Produce the hydrogenation coupling process of low freezing point diesel fuel
Technical field
The invention belongs to petroleum refining fields, and in particular to a kind of hydrogenation coupled work of flexibly production low freezing point diesel fuel product
Skill.
Background technique
Environmental regulation it is increasingly strict, it is desirable that the quality of diesel product is higher and higher, mainly sulfur content, Cetane number,
The limitation of density and condensed-nuclei aromatics content is increasing.Diesel product can be greatly lowered in hydro-upgrading of inferior diesel technology
Sulfur content and arene content, and reduce density and improve Cetane number.In addition, the diesel product of cold district is to solidifying when winter
Point has different limitation and requirement, and the diesel product in China can be divided into 5#, 0#, -10#, -20#, -35# and -50# according to condensation point
Equal different sizes.The condensation point of diesel oil can be effectively reduced in hydrodewaxing technology.
Diesel oil fraction hydrogenating isomerization-visbreaking technology, such as CN1718683A and CN1712499A, are catalyzed using hydrofinishing
Agent and contain β zeolite hydroisomerizing pour point depression catalyst, produces diesel product using one-stage serial process, but identical plus hydrogen changes
Low compared with hydro-upgrading diesel cetane-number under the conditions of matter, process conditions are compared with hydrodewaxing technique when identical low freezing point diesel fuel product
Condition is harsh.
Diesel oil fraction hydrogenating pour point depression technology, such as CN102051232A and CN1257107A, use Hydrobon catalyst
With hydrodewaxing catalyst, low freezing point diesel fuel product is produced using one-stage serial process, but diesel product yield is lower.
Hydrobon catalyst and hydrodewaxing is used alternatingly in CN102453531A, CN103805258A and CN103805254A etc.
Catalyst, obtained diesel product condensation point is low, but diesel yield is relatively low, can only produce a kind of diesel product.
Using hydrogen addition technology CN105087063A, diesel oil distillate is directly passed through after hydroisomerizing pour point depression, using reaction heat
Hydrodewaxing is crossed to produce low freezing point diesel fuel product, but the technique can only produce a kind of diesel product of condensation point specification.
In conclusion the condensation point of diesel product can be greatly lowered in existing hydroisomerizing pour point depression technology, can satisfy
The index request of low-coagulation diesel oil, but yield is lower when production low freezing point diesel fuel product.Existing hydrodewaxing technology can be big
The condensation point of amplitude reduction diesel product can satisfy the index request of low-coagulation diesel oil, but diesel yield is lower, usually less than
90m%, and diesel product Quality advance amplitude is little, and the n-alkane of high cetane number is especially cracked into gas or stone
The Cetane number that will lead to diesel product when naphtha fraction reduces.It is single using product when coupling hydro technology.Above-mentioned technique skill
The diesel product of art production only has one kind, and product flexibility is poor.
Summary of the invention
In view of the deficiencies of the prior art, the present invention provides a kind of hydrogenation coupling process for producing low freezing point diesel fuel, that is, passes through
Extraction section reaction liquid logistics in the gas-liquid separator being arranged in the middle part of from hydroisomerizing pour point depression reactor, and by the diesel oil
Feedstock oil is produced by the hydroisomerizing pour point depression diesel oil that hydroisomerizing pour point depression and hydrodewaxing coupling process flexibly produce different condensation points
Product and hydrodewaxing diesel product.
The hydrogenation coupling process of production low freezing point diesel fuel of the invention, includes the following steps:
A, diesel raw material oil obtains hydrotreated refinery stream by Hydrobon catalyst bed first under Hydrofinishing conditions;
B, the hydrotreated refinery stream that step a is obtained passes through the first hydroisomerizing pour point depression catalyst bed under the conditions of hydroisomerizing pour point depression
Layer, obtains the first hydroisomerizing pour point depression logistics;This part reaction stream is divided into two parts, and a portion passes through gas-liquid separator
Isolated first hydroisomerizing pour point depression liquid stream, and extract hydrogenator out;
C, the first hydroisomerizing pour point depression logistics of remainder continues to add under the conditions of hydroisomerizing pour point depression by second in step b
Hydrogen isomerization-visbreaking catalyst bed, the logistics of hydroisomerizing pour point depression are separated, are fractionated to obtain hydroisomerizing pour point depression high pressure hydrogen-rich gas,
Hydroisomerizing pour point depression gas products, hydroisomerizing pour point depression naphtha product and hydroisomerizing pour point depression diesel product;
D, after the first hydroisomerizing pour point depression liquid stream obtained by step b is mixed with hydrogen, by adding hydrogen under the conditions of hydrodewaxing
Pour point depression catalyst bed, hydrodewaxing logistics separated, is fractionated to obtain hydrodewaxing high pressure hydrogen-rich gas, hydrodewaxing gas,
Hydrodewaxing naphtha and hydrodewaxing diesel product.
Hydrogenation coupling process according to the present invention, wherein can also include step e: step c obtained hydroisomerizing pour point depression
It is recycled after the hydrodewaxing high pressure hydrogen-rich gas mixing that high pressure hydrogen-rich gas and step d are obtained.
In the present invention, the Hydrobon catalyst bed, the first hydroisomerizing pour point depression catalyst bed and second add
Hydrogen isomerization-visbreaking catalyst bed can be set in a hydrogenator, such as can be in a hydroisomerizing pour point depression reactor
Inside set gradually three catalyst beds;Alternatively, Hydrobon catalyst bed is arranged in individual hydrogenator, and the
One hydroisomerizing pour point depression catalyst bed and the second hydroisomerizing pour point depression catalyst bed are arranged in a hydro-upgrading reactor
It is interior;Or Hydrobon catalyst bed and the setting of the first hydroisomerizing pour point depression catalyst bed are dropped in a hydroisomerizing
In solidifying reactor, and the second hydroisomerizing pour point depression catalyst bed is arranged in another hydroisomerizing pour point depression reactor.
The impurity such as S, N, O in diesel raw material oil are effectively removed when passing through Hydrobon catalyst, the certain journey of aromatic hydrocarbons
It is obtained on degree plus hydrogen is saturated, cyclic hydrocarbon generating unit separates when hydrotreated refinery stream continues through hydroisomerizing pour point depression catalyst bed
Ring reaction, low cetane value constituents become high cetane number component, and linear paraffin tautomerizes to branched paraffin, and high condensation point component becomes
Low condensation point component, a part of hydroisomerizing pour point depression logistics continue hydroisomerizing pour point depression, utmostly improve the 16 of diesel oil
Alkane value and condensation point is reduced, obtains low condensation point, but the diesel product that Cetane number is relatively high;A part first plus hydrogen of extraction
Isomerization-visbreaking liquid stream continues to reduce the condensation point of diesel oil after hydrodewaxing catalyst after mixing with hydrogen, obtains hexadecane
Value is relatively slightly lower, but the diesel product of low condensation point.
Compared with prior art, the advantages of diesel oil hydrogenation coupling technique of the invention, is:
It 1, include at least two hydroisomerizing pour point depression catalyst beds in hydroisomerizing pour point depression reactor in the present invention.By setting
The isomerization-visbreaking material extraction step among hydroisomerizing pour point depression reactor bed is set, special operation is not necessarily to, can be realized pair
Effective distribution of hydroisomerizing pour point depression material stock, then make obtained material by different hydrogenation techniques, so as to flexible
Produce the purpose diesel product of different condensation points.Meanwhile abstraction reaction logistics is technically also to be easy among reactor bed
It realizes.And in the prior art, a set of hydrogenation plant is typically only capable to obtain a kind of diesel product of specification;If it is intended to obtaining
The diesel product of different size needs two sets or more of hydrogenation plant.Therefore, the present invention provides a kind of in a set of plus hydrogen for the first time
The hydroconversion process of two or more different size diesel products is produced on process unit simultaneously.
2, the present invention passes through gas by the way that gas-liquid separator is arranged among the catalyst bed of hydroisomerizing pour point depression reactor
Liquid/gas separator extracts diesel raw material by the first hydroisomerizing pour point depression liquid stream of hydrofinishing and hydroisomerizing pour point depression
Reactor, and be sent to the hydrodewaxing reactor being separately provided and carry out hydrodewaxing reaction, it further decreases this plus hydrogen is different
The condensation point of material after structure pour point depression, so that method of the invention can flexibly produce the bavin of different condensation points, different Cetane number
Oil product.
3, in the present invention, the diesel product Cetane number obtained after hydroisomerizing pour point depression is high, and condensation point is relatively slightly higher;Through
Cross that the diesel product condensation point obtained after Partial hydroisomerization pour point depression, hydrodewaxing is relatively low, and Cetane number is relatively slightly lower;It can be with
Meet the needs of the high-quality diesel product of production different size respectively.
4, in the present invention, the impurity such as S, N in feedstock oil are converted into after hydrofinishing and Partial hydroisomerization pour point depression
H2S and NH3, the major part H after gas-liquid separator separates2S and NH3It is present in gas phase, and H in liquid phase2S and NH3Content compared with
It is few, so that the inhibiting effect to hydrodewaxing catalyst molecule sieve is reduced, so that the reactivity of hydrodewaxing catalyst mentions
Height, that is, reaching required reaction temperature when same depression effeCt reduces, and hydroisomerizing pour point depression reactor isomerization-visbreaking is urged
The liquid itself obtained among agent bed has very high temperature and pressure, with the mixed temperature of recycle hydrogen although slightly
It reduces, but still can be directly entered in newly-installed hydrodewaxing reactor and be reacted and reached depression effeCt, thus
It makes full use of this thigh to divide heat entrained by isomerization-visbreaking material, realizes that hydrodewaxing reactor is reacted with hydroisomerizing pour point depression
The coupling operation of device.
Detailed description of the invention
Fig. 1 is principle process schematic diagram of the invention.Wherein, a hydrofining reactor, a hydroisomerizing are set
Pour point depression reactor and a hydrodewaxing reactor.
Wherein: 1- feedstock oil, 2- hydrofining reactor, 3- hydrotreated refinery stream, 4- hydroisomerizing pour point depression reactor, 5-
Hydrodewaxing feed stream, 6- hydroisomerizing pour point depression logistics, 7- hydrodewaxing reactor, the separation of 8- hydroisomerizing pour point depression high pressure
Device, 9- hydrodewaxing high-pressure separator, 10- hydroisomerizing pour point depression fractionating column, 11- hydrodewaxing fractionating column, 12- hydroisomerizing drop
Solidifying gas products, 13- hydroisomerizing pour point depression naphtha product, 14- hydroisomerizing pour point depression diesel product, 15- hydrodewaxing gas
Product, 16- hydrodewaxing naphtha product, 7- hydrodewaxing diesel product, 18- hydroisomerizing pour point depression high-pressure separator gas produce
Object, 19- hydrodewaxing high-pressure separator gaseous product, 20- supplement hydrogen, 21- hydroisomerizing pour point depression recycle hydrogen, 22- hydrodewaxing
Recycle hydrogen, 23- gas-liquid separator.
Specific embodiment
The initial boiling point of diesel raw material described in step a is 100~260 DEG C, and the end point of distillation is 300~450 DEG C.The diesel oil is former
Material oil can be one of straight-run diesel oil, coker gas oil, catalytic diesel oil, hydroprocessed diesel that PETROLEUM PROCESSING obtains etc., from
One of coal tar, coal direct liquefaction oil, ICL for Indirect Coal Liquefaction oil, shale oil that coal obtains etc., it is wherein several to be also possible to them
The miscella of kind.
Hydrobon catalyst described in step a is conventional diesel oil hydrofining catalyst.Generally with VI B race and/
Or group VIII metal is active component, using aluminium oxide or silicon-containing alumina as carrier, group VIB metal is generally Mo and/or W,
Group VIII metal is generally Co and/or Ni.With the poidometer of catalyst, group VIB tenor with oxide be calculated as 10wt%~
35wt%, group VIII metal content are calculated as 3wt%~15wt% with oxide, and property is as follows: specific surface area is 100~650m2/
0.15~0.6mL/g of g, Kong Rongwei.Main catalyst have Fushun Petrochemical Research Institute develop FH-5, FH-98,
3936, the Hydrobon catalysts such as 3996, FHUDS series are also possible to the similar catalysis of function of World Catalyst company exploitation
Agent, such as HC-K, HC-P of Uop Inc., the KF-847 of TK-555, TK-565 catalyst of Topsoe company and Akzo company,
KF-848 etc..Conventional operating condition, generally reaction pressure 3.0MPa~15.0MPa, reaction temperature can be used in operating condition
It is 300 DEG C~430 DEG C, volume space velocity 0.2h when liquid-1~6.0h-1, hydrogen to oil volume ratio is 100:1~2000:1.
Hydroisomerizing pour point depression catalyst described in step b and step c is conventional diesel oil hydrogenation isomerization-visbreaking catalyst, one
As using group VIB and/or group VIII metal as active component, group VIB metal is generally Mo and/or W, and group VIII metal is general
For Co and/or Ni.The carrier of the catalyst contains one of aluminium oxide, silicon-containing alumina and molecular sieve or a variety of, preferably
Containing molecular sieve, the molecular sieve can be beta molecular sieve, Sapo type molecular sieve etc..With the poidometer of catalyst, group VIB
Tenor is calculated as 10wt%~35wt% with oxide, and group VIII metal content is calculated as 3wt%~15wt%, molecular sieve with oxide
Content is 5wt%~40wt%, and alumina content is 10wt%~80wt%;Its specific surface area is 100m2/ g~650m2/ g, Kong Rongwei
0.15mL/g~0.50mL/g.FC-14, FC-20 etc. that main catalyst has Fushun Petrochemical Research Institute to develop.It is right
For catalyst for hydro-upgrading, it is desirable that have certain hydrogenation activity and certain lytic activity, should guarantee alkene in diesel oil distillate
Hydrocarbon and aromatic hydrocarbons plus hydrogen saturation, also require linear paraffin that isomerization reaction occurs.The operating condition of hydroisomerizing pour point depression can be used often
The operating condition of rule, generally are as follows: reaction pressure 3.0MPa~15.0MPa, reaction temperature are 300 DEG C~430 DEG C, and volume is empty when liquid
Fast 0.3h-1~15.0h-1, hydrogen to oil volume ratio is 100:1~2000:1.
A preferred embodiment of the invention, the catalyst that the first hydroisomerizing pour point depression catalyst bed uses are
Hydrogenation catalyst A, the catalyst that the second hydroisomerizing pour point depression catalyst bed uses are hydrogenation catalyst B.The hydrogenation catalyst
The percentage composition x of molecular sieve in agent A1Lower than the percentage composition x of the molecular sieve in the hydrogenation catalyst B2, preferably
x1Compare x2Low 1-6 percentage points, more preferably x1Compare x2Low 2-5 percentage points.According to above-mentioned preferred embodiment, hydroisomerizing
Pour point depression can obtain better open loop and isomeric effect, to facilitate the condensation point and hexadecane that further improve products obtained therefrom
Value.This is because feedstock oil is by after the first hydroisomerizing pour point depression catalyst bed, a part of hydrogenated purification saturation of aromatic hydrocarbons with
An outermost ring has carried out isomerization reaction after the reaction of part open loop isomerization-visbreaking, causes hydrocarbon molecule volume to increase, increases
Steric hindrance has increased accordingly the difficulty for continuing ring-opening reaction and isomerization reaction, therefore the second hydroisomerizing pour point depression is catalyzed
The content of molecular sieve suitably increases to improve the reactivity of catalyst in agent (i.e. catalyst B), can preferably complete subsequent
The open loop of second ring and isomerization reaction, so as to increase the Cetane number of gained diesel oil and reduce condensation point.
Gas-liquid separator described in step b is that hydroisomerizing pour point depression reactor beds interlayer or catalyst bed entrance are arranged
Equipment.Gas-liquid separator includes at least several parts such as reaction stream entrance, liquid phase conduit and gas phase conduit, wherein liquid phase conduit
Isolated liquid phase is pulled out into hydroisomerizing pour point depression reactor, isolated gas phase is introduced lower part and adds hydrogen by gas phase conduit
Isomerization-visbreaking catalyst bed.
The liquid stream of extraction described in step b account for feedstock oil weight percent be 5~95wt%, preferably 10~
80wt%。
Separation described in step c generally comprises hydroisomerizing pour point depression high-pressure separator and low pressure separator separates two
Point.The isolated hydroisomerizing pour point depression high pressure hydrogen-rich gas of its high-pressure separator and liquid, high-pressure separator are isolated
Liquid enters low pressure separator.Low pressure separator is by the isolated hydrocarbon-rich gas of highly pressurised liquid product and low pressure liquid product.It is rich
Appropriate hydrocarbon gas is isolated to the hydroisomerizing pour point depression gaseous product of needs.
Fractionation described in step c carries out in hydroisomerizing pour point depression fractionating column system.Low pressure liquid product is in fractionating column
Middle fractionation obtains hydroisomerizing pour point depression naphtha product and hydroisomerizing pour point depression diesel product.
Hydrodewaxing catalyst described in step d is conventional hydrodewaxing catalyst, generally with group VIB and/or the
VIII race's metal is active component, and group VIB metal is generally Mo and/or W, and group VIII metal is generally Co and/or Ni.The catalysis
The carrier of agent contains one of aluminium oxide, silicon-containing alumina and molecular sieve or a variety of, preferably contains molecular sieve, the molecule
Sieve can be ZSM-5, ZSM-11, ZSM-22, ZSM-35 type molecular sieve, preferably ZSM-5 molecular sieve.With the poidometer of catalyst,
Total metal contents in soil is calculated as 1wt%~20wt% with oxide, and molecular sieve content is 40wt%~85wt%, binder content 10wt%
~40wt%.Main catalyst has the 3881 of Fushun Petrochemical Research Institute's development, FDW-1 catalyst etc..Hydrodewaxing
Operating condition conventional operating condition can be used, generally are as follows: reaction pressure 3.0MPa~15.0MPa, reaction temperature be 200 DEG C
~440 DEG C, volume space velocity 0.3h when liquid-1~15.0h-1, hydrogen to oil volume ratio is 100:1~1500:1.
Separation described in step d carries out in hydrodewaxing high-pressure separator and low pressure separator.Wherein hydrodewaxing
The isolated hydrodewaxing high pressure hydrogen-rich gas of high-pressure separator and liquid, the isolated liquid of high-pressure separator enter low pressure
Separator.Low pressure separator is by the isolated hydrocarbon-rich gas of highly pressurised liquid product and low pressure liquid product.Hydrocarbon-rich gas is through separating
The hydrodewaxing gaseous product needed.
Fractionation described in step d is fractionating column system, and low pressure liquid product is fractionated in fractionating column and obtains hydrodewaxing
Naphtha product and hydrodewaxing diesel product.
Hydroisomerizing pour point depression gas products described in step c and step d and hydrodewaxing gas products can individually be made
For product, mixed gas product can also be mixed into.
Hydroisomerizing pour point depression naphtha product described in step c and step d and hydrodewaxing naphtha product can be single
It is solely used as product, mixing naphtha product can also be mixed into.
It can be used directly as recycle hydrogen after the mixing of high pressure hydrogen-rich gas described in step e, also can choose and pass through
It is recycled after desulphurization of recycle hydrogen system removing hydrogen sulfide.
In conjunction with Fig. 1, method of the invention is specific as follows: it is anti-that feedstock oil 1 is mixed into hydrofinishing with recycle hydrogen 21 first
Device 2 is answered, hydrotreated refinery stream 3 enters hydroisomerizing pour point depression reactor 4, by the anti-of the first hydroisomerizing pour point depression catalyst bed
It answers in logistics and extracts hydrodewaxing liquid charging stock logistics 5 out through gas-liquid separator 23, the logistics after extracting hydrodewaxing feed stream 5 out
Follow-up hydrogenation isomerization-visbreaking catalyst bed is gone successively to, hydroisomerizing pour point depression generates logistics 6 and enters hydroisomerizing pour point depression high pressure
Separator 8 carries out gas-liquid separation, and isolated liquid enters fractionation in fractionating column 10 and obtains hydroisomerizing pour point depression gas products
12, hydroisomerizing pour point depression naphtha product 13 and hydroisomerizing pour point depression diesel product 14, hydrodewaxing liquid charging stock logistics 5 with follow
Ring hydrogen 22 enters hydrodewaxing reactor 7 after mixing, and enters hydrodewaxing by the product stream of hydrodewaxing catalyst bed
Gas-liquid separation is carried out in high-pressure separator 9, isolated liquid enters fractionation in fractionating column 11 and obtains the production of hydrodewaxing gas
Product 15, hydrodewaxing naphtha product 16 and hydrodewaxing diesel product 17, hydroisomerizing pour point depression gas products 12 and plus hydrogen drop
Solidifying gas products 15 can obtain mixed gas product, hydroisomerizing pour point depression naphtha separately as product after can also mixing
Product 13 and hydrodewaxing naphtha product 16 can obtain mixing naphtha product separately as product after can also mixing,
The isolated gas 18 of hydroisomerizing pour point depression high-pressure separator 8 and the isolated gas 19 of hydrodewaxing high-pressure separator 9
It is mixed with supplement hydrogen 20 as recycle hydrogen after circulating hydrogen compressor after mixing.
Illustrate the present invention program and effect below by embodiment.
Embodiment 1-4
Protective agent FZC-100, FZC-105 and FZC106 are China Petroleum and Chemical Corporation Fushun Petrochemical Research Institute
The hydrogenation protecting agent of development and production;Catalyst FHUDS-5 is the petrochemical industry research of Sinopec Group Fushun
The Hydrobon catalyst of institute's development and production;Catalyst FC-20 is Sinopec Group Fushun petrochemical industry
The hydrodewaxing catalyst of research institute's development and production contains beta molecular sieve, FC-20B catalyst, tenor and FC-20 phase
Together, molecular sieve content is 5 percentage points high;Catalyst 3881 is the petrochemical industry research of Sinopec Group Fushun
The hydrodewaxing catalyst of institute's development and production, contains type ZSM 5 molecular sieve.
The main character of table 1 diesel raw material oil
2 embodiment process conditions of table and test result
2 embodiment process conditions of continued and test result
Using hydroisomerizing pour point depression technique of the invention it can be seen from embodiment, by out of hydroisomerizing pour point depression reactor
It extracts a part of reaction stream out, and realizes production heterogeneity using hydroisomerizing pour point depression catalyst and hydrodewaxing catalyst
The purpose of diesel oil, production method are flexible.