can be directly valued at the petrol pool of the refinery.
  • the intermediate cut of hydrocarbons which has a range of boiling temperatures generally between 50 ° C and 140 ° C or 160 ° C is treated by hydrodesulfurization (step a), then the H 2 S formed is separated from the hydrodesulfurized effluent (step b), the softened hydrodesulfurized effluent (step c) is softened into mercaptans and the softened effluent is separated into mercaptans (step d) so as to produce a second intermediate gasoline fraction low in mercaptans and thioethers and a second heavy cut of hydrocarbons containing thioethers and unconverted mercaptans.
  • the first and second heavy cuts of hydrocarbons can be mixed and treated by hydrodesulfurization in a dedicated unit.
  • the gasoline to be treated is first subjected to a prior step consisting in a selective hydrogenation of the diolefins present in the feed, as described in the application for EP 1077247 .
  • the selectively hydrogenated gasoline is then distilled in at least two cuts or three cuts of hydrocarbons, a light cut, an intermediate cut and a heavy cut.
  • the steps described above in the case of the third and fourth variants are applicable.
  • the intermediate fraction is treated separately in a hydrodesulfurization stage (stage a), then a stage of separation of H 2 S (stage b) and then in a stage d softening (step c).
  • the effluent from step c) is subjected to a fractionation step d) so as to produce a second intermediate gasoline fraction low in mercaptans and thioethers content and a second heavy fraction of hydrocarbons containing thioethers and non-mercaptans. converted.
  • the second heavy cut of hydrocarbons is mixed with the heavy cut resulting from the distillation upstream of the hydrodesulfurization step and the mixture is treated by hydrodesulfurization in a dedicated unit.
  • step a) is carried out in a catalytic distillation column incorporating a bed of hydrodesulfurization catalyst allowing simultaneously to desulfurize the gasoline and to separate it into two light and heavy cuts of hydrocarbons.
  • the sections produced are then sent in steps b) and c) separately or as a mixture.
  • steps b) and c) only the light gasoline fraction from the catalytic hydrodesulfurization distillation column is treated in steps b) then c).
  • the effluent from step c) can be split into two hydrocarbon fractions in accordance with step d) described above.
  • the heavy cut from the hydrodesulfurization catalytic distillation column can be treated in a second hydrodesulfurization unit, alone or in mixture with the heavy cut from step d) of fractionation of the gasoline cut. light from the catalytic hydrodesulfurization distillation column.
  • step c) In the cases where step c) is carried out on the light cut, in order to improve the conversion rate of the mercaptans (of recombination) into thioether during step c), a mixture of an olefinic cut in C4 is advantageously carried out upstream of step c) with light gasoline so that step c) is advantageously carried out on a mixture containing the light cut of hydrocarbons and an olefinic cut in C4 and not the light cut alone .
  • the effluent softened in mercaptans is sent to a separation column which separates an olefinic cut C4 and a light cut softened in mercaptans.
  • the olefinic cut C4 withdrawn from the separation column is advantageously recycled in the reactor of step c).
  • step c) is carried out on an intermediate or heavy cut, in order to improve the rate of conversion of the mercaptans (of recombination) into thioether during step c), all or part of the light gasoline is advantageously added to the intermediate or heavy cut upstream of step c) so that step c) is advantageously carried out on a mixture containing olefins provided by the light cut of hydrocarbons.
  • the gasoline to be treated is sent by line 1 and hydrogen by line 3 in a hydrodesulfurization unit 2.
  • the gasoline treated is generally a gasoline cracking, preferably a catalytic cracking essence.
  • Gasoline is characterized by a boiling temperature typically ranging between 30 ° C and 220 ° C.
  • the hydrodesulfurization unit 2 is for example a reactor containing a hydrodesulfurization catalyst (HDS) in a fixed bed or in a fluidized bed, preferably a reactor in a fixed bed is used. The reactor is operated under operating conditions and in the presence of an HDS catalyst, as described above to decompose the sulfur compounds and form hydrogen sulfide (H 2 S).
  • HDS hydrodesulfurization catalyst
  • an effluent (gasoline) containing H 2 S is removed from said hydrodesulfurization reactor 2 via line 4.
  • the effluent is then subjected to a step of removing H 2 S (step b) which consists, in the embodiment of the figure 1 ,
  • step b To treat the effluent in a stabilization column 5 in order to separate the head of the column via line 6 a stream containing C4 hydrocarbons - the majority of H 2 S and unreacted hydrogen and bottom of the column a so-called stabilized gasoline.
  • the stabilized petrol is sent via line 7 to a softening reactor 8 (step c) in order to reduce the mercaptan content of the stabilized petrol.
  • the mercaptans contained in this stabilized gasoline are mainly recombinant mercaptans resulting from the reaction of H 2 S on olefins.
  • the softening reactor implements a catalyst making it possible to carry out the reaction for adding mercaptans to olefins via direct addition to the double bond to produce compounds of the thioether type, of formula R1-S -R2 with R1 and R2 being alkyl radicals, of molecular weight is higher than that of the starting mercaptan.
  • the catalytic reaction for converting mercaptans can optionally be carried out in the presence of hydrogen supplied by line 9.
  • the gasoline stabilized and softened in mercaptans drawn off by line 10 of the reactor 8 is advantageously sent to a separation column 11 which is designed and operated to separate at the head (via line 12) a light stabilized gasoline whose temperature range boiling is preferably between 30 ° C and 160 ° C or between 30 ° C and 140 ° C and which has mercaptan contents and in total sulfur respectively less than 10 ppm by weight and 50 ppm by weight.
  • a heavy petrol is recovered via line 13 which contains the thioether type compounds formed in the softening reactor 8.
  • the light petrol is sent to the petrol pool while the heavy petrol is either hydrodesulfurized in a dedicated hydrotreating unit, or sent to the diesel or distillate pool of the refinery.
  • the figure 2 represents a second embodiment based on that of the figure 1 and which is differentiated by the fact that the stabilized gasoline is treated in the mercaptans softening reactor 8 in the presence of an olefinic hydrocarbon cut, preferably a C4 olefinic cut, provided by line 14.
  • an olefinic hydrocarbon cut preferably a C4 olefinic cut, provided by line 14.
  • the purpose the addition of this olefinic cut is to promote the addition reaction of mercaptans on olefins by providing reactive olefins in the reaction medium.
  • the effluent from the softening reactor is sent to a separation column 15 in order to recover the fraction of the olefinic cut which has not reacted in the softening reactor 8.
  • the separation column 15 used is equivalent to a debutanizer which separates at the head of column 15 a cut C4 which is recycled in the softening reactor 8 via line 16.
  • the bottom cut 17 recovered from column 15 is fractional in column 11 as described under figure 1 in order to provide a light gasoline cut low in sulfur and mercaptans content via line 12 and a heavy gasoline cut containing the thioether compounds formed in the softening reactor 8.
  • the figure 3 illustrates a third embodiment of the method according to the invention.
  • the gasoline charge to be treated which typically comprises hydrocarbons boiling between 30 ° C. and 220 ° C.
  • the gasoline charge to be treated which typically comprises hydrocarbons boiling between 30 ° C. and 220 ° C.
  • a distillation column 20 configured to split the gasoline charge into three sections.
  • a head section comprising the compounds lighter than butane and including the latter is drawn off by line 21.
  • An intermediate section comprising the hydrocarbons having 6 to 7 or 6 to 8 carbon atoms is recovered by line 22.
  • a bottom section consisting of hydrocarbons having a number of carbon atoms greater than 7 or 8 carbon atoms is drawn off by line 23.
  • the petrol charge before being fractionated is advantageously pretreated in a selective hydrogenation reactor 19 of the diolefins to olefins.
  • This catalytic reaction is preferably carried out under the conditions and in the presence of a catalyst as described in the documents. EP 1445299 or EP 1800 750 .
  • the bottom section is treated in a hydrodesulfurization reactor 24 in the presence of hydrogen (supplied by line 25) and a hydrodesulfurization catalyst as described above.
  • the desulphurized effluent is withdrawn from reactor 24 by line 26 and sent to a separation unit 27 of H 2 S, such as for example a stripping column, from which a gas fraction is separated by line 28 essentially containing H 2 S and hydrogen and a low sulfur bottom section through line 29.
  • the intermediate petrol cut is treated by the method according to the invention.
  • the intermediate gasoline cut is sent via line 22 to a hydrodesulfurization reactor 2 to be desulfurized there in the presence of hydrogen supplied by line 3.
  • the effluent from reactor 2 is freed of the H 2 S formed during from the HDS stage in a separation unit 5.
  • the intermediate gasoline depleted in H 2 S is sent via line 7 with optionally hydrogen brought by line 9 into a mercaptan softening reactor 8.
  • the section intermediate gasoline softened in mercaptans is sent via line 10 to a fractionation column 11 operated to separate an intermediate gasoline cut with low mercaptans and sulfur content and an intermediate bottom cut. re in which the thioether compounds produced during the softening stage are concentrated.
  • the intermediate gasoline cut with low mercaptans and sulfur content is evacuated by line 12 to the petrol pool of the refinery while the intermediate bottom cut evacuated by line 13 is either desulphurized in a hydrotreating unit (for example a diesel hydrodesulfurization unit), or sent directly to the refinery's diesel pool.
  • a hydrotreating unit for example a diesel hydrodesulfurization unit
  • the intermediate bottom cut 13 can be desulphurized in the hydrodesulphurization reactor 24 in admixture with the bottom cut 23 resulting from the first fractionation step carried out in column 20.
  • the figure 4 discloses a fourth embodiment of the process according to the invention using catalytic distillation columns.
  • the petrol charge for example a cut of hydrocarbons boiling between 30 ° C and 220 ° C or between 30 ° C and 160 ° C, or even between 30 ° C and 140 ° C, is sent by line 1 in a first column catalytic distillation 40 comprising a reaction section 41 containing a catalyst for the selective hydrogenation of diolefins.
  • the hydrogen necessary for the conduct of the hydrogenation reaction is supplied via line 2.
  • the use of the catalytic column 40 makes it possible to carry out not only the catalytic reaction of selective hydrogenation but also the fractionation into a section of light hydrocarbons at the top of the column and a cut of heavy hydrocarbons at the bottom of the column 40.
  • the cut of light hydrocarbons in mixture with unreacted hydrogen is drawn off by line 42 and the cut of heavy hydrocarbons is drawn off by line 43.
  • the light cut is for example a C4 cut - and the heavy hydrocarbon cut is a boiling cut in the range (C5 - 220 ° C) or (C5 - 160 ° C) or (C5 - 140 ° VS).
  • the cut of heavy hydrocarbons is then treated according to the process of the invention which consists of a hydrodesulfurization step carried out, in this embodiment, in a catalytic distillation column 45 comprising two beds of hydrodesulfurization catalysts. preferably the cut of heavy hydrocarbons is injected with hydrogen (via line 44) between the two beds of hydrodesulfurization catalysts 46.
  • the catalytic distillation column 45 also makes it possible to split the cut of heavy hydrocarbons into one intermediate head cup boiling in the range (C5 - 140 ° C) or (C5 - 160 ° C) and a bottom cup whose boiling temperature is higher than 140 ° C or 160 ° C respectively.
  • the latter in order to reduce the mercaptan content of the intermediate cut, the latter is evacuated via line 47 and subjected to a step of removing H 2 S by means of the stabilization column 5 in order to separate at the top of the column via line 6 a stream containing the majority of the H 2 S and at the bottom of the column via line 7 the stabilized intermediate section.
  • the latter is treated in a softening reactor 8.
  • the intermediate cut softened in mercaptans from reactor 8 is then via line 10 fractionated in column 11 so as to recover at the top (via line 12) a low-content gasoline sulfur, mercaptans and thioethers boiling in the range (C5 - 140 ° C) or (C5 - 160 ° C).
  • the bottom section which contains the sulphides generally comprising at least 10 carbon atoms and more, products of the reaction for adding mercaptans to olefins, is drawn off by line 13 from the bottom of column 11.
  • the intermediate cut is treated in the softening reactor 8 in admixture with the cut of light hydrocarbons, via line 49, coming from the head of the catalytic distillation column 40.
  • the intermediate cut softened in mercaptans from the reactor 8 can optionally undergo a stabilization step carried out in a stabilization column 31 from which a cut C4 is extracted - and a stabilized intermediate cut softened in mercaptans, respectively at the head and at bottom of said column 31.
  • the stabilized intermediate section softened in mercaptans is then sent by line 33 to the fractionation column 11.
  • the mercaptan softening step and the fractionation can be carried out simultaneously by means of a catalytic column equipped with a catalytic bed containing the softening catalyst.
  • a hydrodesulfurization catalyst A is obtained by impregnating “without excess solution” with a transition alumina in the form of beads with a specific surface of 130 m 2 / g and a pore volume of 0.9 ml / g, with a aqueous solution containing molybdenum and cobalt in the form of ammonium heptamolybdate and cobalt nitrate respectively.
  • the catalyst is then dried and calcined in air at 500 ° C.
  • the cobalt and molybdenum content of this sample is 3% by weight of CoO and 10% by weight of MoO 3 .
  • catalyst A 50 ml of catalyst A are placed in a tubular hydrodesulfurization reactor with a fixed bed.
  • the catalyst is first sulfurized by treatment for 4 hours under a pressure of 3.4 MPa at 350 ° C, in contact with a charge consisting of 2% by weight of sulfur in the form of dimethyldisulfide in n-heptane.
  • the treated charge C1 is a catalytic cracking gasoline whose initial boiling point is 55 ° C, the end point is 242 ° C, whose MON is 79.8 and the RON is 89.5. Its sulfur content is 359 ppm by weight.
  • This charge is treated on catalyst A, under a pressure of 2 MPa, with a hydrogen volume ratio on charge to be treated (H 2 / HC) of 360 l / l and a space velocity (VVH) of 4 h -1 .
  • H 2 / HC hydrogen volume ratio on charge to be treated
  • VVH space velocity
  • Table 1 shows the influence of the temperature on the desulfurization rates, and on the octane number by catalyst A at a hydrodesulfurization temperature of 240 ° C (A1) or 270 ° C (A2).
  • Table 1 Hydrodesulfurized gasoline A1 A2 HDS temperature (° C) 240 270 H 2 S, ppm weight 0.5 0.5 Mercaptans, ppm weight (as S) 24 11 Total sulfur, ppm weight 86 19 Total olefins,% by weight 24.6 20.4 Desulfurization rate,% 76.2 94.6 Delta MON 1.1 2.3 Delta RON 1.5 3.9
  • the hydrodesulfurization of the feed C1 with the catalyst A makes it possible to reduce the total sulfur content but also the mercaptans content. It should be noted that it is necessary to treat the charge at a temperature of at least 270 ° C to reach approximately 11 ppm by weight of mercaptans. This increase in the temperature of the hydrodesulfurization reaction also has the effect of promoting the hydrogenation reaction of the olefins which results in a decrease in the total olefin content in the hydrodesulfurized gasoline.
  • Catalyst B is obtained by impregnating a nickel aluminate with a specific surface of 135 m 2 / g and a pore volume of 0.45 ml / g, with an aqueous solution containing molybdenum and nickel. The catalyst is then dried and calcined in air at 500 ° C. The nickel and molybdenum content of this sample is 7.9% by weight of NiO and 13% by weight of MoO 3 .
  • the gasoline A1 as obtained and described in Example 1 is treated in the absence of hydrogen on the demercaptization catalyst B, at a pressure of 1 MPa, a VVH of 3 h -1 and a temperature of 100 ° C. After treatment, the gasoline B1 obtained is cooled.
  • Table 2 presents the main characteristics of the B1 gasoline obtained. Table 2 References of the treated species B1 H 2 S, ppm weight 0 Mercaptans, ppm weight (as S) 8 Total sulfur, ppm weight 86 Total olefins,% by weight 24.6 Demercapture rate,% 67 Hydrogenation rate of olefins,% 0
  • step c The implementation of the demercaptization step (step c) thus makes it possible to convert the mercaptans of essence A1 without hydrogen and without hydrogenating the olefins.
  • a catalyst D is obtained by impregnating an alumina with a specific surface of 239 m 2 / g and a pore volume 0.6 ml / g, with an aqueous solution containing molybdenum and nickel. The catalyst is then dried and calcined in air at 500 ° C. The nickel and molybdenum content of this sample is 9.5% by weight of NiO and 13% by weight of MoO 3 .
  • the essence A1 as obtained and described in example 1 is mixed with a charge C2 to obtain a charge C3.
  • the charge C2 is a light cracked gasoline having undergone a selective hydrogenation of the diolefins, whose initial boiling point is 22 ° C and the end point is 71 ° C, whose MON is 82.5 and RON is 96.9. Its sulfur content is 20 ppm by weight, its mercaptan content less than 3 ppm by weight and its olefin content by 56.7% by weight.
  • the charge C3 is obtained by mixing 80% by weight of gasoline A1 with 20% by weight of charge C2.
  • the mixture obtained is a gasoline with an initial boiling point of 22 ° C and a final point of 242 ° C. Its sulfur content is 73 ppm, its mercaptan content is 19 ppm by weight and its olefin content is 31% by weight.
  • Charge C3 is treated in the presence of hydrogen on the demercaptization catalyst D, under a pressure of 1 MPa, a VVH of 3 h -1 , with a hydrogen by charge ratio of charge to be treated (H 2 / HC) of 2 l / l and a temperature of 100 ° C.
  • the gasoline mixture is cooled so as to recover a gas phase rich in hydrogen and H 2 S and a fraction of liquid gasoline.
  • the liquid fraction is subjected to a stripping treatment by injection of a stream of hydrogen in order to remove any traces of H 2 S dissolved in the gasoline.
  • Table 3 presents the main characteristics of D1 gasoline obtained after stripping. References of hydrodesulfurized gasoline D1 Temperature, ° C 100 Mercaptans, ppm weight 4 Total sulfur, ppm weight 73 Total olefins,% by weight 31 Demercapture rate,% 79 Hydrogenation rate of olefins,% 0
  • the process makes it possible to reduce the content of mercaptans in gasoline A1 by converting them selectively into thioethers, without hydrogenation of the olefins and therefore without loss of octane.

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Description

La présente invention concerne un procédé de production d'essence à basse teneur en soufre et en mercaptans.The present invention relates to a process for producing gasoline with a low sulfur and mercaptan content.

Etat de la techniqueState of the art

La production d'essences répondant aux nouvelles normes environnementales nécessite que l'on diminue de façon importante leur teneur en soufre.The production of gasolines meeting the new environmental standards requires that their sulfur content be significantly reduced.

Il est par ailleurs connu que les essences de conversion, et plus particulièrement celles provenant du craquage catalytique, qui peuvent représenter 30 à 50 % du pool essence, présentent des teneurs élevées en mono-oléfines et en soufre.It is moreover known that the conversion essences, and more particularly those originating from catalytic cracking, which can represent 30 to 50% of the petrol pool, have high contents of mono-olefins and sulfur.

Le soufre présent dans les essences est pour cette raison imputable, à près de 90%, aux essences issues des procédés de craquage catalytique, que l'on appellera dans la suite essences de FCC (Fluid Catalytic Cracking selon la terminologie anglo-saxonne, que l'on peut traduire par craquage catalytique en lit fluidisé). Les essences de FCC constituent donc la charge préférée du procédé de la présente invention.The sulfur present in gasolines is for this reason attributable, to almost 90%, to the gasolines resulting from the processes of catalytic cracking, which one will call hereafter gasolines of FCC (Fluid Catalytic Cracking according to the English terminology, one can translate by catalytic cracking in a fluidized bed). FCC essences therefore constitute the preferred feed for the process of the present invention.

Parmi les voies possibles pour produire des carburants à faible teneur en soufre, celle qui a été très largement retenue consiste à traiter spécifiquement les bases essences riches en soufre par des procédés d'hydrodésulfuration catalytique en présence d'hydrogène. Les procédés traditionnels désulfurent les essences de manière non sélective en hydrogénant une grande partie des mono-oléfines, ce qui engendre une forte perte en indice d'octane et une forte consommation d'hydrogène. Les procédés les plus récents, tels que le procédé Prime G+ (marque commerciale), permettent de désulfurer les essences de craquage riches en oléfines, tout en limitant l'hydrogénation des mono-oléfines et par conséquent la perte d'octane et la forte consommation d'hydrogène qui en résulte. De tels procédés sont par exemple décrits dans les demandes de brevet EP 1077247 et EP 1174485 . US 2004/0129606 et US 2005/0252831 divulguent un procédé de traitement d'une essence contenant des composés soufrés et des oléfines.Among the possible ways to produce fuels with a low sulfur content, the one that has been widely adopted consists in specifically treating the gasoline bases rich in sulfur by catalytic hydrodesulfurization processes in the presence of hydrogen. Traditional processes desulfurize gasolines in a non-selective manner by hydrogenating a large part of the mono-olefins, which generates a high loss in octane number and a high consumption of hydrogen. The most recent processes, such as the Prime G + process (trade mark), make it possible to desulfurize cracked gasolines rich in olefins, while limiting the hydrogenation of mono-olefins and consequently the loss of octane and the high consumption. resulting hydrogen. Such methods are for example described in the applications for EP 1077247 and EP 1174485 . US 2004/0129606 and US 2005/0252831 disclose a process for treating a gasoline containing sulfur compounds and olefins.

Les composés soufrés résiduels généralement présents dans l'essence désulfurée peuvent être séparés en deux familles distinctes : les composés soufrés non convertis présents dans la charge d'une part, et les composés soufrés formés dans le réacteur par des réactions secondaires dites de recombinaison. Parmi cette dernière famille de composés soufrés, les composés majoritaires sont les mercaptans issus de l'addition de l'H2S formé dans le réacteur sur les mono-oléfines présentes dans la charge. Les mercaptans de formule chimique R-SH, où R est un groupement alkyle, sont également appelés mercaptans de recombinaison et représentent généralement entre 20% et 80% poids du soufre résiduel dans les essences désulfurées.The residual sulfur compounds generally present in the desulfurized gasoline can be separated into two distinct families: the unconverted sulfur compounds present in the feed on the one hand, and the sulfur compounds formed in the reactor by so-called recombination side reactions. Among this last family of sulfur compounds, the majority compounds are the mercaptans resulting from the addition of H 2 S formed in the reactor on the mono-olefins present in the feed. The mercaptans of chemical formula R-SH, where R is an alkyl group, are also called recombinant mercaptans and generally represent between 20% and 80% by weight of the residual sulfur in the desulfurized gasolines.

L'obtention d'une essence à très basse teneur en soufre, typiquement à une teneur inférieure à 10 ppm poids telle que requise en Europe, requiert donc l'élimination d'au moins une partie des mercaptans de recombinaison. Cette réduction de la teneur en mercaptans de recombinaison peut être réalisée par hydrodésulfuration catalytique mais cela entraîne l'hydrogénation d'une partie importante des mono-oléfines présentes dans l'essence et qui a alors pour conséquence une forte diminution de l'indice d'octane de l'essence ainsi qu'une surconsommation d'hydrogène.Obtaining a gasoline with a very low sulfur content, typically at a content of less than 10 ppm by weight as required in Europe, therefore requires the elimination of at least part of the recombinant mercaptans. This reduction in the content of recombinant mercaptans can be achieved by catalytic hydrodesulfurization but this results in the hydrogenation of a large part of the mono-olefins present in gasoline and which then results in a sharp reduction in the index of octane from petrol as well as overconsumption of hydrogen.

Afin de limiter ces inconvénients, différentes solutions sont décrites dans la littérature pour désulfurer les essences de craquage à l'aide de combinaison d'étapes d'hydrodésulfuration et d'élimination des mercaptans de recombinaison par une technique judicieusement choisie pour éviter l'hydrogénation des mono-oléfines présentes, afin de préserver l'indice d'octane (voir par exemple US 7799210 , US 6960291 , US 6387249 et US 2007114156 ) .In order to limit these drawbacks, various solutions have been described in the literature for desulfurizing cracked gasolines using a combination of hydrodesulfurization steps and elimination of recombinant mercaptans by a technique judiciously chosen to avoid the hydrogenation of mono-olefins present, in order to preserve the octane number (see for example US 7,799,210 , US 6,960,291 , US 6387249 and US 2007114156 ).

Il apparait cependant que si ces combinaisons mettant en œuvre une étape finale d'élimination des mercaptans de recombinaison sont particulièrement adaptées lorsqu'une très basse teneur en soufre est recherchée, celles-ci peuvent se révéler très couteuses lorsque la quantité de mercaptans à éliminer est élevée; en effet cela nécessite par exemple de fortes consommations d'adsorbant ou de solvant. Une telle situation peut notamment se produire lorsque la teneur en mercaptans admissible dans le pool essence est nettement inférieure à la spécification en soufre total, ce qui est le cas dans nombre de pays, notamment en Asie. En effet, le soufre présent sous forme de mercaptans ou sous forme de sulfure d'hydrogène (H2S) dans les carburants peut, outre induire des problèmes de toxicité et d'odeur, générer l'attaque de nombreux matériaux métalliques et non métalliques présents dans les systèmes de distribution. La quasi-totalité des pays ont donc une spécification très basse en mercaptans dans les carburants (typiquement inférieure à 10 ppm RSH (mesure de la teneur en mercaptans par potentiométrie, méthode ASTM D 3227), y compris dans les cas où la spécification en soufre total est relativement élevée, par exemple entre 50 et 500 ppm poids. D'autres pays ont adopté une mesure de "Doctor Test" pour quantifier les mercaptans avec une spécification négative à respecter (méthode ASTM D4952 - 12).It appears however that if these combinations implementing a final stage of elimination of the recombinant mercaptans are particularly suitable when a very low sulfur content is sought, these can prove to be very expensive when the quantity of mercaptans to be eliminated is high; indeed this requires for example high consumption of adsorbent or solvent. This can happen in particular when the admissible mercaptan content in the petrol pool is significantly lower than the total sulfur specification, which is the case in many countries, notably in Asia. Indeed, the sulfur present in the form of mercaptans or in the form of hydrogen sulfide (H 2 S) in fuels can, in addition to inducing problems of toxicity and odor, generate the attack of many metallic and non-metallic materials present in distribution systems. Almost all countries therefore have a very low specification of mercaptans in fuels (typically less than 10 ppm RSH (measurement of mercaptans content by potentiometry, ASTM D 3227 method), including in cases where the sulfur specification total is relatively high, for example between 50 and 500 ppm by weight Other countries have adopted a measure of "Doctor Test" to quantify the mercaptans with a negative specification to be respected (method ASTM D4952 - 12).

Ainsi dans certains cas, il apparait que la spécification la plus contraignante, car la plus difficile à atteindre sans nuire à l'indice d'octane, est la spécification en mercaptans et non celle du soufre total.Thus in certain cases, it appears that the most restrictive specification, because the most difficult to achieve without harming the octane number, is the mercaptans specification and not that of total sulfur.

Un but de la présente invention est de proposer un procédé de traitement d'une essence contenant du soufre, dont une partie est sous forme de mercaptans, qui permet de diminuer la teneur en mercaptans de ladite fraction hydrocarbonée tout en limitant au maximum la perte d'octane et la consommation de réactifs tels que l'hydrogène ou des solvants d'extraction.An object of the present invention is to provide a process for the treatment of a gasoline containing sulfur, part of which is in the form of mercaptans, which makes it possible to reduce the mercaptan content of said hydrocarbon fraction while minimizing the loss of octane and the consumption of reagents such as hydrogen or extraction solvents.

Résumé de l'inventionSummary of the invention

L'invention a pour objet un procédé de traitement d'une essence contenant des composés soufrés et des oléfines, le procédé comprenant au moins les étapes suivantes:

  1. a) on met en contact dans au moins un réacteur, l'essence, de l'hydrogène et un catalyseur d'hydrodésulfuration à une température comprise entre 200 et 400°C, à une pression comprise entre 0,5 et 5 MPa, avec une vitesse spatiale comprise entre 0,5 et 20 h-1 et un rapport entre le débit d'hydrogène exprimé en normaux m3 par heure et le débit de charge à traiter exprimé en m3 par heure aux conditions standards compris entre 50 Nm3/m3 et 1000 Nm3/m3, de manière à convertir au moins une partie des composés soufrés en H2S;
  2. b) on effectue une étape de séparation de l'H2S formé et présent dans l'effluent issu de l'étape a).
  3. c) on met en contact, dans un réacteur, l'effluent appauvri en H2S issu de l'étape b), avec un catalyseur contenant au moins un sulfure d'au moins un métal de transition choisi parmi un métal du groupe VIb, un métal du groupe VIII et le cuivre, seul ou en mélange ou de plomb déposé sur un support poreux, apte à transformer les composés soufrés de la famille des mercaptans, par réaction avec les oléfines de l'essence en composés soufrés du type thioéther, l'étape c) étant réalisée une température comprise entre 30°C et 250°C, avec une vitesse spatiale liquide comprise entre 0, 5 et 10 h-1, une pression comprise entre 0,4 et 5 MPa et un rapport H2/charge compris entre 0 et 10 Nm3 d'hydrogène par m3 de charge, de manière à produire une essence issue de l'étape c) ayant une teneur en mercaptans réduite par rapport à celle de l'effluent issu de l'étape b).
The subject of the invention is a process for treating a gasoline containing sulfur compounds and olefins, the process comprising at least the following steps:
  1. a) contacting in at least one reactor, petrol, hydrogen and a hydrodesulfurization catalyst at a temperature between 200 and 400 ° C, at a pressure between 0.5 and 5 MPa, with a space speed between 0.5 and 20 h -1 and a ratio between the hydrogen flow rate expressed in normal m 3 per hour and the feed rate to be treated expressed in m 3 per hour at standard conditions between 50 Nm 3 / m 3 and 1000 Nm 3 / m 3 , so as to convert at least part of the sulfur-containing compounds to H 2 S;
  2. b) a step of separating the H 2 S formed and present in the effluent from step a) is carried out.
  3. c) the effluent depleted in H 2 S from step b) is brought into contact in a reactor with a catalyst containing at least one sulfide of at least one transition metal chosen from a metal from group VIb , a group VIII metal and copper, alone or as a mixture or of lead deposited on a porous support, capable of transforming the sulfur compounds of the mercaptan family, by reaction with the olefins of gasoline into sulfur compounds of the thioether type , step c) being carried out at a temperature between 30 ° C and 250 ° C, with a liquid space velocity between 0.5 and 10 h -1 , a pressure between 0.4 and 5 MPa and an H ratio 2 / charge between 0 and 10 Nm 3 of hydrogen per m 3 of charge, so as to produce a gasoline resulting from stage c) having a content of mercaptans reduced compared to that of the effluent resulting from l step b).

Il a en effet été constaté de façon surprenante que l'utilisation d'un catalyseur et de conditions opératoires spécifiques en aval d'un réacteur d'hydrodésulfuration des essences permettait une conversion suffisante des mercaptans de recombinaison, qui sont généralement des composés peu réactifs, en composés du type thioéther par réaction avec les oléfines. Ainsi l'étape c) de démercaptisation, que l'on peut également qualifier d'étape d'adoucissement non désulfurant, permet de produire une essence ayant une spécification de teneur basse en mercaptans sans nécessiter une étape de finition d'hydrodésulfuration sévère et couteuse.It has indeed been surprisingly found that the use of a catalyst and of specific operating conditions downstream of a hydrodesulfurization reactor for gasolines allowed sufficient conversion of recombinant mercaptans, which are generally not very reactive compounds, into thioether-type compounds by reaction with olefins. Thus, step c) of demercaptization, which can also be described as a non-desulfurizing softening step, makes it possible to produce a gasoline having a low mercaptan content specification without requiring a severe and costly hydrodesulfurization finishing step. .

Un autre avantage du procédé selon l'invention vient du fait qu'il permet d'atteindre une teneur très basse en mercaptans (e.g. inférieure à 10 ppm poids) dans l'essence désulfurée finale avec des conditions opératoires pour l'étape d'hydrodésulfuration (étape a) beaucoup moins sévères (par exemple diminution importante de la température et/ou de la pression opératoire), ce qui a pour effet de limiter la perte d'octane, d'augmenter de la durée de vie du catalyseur de l'étape d'hydrodésulfuration et également de réduire la consommation d'énergie.Another advantage of the process according to the invention comes from the fact that it makes it possible to achieve a very low content of mercaptans (eg less than 10 ppm by weight) in the final desulfurized gasoline with operating conditions for the hydrodesulfurization step. (step a) much less severe (for example significant reduction in temperature and / or operating pressure), which has the effect of limiting the loss of octane, of increasing the lifetime of the catalyst of the hydrodesulfurization step and also reduce energy consumption.

Selon un mode de réalisation préféré, le catalyseur de l'étape c) comprend :

  • un support constitué d'alumine gamma ou delta de surface spécifique comprise entre 70 m2/g et 350 m2/g
  • une teneur en poids d'oxyde du métal du groupe VIB comprise entre 1% et 30% poids par rapport au poids total du catalyseur,
  • une teneur en poids d'oxyde du métal du groupe VIII comprise entre 1% et 30 % poids par rapport au poids total du catalyseur,
  • un taux de sulfuration des métaux constituants ledit catalyseur au moins égal à 60%,
  • un rapport molaire entre le métal du groupe VIII et le métal du groupe VIB compris entre 0,6 et 3 mol/mol.
According to a preferred embodiment, the catalyst of step c) comprises:
  • a support consisting of gamma or delta alumina with a specific surface of between 70 m 2 / g and 350 m 2 / g
  • a group VIB metal oxide content by weight of between 1% and 30% by weight relative to the total weight of the catalyst,
  • a group VIII metal oxide content by weight of between 1% and 30% by weight relative to the total weight of the catalyst,
  • a sulfurization rate of the metals constituting said catalyst at least equal to 60%,
  • a molar ratio between the metal of group VIII and the metal of group VIB of between 0.6 and 3 mol / mol.

De préférence le métal du groupe VIII est le nickel et le métal du groupe VIB est le molybdène.Preferably the group VIII metal is nickel and the group VIB metal is molybdenum.

Selon un mode de réalisation, le catalyseur de l'étape c) comprend :

  • un support constitué uniquement d'alumine gamma de surface spécifique comprise entre 180 m2/g et 270 m2/g ;
  • une teneur en poids d'oxyde de nickel comprise entre 4 et 12% par rapport au poids total de catalyseur ;
  • une teneur en poids d'oxyde de molybdène comprise entre 6% et 18% par rapport au poids total de catalyseur ;
  • un rapport molaire nickel/molybdène compris entre 1 et 2,5 mol/mol; et
  • un taux de sulfuration des métaux constituant le catalyseur supérieur à 80%.
According to one embodiment, the catalyst of step c) comprises:
  • a support consisting solely of gamma alumina with a specific surface of between 180 m 2 / g and 270 m 2 / g;
  • a content by weight of nickel oxide of between 4 and 12% relative to the total weight of catalyst;
  • a content by weight of molybdenum oxide of between 6% and 18% relative to the total weight of catalyst;
  • a nickel / molybdenum molar ratio of between 1 and 2.5 mol / mol; and
  • a sulfurization rate of the metals constituting the catalyst greater than 80%.

Le procédé selon l'invention peut comprendre une étape dans laquelle l'effluent issu de l'étape b) est mélangé avec une coupe d'hydrocarbures choisie parmi une coupe GPL (gaz de pétrole liquéfié), une coupe essence issue d'une distillation du pétrole brut, d'une unité de pyrolyse, d'une unité de cokéfaction, d'une unité d'hydrocraquage, d'une unité d'oligomérisation et une coupe oléfinique en C4, et le mélange est traité à l'étape c). Selon une variante préférée selon laquelle l'effluent issu de l'étape b) est traité en mélange avec une coupe oléfinique en C4, l'effluent issu de l'étape c) est fractionné de manière à séparer une coupe oléfinique en C4 non réagie et ladite coupe oléfinique en C4 no réagie est recyclée dans le réacteur de l'étape c). Selon ce mode de réalisation préféré, on mélange l'effluent issu de l'étape b) avec une coupe oléfinique en C4 afin de favoriser la réaction d'addition des mercaptans sur des oléfines dans le réacteur d'adoucissement. Avantageusement, on fractionne l'effluent issu de l'étape c) d'adoucissement de manière à séparer une coupe contenant des oléfines en C4 qui n'ont pas réagi et on recycle ladite coupe oléfinique en C4 dans le réacteur d'adoucissement.The method according to the invention may include a step in which the effluent from step b) is mixed with a hydrocarbon cut chosen from an LPG cut (liquefied petroleum gas), a gasoline cut resulting from a distillation crude oil, a pyrolysis unit, a coking unit, a hydrocracking unit, an oligomerization unit and a C4 olefinic cut, and the mixture is treated in step c ). According to a preferred variant according to which the effluent from step b) is treated as a mixture with an olefinic cut in C4, the effluent from step c) is fractionated so as to separate an unreacted C4 olefinic cut and said unreacted C4 olefinic cut is recycled to the reactor of step c). According to this preferred embodiment, the effluent from step b) is mixed with an olefinic cut at C4 in order to promote the reaction for adding mercaptans to olefins in the softening reactor. Advantageously, the effluent from step c) of softening is fractionated so as to separate a cut containing C4 olefins which have not reacted and said olefinic cut into C4 is recycled in the softening reactor.

Alternativement, avant l'étape a) on effectue une étape de distillation de l'essence de manière à fractionner ladite essence en au moins deux coupes essence légère et lourde et on traite la coupe essence lourde dans les étapes a), b) et c).Alternatively, before step a) a gasoline distillation step is carried out so as to split said gasoline into at least two light and heavy gasoline cuts and the heavy gasoline cut is treated in steps a), b) and c ).

Selon une autre forme de réalisation, l'effluent issu de l'étape b) est mélangé avec la coupe essence légère issue de la distillation de sorte à produire un mélange et ledit mélange est traité à l'étape c).According to another embodiment, the effluent from step b) is mixed with the light gasoline cut from the distillation so as to produce a mixture and said mixture is treated in step c).

Il est également possible dans le cadre de l'invention d'effectuer avant l'étape a) une étape de distillation de l'essence de manière à fractionner ladite essence en au moins deux coupes essence légère et lourde, on traite la coupe essence lourde dans l'étape a), on mélange la coupe essence légère avec l'effluent issu de l'étape a) de sorte à produire un mélange et ledit mélange est traité dans les étapes b) et c).It is also possible within the framework of the invention to carry out before step a) a step of distilling the gasoline so as to fractionate said gasoline in at at least two light and heavy petrol cuts, the heavy petrol cut is treated in step a), the light petrol cut is mixed with the effluent from step a) so as to produce a mixture and said mixture is treated in steps b) and c).

De préférence, dans le cadre des modes de réalisation décrits plus haut, le mélange avec les coupes essences légères contient jusqu'à 50% volume de la coupe essence légère.Preferably, within the framework of the embodiments described above, the mixture with the light gasoline cuts contains up to 50% volume of the light gasoline cut.

Selon un autre mode de réalisation du procédé, avant l'étape a) on effectue une étape de distillation de l'essence de manière à fractionner ladite essence en au moins trois coupes essence légère, intermédiaire et lourde respectivement et ensuite on traite la coupe essence intermédiaire dans l'étape a) puis l'étape b) et l'étape c). Dans ce mode de réalisation, la coupe essence lourde issue de la distillation est avantageusement traitée dans une étape d'hydrodésulfuration dans une unité dédiée et puis soumise à une étape d'adoucissement en mercaptans après élimination de l'H2S. L'étape d'adoucissement de la coupe essence lourde désulfurée peut être effectuée soit dans un réacteur dédié soit dans le même réacteur d'adoucissement que celui qui traite la coupe essence intermédiaire (les coupes intermédiaire et lourdes sont traitées en mélange dans un réacteur d'adoucissement).According to another embodiment of the method, before step a) a gasoline distillation step is carried out so as to split said gasoline into at least three light, intermediate and heavy gasoline cuts respectively and then the gasoline cut is processed intermediate in step a) then step b) and step c). In this embodiment, the heavy gasoline fraction resulting from the distillation is advantageously treated in a hydrodesulfurization step in a dedicated unit and then subjected to a step of softening in mercaptans after elimination of the H 2 S. The step softening of the desulfurized heavy petrol cut can be carried out either in a dedicated reactor or in the same softening reactor as that which processes the intermediate petrol cut (the intermediate and heavy cuts are treated as a mixture in a softening reactor) .

Il est également possible, avant l'étape a) et avant toute éventuelle étape de distillation, de mettre en contact l'essence avec de l'hydrogène et un catalyseur d'hydrogénation sélective pour hydrogéner sélectivement les dioléfines contenues dans ladite essence en oléfines. Cette étape d'hydrogénation sélective des dioléfines peut être opérée dans une colonne de distillation catalytique équipée d'une section comprenant un catalyseur d'hydrogénation sélective.It is also possible, before step a) and before any possible distillation step, to bring the gasoline into contact with hydrogen and a selective hydrogenation catalyst to selectively hydrogenate the diolefins contained in said gasoline into olefins. This step of selective hydrogenation of diolefins can be carried out in a catalytic distillation column equipped with a section comprising a selective hydrogenation catalyst.

Dans le cadre de l'invention et de manière alternative, les étapes a) et/ou c) peuvent être mises en œuvre dans des réacteurs qui sont des colonnes catalytiques incluant au moins un lit catalytique, dans lesquelles se réalisent à la fois la réaction catalytique et la séparation de l'essence en au moins deux coupes (ou fraction). Dans le cas où l'étape a) est réalisée dans une colonne catalytique, les coupes issues de la colonne catalytique sont envoyées à l'étape b) et c) séparément ou en mélange pour en abaisser la teneur en mercaptans. Selon une autre forme de réalisation dans laquelle l'étape a) est effectuée dans une colonne catalytique, seule la coupe légère, soutirée en tête de la colonne catalytique qui concentre les mercaptans, est envoyée aux étapes b) et c).In the context of the invention and alternatively, steps a) and / or c) can be implemented in reactors which are catalytic columns including at least one catalytic bed, in which both the reaction are carried out catalytic and the separation of gasoline into at least two cuts (or fraction). In the case where step a) is carried out in a catalytic column, the sections coming from the catalytic column are sent to step b) and c) separately or as a mixture in order to lower the mercaptans content. According to another embodiment in which step a) is carried out in a catalytic column, only the light cut, drawn off at the head of the catalytic column which concentrates the mercaptans, is sent to steps b) and c).

Selon un mode de réalisation préféré, le procédé comprend en outre une étape d) dans laquelle on envoie l'effluent issu de l'étape c) dans une colonne de fractionnement et on sépare une coupe essence à basse teneur en mercaptans en tête de la colonne de fractionnement et une coupe d'hydrocarbures contenant des composés thioéthers en fond de la colonne de fractionnement.According to a preferred embodiment, the method further comprises a step d) in which the effluent from step c) is sent to a fractionation column and a gasoline cut with a low mercaptan content is separated at the top of the fractionation column and a section of hydrocarbons containing thioether compounds at the bottom of the fractionation column.

Les étapes c) et d) sont de façon avantageuse réalisées de façon concomitante dans une colonne de distillation catalytique comprenant un lit de catalyseur de l'étape c).Steps c) and d) are advantageously carried out concomitantly in a catalytic distillation column comprising a catalyst bed from step c).

De préférence, le catalyseur de l'étape a) contient au moins un métal du groupe VIB et/ou au moins un métal du groupe VIII sur un support ayant une surface spécifique inférieure à 250 m2/g, dans lequel la teneur en métal du groupe VIII exprimée en oxyde est comprise entre 0,5 et 15% poids et la teneur en métal du groupe VIB, exprimée en oxyde, est comprise entre 1,5 et 60% poids par rapport au poids de catalyseur.
Selon un mode de réalisation préféré, le catalyseur de l'étape a) comprend du cobalt et du molybdène et la densité de molybdène, exprimée comme étant le rapport entre ladite teneur en poids de MoO3 et la surface spécifique du catalyseur, est supérieure à 7.10-4 et de préférence supérieure à 12.10-4 g/m2.Preferably, the catalyst of step a) contains at least one group VIB metal and / or at least one group VIII metal on a support having a specific surface of less than 250 m 2 / g, in which the metal content of group VIII expressed as oxide is between 0.5 and 15% by weight and the metal content of group VIB, expressed as oxide, is between 1.5 and 60% by weight relative to the weight of catalyst.
According to a preferred embodiment, the catalyst of step a) comprises cobalt and molybdenum and the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface of the catalyst, is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 .

Avantageusement, l'étape c) est réalisée en absence d'apport d'hydrogène.Advantageously, step c) is carried out in the absence of supply of hydrogen.

Description détaillée de l'inventionDetailed description of the invention - Description de la charge :- Description of the load :

L'invention concerne un procédé de traitement d'essences comprenant tout type de familles chimiques et notamment des dioléfines, des mono-oléfines, et des composés soufrés. La présente invention trouve particulièrement son application dans la transformation des essences de conversion, et en particulier des essences en provenance du craquage catalytique, du craquage catalytique en lit fluide (FCC), d'un procédé de cokéfaction, d'un procédé de viscoréduction, ou d'un procédé de pyrolyse. Par exemple, les essences issues d'unités de craquage catalytique (FCC) contiennent, en moyenne, entre 0,5% et 5% poids de dioléfines, entre 20% et 50% poids de mono-oléfines, entre 10 ppm et 0,5% poids de soufreThe invention relates to a process for the treatment of gasolines comprising all types of chemical families and in particular diolefins, mono-olefins, and sulfur-containing compounds. The present invention finds its application particularly in the conversion of conversion essences, and in particular essences from catalytic cracking, catalytic cracking in a fluid bed (FCC), a coking process, a visbreaking process, or a pyrolysis process. For example, gasolines from catalytic cracking units (FCC) contain, on average, between 0.5% and 5% by weight of diolefins, between 20% and 50% by weight of mono-olefins, between 10 ppm and 0, 5% sulfur weight

L'essence traitée présente généralement une température d'ébullition inférieure à 350°C, de préférence inférieure à 300°C et de façon très préférée inférieure à 220°C. Les charges pour lesquelles s'applique le procédé selon l'invention ont une température d'ébullition comprise entre 0°C et 280°C, de préférence comprise entre 30°C et 250°C. Les charges peuvent également contenir des hydrocarbures à 3 ou 4 atomes de carbone.The gasoline treated generally has a boiling point of less than 350 ° C, preferably less than 300 ° C and very preferably less than 220 ° C. The fillers for which the process according to the invention applies have a boiling temperature of between 0 ° C and 280 ° C, preferably between 30 ° C and 250 ° C. The fillers can also contain hydrocarbons with 3 or 4 carbon atoms.

- Description de l'étape d'hydrodésulfuration catalytique (étape a) - Description of the catalytic hydrodesulfurization stage (stage a)

L'étape d'hydrodésulfuration est mise en œuvre pour réduire la teneur en soufre de l'essence à traiter en convertissant les composés soufrés en H2S qui est ensuite éliminé dans l'étape b). Sa mise en œuvre est particulièrement nécessaire lorsque la charge à désulfurer contient plus de 100 ppm poids de soufre et de façon plus générale plus de 50 ppm poids de soufre.The hydrodesulfurization step is implemented to reduce the sulfur content of the gasoline to be treated by converting the sulfur compounds to H 2 S which is then eliminated in step b). Its implementation is particularly necessary when the feed to be desulfurized contains more than 100 ppm by weight of sulfur and more generally more than 50 ppm by weight of sulfur.

L'étape d'hydrodésulfuration consiste à mettre en contact l'essence à traiter avec de l'hydrogène, dans un ou plusieurs réacteurs d'hydrodésulfuration, contenant un ou plusieurs catalyseurs adaptés pour réaliser l'hydrodésulfuration.The hydrodesulfurization step consists in bringing the gasoline to be treated into contact with hydrogen, in one or more hydrodesulfurization reactors, containing one or more catalysts suitable for carrying out the hydrodesulfurization.

Selon un mode préféré de réalisation de l'invention, l'étape a) est mise en œuvre dans le but de réaliser une hydrodésulfuration de façon sélective, c'est-à-dire avec un taux d'hydrogénation des mono-oléfines inférieur à 80%, de préférence inférieur à 70% et de façon très préférée inférieure à 60%.According to a preferred embodiment of the invention, step a) is implemented with the aim of carrying out hydrodesulfurization selectively, that is to say with a hydrogenation rate of the mono-olefins lower than 80%, preferably less than 70% and very preferably less than 60%.

La pression d'opération de cette étape est généralement comprise entre 0,5 MPa et 5 MPa et de préférence comprise entre 1 MPa et 3 MPa. La température est généralement comprise entre 200°C et 400°C et de préférence comprise entre 220°C et 380°C. Dans le cas où l'étape a) d'hydrodésulfuration est effectuée dans plusieurs réacteurs en série, la température moyenne d'opération de chaque réacteur est généralement supérieure d'au moins 5°C, de préférence d'au moins 10°C et de façon très préférée d'au moins 30°C à la température d'opération du réacteur qui le précède.The operating pressure of this step is generally between 0.5 MPa and 5 MPa and preferably between 1 MPa and 3 MPa. The temperature is generally between 200 ° C and 400 ° C and preferably between 220 ° C and 380 ° C. In the case where step a) of hydrodesulfurization is carried out in several reactors in series, the average operating temperature of each reactor is generally at least 5 ° C. higher, preferably at least 10 ° C. and very preferably at least 30 ° C. at the operating temperature of the reactor which precedes it.

La quantité de catalyseur mise en œuvre dans chaque réacteur est généralement telle que le rapport entre le débit d'essence à traiter exprimé en m3 par heure aux conditions standards, par m3 de catalyseur (également appelé vitesse spatiale) est compris entre 0,5 h-1 et 20 h-1 et de préférence entre 1 h-1 et 15 h-1. De façon très préférée, le réacteur d'hydrodésulfuration est opéré avec une vitesse spatiale comprise entre 2 h-1 et 8 h-1.The amount of catalyst used in each reactor is generally such that the ratio between the flow rate of gasoline to be treated expressed in m 3 per hour at standard conditions, per m 3 of catalyst (also called space speed) is between 0.5 h -1 and 20 h -1 and preferably between 1 h -1 and 15 h -1 . Very preferably, the hydrodesulfurization reactor is operated with a space speed of between 2 h -1 and 8 h -1 .

Le débit d'hydrogène est généralement tel que le rapport entre le débit d'hydrogène exprimé en normaux m3 par heure (Nm3/h) et le débit de charge à traiter exprimé en m3 par heure aux conditions standards est compris entre 50 Nm3/m3 et 1000 Nm3/m3, de préférence entre 70 Nm3/m3 et 800 Nm3/m3.The hydrogen flow rate is generally such that the ratio between the hydrogen flow rate expressed in normal m 3 per hour (Nm 3 / h) and the feed flow rate to be treated expressed in m 3 per hour at standard conditions is between 50 Nm 3 / m 3 and 1000 Nm 3 / m 3 , preferably between 70 Nm 3 / m 3 and 800 Nm 3 / m 3 .

Le taux de désulfuration, qui dépend de la teneur en soufre de la charge à traiter, est généralement supérieur à 50% et de préférence supérieur à 70% de sorte que le produit issu de l'étape a) contient moins de 100 ppm poids de soufre et de façon préférée moins de 50 ppm poids de soufre.The desulfurization rate, which depends on the sulfur content of the feed to be treated, is generally greater than 50% and preferably greater than 70% so that the product resulting from stage a) contains less than 100 ppm by weight of sulfur and preferably less than 50 ppm by weight of sulfur.

Dans le cas éventuel d'un enchaînement de catalyseur, le procédé comprend une succession d'étapes d'hydrodésulfuration, telle que l'activité du catalyseur d'une étape n+1 est comprise entre 1% et 90% de l'activité du catalyseur de l'étape n, comme enseigné dans le document EP 1612255 .In the eventuality of a concatenation of catalyst, the process comprises a succession of hydrodesulfurization steps, such that the activity of the catalyst of a step n + 1 is between 1% and 90% of the activity of the stage n catalyst, as taught in the document EP 1612255 .

Tout catalyseur connu de l'homme de l'art capable de promouvoir les réactions de transformation du soufre organique en H2S en présence d'hydrogène peut être utilisé dans le cadre de l'invention. Toutefois, selon un mode particulier de réalisation de l'invention, il est préféré l'utilisation de catalyseurs présentant une bonne sélectivité vis-à-vis des réactions d'hydrodésulfuration par rapport à la réaction d'hydrogénation des oléfines.Any catalyst known to a person skilled in the art capable of promoting reactions for converting organic sulfur into H 2 S in the presence of hydrogen can be used within the framework of the invention. However, according to a particular embodiment of the invention, it is preferred to use catalysts having good selectivity with respect to hydrodesulfurization reactions compared to the hydrogenation reaction of olefins.

De préférence, le catalyseur d'hydrodésulfuration de l'étape a) contient généralement au moins un métal du groupe VIB et/ou au moins un métal du groupe VIII sur un support (les groupes VIB et VIII selon la classification CAS correspondent respectivement au métaux des groupes 6 et des groupes 8 à 10 de la nouvelle classification IUPAC selon CRC Handbook of Chemistry and Physics, éditeur CRC press, rédacteur en chef D.R. Lide , 81ème édition, 2000-2001 ). Le métal du groupe VIB est de préférence le molybdène ou le tungstène et le métal du groupe VIII est de préférence choisi parmi le nickel ou le cobalt. Selon un mode de réalisation très préféré, le catalyseur de l'étape a) comprend du cobalt et du molybdène.Preferably, the hydrodesulfurization catalyst of step a) generally contains at least one metal from group VIB and / or at least one metal from group VIII on a support (groups VIB and VIII according to the CAS classification correspond respectively to the metals groups 6 and groups 8 to 10 of the new IUPAC classification according to CRC Handbook of Chemistry and Physics, CRC press editor, editor-in-chief DR Lide, 81st edition, 2000-2001 ). The group VIB metal is preferably molybdenum or tungsten and the group VIII metal is preferably chosen from nickel or cobalt. According to a very preferred embodiment, the catalyst of step a) comprises cobalt and molybdenum.

La teneur en métal du groupe VIII exprimée en oxyde est généralement comprise entre 0,5% et 15% poids, préférentiellement entre 1% et 10% poids par rapport au poids total du catalyseur. La teneur en métal du groupe VIb est généralement comprise entre 1,5% et 60% poids, préférentiellement entre 3% et 50% poids par rapport au poids total du catalyseur.The content of group VIII metal expressed as oxide is generally between 0.5% and 15% by weight, preferably between 1% and 10% by weight relative to the total weight of the catalyst. The metal content of group VIb is generally between 1.5% and 60% by weight, preferably between 3% and 50% by weight relative to the total weight of the catalyst.

Le support du catalyseur est habituellement un solide poreux, tel que par exemple une alumine, une silice-alumine, de la magnésie, de la silice ou de l'oxyde de titane, seuls ou en mélange. De manière très préférée, le support est essentiellement constitué d'alumine de transition, c'est-à-dire qu'il comprend au moins 51% poids, de préférence au moins 60% poids, de manière très préféré au moins 80% poids, voire au moins 90% poids d'alumine de transition par rapport au poids total du support. Il peut éventuellement être constitué uniquement d'une alumine de transition.The catalyst support is usually a porous solid, such as for example an alumina, a silica-alumina, magnesia, silica or titanium oxide, alone or as a mixture. Very preferably, the support consists essentially of transition alumina, that is to say that it comprises at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight , or even at least 90% by weight of transition alumina relative to the total weight of the support. It can optionally consist only of a transition alumina.

Le catalyseur d'hydrodésulfuration présente de préférence une surface spécifique inférieure à 250 m2/g, de manière plus préférée inférieure à 230 m2/g, et de manière très préférée inférieure à 190 m2/g.The hydrodesulfurization catalyst preferably has a specific surface of less than 250 m 2 / g, more preferably less than 230 m 2 / g, and very preferably less than 190 m 2 / g.

Pour minimiser l'hydrogénation des oléfines, il est avantageux d'utiliser un catalyseur comprenant du molybdène seul ou en mélange avec du nickel ou du cobalt et dans lequel la densité de molybdène, exprimée comme étant le rapport entre ladite teneur en poids de MoO3 et la surface spécifique du catalyseur, est supérieure à 7.10-4 et de préférence supérieure à 12.10-4 g/m2. De manière très préférée, on choisit un catalyseur comprenant du cobalt et du molybdène dont la densité de molybdène, exprimée comme étant le rapport entre ladite teneur en poids de MoO3 et la surface spécifique du catalyseur, est supérieure à 7.10-4 et de préférence supérieure à 12.10-4 g/m2.To minimize the hydrogenation of olefins, it is advantageous to use a catalyst comprising molybdenum alone or in admixture with nickel or cobalt and in which the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface of the catalyst is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 . Very preferably, a catalyst is chosen comprising cobalt and molybdenum, the density of molybdenum, expressed as being the ratio between said content by weight of MoO 3 and the specific surface area of the catalyst, is greater than 7.10 -4 and preferably greater than 12.10 -4 g / m 2 .

Avantageusement le catalyseur d'hydrodésulfuration, avant sulfuration, présente un diamètre moyen de pore supérieur à 20 nm, de manière préférée supérieur à 25 nm, voire 30 nm et souvent compris entre 20 et 140 nm, de préférence entre 20 et 100 nm, et très préférentiellement entre 25 et 80 nm. Le diamètre de pore est mesuré par porosimétrie au mercure selon la norme ASTM D4284-92 avec un angle de mouillage de 140°.Advantageously, the hydrodesulfurization catalyst, before sulfiding, has an average pore diameter greater than 20 nm, preferably greater than 25 nm, or even 30 nm and often between 20 and 140 nm, preferably between 20 and 100 nm, and very preferably between 25 and 80 nm. The pore diameter is measured by mercury porosimetry according to standard ASTM D4284-92 with a wetting angle of 140 °.

Le dépôt des métaux sur le support est obtenu pour toutes méthodes connues de l'homme de l'art telles que par exemples l'imprégnation à sec, par excès d'une solution contenant les précurseurs de métaux. Ladite solution est choisie de manière à pouvoir solubiliser les précurseurs de métaux dans les concentrations désirées. Dans le cas de la synthèse d'un catalyseur CoMo, par exemple, le précurseur de molybdène peut être l'oxyde de molybdène, l'heptamolybdate d'ammonium. Par ailleurs, pour le cobalt on peut citer par exemple le nitrate de cobalt, l'hydroxyde de cobalt, le carbonate de cobalt. Les précurseurs sont généralement dissous en milieu permettant leur solubilisation dans les concentrations désirés. Celle-ci peut être donc selon les cas réalisés en milieu aqueux et/ou en milieu organique.The deposition of metals on the support is obtained for all methods known to those skilled in the art, such as, for example, dry impregnation, by excess of a solution containing the metal precursors. Said solution is chosen so as to be able to dissolve the metal precursors in the desired concentrations. In the case of the synthesis of a CoMo catalyst, for example, the molybdenum precursor can be molybdenum oxide, ammonium heptamolybdate. Furthermore, for cobalt, mention may, for example, be made of cobalt nitrate, cobalt hydroxide, cobalt carbonate. The precursors are generally dissolved in a medium allowing their solubilization in the desired concentrations. This can therefore be, depending on the case, carried out in an aqueous medium and / or in an organic medium.

Après introduction du ou des métaux et éventuellement mise en forme du catalyseur, le catalyseur est dans une première étape activé. Cette activation peut correspondre soit à une calcination (oxydation) puis à une réduction, soit à une réduction directe, soit à une calcination uniquement. L'étape de calcination est généralement réalisée à des températures allant de 100°C à 600°C et de préférence comprises entre 200°C et 450°C, sous un débit d'air. L'étape de réduction est réalisée dans des conditions permettant de convertir au moins une partie des formes oxydées du métal de base en métal. Généralement, elle consiste à traiter le catalyseur sous un flux d'hydrogène à une température de préférence au moins égale à 300 °C.After introduction of the metal or metals and optionally shaping of the catalyst, the catalyst is in a first activated stage. This activation can correspond either to a calcination (oxidation) then to a reduction, or to a direct reduction, or to a calcination only. The calcination step is generally carried out at temperatures ranging from 100 ° C to 600 ° C and preferably between 200 ° C and 450 ° C, under an air flow. The reduction step is carried out under conditions which make it possible to convert at least part of the oxidized forms of the base metal to metal. Generally, it consists in treating the catalyst under a stream of hydrogen at a temperature preferably at least equal to 300 ° C.

Le catalyseur est de préférence utilisé au moins en partie sous sa forme sulfurée. L'introduction du soufre peut intervenir avant ou après toute étape d'activation, c'est-à-dire de calcination ou de réduction. De préférence, aucune étape d'oxydation du catalyseur n'est réalisée lorsque le soufre ou un composé soufré a été introduit sur le catalyseur. Le soufre ou un composé soufré peut être introduit ex situ, c'est-à-dire en dehors du réacteur où le procédé selon l'invention est réalisé, ou in situ, c'est-à-dire dans le réacteur utilisé pour le procédé selon l'invention. Dans ce dernier cas, le catalyseur est de préférence sulfuré par passage d'une charge contenant au moins un composé soufré, qui une fois décomposé conduit à la fixation de soufre sur le catalyseur. Cette charge peut être gazeuse ou liquide, par exemple de l'hydrogène contenant de l'H2S, ou un liquide contenant au moins un composé soufré.The catalyst is preferably used at least in part in its sulfurized form. The introduction of sulfur can occur before or after any activation step, that is to say calcination or reduction. Preferably, no oxidation step of the catalyst is carried out when the sulfur or a sulfur-containing compound has been introduced onto the catalyst. The sulfur or a sulfur-containing compound can be introduced ex situ, that is to say outside the reactor where the process according to the invention is carried out, or in situ, that is to say in the reactor used for the method according to the invention. In the latter case, the catalyst is preferably sulfurized by passing a charge containing at least one sulfur compound, which once decomposed leads to the fixing of sulfur on the catalyst. This charge can be gaseous or liquid, for example hydrogen containing H 2 S, or a liquid containing at least one sulfur-containing compound.

D'une façon préférée, le composé soufré est ajouté sur le catalyseur de manière ex situ. Par exemple, après l'étape de calcination, un composé soufré peut être introduit sur le catalyseur en présence éventuellement d'un autre composé. Le catalyseur est ensuite séché, puis transféré dans le réacteur servant à mettre en œuvre le procédé selon l'invention. Dans ce réacteur, le catalyseur est alors traité sous hydrogène afin de transformer au moins une partie du métal principal en sulfure. Une procédure qui convient particulièrement pour la sulfuration du catalyseur est celle décrite dans les documents FR 2 708 596 et FR 2 708 597 .Preferably, the sulfur-containing compound is added to the catalyst ex situ. For example, after the calcination step, a sulfur-containing compound can be introduced onto the catalyst in the optional presence of another compound. The catalyst is then dried, then transferred to the reactor used to carry out the process according to the invention. In this reactor, the catalyst is then treated under hydrogen in order to transform at least part of the main metal into sulphide. A procedure which is particularly suitable for the sulfurization of the catalyst is that described in the documents. FR 2 708 596 and FR 2 708 597 .

Selon un mode de réalisation alternatif, l'étape a) est mise en œuvre dans une colonne de distillation catalytique munie d'une section comprenant un catalyseur d'hydrodésulfuration, dans laquelle se réalisent à la fois la réaction catalytique d'hydrodésulfuration et la séparation de l'essence en au moins deux coupes (ou fractions). De préférence, la colonne de distillation catalytique comporte deux lits de catalyseur d'hydrodésulfuration et la charge est envoyée dans la colonne entre les deux lits de catalyseur.According to an alternative embodiment, step a) is carried out in a catalytic distillation column provided with a section comprising a hydrodesulfurization catalyst, in which both the catalytic hydrodesulfurization reaction and the separation are carried out gasoline in at least two cuts (or fractions). Preferably, the catalytic distillation column comprises two beds of hydrodesulfurization catalyst and the charge is sent to the column between the two catalyst beds.

- Étape de séparation de l'hydrogène et de l'H2S (étape b) - Step of separation of hydrogen and H 2 S (step b)

Cette étape est mise en œuvre afin de séparer l'excès d'hydrogène ainsi que l'H2S formé lors de l'étape a) de l'effluent issu de l'étape a). Toute méthode connue de l'homme du métier peut être envisagée.This step is implemented in order to separate the excess hydrogen as well as the H 2 S formed during step a) from the effluent from step a). Any method known to a person skilled in the art can be envisaged.

Selon un premier mode de réalisation préféré, après l'étape a) d'hydrodésulfuration, l'effluent est refroidi à une température généralement inférieure à 80°C et de préférence inférieure à 60°C afin de condenser les hydrocarbures. Les phases gaz et liquide sont ensuite séparées dans un ballon de séparation. La fraction liquide qui contient l'essence désulfurée ainsi qu'une fraction de l'H2S dissous est envoyée vers une colonne de stabilisation ou débutaniseur. Cette colonne sépare une coupe de tête essentiellement constituée d'H2S résiduel et de composés hydrocarbures ayant une température d'ébullition inférieure ou égale à celle du butane et une coupe de fond débarrassée de l'H2S, appelée essence stabilisée, contenant les composés ayant une température d'ébullition supérieure à celle du butane.According to a first preferred embodiment, after the hydrodesulfurization step a), the effluent is cooled to a temperature generally below 80 ° C and preferably below 60 ° C in order to condense the hydrocarbons. The gas and liquid phases are then separated in a separation flask. The liquid fraction which contains the desulfurized gasoline as well as a fraction of the dissolved H 2 S is sent to a stabilization column or debutanizer. This column separates a head section essentially consisting of residual H 2 S and of hydrocarbon compounds having a boiling temperature lower than or equal to that of butane and a bottom section stripped of H 2 S, called stabilized gasoline, containing compounds having a boiling point higher than that of butane.

Selon un second mode de réalisation préféré, après l'étape de condensation, la fraction liquide qui contient l'essence désulfurée ainsi qu'une fraction de l'H2S dissous est envoyée vers une section de stripage, tandis que la fraction gazeuse constituée principalement d'hydrogène et de H2S est envoyée vers une section de purification. Le stripage peut être réalisée en chauffant la fraction hydrocarbonée seule ou avec une injection d'hydrogène ou de vapeur d'eau, dans une colonne de distillation afin d'extraire, en tête les composés légers qui ont été entraînés par dissolution dans la fraction liquide ainsi que l'H2S résiduel dissous. La température de l'essence strippée récupérée en fond de colonne est généralement comprise entre 120°C et 250°C.According to a second preferred embodiment, after the condensation step, the liquid fraction which contains the desulfurized gasoline as well as a fraction of the dissolved H 2 S is sent to a stripping section, while the gaseous fraction constituted mainly hydrogen and H 2 S is sent to a purification section. The stripping can be carried out by heating the hydrocarbon fraction alone or with an injection of hydrogen or water vapor, in a distillation column in order to extract, at the top, the light compounds which have been entrained by dissolution in the liquid fraction. as well as the residual dissolved H 2 S. The temperature of the stripped gasoline recovered at the bottom of the column is generally between 120 ° C and 250 ° C.

L'étape b) est de préférence mise en œuvre afin que le soufre sous forme d'H2S restant dans l'essence désulfurée, avant l'étape de démercaptisation (d'adoucissement) c), représente moins de 30%, de préférence moins de 20% et de manière plus préférée moins de 10% du soufre total présent dans la fraction hydrocarbonée traitée.Step b) is preferably implemented so that the sulfur in the form of H 2 S remaining in the desulfurized gasoline, before the demercaptization (softening) step c) represents less than 30%, preferably less than 20% and more preferably less than 10% of the total sulfur present in the treated hydrocarbon fraction.

- Étape d'adoucissement catalytique de la fraction hydrocarbonée désulfurée issue de l'étape b) (étape c) - Catalytic softening step of the desulfurized hydrocarbon fraction from step b) (step c)

Cette étape consiste à transformer les composés soufrés de la famille des mercaptans en des composés soufrés plus lourds du type thioéther. Ces mercaptans sont essentiellement des mercaptans de recombinaison issus de la réaction de l'H2S formé à l'étape a) avec les oléfines de l'essence.This step consists in transforming the sulfur compounds of the mercaptan family into heavier sulfur compounds of the thioether type. These mercaptans are essentially recombinant mercaptans resulting from the reaction of the H 2 S formed in step a) with the olefins of gasoline.

La réaction de transformation mise en jeu dans cette étape c) consiste à faire réagir les mercaptans sur les oléfines pour former des composés soufrés plus lourds du type thioéther. Il est à noter que cette étape est à distinguer d'une étape d'hydrodésulfuration "classique" qui a pour objectif de transformer, en présence d'hydrogène, les composés soufrés en H2S.The transformation reaction involved in this step c) consists in reacting the mercaptans on the olefins to form heavier sulfur compounds of the thioether type. It should be noted that this step is to be distinguished from a "conventional" hydrodesulfurization step which aims to transform, in the presence of hydrogen, the sulfur-containing compounds into H 2 S.

Cette étape permet également de convertir l'H2S résiduel, qui n'aurait pas été totalement éliminé lors de l'étape b), en thioéther par réaction avec les oléfines présentes dans la charge.This step also makes it possible to convert the residual H 2 S, which would not have been completely eliminated during step b), into thioether by reaction with the olefins present in the feed.

La réaction de démercaptisation (ou d'adoucissement) s'effectue sur un catalyseur comprenant au moins un sulfure d'un métal choisi parmi le groupe VIB, le groupe VIII, le cuivre et le plomb, déposé sur un support poreux apte à transformer les composés soufrés de la famille des mercaptans, par réaction avec les oléfines de l'essence en composés soufrés du type thioéther.The demercaptization (or softening) reaction is carried out on a catalyst comprising at least one sulfide of a metal chosen from group VIB, group VIII, copper and lead, deposited on a porous support capable of transforming the sulfur compounds of the mercaptan family, by reaction with petroleum olefins to sulfur compounds of the thioether type.

De manière très préférée, le catalyseur comprend au moins un élément du groupe VIII (groupes 8, 9 et 10 de la nouvelle classification périodique Handbook of Chemistry and Physics, 76ième édition, 1995-1996 ), au moins un élément du groupe VIB (groupe 6 de la nouvelle classification périodique Handbook of Chemistry and Physics, 76ième édition, 1995-1996 ) et un support. L'élément du groupe VIII est choisi de préférence parmi le nickel et le cobalt et en particulier le nickel. L'élément du groupe VIB est de préférence choisi parmi le molybdène et le tungstène et de manière très préférée le molybdène.Very preferably, the catalyst comprises at least one element from group VIII (groups 8, 9 and 10 of the new periodic classification Handbook of Chemistry and Physics, 76th edition, 1995-1996 ), at least one element from group VIB (group 6 of the new periodic classification) Handbook of Chemistry and Physics, 76th edition, 1995-1996 ) and a support. The element of group VIII is preferably chosen from nickel and cobalt and in particular nickel. The element of group VIB is preferably chosen from molybdenum and tungsten and very preferably molybdenum.

Le support du catalyseur de l'étape c) est de préférence choisi parmi l'alumine, l'aluminate de nickel, la silice, le carbure de silicium, ou un mélange de ces oxydes. On utilise, de manière préférée, de l'alumine et de manière encore plus préférée, de l'alumine pure. De manière préférée, on utilise un support présentant un volume poreux total mesuré par porosimétrie au mercure compris entre 0,4 et 1,4 cm3/g et préférentiellement compris entre 0,5 et 1,3 cm3/g. La surface spécifique du support est de préférence comprise entre 70 m2/g et 350 m2/g.The catalyst support of step c) is preferably chosen from alumina, nickel aluminate, silica, silicon carbide, or a mixture of these oxides. Alumina is preferably used, and even more preferably alumina is used. pure. Preferably, a support is used which has a total pore volume measured by mercury porosimetry of between 0.4 and 1.4 cm 3 / g and preferably between 0.5 and 1.3 cm 3 / g. The specific surface of the support is preferably between 70 m 2 / g and 350 m 2 / g.

Selon une variante préférée, le support est une alumine gamma cubique ou une alumine delta.According to a preferred variant, the support is a cubic gamma alumina or a delta alumina.

Le catalyseur mis en œuvre à l'étape c) comprend de manière préférée:

  • un support constitué d'alumine gamma ou delta de surface spécifique comprise entre 70 m2/g et 350 m2/g
  • une teneur en poids d'oxyde de l'élément du groupe VIB comprise entre 1% et 30% poids par rapport au poids total du catalyseur,
  • une teneur en poids d'oxyde de l'élément du groupe VIII comprise entre 1% et 30 % poids par rapport au poids total du catalyseur,
  • un taux de sulfuration des métaux constituants ledit catalyseur au moins égal à 60%,
  • un rapport molaire entre le métal du groupe VIII et le métal du groupe VIB compris entre 0,6 et 3 mol/mol,
The catalyst used in step c) preferably comprises:
  • a support consisting of gamma or delta alumina with a specific surface of between 70 m 2 / g and 350 m 2 / g
  • a content by weight of oxide of the element of group VIB of between 1% and 30% by weight relative to the total weight of the catalyst,
  • a content by weight of oxide of the element of group VIII of between 1% and 30% by weight relative to the total weight of the catalyst,
  • a sulfurization rate of the metals constituting said catalyst at least equal to 60%,
  • a molar ratio between the metal of group VIII and the metal of group VIB of between 0.6 and 3 mol / mol,

En particulier, il a été trouvé que les performances sont améliorées lorsque le catalyseur de l'étape c) présente les caractéristiques suivantes :

  • un support constitué d'alumine gamma de surface comprise entre 180 m2/g et 270 m2/g
  • la teneur en poids d'oxyde de l'élément du groupe VIB sous forme oxyde est comprise entre 4% et 20% poids, de préférence entre 6 et 18% poids par rapport au poids total de catalyseur;
  • la teneur en métal du groupe VIII exprimée sous forme d'oxyde est comprise entre 3 et 15% poids, de préférence comprise entre 4% poids et 12% poids par rapport au poids total de catalyseur;
  • le rapport molaire entre le métal non noble du groupe VIII et le métal du groupe VIB est compris entre 0,6 et 3 mol/mol, de manière préférée entre 1 et 2,5 mol/mol;
  • un taux de sulfuration des métaux constituants ledit catalyseur au moins égal à 60%.
In particular, it has been found that the performances are improved when the catalyst of step c) has the following characteristics:
  • a support consisting of gamma alumina with a surface of between 180 m 2 / g and 270 m 2 / g
  • the content by weight of oxide of the element of group VIB in oxide form is between 4% and 20% by weight, preferably between 6 and 18% by weight relative to the total weight of catalyst;
  • the metal content of group VIII expressed in the form of oxide is between 3 and 15% by weight, preferably between 4% by weight and 12% by weight relative to the total weight of catalyst;
  • the molar ratio between the non-noble metal of group VIII and the metal of group VIB is between 0.6 and 3 mol / mol, preferably between 1 and 2.5 mol / mol;
  • a sulfurization rate of the metals constituting said catalyst at least equal to 60%.

Un mode de réalisation très préféré de l'invention correspond à la mise en œuvre pour l'étape c) d'un catalyseur contenant une teneur en poids par rapport au poids total de catalyseur d'oxyde de nickel (sous forme NiO) comprise entre 4 et 12%, une teneur en poids par rapport au poids total de catalyseur d'oxyde de molybdène (sous forme MoO3) comprise entre 6% et 18%, un rapport molaire nickel/molybdène compris entre 1 et 2,5, les métaux étant déposés sur un support constitué uniquement d'alumine gamma de surface spécifique comprise entre 180 m2/g et 270 m2/g et le taux de sulfuration des métaux constituant le catalyseur étant supérieur à 80%.A very preferred embodiment of the invention corresponds to the use for step c) of a catalyst containing a content by weight relative to the total weight of nickel oxide catalyst (in NiO form) between 4 and 12%, a content by weight relative to the total weight of molybdenum oxide catalyst (in MoO 3 form) of between 6% and 18%, a nickel / molybdenum molar ratio of between 1 and 2.5, the metals being deposited on a support consisting solely of gamma alumina with a specific surface of between 180 m 2 / g and 270 m 2 / g and the sulfurization rate of the metals constituting the catalyst being greater than 80%.

Le catalyseur pour l'étape c) peut être préparé au moyen de toute technique connue de l'homme du métier, et notamment par imprégnation des métaux sur le support sélectionné.The catalyst for step c) can be prepared using any technique known to those skilled in the art, and in particular by impregnating the metals on the selected support.

Après introduction des métaux, et éventuellement une mise en forme du catalyseur, celui-ci subi un traitement d'activation. Ce traitement a généralement pour but de transformer les précurseurs moléculaires des éléments en phase oxyde. Il s'agit dans ce cas d'un traitement oxydant mais un simple séchage du catalyseur peut également être effectué. Dans le cas d'un traitement oxydant, également appelé calcination, celui-ci est généralement mis en œuvre sous air ou sous oxygène dilué, et la température de traitement est généralement comprise entre 200°C et 550°C, de préférence entre 300°C et 500°C.After introduction of the metals, and possibly shaping of the catalyst, the latter undergoes an activation treatment. This treatment generally aims to transform the molecular precursors of the elements in the oxide phase. In this case it is an oxidizing treatment but a simple drying of the catalyst can also be carried out. In the case of an oxidizing treatment, also called calcination, it is generally carried out in air or under dilute oxygen, and the treatment temperature is generally between 200 ° C and 550 ° C, preferably between 300 ° C and 500 ° C.

Après calcination, les métaux déposés sur le support se trouvent sous forme d'oxyde. Dans le cas du nickel et du molybdène, les métaux se trouvent principalement sous forme de MoO3 et de NiO. Avant mise en contact avec la charge à traiter, les catalyseurs subissent une étape de sulfuration. La sulfuration est de préférence réalisée en milieu sulforéducteur, c'est-à-dire en présence d'H2S et d'hydrogène, afin de transformer les oxydes métalliques en sulfures tels que par exemple, le MoS2 et le Ni3S2. La sulfuration est réalisée en injectant sur le catalyseur un flux contenant de l'H2S et de l'hydrogène, ou bien un composé soufré susceptible de se décomposer en H2S en présence du catalyseur et de l'hydrogène. Les polysulfures tel que le diméthyldisulfure (DMDS) sont des précurseurs d'H2S couramment utilisés pour sulfurer les catalyseurs. La température est ajustée afin que l'H2S réagisse avec les oxydes métalliques pour former des sulfures métalliques. Cette sulfuration peut être réalisée in situ ou ex situ (en dedans ou dehors du réacteur) du réacteur de démercaptisation, à une température comprise entre 200°C et 600°C et plus préférentiellement entre 300°C et 500°C.After calcination, the metals deposited on the support are in the form of oxide. In the case of nickel and molybdenum, the metals are mainly found in the form of MoO 3 and NiO. Before being brought into contact with the feed to be treated, the catalysts undergo a sulfurization step. The sulfurization is preferably carried out in a sulforeductive medium, that is to say in the presence of H 2 S and of hydrogen, in order to transform the metal oxides into sulphides such as for example, MoS 2 and Ni 3 S 2 . Sulfurization is carried out by injecting a flux containing H 2 S and hydrogen onto the catalyst, or else a sulfur-containing compound capable of decomposing into H 2 S in the presence of the catalyst and hydrogen. Polysulfides such as dimethyldisulfide (DMDS) are precursors of H 2 S commonly used to sulfurize catalysts. The temperature is adjusted so that the H 2 S reacts with the metal oxides to form metal sulfides. This sulfurization can be carried out in situ or ex situ (inside or outside the reactor) of the demercaptization reactor, at a temperature between 200 ° C and 600 ° C and more preferably between 300 ° C and 500 ° C.

L'étape c) d'adoucissement en mercaptans, consiste en la mise en contact de la l'essence désulfurée et débarrassée d'au moins une partie de l'H2S avec le catalyseur sous forme sulfure. Les réactions de démercaptisation selon l'invention se caractérisent par une réaction des mercaptans sur les oléfines via une addition directe sur la double liaison pour produire des composés du type thioéther, de formule R1-S-R2 avec R1 et R2 étant des radicaux alkyles, dont le point d'ébullition est plus élevé que celui des mercaptans de départ.Step c) of softening in mercaptans, consists in bringing the desulphurized gasoline and freed of at least part of the H 2 S into contact with the catalyst in sulphide form. The demercaptization reactions according to the invention are characterized by a reaction of the mercaptans on the olefins via a direct addition on the double bond to produce compounds of the thioether type, of formula R1-S-R2 with R1 and R2 being alkyl radicals, whose boiling point is higher than that of the starting mercaptans.

Cette étape d'adoucissement peut être réalisée en absence (sans apport ou addition d'hydrogène) ou en présence d'hydrogène apporté dans le réacteur. De préférence, elle est réalisée en absence d'apport d'hydrogène. Lorsque de l'hydrogène est utilisé, celui-ci est injecté avec la charge de manière à maintenir un état de surface hydrogénant du catalyseur propre aux hautes conversions en démercaptisation. Typiquement, l'étape c) fonctionne avec un rapport H2/charge compris entre 0 et 10 Nm3 d'hydrogène par m3 de charge, de manière très préférée entre 0 et 5 Nm3 d'hydrogène par m3 de charge, et de manière encore plus préférée entre 0 et 2 Nm3 d'hydrogène par m3 de charge.This softening step can be carried out in the absence (without addition or addition of hydrogen) or in the presence of hydrogen supplied to the reactor. Preferably, it is carried out in the absence of hydrogen supply. When hydrogen is used, this is injected with the charge so as to maintain a hydrogenating surface state of the catalyst suitable for high conversions to demercaptization. Typically, step c) operates with a H 2 / feed ratio of between 0 and 10 Nm 3 of hydrogen per m 3 of feed, very preferably between 0 and 5 Nm 3 of hydrogen per m 3 of feed, and even more preferably between 0 and 2 Nm 3 of hydrogen per m 3 of feed.

La totalité de la charge est généralement injectée à l'entrée du réacteur. Toutefois, il peut être avantageux, dans certains cas d'injecter une fraction ou la totalité de la charge entre deux lits catalytiques consécutifs placés dans le réacteur.The entire charge is generally injected at the inlet of the reactor. However, it may be advantageous in certain cases to inject a fraction or all of the charge between two consecutive catalytic beds placed in the reactor.

L'essence à traiter est mise en contact avec le catalyseur à une température comprise entre 30°C et 250°C, et de préférence entre 60°C et 220°C, et de manière encore plus préférée entre 90°C et 200°C, avec une vitesse spatiale liquide (LHSV) comprise entre 0,5 h-1 et 10 h-1, l'unité de la vitesse spatiale liquide étant le litre de charge par litre de catalyseur et par heure (l/l.h). La pression est comprise entre 0,2 MPa et 5 MPa, de préférence entre 0,5 et 2 MPa et de manière encore plus préférée entre 0,6 et 1 MPa.The gasoline to be treated is brought into contact with the catalyst at a temperature between 30 ° C and 250 ° C, and preferably between 60 ° C and 220 ° C, and even more preferably between 90 ° C and 200 ° C, with a liquid space speed (LHSV) of between 0.5 h -1 and 10 h -1 , the unit of the liquid space speed being the liter of feed per liter of catalyst and per hour (l / lh). The pressure is between 0.2 MPa and 5 MPa, preferably between 0.5 and 2 MPa and even more preferably between 0.6 and 1 MPa.

Lors de cette étape c), les mercaptans qui se combinent avec les oléfines de la charge pour former des composés thioéther, ont un nombre de carbone typiquement compris entre 5 et 12 et sont de plus généralement ramifiés. A titre d'exemple, les mercaptans pouvant être contenus dans la charge de l'étape c) sont le 2-méthylhexan-2-thiol, le 4-méthylheptan-4-thiol, le 2-éthyl-hexan-3-thiol ou le 2,2,4-triméthylpentan-4-thiol.During this step c), the mercaptans which combine with the olefins of the feed to form thioether compounds, have a carbon number typically between 5 and 12 and are more generally branched. By way of example, the mercaptans which may be contained in the feed of step c) are 2-methylhexan-2-thiol, 4-methylheptan-4-thiol, 2-ethyl-hexan-3-thiol or 2,2,4-trimethylpentan-4-thiol.

A l'issue de l'étape c) la fraction hydrocarbonée traitée dans les conditions énoncées ci-dessus présente donc une teneur en mercaptans réduite (ces derniers ont été convertis en composés thioéther). Généralement, l'essence produite à l'issue de l'étape c) contient moins de 20 ppm poids de mercaptans, et de préférence moins de 10 ppm poids, et de manière encore plus préférée moins de 5 ppm poids. Lors de cette étape c), qui ne nécessite pas d'apporter de l'hydrogène, les oléfines ne sont pas ou très peu hydrogénée, ce qui permet de maintenir un bon indice d'octane de l'effluent en sortie de l'étape c). Le taux d'hydrogénation des oléfines est en règle générale inférieur à 2%.At the end of step c) the hydrocarbon fraction treated under the conditions set out above therefore has a reduced mercaptan content (the latter have been converted to thioether compounds). Generally, the gasoline produced at the end of step c) contains less than 20 ppm by weight of mercaptans, and preferably less than 10 ppm by weight, and even more preferably less than 5 ppm by weight. During this step c), which does not require the supply of hydrogen, the olefins are not or very little hydrogenated, which makes it possible to maintain a good octane number of the effluent at the outlet of the step vs). The rate of hydrogenation of olefins is generally less than 2%.

- Étape de fractionnement de l'essence adoucie issue de l'étape c) (étape d) optionnelle) - Fractionation step of softened gasoline from step c) (optional step d))

A l'issue de l'étape c) l'essence traitée dans les conditions énoncées ci-dessus présente donc une teneur réduite en mercaptans. En effet ces derniers ont été convertis en composés du type thioéther dont le point moléculaire est supérieur aux mercaptans de départ.At the end of step c) the gasoline treated under the conditions set out above therefore has a reduced content of mercaptans. Indeed the latter were converted into compounds of the thioether type whose molecular point is higher than the starting mercaptans.

Conformément à l'invention et de manière optionnelle, on procède à une étape de fractionnement (étape d) de l'essence adoucie en mercaptans en au moins une coupe légère et une coupe lourde d'hydrocarbures. Cette étape de fractionnement est conduite dans des conditions telles que les composés soufrés du type thioéther formés à l'étape c) et éventuellement les mercaptans résiduels les plus lourds et les plus réfractaires qui n'ont pas réagi lors de l'étape c) se concentrent dans la coupe lourde d'hydrocarbures. De préférence, l'étape de fractionnement est menée de manière à ce que la coupe légère d'hydrocarbures à faible teneur en soufre, en particulier en mercaptans et en composés sulfure, présente une température d'ébullition finale comprise entre 130 et 160°C. Il est bien entendu possible pour l'homme du métier choisir le point de coupe (i.e. la température d'ébullition finale de la coupe légère d'hydrocarbures) en fonction de la teneur en soufre visée dans ladite coupe légère d'hydrocarbures. Typiquement la coupe essence légère présente une teneur en mercaptans inférieure à 10 ppm poids, de préférence inférieure à 5 ppm poids et de manière plus préférée inférieure à 1 ppm poids et une teneur en soufre total inférieure à 50 ppm poids, de préférence inférieure à 20 ppm poids et de manière plus préférée inférieure à 10 ppm poids. La coupe légère d'hydrocarbures à basse teneur en soufre et en mercaptans est avantageusement envoyée au pool essence de la raffinerie. Quant à la coupe lourde d'hydrocarbures qui concentre les composés soufrés du type thioéthers et les mercaptans réfractaires à la réaction d'addition avec les oléfines, elle est avantageusement traitée dans une unité d'hydrodésulfuration qui applique des conditions d'hydrotraitement plus sévères (plus haute température, quantité d'hydrogène mise en jeu plus élevée) ou est alternativement envoyée au pool gazole de la raffinerie.According to the invention and optionally, a fractionation step (step d) of the gasoline softened into mercaptans is carried out into at least one light cut and one heavy cut of hydrocarbons. This fractionation step is carried out under conditions such that the sulfur-containing compounds of the thioether type formed in step c) and optionally the heaviest and most refractory residual mercaptans which have not reacted during step c) concentrate in heavy cutting of hydrocarbons. Preferably, the fractionation step is carried out in such a way that the light cutting of hydrocarbons with a low sulfur content, in particular mercaptans and sulphide compounds, has a final boiling temperature of between 130 and 160 ° C. . It is of course possible for a person skilled in the art to choose the cutting point (ie the final boiling temperature of the light cut of hydrocarbons) as a function of the sulfur content targeted in said light cut of hydrocarbons. Typically the light petrol cut has a mercaptan content of less than 10 ppm by weight, preferably less than 5 ppm by weight and more preferably less than 1 ppm by weight and a total sulfur content of less than 50 ppm by weight, preferably less than 20 ppm by weight and more preferably less than 10 ppm by weight. The light cut of hydrocarbons with low sulfur and mercaptan content is advantageously sent to the petrol pool of the refinery. As for the heavy cut of hydrocarbons which concentrates the sulfur-containing compounds of the thioether type and the mercaptans refractory to the addition reaction with the olefins, it is advantageously treated in a unit. hydrodesulfurization which applies more severe hydrotreatment conditions (higher temperature, higher quantity of hydrogen used) or is alternatively sent to the diesel pool of the refinery.

Il est à noter que l'étape d'adoucissement en mercaptans (étape c) et le fractionnement (étape d) peuvent être conduites de manière simultanée au moyen d'une colonne catalytique équipée d'un lit catalytique contenant le catalyseur d'adoucissement. De préférence, la colonne de distillation catalytique comporte deux lits de catalyseur d'adoucissement et la charge est envoyée dans la colonne entre les deux lits de catalyseur.It should be noted that the step of softening mercaptans (step c) and the fractionation (step d) can be carried out simultaneously by means of a catalytic column equipped with a catalytic bed containing the softening catalyst. Preferably, the catalytic distillation column has two softening catalyst beds and the charge is sent to the column between the two catalyst beds.

Schémas pouvant être mis en œuvre dans le cadre de l'invention.Schemes that can be implemented in the context of the invention.

Différents schémas peuvent être mis en œuvre afin de produire, à moindre coût, une essence désulfurée et à teneur réduite en mercaptans. Le choix du schéma optimal dépend en fait des caractéristiques des essences à traiter et à produire ainsi que des contraintes propres à chaque raffinerie.Different schemes can be implemented in order to produce, at a lower cost, a desulfurized gasoline with a reduced mercaptan content. The choice of the optimal scheme depends in fact on the characteristics of the species to be treated and produced as well as on the constraints specific to each refinery.

Les schémas décrits ci-dessous sont donnés à titre d'illustration de manière non limitative.The diagrams described below are given by way of illustration without limitation.

Selon une première variante, l'étape c) d'adoucissement catalytique peut être mise en œuvre directement en série avec l'étape b) de séparation. En particulier, dans le cas où l'étape b) de séparation est réalisée à une température compatible avec la température d'opération de l'étape c) d'adoucissement catalytique, l'effluent issu de l'étape b) est directement envoyé dans l'étape c). Il peut également être envisagé d'ajuster la température entre les étapes b) et c) au moyen de dispositifs d'échange thermique.According to a first variant, step c) of catalytic softening can be implemented directly in series with step b) of separation. In particular, in the case where step b) of separation is carried out at a temperature compatible with the operating temperature of step c) of catalytic softening, the effluent from step b) is sent directly in step c). It can also be envisaged to adjust the temperature between steps b) and c) by means of heat exchange devices.

Selon une deuxième variante, avant l'étape c) d'adoucissement catalytique, on procède à un mélange de l'essence issue de l'étape b) avec une coupe GPL (gaz de pétrole liquéfié) ou une autre coupe essence contenant du soufre telle que par exemple, les essences de distillation du pétrole brut, les essences issues de tout procédé de craquage telles que les essences issues de pyrolyse, de procédés de cokéfaction ou d'hydrocraqueur, ou une essence issue d'une unité d'oligomérisation et ensuite on traite le mélange à l'étape c). Il est également possible de traiter dans l'étape c) d'adoucissement l'essence issue de l'étape b) en mélange avec une coupe d'hydrocarbures oléfiniques en C4 pour favoriser la réaction catalytique d'addition des mercaptans (de recombinaison) avec des oléfines.According to a second variant, before step c) of catalytic softening, a mixture of the gasoline obtained from step b) is mixed with an LPG cut (liquefied petroleum gas) or another gasoline cut containing sulfur. such as, for example, petroleum distillation essences, essences resulting from any cracking process such as essences resulting from pyrolysis, coking or hydrocracker processes, or a essence originating from an oligomerization unit and then the mixture is treated in step c). It is also possible to treat in step c) softening the essence from step b) mixed with a cut C4 olefinic hydrocarbons to promote the catalytic reaction of addition of mercaptans (recombination) with olefins.

Selon une troisième variante, on procède à une étape de distillation de l'essence à traiter afin de séparer deux coupes (ou fractions), à savoir une coupe légère et une coupe lourde et on traite la coupe lourde selon le procédé de l'invention. Ainsi selon une première forme de réalisation, on traite la coupe lourde par hydrodésulfuration (étape a), puis on sépare l'H2S formé présent dans la coupe lourde hydrodésulfurée (étape b), on mélange ensuite la coupe légère (issue de la distillation) avec la coupe lourde issue de l'étape b) et enfin on traite le mélange à l'étape c). Alternativement, selon un second mode de réalisation de la troisième variante, on procède à un mélange de la coupe légère avec la coupe lourde hydrodésulfurée issue de l'étape a), on traite à l'étape b) et c) le mélange ainsi obtenu. Cette troisième variante présente l'avantage de ne pas hydrotraiter la coupe légère qui est riche en oléfines et généralement pauvre en soufre, ce qui permet de limiter la perte d'octane par hydrogénation des oléfines. De manière préférée, dans cette troisième variante, la charge traitée dans l'étape c) est constituée de l'intégralité de la coupe lourde désulfurée et d'une partie comprise entre 0 et 50% volume de la coupe légère. Dans le cadre de cette troisième variante, la coupe légère a une gamme de température d'ébullition inférieure à 100°C et la coupe lourde une gamme de température supérieure à 65 °C.According to a third variant, a step of distilling the gasoline to be treated is carried out in order to separate two cuts (or fractions), namely a light cut and a heavy cut, and the heavy cut is treated according to the process of the invention. . Thus according to a first embodiment, the heavy cut is treated by hydrodesulfurization (step a), then the H 2 S formed present in the heavy hydrodesulfurized cut (step b) is separated, then the light cut (after the distillation) with the heavy cut from step b) and finally the mixture is treated in step c). Alternatively, according to a second embodiment of the third variant, a light cut is mixed with the heavy hydrodesulfurized cut from step a), the mixture thus obtained is treated in step b) and c) . This third variant has the advantage of not hydrotreating the light cut which is rich in olefins and generally poor in sulfur, which makes it possible to limit the loss of octane by hydrogenation of the olefins. Preferably, in this third variant, the charge treated in step c) consists of the entire desulfurized heavy cut and a portion of between 0 and 50% volume of the light cut. In the context of this third variant, the light cut has a boiling temperature range of less than 100 ° C. and the heavy cut has a temperature range of more than 65 ° C.

Selon une quatrième variante, on effectue une distillation de l'essence en deux coupes : une première coupe légère et une première coupe lourde d'hydrocarbures. La première coupe légère a une température d'ébullition comprise entre la température d'ébullition initiale de l'essence à traiter et une température d'ébullition finale située entre 140 °C et 160°C. La première coupe légère d'hydrocarbures est ensuite traitée par hydrodésulfuration (étape a), puis on sépare l'H2S formé de l'effluent hydrodésulfuré (étape b), on adoucie en mercaptans l'effluent hydrodésulfuré (étape c) et on fractionne l'effluent adouci en mercaptans (étape d) de manière à produire une seconde coupe essence légère (dont la température d'ébullition est comprise entre la température d'ébullition initiale de l'essence à traiter et une température d'ébullition finale inférieure ou égale à 140°C) à basse teneur en mercaptans et thioéthers et une seconde coupe lourde d'hydrocarbures contenant les thioéthers et les mercaptans non convertis. Optionnellement, les première et seconde coupes lourdes d'hydrocarbures peuvent être mélangées et traitées par hydrodésulfuration dans une unité dédiée.According to a fourth variant, a distillation of the gasoline is carried out in two cuts: a first light cut and a first heavy cut of hydrocarbons. The first light cut has a boiling temperature between the initial boiling temperature of the gasoline to be treated and a final boiling temperature between 140 ° C and 160 ° C. The first light cut of hydrocarbons is then treated by hydrodesulfurization (step a), then the H 2 S formed is separated from the hydrodesulfurized effluent (step b), the hydrodesulfurized effluent is softened in mercaptans (step c) and splits the softened effluent into mercaptans (step d) so as to produce a second light gasoline cut (the boiling temperature of which is between the initial boiling temperature of the gasoline to be treated and a lower final boiling temperature or equal to 140 ° C.) with a low content of mercaptans and thioethers and a second heavy cut of hydrocarbons containing thioethers and unconverted mercaptans. Optionally, the first and second heavy cuts of hydrocarbons can be mixed and treated by hydrodesulfurization in a dedicated unit.

Selon une cinquième variante, on effectue une distillation de l'essence en trois coupes légère, intermédiaire et lourde d'hydrocarbures à l'aide d'une ou plusieurs colonnes à distiller. La coupe légère d'hydrocarbures a de préférence une température d'ébullition comprise entre la température d'ébullition initiale de l'essence à traiter et une température d'ébullition finale située entre 50 °C et 90 °C. Une telle coupe légère d'hydrocarbures contient généralement peu de soufre et donc peut être directement valorisée au pool essence de la raffinerie. La coupe intermédiaire d'hydrocarbures qui a une gamme de températures d'ébullition généralement comprise entre 50 °C et 140 °C ou 160°C est traitée par hydrodésulfuration (étape a), puis on sépare l'H2S formé de l'effluent hydrodésulfuré (étape b), on adoucie en mercaptans l'effluent hydrodésulfuré (étape c) et on fractionne l'effluent adouci en mercaptans (étape d) de manière à produire une seconde coupe essence intermédiaire basse teneur en mercaptans et thioéthers et une seconde coupe lourde d'hydrocarbures contenant les thioéthers et les mercaptans non convertis. Optionnellement, les première et seconde coupes lourdes d'hydrocarbures peuvent être mélangées et traitées par hydrodésulfuration dans une unité dédiée.According to a fifth variant, a distillation of the gasoline is carried out in three light, intermediate and heavy cuts of hydrocarbons using one or more columns to be distilled. The light cut of hydrocarbons preferably has a boiling temperature between the initial boiling temperature of the gasoline to be treated and a final boiling temperature between 50 ° C and 90 ° C. Such a light cut of hydrocarbons generally contains little sulfur and therefore can be directly valued at the petrol pool of the refinery. The intermediate cut of hydrocarbons which has a range of boiling temperatures generally between 50 ° C and 140 ° C or 160 ° C is treated by hydrodesulfurization (step a), then the H 2 S formed is separated from the hydrodesulfurized effluent (step b), the softened hydrodesulfurized effluent (step c) is softened into mercaptans and the softened effluent is separated into mercaptans (step d) so as to produce a second intermediate gasoline fraction low in mercaptans and thioethers and a second heavy cut of hydrocarbons containing thioethers and unconverted mercaptans. Optionally, the first and second heavy cuts of hydrocarbons can be mixed and treated by hydrodesulfurization in a dedicated unit.

Selon une sixième variante, l'essence à traiter est soumise d'abord à une étape préalable consistant en une hydrogénation sélective des dioléfines présentes dans la charge, comme décrite dans la demande de brevet EP 1077247 . L'essence hydrogénée sélectivement est ensuite distillée en au moins deux coupes ou en trois coupes d'hydrocarbures, une coupe légère, une coupe intermédiaire et une coupe lourde. Dans le cas du fractionnement en deux coupes d'hydrocarbures, les étapes décrites plus haut dans le cas des troisième et quatrième variantes sont applicables. Dans le cas du fractionnement en trois coupes d'hydrocarbures, la coupe intermédiaire est traitée séparément dans une étape d'hydrodésulfuration (étape a), puis une étape de séparation de l'H2S (étape b) et puis dans une étape d'adoucissement (étape c). Eventuellement l'effluent issu de l'étape c) est soumis à une étape de fractionnement d) de manière à produire une seconde coupe essence intermédiaire basse teneur en mercaptans et thioéthers et une seconde coupe lourde d'hydrocarbures contenant les thioéthers et les mercaptans non convertis. Optionnellement, la seconde coupe lourde d'hydrocarbures est mélangée à la coupe lourde issue de la distillation en amont de l'étape d'hydrodésulfuration et le mélange est traité par hydrodésulfuration dans une unité dédiée.According to a sixth variant, the gasoline to be treated is first subjected to a prior step consisting in a selective hydrogenation of the diolefins present in the feed, as described in the application for EP 1077247 . The selectively hydrogenated gasoline is then distilled in at least two cuts or three cuts of hydrocarbons, a light cut, an intermediate cut and a heavy cut. In the case of splitting into two hydrocarbon fractions, the steps described above in the case of the third and fourth variants are applicable. In the case of fractionation into three hydrocarbon fractions, the intermediate fraction is treated separately in a hydrodesulfurization stage (stage a), then a stage of separation of H 2 S (stage b) and then in a stage d softening (step c). Optionally, the effluent from step c) is subjected to a fractionation step d) so as to produce a second intermediate gasoline fraction low in mercaptans and thioethers content and a second heavy fraction of hydrocarbons containing thioethers and non-mercaptans. converted. Optionally, the second heavy cut of hydrocarbons is mixed with the heavy cut resulting from the distillation upstream of the hydrodesulfurization step and the mixture is treated by hydrodesulfurization in a dedicated unit.

Il est à noter qu'il est envisageable de réaliser les étapes d'hydrogénation des dioléfines et de fractionnement en deux ou trois coupes simultanément au moyen d'une colonne de distillation catalytique qui inclut une colonne de distillation équipée d'un lit catalytique.It should be noted that it is possible to carry out the steps of hydrogenation of diolefins and of fractionation in two or three cuts simultaneously by means of a catalytic distillation column which includes a distillation column equipped with a catalytic bed.

Dans une septième variante, l'étape a) est effectuée dans une colonne de distillation catalytique incorporant un lit de catalyseur d'hydrodésulfuration permettant simultanément de désulfurer l'essence et de la séparer en deux coupes légère et lourde d'hydrocarbures. Les coupes produites sont ensuite envoyées dans les étapes b) et c) séparément ou en mélange. De façon alternative, seule la coupe essence légère issue de la colonne de distillation catalytique d'hydrodésulfuration est traitée dans les étapes b) puis c). Dans ce cas, l'effluent de l'étape c) peut être fractionné en deux coupes d'hydrocarbures conformément à l'étape d) décrite plus-haut. Dans ce cas également, la coupe lourde issue de la colonne de distillation catalytique d'hydrodésulfuration peut être traitée dans une seconde unité d'hydrodésulfuration, seule ou en mélange avec la coupe lourde issue de l'étape d) de fractionnement de la coupe essence légère issue de la colonne de distillation catalytique d'hydrodésulfuration.In a seventh variant, step a) is carried out in a catalytic distillation column incorporating a bed of hydrodesulfurization catalyst allowing simultaneously to desulfurize the gasoline and to separate it into two light and heavy cuts of hydrocarbons. The sections produced are then sent in steps b) and c) separately or as a mixture. Alternatively, only the light gasoline fraction from the catalytic hydrodesulfurization distillation column is treated in steps b) then c). In this case, the effluent from step c) can be split into two hydrocarbon fractions in accordance with step d) described above. In this case also, the heavy cut from the hydrodesulfurization catalytic distillation column can be treated in a second hydrodesulfurization unit, alone or in mixture with the heavy cut from step d) of fractionation of the gasoline cut. light from the catalytic hydrodesulfurization distillation column.

Dans les cas où l'étape c) est réalisée sur la coupe légère, afin d'améliorer le taux de conversion des mercaptans (de recombinaison) en thioéther lors de l'étape c), un mélange d'une coupe oléfinique en C4 est avantageusement réalisé en amont de l'étape c) avec l'essence légère de manière à ce que l'étape c) soit avantageusement réalisée sur un mélange contenant la coupe légère d'hydrocarbures et une coupe oléfinique en C4 et non la coupe légère seule. A l'issue de l'étape c), l'effluent adouci en mercaptans est envoyé dans une colonne de séparation qui sépare une coupe oléfinique C4 et une coupe légère adoucie en mercaptans. La coupe oléfinique C4 soutirée de la colonne de séparation est avantageusement recyclée dans le réacteur de l'étape c).In the cases where step c) is carried out on the light cut, in order to improve the conversion rate of the mercaptans (of recombination) into thioether during step c), a mixture of an olefinic cut in C4 is advantageously carried out upstream of step c) with light gasoline so that step c) is advantageously carried out on a mixture containing the light cut of hydrocarbons and an olefinic cut in C4 and not the light cut alone . At the end of step c), the effluent softened in mercaptans is sent to a separation column which separates an olefinic cut C4 and a light cut softened in mercaptans. The olefinic cut C4 withdrawn from the separation column is advantageously recycled in the reactor of step c).

Dans les cas où l'étape c) est réalisée sur une coupe intermédiaire ou lourde, afin d'améliorer le taux de conversion des mercaptans (de recombinaison) en thioéther lors de l'étape c), tout ou partie de l'essence légère est avantageusement ajoutée à la coupe intermédiaire ou lourde en amont de l'étape c) de manière à ce que l'étape c) soit avantageusement réalisée sur un mélange contenant des oléfines apportées par la coupe légère d'hydrocarbures.In cases where step c) is carried out on an intermediate or heavy cut, in order to improve the rate of conversion of the mercaptans (of recombination) into thioether during step c), all or part of the light gasoline is advantageously added to the intermediate or heavy cut upstream of step c) so that step c) is advantageously carried out on a mixture containing olefins provided by the light cut of hydrocarbons.

Parmi l'ensemble des variantes possibles, les deux variantes suivantes sont celles qui sont préférées :

  1. 1 - L'essence est distillée en deux coupes (ou fractions), une coupe (ou fraction) légère et une coupe (ou fraction) lourde et seule la coupe lourde est traitée dans l'étape a) d'hydrodésulfuration et dans l'étape b) de séparation de l'H2S où l'essence désulfurée est stabilisée. La fraction lourde stabilisée est ensuite traitée, après un ajustement éventuel de la température entre les étapes b) et c) au moyen de dispositifs d'échange thermique, dans l'étape c) d'adoucissement en absence d'hydrogène. L'avantage de cette mise en œuvre particulière est de limiter au maximum l'investissement nécessaire tout en produisant une essence adoucie en mercaptans qui ne nécessite pas de traitement ultérieur avant son envoi au pool essence.
  2. 2 - L'essence est distillée en deux coupes (ou fractions), une coupe (ou fraction) légère et une coupe (ou fraction) lourde et seule la fraction lourde est traitée dans l'étape a) d'hydrodésulfuration et dans l'étape b) de séparation de l'H2S où l'essence désulfurée est stabilisée ou uniquement débarrassée de l'H2S par stripage. La charge traitée dans l'étape c), avec ou sans apport d'hydrogène, comprend l'intégralité de la fraction lourde désulfurée et d'une partie comprise entre 10 et 50% volume de la coupe légère. L'effluent issu de l'étape c) est ensuite stabilisé dans une étape similaire à l'étape b). L'avantage de cette mise en œuvre particulière est de maximiser la conversion des mercaptans lors de l'étape c) grâce à l'emploi de la coupe légère riche en oléfines afin de favoriser la réaction de conversion des mercaptans en thioéthers.
Among the set of possible variants, the following two variants are those which are preferred:
  1. 1 - The gasoline is distilled in two cuts (or fractions), a light cut (or fraction) and a heavy cut (or fraction) and only the heavy cut is treated in step a) of hydrodesulfurization and in the step b) of separation of the H 2 S where the desulfurized gasoline is stabilized. The stabilized heavy fraction is then treated, after a possible adjustment of the temperature between steps b) and c) by means of heat exchange devices, in step c) of softening in the absence of hydrogen. The advantage of this particular implementation is to limit as much as possible the necessary investment while producing a petrol softened in mercaptans which does not require any further treatment before it is sent to the petrol pool.
  2. 2 - The gasoline is distilled in two cuts (or fractions), a light cut (or fraction) and a heavy cut (or fraction) and only the heavy fraction is treated in step a) of hydrodesulfurization and in the step b) of separation of the H 2 S where the desulfurized gasoline is stabilized or only freed from the H 2 S by stripping. The feed treated in step c), with or without the addition of hydrogen, comprises the entire desulfurized heavy fraction and a portion of between 10 and 50% by volume of the light cut. The effluent from step c) is then stabilized in a step similar to step b). The advantage of this particular implementation is to maximize the conversion of mercaptans during step c) thanks to the use of the light cut rich in olefins in order to promote the reaction of conversion of mercaptans into thioethers.

D'autres caractéristiques et avantages de l'invention vont apparaître maintenant à la lecture de la description qui va suivre, donnée à titre uniquement illustratif et non limitatif, et en référence aux figures annexées :

  • La figure 1 est un schéma du procédé selon l'invention et selon un premier mode de réalisation;
  • La figure 2 est un schéma du procédé selon un second mode de réalisation;
  • La figure 3 représente un schéma du procédé alternatif selon un troisième mode de réalisation;
  • La figure 4 représente un quatrième mode de réalisation du procédé selon l'invention.
Other characteristics and advantages of the invention will now appear on reading the description which follows, given by way of illustration only and without limitation, and with reference to the appended figures:
  • The figure 1 is a diagram of the method according to the invention and according to a first embodiment;
  • The figure 2 is a diagram of the method according to a second embodiment;
  • The figure 3 shows a diagram of the alternative method according to a third embodiment;
  • The figure 4 shows a fourth embodiment of the method according to the invention.

Sur les figures, les éléments semblables sont généralement désignés par des signes de référence identiques.In the figures, similar elements are generally designated by identical reference signs.

En référence à la figure 1 et selon un premier mode de réalisation du procédé selon l'invention, on envoie par la ligne 1 l'essence à traiter et de l'hydrogène par la ligne 3 dans une unité d'hydrodésulfuration 2. L'essence traitée est généralement une essence de craquage, de préférence une essence de craquage catalytique. L'essence se caractérise par une température d'ébullition s'étendant typiquement entre 30°C et 220°C. L'unité d'hydrodésulfuration 2 est par exemple un réacteur contenant un catalyseur d'hydrodésulfuration (HDS) en lit fixe ou en lit fluidisé, de préférence on utilise un réacteur en lit fixe. Le réacteur est opéré dans des conditions opératoires et en présence d'un catalyseur d'HDS, comme décrit plus haut pour décomposer les composés soufrés et former du sulfure d'hydrogène (H2S). Ainsi on soutire dudit réacteur d'hydrodésulfuration 2 par la ligne 4 un effluent (essence) contenant de l'H2S. L'effluent subi ensuite une étape d'élimination de l'H2S (étape b) qui consiste, dans le mode de réalisation de la figure 1, à traiter l'effluent dans une colonne de stabilisation 5 afin de séparer en tête de la colonne via la ligne 6 un flux contenant des hydrocarbures en C4-, la majorité de l'H2S et de l'hydrogène non réagi et en fond de la colonne une essence dite stabilisée.With reference to the figure 1 and according to a first embodiment of the method according to the invention, the gasoline to be treated is sent by line 1 and hydrogen by line 3 in a hydrodesulfurization unit 2. The gasoline treated is generally a gasoline cracking, preferably a catalytic cracking essence. Gasoline is characterized by a boiling temperature typically ranging between 30 ° C and 220 ° C. The hydrodesulfurization unit 2 is for example a reactor containing a hydrodesulfurization catalyst (HDS) in a fixed bed or in a fluidized bed, preferably a reactor in a fixed bed is used. The reactor is operated under operating conditions and in the presence of an HDS catalyst, as described above to decompose the sulfur compounds and form hydrogen sulfide (H 2 S). Thus an effluent (gasoline) containing H 2 S is removed from said hydrodesulfurization reactor 2 via line 4. The effluent is then subjected to a step of removing H 2 S (step b) which consists, in the embodiment of the figure 1 , To treat the effluent in a stabilization column 5 in order to separate the head of the column via line 6 a stream containing C4 hydrocarbons - the majority of H 2 S and unreacted hydrogen and bottom of the column a so-called stabilized gasoline.

L'essence stabilisée est envoyée par la ligne 7 dans un réacteur 8 d'adoucissement (étape c) afin de réduire la teneur en mercaptans de l'essence stabilisée. Les mercaptans contenus dans cette essence stabilisée sont majoritairement des mercaptans de recombinaison issus de la réaction de l'H2S sur les oléfines. Comme précisé ci-avant, le réacteur d'adoucissement met en œuvre un catalyseur permettant de réaliser la réaction d'addition des mercaptans sur les oléfines via une addition directe sur la double liaison pour produire des composés du type thioéther, de formule R1-S-R2 avec R1 et R2 étant des radicaux alkyles, de poids moléculaire est plus élevé que celui du mercaptan de départ. La réaction catalytique de conversion des mercaptans peut être éventuellement menée en présence d'hydrogène apporté par la ligne 9.The stabilized petrol is sent via line 7 to a softening reactor 8 (step c) in order to reduce the mercaptan content of the stabilized petrol. The mercaptans contained in this stabilized gasoline are mainly recombinant mercaptans resulting from the reaction of H 2 S on olefins. As specified above, the softening reactor implements a catalyst making it possible to carry out the reaction for adding mercaptans to olefins via direct addition to the double bond to produce compounds of the thioether type, of formula R1-S -R2 with R1 and R2 being alkyl radicals, of molecular weight is higher than that of the starting mercaptan. The catalytic reaction for converting mercaptans can optionally be carried out in the presence of hydrogen supplied by line 9.

Comme indiqué sur la figure 1, l'essence stabilisée et adoucie en mercaptans soutirée par la ligne 10 du réacteur 8 est avantageusement envoyée dans une colonne de séparation 11 qui est conçue et opérée pour séparer en tête (via la ligne 12) une essence légère stabilisée dont la gamme de températures d'ébullition est de préférence comprise entre 30°C et 160 °C ou entre 30 °C et 140°C et qui présente des teneurs en mercaptans et en soufre total respectivement inférieures à 10 ppm poids et 50 ppm poids. En fond de la colonne de séparation 11, on récupère par la ligne 13 une essence lourde qui contient les composés du type thioéther formés dans le réacteur d'adoucissement 8. L'essence légère est envoyée au pool essence tandis que l'essence lourde est soit hydrodésulfurée dans une unité d'hydrotraitement dédiée, soit envoyée au pool diesel ou distillat de la raffinerie.As shown on the figure 1 , the gasoline stabilized and softened in mercaptans drawn off by line 10 of the reactor 8 is advantageously sent to a separation column 11 which is designed and operated to separate at the head (via line 12) a light stabilized gasoline whose temperature range boiling is preferably between 30 ° C and 160 ° C or between 30 ° C and 140 ° C and which has mercaptan contents and in total sulfur respectively less than 10 ppm by weight and 50 ppm by weight. At the bottom of the separation column 11, a heavy petrol is recovered via line 13 which contains the thioether type compounds formed in the softening reactor 8. The light petrol is sent to the petrol pool while the heavy petrol is either hydrodesulfurized in a dedicated hydrotreating unit, or sent to the diesel or distillate pool of the refinery.

La figure 2 représente un second mode de réalisation basé sur celui de la figure 1 et qui se différencie par le fait que l'essence stabilisée est traitée dans le réacteur d'adoucissement en mercaptans 8 en présence d'une coupe d'hydrocarbures oléfiniques, de préférence une coupe oléfinique en C4, apportée par la ligne 14. La finalité de l'ajout de cette coupe oléfinique est de favoriser la réaction d'addition des mercaptans sur des oléfines en apportant des oléfines réactives dans le milieu réactionnel. Comme indiqué dans la figure 2, l'effluent issu du réacteur d'adoucissement est envoyé dans une colonne de séparation 15 afin de récupérer la fraction de la coupe oléfinique qui n'a pas réagi dans le réacteur d'adoucissement 8. Si la coupe oléfinique est une coupe C4, la colonne de séparation 15 mise en œuvre est équivalente à un débutaniseur qui sépare en tête de la colonne 15 une coupe C4 qui est recyclée dans le réacteur d'adoucissement 8 via la ligne 16. La coupe de fond 17 récupérée de la colonne 15 est fractionnée dans la colonne 11 comme décrit dans le cadre de la figure 1 afin de fournir une coupe essence légère basse teneur en soufre et en mercaptans par la ligne 12 et une coupe essence lourde contenant les composés thioéthers formés dans le réacteur d'adoucissement 8.The figure 2 represents a second embodiment based on that of the figure 1 and which is differentiated by the fact that the stabilized gasoline is treated in the mercaptans softening reactor 8 in the presence of an olefinic hydrocarbon cut, preferably a C4 olefinic cut, provided by line 14. The purpose the addition of this olefinic cut is to promote the addition reaction of mercaptans on olefins by providing reactive olefins in the reaction medium. As stated in the figure 2 , the effluent from the softening reactor is sent to a separation column 15 in order to recover the fraction of the olefinic cut which has not reacted in the softening reactor 8. If the olefinic cut is a C4 cut, the separation column 15 used is equivalent to a debutanizer which separates at the head of column 15 a cut C4 which is recycled in the softening reactor 8 via line 16. The bottom cut 17 recovered from column 15 is fractional in column 11 as described under figure 1 in order to provide a light gasoline cut low in sulfur and mercaptans content via line 12 and a heavy gasoline cut containing the thioether compounds formed in the softening reactor 8.

La figure 3 illustre un troisième mode de réalisation du procédé selon l'invention. La charge d'essence à traiter qui comprend typiquement des hydrocarbures bouillant entre 30°C et 220°C est d'abord envoyée dans une colonne de distillation 20 configurée pour fractionner la charge essence en trois coupes. Une coupe de tête comprenant les composés plus légers que le butane et y compris celui-ci est soutirée par la ligne 21. Une coupe intermédiaire comprenant les hydrocarbures ayant 6 à 7 ou 6 à 8 atomes de carbone est récupérée par ligne 22. Enfin une coupe de fond constituée d'hydrocarbures ayant un nombre d'atome de carbone supérieur à 7 ou 8 atomes de carbone est soutirée par la ligne 23.The figure 3 illustrates a third embodiment of the method according to the invention. The gasoline charge to be treated, which typically comprises hydrocarbons boiling between 30 ° C. and 220 ° C., is first sent to a distillation column 20 configured to split the gasoline charge into three sections. A head section comprising the compounds lighter than butane and including the latter is drawn off by line 21. An intermediate section comprising the hydrocarbons having 6 to 7 or 6 to 8 carbon atoms is recovered by line 22. Finally a bottom section consisting of hydrocarbons having a number of carbon atoms greater than 7 or 8 carbon atoms is drawn off by line 23.

On note également que la charge essence avant d'être fractionnée est avantageusement prétraitée dans un réacteur d'hydrogénation sélective 19 des dioléfines en oléfines. Cette réaction catalytique est de préférence opérée dans les conditions et en présence d'un catalyseur comme décrite dans les documents EP 1445299 ou EP 1800750 .It should also be noted that the petrol charge before being fractionated is advantageously pretreated in a selective hydrogenation reactor 19 of the diolefins to olefins. This catalytic reaction is preferably carried out under the conditions and in the presence of a catalyst as described in the documents. EP 1445299 or EP 1800 750 .

En référence à la figure 3, la coupe de fond est traitée dans un réacteur d'hydrodésulfuration 24 en présence d'hydrogène (apporté par la ligne 25) et d'un catalyseur d'hydrodésulfuration tel que décrit plus haut. L'effluent désulfuré est soutiré du réacteur 24 par la ligne 26 et envoyé dans une unité de séparation 27 de l'H2S, comme par exemple une colonne de stripage, d'où l'on sépare par la ligne 28 une fraction gazeuse contenant essentiellement de l'H2S et de l'hydrogène et une coupe de fond à basse teneur en soufre par la ligne 29.With reference to the figure 3 , the bottom section is treated in a hydrodesulfurization reactor 24 in the presence of hydrogen (supplied by line 25) and a hydrodesulfurization catalyst as described above. The desulphurized effluent is withdrawn from reactor 24 by line 26 and sent to a separation unit 27 of H 2 S, such as for example a stripping column, from which a gas fraction is separated by line 28 essentially containing H 2 S and hydrogen and a low sulfur bottom section through line 29.

Comme indiqué dans la figure 3, la coupe essence intermédiaire est traitée par le procédé selon l'invention. Ainsi la coupe essence intermédiaire est envoyée par la ligne 22 dans un réacteur d'hydrodésulfuration 2 pour y être désulfurée en présence d'hydrogène apporté par la ligne 3. L'effluent issu du réacteur 2 est débarrassé de l'H2S formé lors de l'étape d'HDS dans une unité de séparation 5. L'essence intermédiaire appauvrie en H2S est envoyée par la ligne 7 avec éventuellement de l'hydrogène amené par la ligne 9 dans un réacteur d'adoucissement en mercaptans 8. Afin d'améliorer la conversion des mercaptans en composés thioéthers par addition sur des oléfines, il est possible d'apporter dans le réacteur d'adoucissement 8, via la ligne 34, des composés oléfiniques légers contenus dans la coupe de tête 21. La coupe essence intermédiaire adoucie en mercaptans est envoyée par la ligne 10 dans une colonne de fractionnement 11 opérée pour séparer une coupe essence intermédiaire à basse teneur en mercaptans et en soufre et une coupe de fond intermédiaire dans laquelle sont concentrés les composés thioéthers produits lors de l'étape d'adoucissement. La coupe essence intermédiaire à basse teneur en mercaptans et en soufre est évacuée par la ligne 12 vers le pool essence de la raffinerie tandis que la coupe de fond intermédiaire évacuée par la ligne 13 est soit désulfurée dans une unité d'hydrotraitement (par exemple une unité d'hydrodésulfuration de gazole), soit directement envoyé au pool gazole de la raffinerie. Comme également représenté sur la figure 3, il est possible de stabiliser l'effluent d'hydrocarbures issu du réacteur d'adoucissement 8 en le traitant dans une colonne de stabilisation (ou débutaniseur) 31 d'où l'on sépare en tête une fraction d'hydrocarbures légers ayant un nombre d'atomes de carbone inférieur ou égal à 4 et en fond une coupe essence intermédiaire stabilisée et adoucie en mercaptans, laquelle est envoyée par la ligne 33 dans la colonne de fractionnement 11. Avantageusement, la coupe intermédiaire de fond 13 peut être désulfurée dans le réacteur d'hydrodésulfuration 24 en mélange avec la coupe de fond 23 issue de la première étape de fractionnement effectuée dans la colonne 20.As stated in the figure 3 , the intermediate petrol cut is treated by the method according to the invention. Thus the intermediate gasoline cut is sent via line 22 to a hydrodesulfurization reactor 2 to be desulfurized there in the presence of hydrogen supplied by line 3. The effluent from reactor 2 is freed of the H 2 S formed during from the HDS stage in a separation unit 5. The intermediate gasoline depleted in H 2 S is sent via line 7 with optionally hydrogen brought by line 9 into a mercaptan softening reactor 8. In order to improve the conversion of mercaptans to thioether compounds by addition to olefins, it is possible to bring into the softening reactor 8, via line 34, light olefinic compounds contained in the head section 21. The section intermediate gasoline softened in mercaptans is sent via line 10 to a fractionation column 11 operated to separate an intermediate gasoline cut with low mercaptans and sulfur content and an intermediate bottom cut. re in which the thioether compounds produced during the softening stage are concentrated. The intermediate gasoline cut with low mercaptans and sulfur content is evacuated by line 12 to the petrol pool of the refinery while the intermediate bottom cut evacuated by line 13 is either desulphurized in a hydrotreating unit (for example a diesel hydrodesulfurization unit), or sent directly to the refinery's diesel pool. As also shown in the figure 3 , it is possible to stabilize the hydrocarbon effluent from the softening reactor 8 by treating it in a stabilization column (or debutanizer) 31 from which a fraction of hydrocarbons is separated at the head light having a number of carbon atoms less than or equal to 4 and at the bottom an intermediate gasoline cut stabilized and softened in mercaptans, which is sent by line 33 to the fractionation column 11. Advantageously, the intermediate bottom cut 13 can be desulphurized in the hydrodesulphurization reactor 24 in admixture with the bottom cut 23 resulting from the first fractionation step carried out in column 20.

La figure 4 divulgue un quatrième mode de réalisation du procédé selon l'invention mettant en œuvre des colonnes de distillation catalytiques.The figure 4 discloses a fourth embodiment of the process according to the invention using catalytic distillation columns.

La charge essence, par exemple une coupe d'hydrocarbures bouillant entre 30 °C et 220°C ou entre 30°C et 160°C, voire entre 30°C et 140°C, est envoyée par la ligne 1 dans une première colonne de distillation catalytique 40 comportant une section réactionnelle 41 contenant un catalyseur d'hydrogénation sélective des dioléfines. L'hydrogène nécessaire pour la conduite de la réaction d'hydrogénation est apporté via la ligne 2. La mise en œuvre de la colonne catalytique 40 permet de réaliser non seulement la réaction catalytique d'hydrogénation sélective mais également le fractionnement en une coupe d'hydrocarbures légers en tête de colonne et une coupe d'hydrocarbures lourds en fond de la colonne 40. Ainsi la coupe d'hydrocarbures légers en mélange avec l'hydrogène non réagi est soutirée par la ligne 42 et la coupe d'hydrocarbures lourds est soutirée par la ligne 43. La coupe légère est par exemple une coupe C4- et la coupe d'hydrocarbures lourds est une coupe bouillant dans la gamme (C5 - 220°C) ou (C5 - 160 °C) ou (C5 - 140 °C).The petrol charge, for example a cut of hydrocarbons boiling between 30 ° C and 220 ° C or between 30 ° C and 160 ° C, or even between 30 ° C and 140 ° C, is sent by line 1 in a first column catalytic distillation 40 comprising a reaction section 41 containing a catalyst for the selective hydrogenation of diolefins. The hydrogen necessary for the conduct of the hydrogenation reaction is supplied via line 2. The use of the catalytic column 40 makes it possible to carry out not only the catalytic reaction of selective hydrogenation but also the fractionation into a section of light hydrocarbons at the top of the column and a cut of heavy hydrocarbons at the bottom of the column 40. Thus the cut of light hydrocarbons in mixture with unreacted hydrogen is drawn off by line 42 and the cut of heavy hydrocarbons is drawn off by line 43. The light cut is for example a C4 cut - and the heavy hydrocarbon cut is a boiling cut in the range (C5 - 220 ° C) or (C5 - 160 ° C) or (C5 - 140 ° VS).

La coupe d'hydrocarbures lourds est traitée ensuite selon le procédé de l'invention qui consiste en une étape d'hydrodésulfuration conduite, dans ce mode de réalisation, dans une colonne de distillation catalytique 45 comportant deux lits de catalyseurs d'hydrodésulfuration 46. De préférence la coupe d'hydrocarbures lourds est injectée avec de l'hydrogène (via la ligne 44) entre les deux lits de catalyseurs d'hydrodésulfuration 46. La colonne de distillation catalytique 45 permet en outre de fractionner la coupe d'hydrocarbures lourds en une coupe de tête intermédiaire bouillant dans la gamme (C5 - 140°C) ou (C5 - 160°C) et une coupe de fond dont la température d'ébullition est supérieure à 140°C ou 160°C respectivement. Conformément à l'invention, afin de réduire la teneur en mercaptans de la coupe intermédiaire, cette dernière est évacuée par la ligne 47 et soumis à une étape d'élimination d'H2S au moyen de la colonne de stabilisation 5 afin de séparer en tête de colonne via la ligne 6 un flux contenant la majorité de l'H2S et en fond de colonne via la ligne 7 la coupe intermédiaire stabilisée. Cette dernière est traitée dans un réacteur d'adoucissement 8. La coupe intermédiaire adoucie en mercaptans issue du réacteur 8 est ensuite via la ligne 10 fractionnée dans la colonne 11 de manière à récupérer en tête (via la ligne 12) une essence basse teneur en soufre, en mercaptans et en thioéthers bouillant dans la gamme (C5 - 140°C) ou (C5 - 160°C). La coupe de fond qui contient les sulfures comprenant généralement au moins 10 atomes de carbone et plus, produits de la réaction d'addition des mercaptans sur les oléfines, est soutirée par la ligne 13 du fond de la colonne 11. De manière optionnelle et indiquée dans la figure 4, on traite dans le réacteur d'adoucissement 8 la coupe intermédiaire en mélange avec la coupe d'hydrocarbures légers, via la ligne 49, provenant de la tête de la colonne de distillation catalytique 40.The cut of heavy hydrocarbons is then treated according to the process of the invention which consists of a hydrodesulfurization step carried out, in this embodiment, in a catalytic distillation column 45 comprising two beds of hydrodesulfurization catalysts. preferably the cut of heavy hydrocarbons is injected with hydrogen (via line 44) between the two beds of hydrodesulfurization catalysts 46. The catalytic distillation column 45 also makes it possible to split the cut of heavy hydrocarbons into one intermediate head cup boiling in the range (C5 - 140 ° C) or (C5 - 160 ° C) and a bottom cup whose boiling temperature is higher than 140 ° C or 160 ° C respectively. In accordance with the invention, in order to reduce the mercaptan content of the intermediate cut, the latter is evacuated via line 47 and subjected to a step of removing H 2 S by means of the stabilization column 5 in order to separate at the top of the column via line 6 a stream containing the majority of the H 2 S and at the bottom of the column via line 7 the stabilized intermediate section. The latter is treated in a softening reactor 8. The intermediate cut softened in mercaptans from reactor 8 is then via line 10 fractionated in column 11 so as to recover at the top (via line 12) a low-content gasoline sulfur, mercaptans and thioethers boiling in the range (C5 - 140 ° C) or (C5 - 160 ° C). The bottom section which contains the sulphides generally comprising at least 10 carbon atoms and more, products of the reaction for adding mercaptans to olefins, is drawn off by line 13 from the bottom of column 11. Optionally and indicated in the figure 4 , the intermediate cut is treated in the softening reactor 8 in admixture with the cut of light hydrocarbons, via line 49, coming from the head of the catalytic distillation column 40.

Comme indiqué dans la figure 4, la coupe intermédiaire adoucie en mercaptans issue du réacteur 8 peut éventuellement subir une étape de stabilisation réalisée dans une colonne de stabilisation 31 d'où l'on extrait une coupe C4- et une coupe intermédiaire stabilisée adoucie en mercaptans, respectivement en tête et en fond de ladite colonne 31. La coupe intermédiaire stabilisée adoucie en mercaptans est envoyée ensuite par ligne 33 dans la colonne de fractionnement 11.As stated in the figure 4 , the intermediate cut softened in mercaptans from the reactor 8 can optionally undergo a stabilization step carried out in a stabilization column 31 from which a cut C4 is extracted - and a stabilized intermediate cut softened in mercaptans, respectively at the head and at bottom of said column 31. The stabilized intermediate section softened in mercaptans is then sent by line 33 to the fractionation column 11.

Il est à noter que l'étape d'adoucissement en mercaptans et le fractionnement peuvent être conduits de manière simultanée au moyen d'une colonne catalytique équipée d'un lit catalytique contenant le catalyseur d'adoucissement.It should be noted that the mercaptan softening step and the fractionation can be carried out simultaneously by means of a catalytic column equipped with a catalytic bed containing the softening catalyst.

Exemple 1 (comparatif)Example 1 (comparative)

Un catalyseur A d'hydrodésulfuration est obtenu par imprégnation « sans excès de solution » d'une alumine de transition se présentant sous forme de billes de surface spécifique de 130 m2/g et de volume poreux 0,9 ml/g, avec une solution aqueuse contenant du molybdène et du cobalt sous forme d'heptamolybdate d'ammonium et de nitrate de cobalt respectivement. Le catalyseur est ensuite séché et calciné sous air à 500 °C. La teneur en cobalt et en molybdène de cet échantillon est de 3% poids de CoO et 10% poids de MoO3.A hydrodesulfurization catalyst A is obtained by impregnating “without excess solution” with a transition alumina in the form of beads with a specific surface of 130 m 2 / g and a pore volume of 0.9 ml / g, with a aqueous solution containing molybdenum and cobalt in the form of ammonium heptamolybdate and cobalt nitrate respectively. The catalyst is then dried and calcined in air at 500 ° C. The cobalt and molybdenum content of this sample is 3% by weight of CoO and 10% by weight of MoO 3 .

50 ml du catalyseur A sont placés dans un réacteur d'hydrodésulfuration tubulaire à lit fixe. Le catalyseur est tout d'abord sulfuré par traitement pendant 4 heures sous une pression de 3,4 MPa à 350°C, au contact d'une charge constituée de 2% poids de soufre sous forme de diméthyldisulfure dans du n-heptane.50 ml of catalyst A are placed in a tubular hydrodesulfurization reactor with a fixed bed. The catalyst is first sulfurized by treatment for 4 hours under a pressure of 3.4 MPa at 350 ° C, in contact with a charge consisting of 2% by weight of sulfur in the form of dimethyldisulfide in n-heptane.

La charge traitée C1 est une essence de craquage catalytique dont le point initial d'ébullition est de 55°C, le point final est de 242°C, dont le MON est de 79,8 et le RON est de 89,5. Sa teneur en soufre est de 359 ppm poids.The treated charge C1 is a catalytic cracking gasoline whose initial boiling point is 55 ° C, the end point is 242 ° C, whose MON is 79.8 and the RON is 89.5. Its sulfur content is 359 ppm by weight.

Cette charge est traitée sur le catalyseur A, sous une pression de 2 MPa, avec un rapport volumique hydrogène sur charge à traiter (H2/HC) de 360 l/l et une vitesse spatiale (VVH) de 4 h-1. Après traitement, le mélange d'essence et d'hydrogène est refroidi, l'hydrogène riche en H2S est séparé de l'essence liquide, et l'essence est soumise à un traitement de stripage par injection d'un flux d'hydrogène afin d'éliminer les traces résiduelles d'H2S dissous dans l'essence.This charge is treated on catalyst A, under a pressure of 2 MPa, with a hydrogen volume ratio on charge to be treated (H 2 / HC) of 360 l / l and a space velocity (VVH) of 4 h -1 . After treatment, the mixture of petrol and hydrogen is cooled, the hydrogen rich in H 2 S is separated from the liquid petrol, and the petrol is subjected to a stripping treatment by injection of a flux of hydrogen in order to eliminate the residual traces of H 2 S dissolved in the gasoline.

Le tableau 1 montre l'influence de la température sur les taux de désulfuration, et sur l'indice d'octane par le catalyseur A à une température d'hydrodésulfuration de 240 °C (A1) ou 270 °C (A2). Tableau 1 Essence hydrodésulfurée A1 A2 Température de l'HDS (°C) 240 270 H2S, ppm poids 0.5 0.5 Mercaptans, ppm poids (en tant que S) 24 11 Soufre total, ppm poids 86 19 Oléfines total, % poids 24.6 20.4 Taux de désulfuration, % 76.2 94.6 Delta MON 1.1 2.3 Delta RON 1.5 3.9 Table 1 shows the influence of the temperature on the desulfurization rates, and on the octane number by catalyst A at a hydrodesulfurization temperature of 240 ° C (A1) or 270 ° C (A2). Table 1 Hydrodesulfurized gasoline A1 A2 HDS temperature (° C) 240 270 H 2 S, ppm weight 0.5 0.5 Mercaptans, ppm weight (as S) 24 11 Total sulfur, ppm weight 86 19 Total olefins,% by weight 24.6 20.4 Desulfurization rate,% 76.2 94.6 Delta MON 1.1 2.3 Delta RON 1.5 3.9

L'hydrodésulfuration de la charge C1 avec le catalyseur A permet de diminuer la teneur en soufre total mais aussi la teneur en mercaptans. Il est à noter qu'il est nécessaire de traiter la charge à une température d'au moins 270°C pour atteindre environ 11 ppm poids de mercaptans. Cette augmentation de la température de la réaction d'hydrodésulfuration a pour effet de favoriser également la réaction d'hydrogénation des oléfines qui se traduit par une baisse de la teneur en oléfines totale dans l'essence hydrodésulfurée.The hydrodesulfurization of the feed C1 with the catalyst A makes it possible to reduce the total sulfur content but also the mercaptans content. It should be noted that it is necessary to treat the charge at a temperature of at least 270 ° C to reach approximately 11 ppm by weight of mercaptans. This increase in the temperature of the hydrodesulfurization reaction also has the effect of promoting the hydrogenation reaction of the olefins which results in a decrease in the total olefin content in the hydrodesulfurized gasoline.

Exemple 2 (selon l'invention)Example 2 (according to the invention)

Un catalyseur B, est obtenu par imprégnation d'un aluminate de nickel de surface spécifique de 135 m2/g et de volume poreux 0,45 ml/g, par une solution aqueuse contenant du molybdène et du nickel. Le catalyseur est ensuite séché et calciné sous air à 500 °C. La teneur en nickel et en molybdène de cet échantillon est de 7,9% poids de NiO et 13% poids de MoO3.Catalyst B is obtained by impregnating a nickel aluminate with a specific surface of 135 m 2 / g and a pore volume of 0.45 ml / g, with an aqueous solution containing molybdenum and nickel. The catalyst is then dried and calcined in air at 500 ° C. The nickel and molybdenum content of this sample is 7.9% by weight of NiO and 13% by weight of MoO 3 .

L'essence A1 telle que obtenue et décrite dans l'exemple 1 est traitée en absence d'hydrogène sur le catalyseur B de démercaptisation, à une pression de 1 MPa, une VVH de 3 h-1 et une température de 100°C. Après traitement, l'essence B1 obtenue est refroidie.The gasoline A1 as obtained and described in Example 1 is treated in the absence of hydrogen on the demercaptization catalyst B, at a pressure of 1 MPa, a VVH of 3 h -1 and a temperature of 100 ° C. After treatment, the gasoline B1 obtained is cooled.

Le tableau 2 présente les principales caractéristiques de l'essence B1 obtenue. Tableau 2 Références de l'essence traitée B1 H2S, ppm poids 0 Mercaptans, ppm poids (en tant que S) 8 Soufre total, ppm poids 86 Oléfines total, % poids 24.6 Taux de démercaptisation, % 67 Taux d'hydrogénation des oléfines,% 0 Table 2 presents the main characteristics of the B1 gasoline obtained. Table 2 References of the treated species B1 H 2 S, ppm weight 0 Mercaptans, ppm weight (as S) 8 Total sulfur, ppm weight 86 Total olefins,% by weight 24.6 Demercapture rate,% 67 Hydrogenation rate of olefins,% 0

La mise en œuvre de l'étape de démercaptisation (étape c) permet ainsi de convertir les mercaptans de l'essence A1 sans hydrogène et sans hydrogéner les oléfines.The implementation of the demercaptization step (step c) thus makes it possible to convert the mercaptans of essence A1 without hydrogen and without hydrogenating the olefins.

Exemple 3 (selon l'invention) Example 3 (according to the invention)

Un catalyseur D, est obtenu par imprégnation d'une alumine de surface spécifique de 239 m2/g et de volume poreux 0,6 ml/g, par une solution aqueuse contenant du molybdène et du nickel. Le catalyseur est ensuite séché et calciné sous air à 500 °C. La teneur en nickel et en molybdène de cet échantillon est de 9,5% poids de NiO et 13% poids de MoO3.A catalyst D, is obtained by impregnating an alumina with a specific surface of 239 m 2 / g and a pore volume 0.6 ml / g, with an aqueous solution containing molybdenum and nickel. The catalyst is then dried and calcined in air at 500 ° C. The nickel and molybdenum content of this sample is 9.5% by weight of NiO and 13% by weight of MoO 3 .

L'essence A1 telle que obtenue et décrite dans l'exemple 1 est mélangée avec une charge C2 pour obtenir une charge C3. La charge C2 est une essence craquée légère ayant subi une hydrogénation sélective des dioléfines, dont le point initial d'ébullition est de 22°C et le point final est de 71 °C, dont le MON est de 82,5 et le RON est de 96,9. Sa teneur en soufre est de 20 ppm poids, sa teneur en mercaptans inférieure à 3 ppm poids et sa teneur en oléfines à 56,7 % poids.The essence A1 as obtained and described in example 1 is mixed with a charge C2 to obtain a charge C3. The charge C2 is a light cracked gasoline having undergone a selective hydrogenation of the diolefins, whose initial boiling point is 22 ° C and the end point is 71 ° C, whose MON is 82.5 and RON is 96.9. Its sulfur content is 20 ppm by weight, its mercaptan content less than 3 ppm by weight and its olefin content by 56.7% by weight.

La charge C3 est obtenue par mélange de 80% poids d'essence A1 avec 20% poids de charge C2. Le mélange obtenu est une essence dont le point initial d'ébullition est de 22°C et le point final de 242°C. Sa teneur en soufre est de 73 ppm, sa teneur en mercaptans est de 19 ppm poids et sa teneur en oléfines est de 31% poids.The charge C3 is obtained by mixing 80% by weight of gasoline A1 with 20% by weight of charge C2. The mixture obtained is a gasoline with an initial boiling point of 22 ° C and a final point of 242 ° C. Its sulfur content is 73 ppm, its mercaptan content is 19 ppm by weight and its olefin content is 31% by weight.

La charge C3 est traitée en présence d'hydrogène sur le catalyseur D de démercaptisation, sous une pression de 1 MPa, une VVH de 3 h-1, avec un rapport volumique hydrogène sur charge à traiter (H2/HC) de 2 l/l et une température de 100°C. Après traitement, le mélange d'essence est refroidi de manière à récupérer une phase gazeuse riche en hydrogène et H2S et une fraction d'essence liquide. La fraction liquide est soumise à un traitement de stripage par injection d'un flux d'hydrogène afin d'éliminer les traces éventuelles d'H2S dissous dans l'essence.Charge C3 is treated in the presence of hydrogen on the demercaptization catalyst D, under a pressure of 1 MPa, a VVH of 3 h -1 , with a hydrogen by charge ratio of charge to be treated (H 2 / HC) of 2 l / l and a temperature of 100 ° C. After treatment, the gasoline mixture is cooled so as to recover a gas phase rich in hydrogen and H 2 S and a fraction of liquid gasoline. The liquid fraction is subjected to a stripping treatment by injection of a stream of hydrogen in order to remove any traces of H 2 S dissolved in the gasoline.

Le tableau 3 présente les principales caractéristiques de l'essence D1 obtenue après stripage. Références de l'essence hydrodésulfurée D1 Température, °C 100 Mercaptans, ppm poids 4 Soufre total, ppm poids 73 Oléfines total, % poids 31 Taux de démercaptisation, % 79 Taux d'hydrogénation des oléfines,% 0 Table 3 presents the main characteristics of D1 gasoline obtained after stripping. References of hydrodesulfurized gasoline D1 Temperature, ° C 100 Mercaptans, ppm weight 4 Total sulfur, ppm weight 73 Total olefins,% by weight 31 Demercapture rate,% 79 Hydrogenation rate of olefins,% 0

Le procédé permet de réduire la teneur en mercaptans de l'essence A1 en les convertissant sélectivement en thioéthers, sans hydrogénation des oléfines et donc sans perte d'octane.The process makes it possible to reduce the content of mercaptans in gasoline A1 by converting them selectively into thioethers, without hydrogenation of the olefins and therefore without loss of octane.

Claims (15)

  1. A process for the treatment of a gasoline containing sulfur-containing compounds and olefins, the process comprising at least the following steps:
    a) bringing the gasoline, hydrogen and a hydrodesulfurization catalyst into contact in at least one reactor at a temperature in the range 200°C to 400°C, at a pressure in the range 0.5 to 5 MPa, at a space velocity in the range 0.5 to 20 h-1 and with a ratio between the flow rate of hydrogen, expressed in normal m3 per hour, and the flow rate of the feed to be treated, expressed in m3 per hour under standard conditions, in the range 50 Nm3/m3 to 1000 Nm3/m3, in order to convert at least a portion of the sulfur-containing compounds into H2S;
    b) carrying out a step for separating the H2S which is formed and present in the effluent obtained from step a);
    c) bringing all or part of the H2S-depleted effluent obtained from step b) into contact, in a reactor, with a catalyst containing at least one sulfide of at least one transition metal selected from metal from group VIb, a metal from group VIII and copper alone or as a mixture, or lead deposited on a porous support capable of transforming the sulfur-containing compounds from the mercaptans family into sulfur-containing compounds of tioether type by reaction with the olefins of the gasoline, step c) being carried out at a temperature in the range 30°C to 250°C, with a liquid space velocity in the range 0.5 h-1 to 10 h-1, a pressure in the range 0.2 to 5 MPa and an H2/feed ratio in the range 0 to 10 Nm3 of hydrogen per m3 of feed, in order to produce a gasoline obtained from step c) with a reduced mercaptans content compared with that of the effluent obtained from step b).
  2. The process according to claim 1, in which the catalyst for step c) comprises:
    • a support constituted by gamma or delta alumina with a specific surface area in the range 70 m2/g to 350 m2/g;
    • a quantity by weight of oxide of the metal from group VIb in the range 1% to 30% by weight with respect to the total catalyst weight;
    • a quantity by weight of oxide of the metal from group VIII in the range 1% to 30% by weight with respect to the total catalyst weight;
    • a percentage sulfurization of the constituent metals of said catalyst of at least 60%;
    • a molar ratio between the metal from group VIII and the metal from group VIb in the range 0.6 to 3 mol/mol.
  3. The process according to claim 1 or 2, in which the metal from group VIII is nickel and the metal from group VIb is molybdenum.
  4. The process according to claim 3, in which the catalyst for step c) comprises:
    • a support constituted solely by gamma alumina with a specific surface area in the range 180 m2/g to 270 m2/g;
    • a quantity by weight of nickel oxide in the range 4% to 12% with respect to the total catalyst weight;
    • a quantity by weight of molybdenum oxide in the range 6% to 18% with respect to the total catalyst weight;
    • a nickel/molybdenum molar ratio in the range 1 to 2.5 ; and
    • a percentage sulfurization of the constituent metals of the catalyst of more than 80%.
  5. The process according to one of the preceding claims, in which the effluent obtained from step b) is mixed with an LPG cut or a gasoline cut obtained from crude oil distillation, a pyrolysis unit, a cokefaction unit, a hydrocracking unit or an oligomerization unit, and the mixture is treated in step c).
  6. The process according to one of the preceding claims, in which before step a), a step for distillation of the gasoline is carried out in order to fractionate said gasoline into at least two gasoline cuts, light and heavy, and the heavy gasoline cut is treated in steps a), b) and c) .
  7. The process according to claim 6, in which the effluent obtained from step b) is mixed with the light gasoline cut so as to produce a mixture, and said mixture is treated in step c).
  8. The process according to one of claims 5, in which before step a), a step for distillation of the gasoline is carried out in order to fractionate said gasoline into at least two gasoline cuts, light and heavy, the heavy gasoline cut is treated in step a), the light gasoline cut is mixed with the effluent obtained from step a) so as to produce a mixture and said mixture is treated in steps b) and c).
  9. The process according to claim 7 or claim 8, in which the mixture contains up to 50% by volume of the light gasoline cut.
  10. The process according to one of claims 1 to 5, in which before step a), a step for distillation of the gasoline is carried out so as to fractionate said gasoline into at least three gasoline cuts, respectively light, intermediate and heavy, each of the intermediate and heavy cuts is treated separately in steps a) and b) and in which the effluents obtained from steps b) are treated as a mixture or separately in step c).
  11. The process according to any one of the preceding claims, in which before step a) and before optionally the distillation step, the gasoline is brought into contact with hydrogen and a selective hydrogenation catalyst in order to selectively hydrogenate the diolefins contained in said gasoline into olefins.
  12. The process according to any one of the preceding claims, in which the catalyst for step a) contains at least one metal from group VIb and/or at least one metal from group VIII on a support with a specific surface area of less than 250 m2/g, in which the quantity of metal from group VIII, expressed as the oxide, is in the range 0.5% to 15% by weight and the quantity of metal from group VIb, expressed as the oxide, is in the range 1.5% to 60% by weight with respect to the weight of the catalyst.
  13. The process according to claim 12, in which the catalyst for step a) comprises cobalt and molybdenum and the density of molybdenum, expressed as the ratio between said MoO3 content by weight and the specific surface area of the catalyst, is more than 7 × 10-4 and preferably more than 12 × 10-4g/m2.
  14. The process according to one of the preceding claims, in which step c) is carried out without adding hydrogen.
  15. The process according to one of the preceding claims, in which step a) is carried out in a catalytic column which separates the gasoline into at least two gasoline cuts, light and heavy, and the light cut is treated in step b) and step c).
EP14305833.7A 2013-06-19 2014-06-02 Method for producing gasoline with low sulphur and mercaptan content Active EP2816094B1 (en)

Applications Claiming Priority (2)

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FR1355749A FR3007416B1 (en) 2013-06-19 2013-06-19 PROCESS FOR PRODUCING LOW SULFUR AND MERCAPTAN GASOLINE
FR1453795A FR3020376B1 (en) 2014-04-28 2014-04-28 PROCESS FOR PRODUCING LOW TEMPERATURE GASOLINE IN SULFUR AND MARCAPTANS

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FR3035117B1 (en) 2015-04-15 2019-04-19 IFP Energies Nouvelles PROCESS FOR SOFTENING OF SULFIDE COMPOUNDS OF AN OLEFINIC ESSENCE
FR3049955B1 (en) * 2016-04-08 2018-04-06 IFP Energies Nouvelles PROCESS FOR TREATING A GASOLINE
FR3056599B1 (en) * 2016-09-26 2018-09-28 IFP Energies Nouvelles PROCESS FOR TREATING GASOLINE BY SEPARATING INTO THREE CUTS
FR3057578B1 (en) * 2016-10-19 2018-11-16 IFP Energies Nouvelles PROCESS FOR HYDRODESULFURING OLEFINIC ESSENCE
FR3075072B1 (en) * 2017-12-14 2021-11-26 Ifp Energies Now FCC GASOLINE SELECTIVE HYDRODESULFURATION CATALYST
FR3099175B1 (en) * 2019-07-23 2021-07-16 Ifp Energies Now PROCESS FOR THE PRODUCTION OF A GASOLINE WITH LOW SULFUR AND MERCAPTANS
FR3099173B1 (en) * 2019-07-23 2021-07-09 Ifp Energies Now PROCESS FOR THE PRODUCTION OF A GASOLINE WITH LOW SULFUR AND MERCAPTANS
FR3108333B1 (en) * 2020-03-20 2022-03-11 Ifp Energies Now PROCESS FOR THE PRODUCTION OF A GASOLINE WITH LOW SULFUR AND MERCAPTANS CONTENT

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2708597B1 (en) 1993-07-30 1995-09-29 Inst Francais Du Petrole Process for the isomerization of olefins on metal catalysts impregnated with organic sulfur compounds before loading into the reactor.
FR2708596B1 (en) 1993-07-30 1995-09-29 Inst Francais Du Petrole Process for the isomerization of external olefins to internal olefins in conjunction with the hydrogenation of diolefins.
FR2797639B1 (en) 1999-08-19 2001-09-21 Inst Francais Du Petrole PROCESS FOR PRODUCING LOW SULFUR ESSENCE
US6387249B1 (en) 1999-12-22 2002-05-14 Exxonmobil Research And Engineering Company High temperature depressurization for naphtha mercaptan removal
US6469223B2 (en) * 2000-01-04 2002-10-22 Fina Technology, Inc. Selective hydrogenation of dienes
CN1264957C (en) * 2000-02-11 2006-07-19 催化蒸馏技术公司 Process for the desulfurization of petroleum feeds
FR2811328B1 (en) 2000-07-06 2002-08-23 Inst Francais Du Petrole PROCESS INCLUDING TWO STAGES OF GASOLINE HYDRODESULFURATION AND AN INTERMEDIATE REMOVAL OF THE H2S FORMED DURING THE FIRST STAGE
US6755974B2 (en) 2001-06-19 2004-06-29 Exxonmobil Research And Engineering Company Continuous naphtha treatment method
US6824676B1 (en) * 2002-03-08 2004-11-30 Catalytic Distillation Technologies Process for the selective desulfurization of a mid range gasoline cut
US20040129606A1 (en) * 2003-01-07 2004-07-08 Catalytic Distillation Technologies HDS process using selected naphtha streams
FR2850113B1 (en) 2003-01-22 2007-03-02 Inst Francais Du Petrole METHOD FOR OBTAINING A CHARGE USABLE IN AN ETHERIFICATION UNIT
US7799210B2 (en) * 2004-05-14 2010-09-21 Exxonmobil Research And Engineering Company Process for removing sulfur from naphtha
FR2872516B1 (en) 2004-07-01 2007-03-09 Inst Francais Du Petrole METHOD OF HYDRODESULFURING ESSENCES USING A CONTROLLED POROSITY CATALYST
US20070114156A1 (en) 2005-11-23 2007-05-24 Greeley John P Selective naphtha hydrodesulfurization with high temperature mercaptan decomposition
FR2895415B1 (en) * 2005-12-22 2011-07-15 Inst Francais Du Petrole SELECTIVE HYDROGENATION PROCESS USING A CATALYST HAVING A SPECIFIC SUPPORT
FR2895414B1 (en) 2005-12-22 2011-07-29 Inst Francais Du Petrole SELECTIVE HYDROGENATION PROCESS USING A CATALYST HAVING CONTROLLED POROSITY
CN101885985B (en) * 2010-07-02 2013-01-16 中国石油大学(北京) Production method for ultra-low sulfur and high-octane number gasoline
CN102010751B (en) * 2010-12-10 2014-06-18 中国石油大学(北京) Efficient combined production method for gasoline with ultralow sulfur and high octane value
CN103087771B (en) * 2011-11-07 2015-06-03 中国石油化工股份有限公司 Hydrogenation method for deeply desulfurizing gasoline

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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KR20140147737A (en) 2014-12-30
US20140374315A1 (en) 2014-12-25
RU2665701C2 (en) 2018-09-04
KR102322556B1 (en) 2021-11-04
US9957448B2 (en) 2018-05-01
RU2014124384A (en) 2015-12-27
BR102014014718B1 (en) 2021-02-09
CN104232156B (en) 2018-12-07
BR102014014718A2 (en) 2015-06-02
EP2816094A1 (en) 2014-12-24

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