US3846277A - Dewaxing of oils - Google Patents

Dewaxing of oils Download PDF

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Publication number
US3846277A
US3846277A US00285784A US28578472A US3846277A US 3846277 A US3846277 A US 3846277A US 00285784 A US00285784 A US 00285784A US 28578472 A US28578472 A US 28578472A US 3846277 A US3846277 A US 3846277A
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United States
Prior art keywords
wax
refrigerant
parts
oil
high pressure
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US00285784A
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H Mcintosh
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Texaco Inc
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Texaco Inc
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Priority to US00285784A priority Critical patent/US3846277A/en
Priority to CA175,288A priority patent/CA1015299A/en
Priority to GB3707773A priority patent/GB1392159A/en
Priority to ZA735349A priority patent/ZA735349B/xx
Priority to AU59030/73A priority patent/AU471951B2/en
Priority to ES418146A priority patent/ES418146A1/es
Priority to NL7311737A priority patent/NL7311737A/xx
Priority to BE135032A priority patent/BE804126A/xx
Priority to BR6621/73A priority patent/BR7306621D0/pt
Priority to FR7331056A priority patent/FR2197964B1/fr
Priority to DE19732343515 priority patent/DE2343515A1/de
Priority to TR17474A priority patent/TR17474A/xx
Priority to JP48096767A priority patent/JPS4964607A/ja
Priority to SE7311822A priority patent/SE396615B/xx
Priority to IT28386/73A priority patent/IT995240B/it
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Publication of US3846277A publication Critical patent/US3846277A/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
    • 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
    • C10G73/06—Recovery of petroleum waxes from hydrocarbon oils; Dewaxing of hydrocarbon oils with the use of solvents

Definitions

  • This invention relates to oils such as lubricating oils. More particularly it relates to the dewaxing of oils including petroleum lubricating oils.
  • oils contain parain or waxy component which must be removed during processing.
  • fractions containing the lubricating oil constituents are separated by distillation, usually by vacuum distillation.
  • the raw lubricating oil distillate contains waxy constituents which cause the oil to have a high cloud point and high pour test.
  • a common method of separating wax and waxy materials from hydrocarbon oil is by the solvent dewaxing process in which the waxy material is crystallized from a solvent-diluted mixture at a reduced temperature.
  • the solvent dilutes the supernatant liquid and reduces its viscosity so that more complete and rapid separation of the supernatant liquid from crystallized Wax may be effected.
  • Solvents commonly used in solvent dewaxing include ketones, for example, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and their mixtures.
  • the ketone solvent is modified by the addition of an aromatic hydrocarbon, for example, benzene or toluene.
  • oils typically petroleum lubricating oils
  • Typical of the prior art patents relating to this are U.S. Pats. 2,067,128; 2,164,773; U.S. Pat. 3,594,513; and U.S. Pat. 3,554,896.
  • dewaxing is characterized by use of steps carried out at very low temperature and by other steps conducted at elevated temperature.
  • the refrigeration load needed to cool the system-even when using volatilizing refrigerant may be substantial; and the heat input required to heat up the various streams for distillation may also be substantial.
  • novel 3,846,277 Patented Nov. 5, 1974 ICC process of this invention for separating wax from a waxbearing oil may comprise:
  • the charge wax-bearing oils which may be treated in practice of this invention may include vegetable oils, typified by soy bean oils; or animal oils, typified by byproduct oils recovered e.g. from various meateprocessing operations; or mineral oils, typified by petroleum lubrieating oil fractions.
  • the charge wax-bearing oil may typically contain wax in amount of 5 %-25%.
  • the waxy component may contain saturated acids, whereas the oily component may include unsaturated acids.
  • the waxy component may include triglycerides whereas the oily component may include monoand di-glycerides.
  • the waxy component may include high molecular weight paraflins while the oily component may include lower molecular weight hydrocarbons, unsaturates, aromatics, etc.
  • the preferred charge oil may be a petroleum oil, typically a refined vacuum distillate suitable for use in the manufacture of base oil for e.g. a SAE 20 motor oil.
  • the Wax-bearing charge oil may typically be characterizedl by the following properties:
  • the dewaxing solvent may be methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and mixtures thereof.
  • the ketone solvent is preferably modified with an aromatic solvent such as benzene or toluene.
  • the preferred solvent is a mixture of equal parts of methyl ethyl ketone and toluene.
  • the refrigerant may be a hydrocarbon such as etbane, ethylene, propane, butene, etc.; a Freon such as dichlorodifiuoro methane; ammonia; etc.
  • the preferred refrigerant may be a hydrocarbon, most preferably propane.
  • This charge mixture at temperature of C.-80 C., preferably C.-35 C., say 30 C. and 15-250 p.s.i.a., preferably 230-250 p.s.i.a., say 240 p.s.i.a. (which initial pressure is at least sufficient to maintain the refrigerant in liquid phase) may be heated to 25 C.-100 C., preferably 45 C.-55 C., say 50 C. thereby achieving complete solution of the charge oil, solvent, and refrigerant.
  • the charge mixture in total amount of 2-16 parts, preferably 5-9 parts, say 7 parts may then be cooled to 20 C.- 95 C., preferably 40 C.- 50 C., say 45 C. at 65-250 p.s.i.a., preferably 230-250 p.s.i.a., say 240 p.s.i.a.-at which conditions the charge mixture is above the temperature at which wax precipitation begins.
  • the so-cooled oil-solvent-refrigerant mixture may be passed to an evaporative cooling operation, typically carried out in a vertically extending7 chiller vessel.
  • the mixture may be subjected in a first chilling step to decreasing pressure over 3-100 minutes, preferably 25-75 minutes, say 55 minutes.
  • the cooling rate may be controlled by adjusting a high pressure control valve on the outlet of the chiller vessel.
  • additional refrigerant typically 25% of the total refrigerant
  • Throttling control may permit maintenance of the cooling rate at 0.25-85 C./min., preferably 0.4-0.7 C./min., say 0.55 C./min.
  • the temperature may drop to minus 5 C.-16 C., preferably 14 C.-16 C., say 15 C. as the pressure drops to 50- 115 p.s.i.a., preferably 95-115 p.s.i.a., say 105 p.s.i.a.
  • the liquid refrigerant may vaporize or volatilize as a stream of high pressure refrigerant vapor in amount of 1.5-2.4 parts, preferably 1.8-2.1 parts, say 2 parts.
  • the high pressure control valve may be closed.
  • the high pressure control Valve When the pressure in the chiller has dropped to the level noted supra, it is preferred to close the high pressure control Valve and to direct the volatilizing liquid refrigerant into a low pressure receiving system.
  • the oilsolvent refrigerant mixture may, during this second chilling step, be cooled further by passage through a low pressure control valve.
  • Control of the low pressure control valve may permit a decreasing pressure over 3-100 minutes, preferably 40-75 minutes, say 60 minutes during which time, the pressure may drop to 15-55 p.s.i.a., preferably -40 p.s.i.a., say 35 p.s.i.a.
  • the mixture may be cooled at a rate of 0.25-85 C./min., preferably 0.4- 0.7 C./min., say 0.55 C./min. to a temperature of minus C.-minus 7 C., preferably minus 20 C.-minus 15 C., say minus 18 C.
  • %-75% preferably %-65%, say 50% of the liquid refrigerant (based upon the refrigerant initially charged to the first chilling step) may be volatilized as chilling is effected; and l-4 TABLE Parts Component Broad Typical Preferred Wax 0. 05-0. 25 0. 10-0. l5 0. 12 Oil 0. ⁇ l5-0. 75 0. 90-0. 85 0. 88 Solvent 1. 00-7. 00 2. 00-4. 00 3. 00
  • This first slurry may be withdrawn from the chilling operation upon completion of chilling and crystallizing (the low pressure control valve having been closed) and passed to a primary or first filtration operation.
  • wax may be separated as slack wax from the oil-solvent mixture.
  • 0.15-0.50 parts preferably O20-0.30 parts say 0.25 parts of slack wax may be recovered containing 0.03-0.38 parts, preferably 008-018 parts, say 0.13 parts of occluded oil.
  • First filtrate may be recovered at minus 40 C minus 7 C., preferably minus 20 C.-minus 15 C., say minus 18 C.
  • First filtrate may contain 0.50-0.85 parts, preferably D70-0.80 parts, say 0.75 parts of oil, 0.5-6.5 parts, preferably 3.0-5.0 parts, say 3.5 parts of solvents (including 1-2, preferably l.25-l.75 parts, say 1.5 parts of wash solvent), and less than 0.05 parts, preferably 0.01-0.03 parts, say 0.01 parts of wax.
  • volatilized high pressure refrigerant ⁇ vapor may be cooled in indirect heat exchange against the first (or primary) filtrate thereby forming a cooled and at least partially condensed high pressure refrigerant.
  • this refrigerant stream may be cooled to minus 5 C.- 16 C., preferably 14 C.16 C., say 15 C.
  • a portion, preferably 5%-85%, more preferably 70%-80%, say 75% of of this refrigerant stream may be condensed against primary filtrate.
  • the slack wax recovered in the primary filtration operation may be mixed with O.2-2.0 parts, preferably 0.5 0-1.5 0 parts, say 1.0 parts of dewaxing solvent at minus 40 C.- minus 7 C., preferably minus 20 C minus 15 C., say minus 18 C. to form a slurry of repulped Wax which may be passed to a second (or secondary) filtration operation.
  • it may be filtered at minus 37 C.-rninus 4 C., preferably minus 18 C.-minus 12 C., say minus 15 C. to yield a second filter cake containing deoiled Wax in amount of 0.15-0.20 parts, preferably 0.15-0.18 parts, say 0.18 parts.
  • the secondary ltrate at minus 37 C.- minus 4 C., preferably minus 18 C.-minus 12 C., say minus 15 C. may be Withdrawn in amount of 0.5-1.5 parts, preferably 0.75-1.25 parts, say 1.0 parts (including 0.3-0.7 parts, preferably 0.4-0.6 parts, say 0.5 parts of wash solvent).
  • secondary filtrate may be heat exchanged in indirect heat exchange against the cooled partially condensed high pressure refrigerant (or alternatively against that portion of the high pressure refrigerant which is still in vapor phase.
  • the cooled partially condensed high pressure refrigerant in amount of 1.5-2.4 parts, preferably 1.8-2.1 parts, say 2 parts (of which 60%-80%, preferably 70%-80%, say 75% is in liquid phase) at minus 5 C.-16 C., preferably 14 C.-16 C., say 15 C.
  • 65-250 p.s.i.a. preferably 230-250 p.s.i.a., say 240 p.s.i.a, may be further condensed so that essentially 100% of the refrigerant may be condensed (ie. including that percentage condensed against primary filtrate).
  • this condensate may be at its bubbling point-with a minimum of sub-cooling.
  • the recycled high pressure refrigerant in amount of 1.5-2.4 parts, preferably 1.8-2.1 parts, say 2 parts at minus 5 C.- 16 C., preferably 14 C.-l6 C., say 15 C. at 65-250 p.s.i.a., preferably 230-250 p.s.i.a., say 240 p.s.i.a. may be divided; one portion, typically 1 part, may be mixed with the secondary filtrate passing to the refrigerant collection drum and a second portion, typically 1 part, may be recycled to the chiller drums to provide additional cooling, preferably during the second chilling step.
  • volatilized low pressure refrigerant vapor at minus C.-10 C. preferably minus 5 C.-0 C. say minus 1.5 C. and 15-55 p.s.i.a., preferably -40 p.s.i.a., say 35 p.s.i.a.
  • volatilized low pressure refrigerant vapor at minus C.-10 C. preferably minus 5 C.-0 C. say minus 1.5 C. and 15-55 p.s.i.a., preferably -40 p.s.i.a., say 35 p.s.i.a.
  • volatilized low pressure refrigerant vapor at minus C.-10 C. preferably minus 5 C.-0 C. say minus 1.5 C. and 15-55 p.s.i.a., preferably -40 p.s.i.a., say 35 p.s.i.a.
  • the mixed refrigerant streams may be compressed to 15-275 p.s.i.a., preferably 230-260 p.s.i.a., say 250 p.s.i.a. and 20 C.-80 C., preferably 60 C.-70 C., say 65 C., and then cooled if necessary and condensed to C.-70 C., say C.
  • 1-4 parts, preferably 1.4-3 parts, say 2 parts of cooled refrigerant may be added to the compressed high pressure refrigerant stream passing to the refrigerant collection drum.
  • 5-15 parts, preferably 8-12 parts, say 10 parts of a drawn-off side stream of cooled refrigerant may be passed to solvent cooler wherein it may cool solvent.
  • solvent cooler As it passes through the solvent cooler, it may be heated to minus 40 C.-0 C., preferably minus 40 C.-minus 15 C., say minus 35 C. as it volatilizes at 15-30 p.s.i.a., preferably 15-20 p.s.i.a., say 15 p.s.i.a.
  • the volatilized drawn-off refrigerant may be compressed to 15-55 p.s.i.a., preferably 30-40 p.s.i.a., say 35 p.s.i.a. and minus 10 C.-10 C., preferably minus 5 C.- 5 C., say 0 C. and then blended into the stream of volatilized low pressure refrigerant passing from the chiller vessels.
  • the first or primary filtrate after it has been heated to minus 5 C.- 45 C., preferably minus 15 C.-20 C., say 17 C. by heat exchange against volatilized high pressure refrigerant, may be further heated typically to 150 C. and passed to a dewaxed oil stripping operation. Stripping of solvent from dewaxed oil may be carried out at 15-20 p.s.i.a., say 18.5 p.s.i.a. in a dewaxed oil stripping column to yield as overhead (at 90 C.-l20 C., preferably 100 C.-l10 C. say 104 C.), 0.5-6.5 parts, preferably 1.5-3.5 parts, say 3.5 parts of solvent which may be condensed against water and passed to a solvent receiver.
  • Typical dewaxed oil may have the following properties:
  • the secondary filtrate containing 0.25-1.5 parts, preferably 0.5-1.0 parts, say 0.7 parts of solvent and (ll-0.5 parts, preferably 0.2-0.4 parts, say 0.3 parts of oil at minus 18 C.-minus 12 C., say minus 15 C. may be heat exchanged against the cooled high pressure refrigerant and thereby warmed to minus 10 C.-15 C., preferably 0 C.-10 C., say 5 C.; and it may then be combined with the cooled stream of high pressure refrigerant.
  • the wax recovered as second filter cake from secondary filtration may be sluiced with 0.5-2.0 parts, preferably 0.75-1.5 parts, say 1.25 parts of hot wax-solvent mixture at 75 C.-l7 5 C., preferably C.-150 C., say 120 C.
  • the sluiced mixture in total amount of 1.0-4.0 parts, preferably 2-3 parts, say 2.5 parts may be heated to 75 C.-175 C., preferably 100 C.-150 C., say 120 C. and 30%-70%, preferably 40%-60%, say 50% of this heated mixture may be used as sluicing liquid.
  • the net molten filter cake may be heated, typically to about C. and passed to wax stripping operation at 5-50 p.s.i.a., preferably 15-20 p.s.i.a., say 18.5 p.s.i.a. 0.15-0.20 parts, preferably 0.15-0.18 parts, say 0.15 parts of deoiled wax may be withdrawn as stripped bottoms at C.-200 C., say 195 C. Stripped solvent overhead, in amount of 0.5-1.5 parts preferably 0.8-1.2 parts, say 1.0 parts at 90 C.-l20 C., preferably 100 C.-1 10 C., say 104 C. may be Withdrawn as overhead, condensed in indirect heat exchange with water, and passed to a solvent receiver.
  • 0.5-50 parts, preferably 1-3 parts, say 2 parts of solvent may -be Withdrawn from the solvent receiver at 10 C.'- 60 C., preferably 20 C.-50 C., say 45 C. and mixed with the waxy feed to provide dilution.
  • 1.0-5.0 parts, preferably 2.0-3.0 parts, say 2.5 parts of solvent may be withdrawn from the solvent receiver at 10 C.-60 C., preferably 20 C.-50 C., say 45 C. and passed into indirect heat exchange ⁇ with the drawn off side stream of cooled refrigerant from the low pressure refrigerant stream.
  • the solvent may be cooled to minus 40 C.-minus 7 C., preferably minus 20 C.-minus 15 C., say minus 18 C.
  • a first portion for the cooled solvent (1.0-3.0 parts, preferably 1.5-2.0 parts, say 1.5 parts) may be passed to the primary ltration operation as wash solvent, a second portion (0l-1.0 parts, preferably 0.3-0.7 parts, say 0.5 parts) to the primary filter for repnlping the slack Wax, and a third portion (0.l-l.0 parts, preferably 0.3-0.7 parts, said 0.5 parts) to the secondary filtration operation as Wash liquor.
  • the improved refrigeration heat exchange circuit permits reduction of refrigeration capacity by as much as 50% or more in illustrative embodiments.
  • This decrease in operating costs and capital costs permits recovery of dewaxed oil with substantia'l savings.
  • the net effect may be to eliminate one substantial compressor and to reduce the total compressor horsepower to less than one half that otherwise required.
  • the novel process of this invention permits replacement of expensive vapor compressors with liquid pumps; and the savings attendant on this substitution may decrease capital costs to 0.03 %0.l% based upon the costs incurred with vapor compressors.
  • the charge wax-bearing petroleum oil may be a solvent refined vacuum distillate suitable for use in the manufacture of base oil for SAE 20 motor oil. It has an API gravity of 30.6, a pour point of 41 C., a cloud point of 50 C., a viscosity at 37.8 C. of 78 cs., and contains 10.2% wax.
  • This wax-bearing petroleum oil in amount of l part at 30 C., is admitted through line 10 and passed to line 11 wherein it is contacted with 2 parts of solvent at 30 C.
  • Dewaxing solvent includes 50% methyl ethyl ketone and 50% toluene.
  • This charge mixture at 30 C. and 250 p.s.i.a., is passed to heat exchanger 13 (heated by steam in line 14) wherein it is heated to 55 C. and 245 p.s.i.a. at which point, intimate mixing and complete solution is achieved.
  • Charge mixture is passed to head exchanger 15, cooled by cooling water in line 16.
  • Charge mixture leaves heat exchanger 15 at 43 C. and 235 p.s.i.a. through line 17.
  • Mixing the propane refrigerant and oil-solvent solution occurs at the junction of lines 12 and 17 and throughout manifold 18.
  • the resulting cooled mixture of oil-solvent-refrigerant is then passed to the chilling operation through manifold 18.
  • the chilling operation may include in this embodiment, a group of four chillers arranged in parallel.
  • Each chiller includes chiller feed line 19 (for the rst chiller; for the other chillers 19a, 19b, and 19C), chiller inlet valve 20 (for the first chiller; for the other chiller inlet valves 20a, 2017, and 20c), and chiller inlet line 21 (for the first chiller; for the other chillers 21a, 2lb, and 21C).
  • the chiller 22 (for the first chiller; for the Others 22a, 22b, and 22C) is fitted with volatilized high pressure refrigerant vapor line' 23 (for the first chiller; for the other chillers 23a, 2311, and 23C) and a high pressure chiller outlet back pressure coritrol valve 24 (for the first chiller; for the other chillers 24a, 24h, and 24e).
  • the high pressure chiller outlet valve 24 feeds through a high pressure outlet line 25 (for the first chiller; for the other chillers, 25a, 25h, and 25C) in to high pressure manifold 26 bearing high pressure, back pressure valve 27.
  • Each of the chillers is also fitted 'with volatilized low pressure refrigerant vapor line 28 (for the first chiller; for the other chillers 28a, 28b, and 28e) including low pressure chiller outlet (back pressure) valve 29 (for the first chiller; for the other chillers 29a, 29b, and 29C) .which control passage of volatilized low pressure refrigerant vapor to manifold 30.
  • Manifold 30 includes low pressure back pressure control valve 31.
  • Each of the chillers bears charge slurry outlet line 32 (for the first chiller; for the other chillers 32a, B2b, and 32C), and slurry outlet valves 33 (for the first chiller; for the others 33a, 3312, and 33C) which permit control of the slurry passing to slurry manifold 34.
  • Manifold 35 bears additional refrigerant valves 36 (for chiller 22; for the others, 36a, 36h, and 36C) which permit passage of refrigerant through line 37 (for chiller 22; for the others 37a, 37b, and 37e) during the chilling.
  • each chiller 22, 22a, 22h, and 22e are operated on a sequential program including (i) filling, (ii) chilling in a rst chilling step with evolution of high pressure refrigerant, (iii) chilling in a second chilling step with evolution of low pressure refrigerant, and (iv) emptying.
  • each chiller is in one stage 0r mode of the program; and the inlet and outlet valves (eg. valves 20, 24, 29, and 33 in the case of chiller 22) are opened or closed to permit passage of materials in accordance with the mode of the program being followed by the particular chiller.
  • the cooled oil-solventrefrigerant mixture in line 18 at 43 and 235 p.s.i.a. (containing 1 part of wax-bearing oil charge, 3 parts of propane refrigerant, 1.1 parts of secondary filtrate, and 2 parts of dewaxing solvent) is passed through manifold 18 into chiller feed line 19 through open chiller inlet valve 20 and chiller inlet line 21 into chiller 22.
  • valves 36, 33, 24, and 29 are closed.
  • chillers 22a, 22h, and 22C may be operating in different modes of the cycle during the time in which chiller 22 is filling.
  • chiller 22a for example may be in the first chilling mode
  • chiller 22h in the second chilling mode
  • chiller 22a ⁇ may be in the emptying mode.
  • the entire cycle will be described with reference to chiller 22.
  • valve 20 When chiller 22 is filled, valve 20 is closed, valve 24 is opened and propane refrigerant is permitted t0 evaporate until the pressure in the chiller 22 drops from initial pressure of 230 p.s.i.a. to final pressure of p.s.i.a. As this occurs, the temperature in chiller 22 drops to 15 C. and 50% of the wax contained in the charge precipitates and forms a slurry.
  • the rate of cooling in chiller 22 is preferably maintained at about 0.55 C./min. by controllably opening high pressure, back pressure valve 27. During this first or high pressure chilling step, 2 parts of high pressure propane refrigerant is passed through valve 27.
  • the pressure in the chiller is 105 p.s.i.a. and the temperature is 15 C. this state being arrived at after about 55 minutes.
  • 1 part of additional refrigerant is admitted to chiller 22 from manifold 35 through line 37 and valve 36 (which is now opened)
  • Valve 24 is then closed.
  • Low pressure chiller outlet valve 29 is then opened; and the second chilling operation is initiated under the control of low pressure, back pressure valve 31.
  • the cooling rate is controlled to be 0.55 C./min. and as the pressure drops from 105 p.s.i.a. to 35 p.s.i.a. over 60 minutes, the temperature falls from 15 C. to minus 18 C. During this time, 50% more wax precipitates; and the resultant first slurry contains 0.25 parts of wax and 3.85 parts of liquid.
  • the first slurry is withdrawn from chiller 22 over 30 minutes (at this point valves 20, 24, 29 and 36 are closed and valve 33 is open) through valve 33 and passes through manifold 34 to primary filter 38.
  • Filtration at minus 18 C. and 15 p.s.i.a. yields 4.25 parts of rst filtrate withdrawn through line 39 containing 0.75 parts of deWaxed-oil and 3.5 parts of solvent.
  • the first filter cake, withdrawn through line 40 contains slack Wax.
  • the 2 parts of volatilized high pressure refrigerant leaving valve 27 at an average temperature of 30 C. and 105 p.s.i.a. are passed through line 41 to collector 42 and thence through line 43 and valve 44 and line 45 first high pressure refrigerant cooler and partial condenser 46 wherein it is heat exchanged against primary filtrate at minus 18 C. and 250 p.s.i.a.
  • first high pressure refrigerant cooler and partial condenser 46 wherein it is heat exchanged against primary filtrate at minus 18 C. and 250 p.s.i.a.
  • the primary filtrate passed from line 39, pump 63 and line 64 is heated to 17 C. and the refrigerant is cooled to 15 C. at 95 p.s.i.a. and is partially (75%) condensed.
  • the slack Wax (1.35 parts) recovered in primary filtration operation 38 is mixed with 0.5 parts of dewaxing solvent at minus 18 C. admitted through line 46, to form a slurry of repulped wax which passes through line 40 to secondary filter 47. Filtration of the repulped wax yields 1.25 parts of deoiled wax filter cake which contains dewaxing solvent and 1.1 parts of secondary filtrate at minus 15 C. which also contains dewaxing solvent. Second filtrate is passed through line 48 at minus 15 C. through pump 49 to heat exchanger 50 wherein it is heat exchanged against the cooled high pressure refrigerant leaving heat exchanger 46 through line 51.
  • 1 part of refrigerant liquid in line 56 at 15 C. is pumped through line 58 to line 35 and thence to chiller 22 to which it is introduced prior to the second chilling step.
  • 1 part of liquid in line 56 is passed through manifold 57 and mixed with secondary filtrate at 5 C. from line 53, the mixture being at 12 C.
  • the refrigerant in line 51 into direct Contact with the stream in line 52 thereby eliminating line 53 and replacing heat exchanger 50 with, e.g. an absorption vessel, the net total liquid being passed through line 54.
  • the combined secondary filtrate and condensed high pressure refrigerant is joined in manifold 57 by recycle lovt pressure refrigerant liquid in amount of 2 parts at 43 C. and 250 p.s.i.a. from line 99; and the total mixture in amount of 4.1 parts at 16 C. and 250 p.s.i.a. is passed through manifold 57 to recycle refrigerant drum 59; refrigerant in drum 59 is passed through line 60 and heat exchanger 61 wherein it is heated to 43 C. by steam from line 62 and passed through line 12.
  • the second portion of low pressure refrigerant at 43 C. and 250 p.s.i.a from line 71 may be volatilized to minus 40 C. and 15 p.s.i.a. as it cools the stream of dewaxing solvent in line '73 to minus 18 C. at 250 p.s.i.a. in line 74.
  • the volatilized refrigerant in line 75 may be compressed in compressor 76 to C. and 35 p.s.i.a. and passed through line 65 to the inlet of compressor 66 at manifold 30. Compressed refrigerant may be passed through line 65 to manifold 30.
  • the first or primary filtrate which has been passed through line 39, pump 63, and line 64 into heat exchange against volatilized high pressure refrigerant in heat exchanger 46 is then passed in amount of 4.25 parts at 17 C. and 240 p.s.i.a. through line 80 to heat exchanger 81, heated by steam from line 82 and passed to dewaxedoil stripping operation 83.
  • Overhead at 104 C. and 18.5 p.s.i.a., containing 1.75 parts of toluene and 1.75 parts of methyl ethyl ketone is passed through line 84 to condenser 85 cooled by water in line 86 and passed to de- Waxing solvent collection drum 87.
  • Dewaxed oil bottoms at 205 C. and 220 p.s.i.a. are recovered in line 88 in amount of 0.75 parts.
  • the dewaxed oil is characterized by API gravity of 30.4, pour point of minus 15 C., cloud point of minus 10 C., viscosity at 37.8 C. of 75 cs., and a wax contact of 0.01%.
  • Wax (0.15 parts) recovered from secondary filtration in amount of 1.25 parts is sluiced with 1.25 parts of recycled wax-solvent mixture at C. to form a sluiced mixture at 60 C. containing 0.30 parts of wax and 2.2 parts of solvent in line 89 and is heated to 120 C. at 100 p.s.i.a. in heat exchanger 90 heated by steam in line 91.
  • 1.25 parts of the so-heated mixture are withdrawn and passed through line 92 to the sluicing operation in secondary filtration operation 47.
  • 1.25 parts of the soheated mixture are passed to Wax-stripping operation 93 through line 94.
  • the novel process of this invention permits attainment of unexpected and unobvious economies in the dewaxing of wax-bearing oils.
  • the novel process permits decrease in the compression load (for compressing high pressure refrigerant) by about 50%; and specifically in practice this may mean that the number of compressors may be cut in half. In terms of investment costs, this may decrease the cost of the equipment required for dewaxing by 20%.
  • step (d) filtering said first slurry from step (c) thereby forming (i) a first filter cake of slack wax containing Wax crystals and occluded oil-solvent mixture and (ii) a first filtrate containing dewaxed oil and solvent;
  • step (d) filtering said first slurry from step (c) thereby forming (i) a first filter cake of slack wax containing Wax crystals and occluded oil-solvent mixture and (ii) a first filtrate containing dewaxed oil and solvent;
  • the method of separating Wax from a Wax-bearing petroleum oil which comprises:
  • step (d) filtering said first slurry from step (c) thereby forming (i) a first filter cake of slack wax containing ⁇ wax crystals and occluded oil-solvent mixture and (ii) a first filtrate containing dewaxed oil and sollvent;
  • step (d) filtering said first slurry from step (c) thereby forming (i) a first filter cake of slack wax containing wax crystals and occluded oil-solvent mixture and (ii) a first filtrate containing dewaxed oil and solvent;

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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)
  • Fats And Perfumes (AREA)
  • Lubricants (AREA)
US00285784A 1972-09-01 1972-09-01 Dewaxing of oils Expired - Lifetime US3846277A (en)

Priority Applications (15)

Application Number Priority Date Filing Date Title
US00285784A US3846277A (en) 1972-09-01 1972-09-01 Dewaxing of oils
CA175,288A CA1015299A (en) 1972-09-01 1973-06-29 Dewaxing of oils
GB3707773A GB1392159A (en) 1972-09-01 1973-08-03 Dewaxing of oils
ZA735349A ZA735349B (en) 1972-09-01 1973-08-06 Dewaxing of oils
AU59030/73A AU471951B2 (en) 1972-09-01 1973-08-08 Dewaxing of oils
ES418146A ES418146A1 (es) 1972-09-01 1973-08-23 Un metodo de separacion de la cera de un aceite que contie-ne ceras.
NL7311737A NL7311737A (OSRAM) 1972-09-01 1973-08-25
BR6621/73A BR7306621D0 (pt) 1972-09-01 1973-08-28 Processo de desparafinacao de oleos
BE135032A BE804126A (fr) 1972-09-01 1973-08-28 Procede d'elimination des cires d'huiles
FR7331056A FR2197964B1 (OSRAM) 1972-09-01 1973-08-28
DE19732343515 DE2343515A1 (de) 1972-09-01 1973-08-29 Verfahren zur loesungsmittel-entparaffinierung von mineraloelen
TR17474A TR17474A (tr) 1972-09-01 1973-08-29 Yaglarin mumunun alinmasi
JP48096767A JPS4964607A (OSRAM) 1972-09-01 1973-08-30
SE7311822A SE396615B (sv) 1972-09-01 1973-08-30 Sett att separera vax fran vaxhaltig olja genom blandning av den vaxhaltiga oljan med ett avvaxande losningsmedel och ett flytande koldmedel, varvid trycket pa blandningen senkes i tva steg
IT28386/73A IT995240B (it) 1972-09-01 1973-08-30 Procedimento di deparaffinazione degli olii

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00285784A US3846277A (en) 1972-09-01 1972-09-01 Dewaxing of oils

Publications (1)

Publication Number Publication Date
US3846277A true US3846277A (en) 1974-11-05

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ID=23095676

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Application Number Title Priority Date Filing Date
US00285784A Expired - Lifetime US3846277A (en) 1972-09-01 1972-09-01 Dewaxing of oils

Country Status (15)

Country Link
US (1) US3846277A (OSRAM)
JP (1) JPS4964607A (OSRAM)
AU (1) AU471951B2 (OSRAM)
BE (1) BE804126A (OSRAM)
BR (1) BR7306621D0 (OSRAM)
CA (1) CA1015299A (OSRAM)
DE (1) DE2343515A1 (OSRAM)
ES (1) ES418146A1 (OSRAM)
FR (1) FR2197964B1 (OSRAM)
GB (1) GB1392159A (OSRAM)
IT (1) IT995240B (OSRAM)
NL (1) NL7311737A (OSRAM)
SE (1) SE396615B (OSRAM)
TR (1) TR17474A (OSRAM)
ZA (1) ZA735349B (OSRAM)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4541917A (en) * 1983-12-19 1985-09-17 Exxon Research And Engineering Co. Modified deoiling-dewaxing process
EP0715002B1 (en) * 1994-11-30 2001-07-04 The Dow Chemical Company Stable coating solutions for preparing electrocatalytic mixed oxide coatings on metal substrates or metal-coated conductive substrates, and a method for the preparation of dimensionally stable anodes using such solutions

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109554222A (zh) * 2018-11-14 2019-04-02 陈同翔 一种食用油降温脱蜡系统

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4541917A (en) * 1983-12-19 1985-09-17 Exxon Research And Engineering Co. Modified deoiling-dewaxing process
EP0715002B1 (en) * 1994-11-30 2001-07-04 The Dow Chemical Company Stable coating solutions for preparing electrocatalytic mixed oxide coatings on metal substrates or metal-coated conductive substrates, and a method for the preparation of dimensionally stable anodes using such solutions

Also Published As

Publication number Publication date
DE2343515A1 (de) 1974-03-07
TR17474A (tr) 1975-07-23
FR2197964A1 (OSRAM) 1974-03-29
GB1392159A (en) 1975-04-30
IT995240B (it) 1975-11-10
SE396615B (sv) 1977-09-26
AU471951B2 (en) 1976-05-06
ZA735349B (en) 1974-12-24
BE804126A (fr) 1974-02-28
FR2197964B1 (OSRAM) 1980-01-11
JPS4964607A (OSRAM) 1974-06-22
NL7311737A (OSRAM) 1974-03-05
AU5903073A (en) 1975-02-13
BR7306621D0 (pt) 1974-07-18
CA1015299A (en) 1977-08-09
ES418146A1 (es) 1976-03-16

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