Classifications

• • 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
  • C10G73/00—Recovery or refining of mineral waxes, e.g. montan wax
  • C10G73/02—Recovery of petroleum waxes from hydrocarbon oils; Dewaxing of hydrocarbon oils
  • C10G73/04—Recovery of petroleum waxes from hydrocarbon oils; Dewaxing of hydrocarbon oils with the use of filter aids

Definitions

• paraffinic waxes in petroleum and petroleum products makes handling very difficult, primarily because of the tendency of the waxes to crystallize below certain temperatures, which vary from case to case. (See Ullmann's Enzyclopadie der techn. Chemie, 4th edition, vol. 20, p. 548 ff, Verlag Chemie 1981). Lighter petroleum fractions can be simply cooled down to the wax Crystallization temperature of the waxes and pressing are removed via filters.
• the predominantly technically used process for dewaxing wax-containing oils works with solvents, mostly low-boiling aliphatic hydrocarbons such as pentane, hexane, heptane, octane etc., ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like, also aromatic hydrocarbons such as benzene, toluene, xylene and the like. and mixtures of solvents.
• solvents mostly low-boiling aliphatic hydrocarbons such as pentane, hexane, heptane, octane etc., ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like, also aromatic hydrocarbons such as benzene, toluene, xylene and the like. and mixtures of solvents.
• solvents mostly low-boiling alipha
• wax-containing distillate oils are particularly suitable, in particular those with a boiling range of approximately 300 to approximately 600 degrees C, a density of approximately 0.08 - 0.09 g / cc at 15 degrees C, a viscosity of approx. 10 - 20 cSt / 100 degrees C, a "pour point" of approx. 30 - 50 degrees C and a wax content (dry) of approx. 10 - approx. 25 wt. -%.
• distillate oils from those fractions that include lubricating oils and special oils in the boiling range 300 - 600 degrees C, especially those with an average boiling point of approx. 400 - 450 degrees C.
• aliphatic hydrocarbons with a boiling point ⁇ 150 degrees C including the self-cooling gases such as propane, propylene, butane, pentane, isooctane, etc.
• aromatic hydrocarbons such as Toluene, xylene Ketones such as Acetone, dimethyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, optionally also halogenated hydrocarbons such as methylene chloride, dichloroethane or N-alkylpyrrolidones such as N-methylpyrrolidone, N-ethylpyrrolidone.
• solvents for example ketones and aromatic hydrocarbons such as methyl ethyl ketone / toluene or methyl isobutyl ketone / toluene
• the solvent L in the process according to the invention is added in the customary amounts, for example 0.5-10 parts by volume, preferably 2-7 parts by volume, based on the substrate to be dewaxed.
• the starting monomers for the polymerization P-1 and P-2 (which are already used in the art for the production of polyalkyl (meth) acrylates (PMMA)) are known per se.
• the polymerization of the monomers can also be carried out in a manner known per se.
• the polyalkylacrylates P1 are composed of acrylic esters of C10-C40 alkanols, in particular of acrylic esters of C18-C24 alkanols, for example of the behenyl alcohol type.
• the molecular weight M is advantageously in the range from 10,000 to 1,500,000, preferably from 50,000 to 500,000.
• the determination can be carried out by means of gel permeation chromatography. (See Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 18, pg. 209, 749, J. Wiley 1982).
• Characteristic of the polyalkyl methacrylates P-2 is that this more than 10 wt .-%, preferably more than 15 wt .-% esters of methacrylic acid contain branched alkyl groups.
• the polymers P-2 are esters of C1-C40 alkanols, with preference for the esters of C10-C24, in particular C12-C18 alcohols.
• the polymer P-2 can contain 0.1 to 20% by weight, in particular 1-15% by weight, of C1-C9-alkyl methacrylates.
• the molecular weight M is generally in the range 3,000 to 500,000, preferably 50,000 to 300,000.
• the radical polymerization is advantageously carried out in a solvent which is compatible with the substrate to be dewaxed, such as, for example, in mineral oil.
• a solvent which is compatible with the substrate to be dewaxed
• man uses conventional polymerization initiators such as per compounds, especially peresters such as tert-butyl perpivalate, tert-butyl peroctoate, tert-butyl perbenzoate and the like. in the usual amounts, for example 0.1 to 5, preferably 0.3 to 1% by weight, based on the monomers (cf. Th. Völker, H. Rauch-Puntigam, acrylic and methacrylic compounds, Springer-Verlag 1967).
• Molecular weight regulators in particular sulfur regulators, special mercaptans such as dodecyl mercaptan in the usual amounts, for example 0.01 to 2% by weight, based on the monomers, can also be added to the batches in a manner known per se.
• a protective gas such as CO2.
• the procedure is appropriately such that the monomers are dissolved in a suitable polymerization vessel equipped with a stirrer in the solvent, if appropriate together with the regulator and initiator and first degassed, for example using CO2 snow, and then heated.
• the initiator can also be added to the heated mixture in some cases. If necessary, further monomer and initiator and regulator are metered in.
• the temperature generally rises further, for example to 140 ⁇ 10 degrees C.
• suitable conditions for the postpolymerization can be established by adding heat and / or further addition of initiator.
• the total polymerization time is generally less than 12 hours.
• the polymer components P-1 and P-2 can advantageously be used as separately prepared preparations. They are then mixed in the abovementioned weight ratios and the intended proportions of the substrates to be dewaxed, either in bulk or in a compatible solvent such as wax-free mineral oil or one of the solvents or mixtures L, taking care that the cloud point the oils to be dewaxed are exceeded, for example by heating to 50-120 degrees C.
• the polymers P-1 and P-2 can be added together or separately. The addition can take place before cooling or during cooling, but then in cooled solvents. The cooling can take place, for example, in accordance with US Pat. No. 3,773,650.
• the mixture of the polymers P-1 and P-2 is advantageously added together with the dewaxing solvent L in a cooling zone and at a temperature which is matched to the "pour point" of the dewaxed oil to be obtained.
• the cooling step causes the formation of a fluid liquid slurry, which contains solid wax particles, dewaxed oil and solvent L.
• the wax particles usually contain polymer P-1 and P-2.
• the temperature to which cooling must depend on the type of substrate to be dewaxed and the overall procedure. In general, dewaxing is carried out in the temperature range from 0 degrees C to -50 degrees C, when using a solvent mixture L of a ketone and an aromatic hydrocarbon, the dewaxing temperature is to be set at -10 degrees C to -30 degrees C.
• the filtration apparatus consists of a steel filter with a lid and cooling jacket and is cooled in circulation using a cryostat. Filter cloth from the dewaxing plant of the corresponding refinery is used.
• the filter volume is 100 ml.
• the filter is connected to a measuring cylinder via a glass attachment with a 2-way valve.
• a defined vacuum can be applied to the filtration apparatus using an oil rotary vane pump, a pressure reducing valve and a pressure gauge.
• the mineral oil distillate to be dewaxed is mixed with the dewaxing solvents in the heat (above the cloud point) and stirred until a clear solution results. This is carried out with the help of a cryostat with temperature control cooled down to the desired filtration temperature.
• the filter is pre-cooled to this temperature.
• the mixture is transferred to the precooled filter and a vacuum is applied.
• the filtrate volume is measured as a function of time and the filtration rate F is determined as the slope of the linear plot of V / 2S2 against t / V, where V is the filtrate volume, t is the time in seconds and S is the filter area in cm2.
• Dewaxing additives Dewaxing Polyalkyl acrylate Polyalkyl methacrylate % branches Mixing ratio Filterability F (cm2 / s) Filtration time (sec.) Oil yield% - - - - 1.1 x 10 ⁇ 2 2460 73.7 P-1 - - 9 x 10 ⁇ 2 300 83.0 P-1 P-2-1 17.9 1: 1 26 x 10 ⁇ 2 90 83.9 P-1 P-2-1 17.9 2: 1 47 x 10 ⁇ 2 70 85.4 P-1 P-2-2 27.2 1: 1 48 x 10 ⁇ 2 60 84.6 P-1 P-2-3 38.9 1: 1 70 x 10 ⁇ 2 40 84.7 P-1 V-2-1 0 1: 1 18 X 10 ⁇ 2 150 83.7
• Example 3 Dewaxing from Bright Stock 95 of a Spanish refinery Solvent: isooctane Conditions of the laboratory experiments as described in Example 8 Dewaxing additives Dewaxing Polyalkyl acrylate Polyalkyl methacryl
• the feedstock to solvent ratio was 1: 3. It was cooled from +70 degrees C to -17 degrees C at 3.5 degrees C / min., At -17 degrees C the filtration took place
• Dewaxing additives Dewaxing Polyacrylate Polymethacrylate % branches Mixing ratio dosage Filterability F (cm2 / s) Filtration time (sec.) Oil yield% Paraffin Oil% - - - - - 1.5 x 10 ⁇ 2 1 100 42.4 63.4 P-1 - - - 250 3.6 x 10 ⁇ 2 420 57.3 - 500 3.6 x 10 ⁇ 2 480 57.4 58 - P-2-1 17.9 - 250 1.8 x 10 ⁇ 2 840 43.2 - 500 1.4 x 10 ⁇ 2 1 260 44.9 - P-1 P-2-1 17.9 1: 1 250 4.1 x 10 ⁇ 2 420 57.1 - 500 3.8 x 10 ⁇ 2 440 57.5 - P-1 P-2-1 17.9 2: 1 250 4.1 x 10 ⁇

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Lubricants (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 1989
  • 1989-10-06 DE DE3933376A patent/DE3933376A1/de not_active Withdrawn
• 1990
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  • 1990-09-26 DE DE9090118450T patent/DE59000545D1/de not_active Expired - Lifetime
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