US2378763A - Making lubricating oil constituents - Google Patents

Making lubricating oil constituents Download PDF

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US2378763A
US2378763A US504944A US50494443A US2378763A US 2378763 A US2378763 A US 2378763A US 504944 A US504944 A US 504944A US 50494443 A US50494443 A US 50494443A US 2378763 A US2378763 A US 2378763A
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oil
acid
lubricating oil
constituents
propane
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Frederick E Frey
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Phillips Petroleum Co
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    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING 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
    • C10G50/00Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation
    • C10G50/02Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation of hydrocarbon oils for lubricating purposes

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  • This invention relates to the treatment oi'V hydrocarbons. More particularly it relates to the improvement of lubricating oil stocks by treatment with concentrated hydroiiuoric acid.
  • Lubricating oils of high quality have been manufactured from crude oil fractions having suitable boiling ranges by many processes, including sulfuric acid rening, aluminum chloride reilning, and solvent extraction.
  • sulfuric acid or aluminum chloride processes the treating reagents are consumed by reaction with the'oil and are not economically recoverable from the resulting sludges.
  • solvent refining the action is simply one of separating high-quality lubricating ingredients from the crude oil, or removing the undesirable or low-quality constituents; thus the yield of finished lubricating oil can be no greater than the proportion of lubricating oil-grade hydrocarbons in the raw material.
  • An object of this invention is to produce highquality lubricating oil in high yield by a chemical process in which the chemical reagent is recovarable.
  • Another object of this invention is to convert paraln wax to. normally liquid hydrocarbons suitable for blending in lubricating oil.
  • Another object of this invention is to improve cyclic materials for use as ingredients in lubricating oil.
  • Another object is to combine advantageously, into a process for manufacturing lubricating oil, steps for treating oil stocks with hydrofluoric acid with steps for solvent reiining of the oil stocks.
  • a lubricating oil stock is treated with concentrated or substantially anhydrous liquid hydrofiuoric acid under conditions selected to improve or modify the properties of the oil.
  • Properties which may be changed include one or more of the following: viscosity or viscosity index, flash and iire points, pour point, and carbon residue.
  • Aromatics may undergo condensation reactions with added alkylating agents, such as ethylene, propylene, halogenated hydrocarbons, alcohols,
  • Sulfur, nitrogen, and oxygen compounds in the lubricating oil may be simultaneously removed by absorption in, or formation of loose compounds with, the hydroiiuoric acid.
  • relatively drastic conditions such as at a temperature in the range of 300 to 450 F., or with a contact time of one ,or more hours, the absolute viscosity-decreases substantially.
  • the extent of reaction is conthe oil.
  • hydrofiuoric acid used in the treatment. That is, hydrogen filoride tends to form molecular complexes and addition compounds with some of the more reactive or less stable hydrocarbons found in lubricating oil, and if the proportion of hydrofluoric acid is limited, say to from 5 to about 50 per cent by weight of the lubricating oil being treated, the reaction slows down or stops after the more reactive constituents have been removed by reaction with the acid.
  • a low-temperature process may be controlled in this-manner to produce results similarto those obtained by solvent refining.
  • Crude lubricating oil stocks vary widely in composition.
  • the various components may be classied in the following groups:
  • Asphaltic constituents are tarry or pitchy materials of aromatic structure. Resins are similar but of lower molecular weight and more soluble in paraiin hydrocarbons. These constituents cause sludge and varnish formation in motor oils, and therefore must be removed by oil-refining processes.
  • naphthenes saturated liquid hyl drocarbons Ywhich are predominantly cyclic in having one or more cyclic nuclei with long ali-v phatic chains attached thereto.
  • Viscosityindex is high; the pour point is low;
  • the eiiiciency of the extraction of cyclics and the like from lube oil stock by concentrated hydrouoric acid may be greatly increased by concurrently using a deasphalting diluent or selective solvent which is immiscible with hydrouoric acid.
  • a deasphalting diluent or selective solvent which is immiscible with hydrouoric acid Liquid propane is a preferred diluent.
  • propane dissolves paraiilns and cycloalkyl hydrocarbons in lubricating oil, but precipitates substantial proportions of asphaltic and resinous materials.
  • propane dissolves paraiilns and cycloalkyl hydrocarbons in lubricating oil, but precipitates substantial proportions of asphaltic and resinous materials.
  • propane as a diluent for treating lube ⁇ oil stocks with hydrouoric acid greatly increases the selective solvent powerA of the acid for removing asphaltic, resi-v nous, and aromatic constituents from the oil.
  • butane, pentanes, or mixtures are alsol advanlower pressures may be used than with propane.
  • the carbon-forming tendency is low; and the oils are stable against oxidation.
  • the parailins have very high viscosity indices., and good lubricating properties. However, the carbon-forming tendency is greater than for c'yclo-alkyl compounds.- As many of the paraflins present in lubricatingl oil stocks have high melting points, the proportion of paraiiins which may be present in the final lubricating oil is limited mainly by the maximum permissible pour point of depressants. i
  • the structure of the color bodies is not fully known. They-are objectionable mainly because of consumer demand for oil of clear and standard appearance.
  • Concentrated hydrouoric acid has both a solvent eilect and a chemical eflect upon the lubricating oil. By its solvent effect, it dissolves vasphaltic, resin-forming, and other cyclic hydrocarbons preferentially to cycloalkyl and parafiinic hydrocarbons. The extent of the solvent effect is dependent upon the temperature, the pressure, the proportion of hydroluoric acid, and the The -allowable proportion of parafns may be increasedsomewhat by using pour point v alims.l Cyclo-alkyl compounds appear. t be con'i- ⁇ Next to propane, butane is preferred.
  • ldrogen-to-carbon ratio that is, the viscosity index oi the oil must be increased.
  • Mixed-base crudes such as are found in Oklahoma, Kansas, and Illinois, require treatment to remove unstable easily oxidizable or varnish-forming constituents and'to modify the pour point and viscosity index.
  • cyclic materials such as benzene, terpenes, and the like
  • the added cyclic compounds react in the presence of hydroiiuoric acid with part of the y high-molecular-weight paralns or waxes of the oil to produce highly desirable cyclo-alkyl compounds and paraillns of relatvely low molecular weight. This decreases the pour point of the oil without excessively decreasing the viscosity index and produces a maximum yield of reilned lubricating oil.
  • the added alkylating agents react in the presence of hydrofiuoric acid with naphthenic and aromatic constituents of the oil to produce compounds of increased paralnicity or hydrogen-to-carbon ratio. This increases the viscosity index of the oil and gives a much higher yield of refined oil than solvent extraction methods, which simply remove naphthenic components from the crude oil.
  • alkylating agents In treating mixed-base crudes, it may sometimes be desirable to add alkylating agents, depending upon whether the properties of the specific crude treated approach those of paraffinbase crudesor of asphalt-base crudes.
  • a-simple treatment with hydroiluoricA acid in the presence of a solvent, followed by a decolorizing, and in some cases a dewaxing, step gives very satisfactory results.
  • Liquid propane and crude lubricating oils are admitted, as through inlets i0 and il, respectively, to mixer I2, in which they are mixed together at a deasphalting temperature.
  • a cyclic hydrocarbon such as benzene
  • low-boiling parailins such as liquid propane
  • Treater I8 may be operated at a temperature in the range of about to about 450 F. The exact temperature chosen in a particular instance Will depend upon the characteristics of the crude oil, the solvent effect desired, the chemical effect desired, and the proportion of hydrofluoric acid used. In most instances the preferred temperat ture is in the range of 100 to 300 F. In general,
  • the hydrofluoric acid in the absence of alkylating agents, the other constituents may undergov some molecular rearrangement and reconstruction reactions but, as a whole, are not greatly If an alkylating agent, such as an changed. olefin, a nonprimary alkyl halide, or a nonprimary alcohol, is present, considerable reaction rendering them more suitable -as constituents in matics, which act to decrease the pour point of the lubricating oil. For this reason it is advantageous in some instances, for example when the crude oill, contains relatively large proportions of wax or has a relatively high pourpoint, to add a low-boiling aromatic to the reaction mixture. At temperatures above about 200 F., ethylene, primary alcohols, and primary alkyl halides may be used as galkylating agents. f
  • the proportion of hydrofiuoric acid in the mixture may vary from about 0.1 to parts or more by weight per part of the crude oil, depending upon the nature of the crude oil and the desired characteristics of the refined oil.
  • the optimum proportion of acid usually is in the range of about 0.5 to 4 parts by weight per part of the crude oil.
  • the reacted mixture from treater 'I8 is passed through conduit 22 to cooler 23, wherein by iiash evaporation of part of the propane and hydrogen fluoride from the mixture, the remainder is cooled to the desired separating temperature.
  • the separating temperature determines the extent of the solvent action of the acid. The optimum temperature is usually in the range of 50 to 300 F. though at times it may exceed this range in either direction. At low temperatures, such as 50 F., only the unsaturated compounds, aromatics, and nitrogen-, sulfur, and oxygen-containing compounds dissolve appreciably in the acid. At high temperatures, such as 300 F. and above, substantially all aromatics and substantial proportions of nonaromatic cyclic compounds are extracted-by, and removed in, the acid phase. i v
  • Vapors from cooler 23 are condensed andrecycled through conduit 24 and pump 25 to treater I8.
  • Liquids are passed through conduit 26to separator 21, wherein they are separated by centrifugal or gravitational means at the Adesired separating temperature into two liquid phases.
  • separator 21 may be by-passed-all hydrogen uoride being ashed or distilled overhead and recycled from cooler 23 and/or fractionator 23.
  • the resulting hydrogen uoride-freed hydrocarbon mixture is passed through conduit 3
  • the deasphalting unit consists essentially of ameans for adjusting the tem- By treating the oil with several relatively i n uv) ing temperature may be in the range o! about to 200 F. depending upon the degree of deasphalting desired.
  • Asphaltic and resinous substances may be withdrawn through outlet 32, and the deasphalted hydrocarbon mixture is passed through conduit 33 to dewaxing unit 3.
  • the propane-oil solution is chilled slowly to a temperature in the range of about -50 to 70 F., whereupon wax crystallizes out. The wax is then removed by known means,
  • dewaxing mainly to reduce the pour point of the oil to adesired value.
  • the dewaxing temperature should be inthe range of about 20 to 40 F. below the desired pour point.
  • the chilling rate should not be more than about 3 F. per minute. Filter-aids may be added if desired. Cooling of the mixture is effected by evaporation of part of the propane, which may be recycled, as through conduit 35 and pump 36 to mixer I2. Wax may be withdrawn through out,- let31.
  • dewaxed'oil is passed through conduit 38 to decolorizer 39, in which it is subjected at a suitable temperature to the action of a contact mass having catalytic properties for hydrovgenation and/or dehydrogenation at relatively higher temperatures, such as nely divided nickel, bauxite, etc. l
  • Decolorizer 39 may consist of a conventional bauxite or clay treater such as is well-rknown in the art of reiining lubricating oil, Preferably it is a bauxite filter bed.
  • the propane-oil mixture is allowed to percolate through the bauxite at a temperature in the range of about 50 to 500 F.
  • the most eflicient decolorization usually occurs at temperatures in the range of to 300 F.
  • organically combined iiuorine is also substantially completely removed.
  • deasphalted propane-oil mixture vlis passed through conduit 40 to depropanizer 4 I.
  • depropanizer 4I the oil is freed from propane by.dis
  • outlet 43 is-withdrawn through outlet 43. If desired, it may be fractionated, as by vacuum distillation, into several cuts of different viscosity, or it maybe blended with otherv oils to modify its properties.
  • the heavier or acid layer from separatorA 21- may be recycled in part through conduit 2-I to ⁇ treater I8;/pref erably a substantial proportionis passed throughvconduit 44 to column 45, and'aproportionof about 1 to 5 times the weightofwax available for the presently described conversiongto a is passed through conduit ,y
  • the temperature- may be from about 150 to'a'bout- 450 F. Preferably itis in the. range of 250 to ⁇ 35'0il3., ⁇ At low temperatures the rate of reaction isflow, whereas at high temperatures excessive 'cracking' occurs. 1' fThe' mixture,
  • the pressure should be sumcient to maintain liquidorv mixed-phase conditions; usually it will be in the range of about 50 to 2000 pounds per square inch.
  • the contact time may Vary from l to 100 minutes or more. The optimum contact time varies inversely with the temperature.
  • petroleum waxes such as those obtained from lubricating oil ⁇ i'ractions, react with low-molecular-weight cyclic compounds having double bonds, such as aromatics, cyclooleiins, terpenes, and the like, to proyduce cyclo-alkyl compounds, consisting oi' cyclic nuclei with one or more attached alkyl groups', and Darafns of a molecular weight lower than that of the original wax.
  • a diluent or solvent such as light naphtha or propane, may be used in reactor 41 to reduce the viscosity of the mixture and to facilitate handling it.
  • the mixture from reactor 41 passes through conduit 48 to separator 49, in which it is separated, by cooling and centrifugal or gravitational means. into two liquid phases.
  • the lighter or hydrocarbon phase is passed through conduit 50 to fractionator l.
  • an overhead fraction comprising unreacted low-molecular-weight reactants, diluent or solvent, and hydrogen fluoride, is recycled via conduit 52 to reactor 41.
  • the bottom fraction which consists mainly of cyclo-alkyl'hydrocarbons having long alkyl groups, is withdrawn through outlet 53. This fraction is suitable for use as a pour-point depressant in lubricating oils.
  • the lower or acid layer from separator 49 is passed through conduit 54 to column 45.
  • Column 45 is operated with a. high enough kettle bottom temperature, preferably in the range 300 to 500 F., to split out substantially all organically coma blned uorine as hydrogen uoride.
  • This hydrogen iluoride, any water incidentally introduced into the process, and a, substantial proportion of the hydrocarbons present pass overhead through conduit 55 to column ⁇ 56.
  • a high-boiling residue oil is withdrawn through outlet 5l.
  • the increase in pour point indicates an increase in paraiiin .content anda corresponding decrease in naphthenes.
  • This invention is broadly applicable to many modified processes for reiining oils. It may be applied to the refining of various grades of crude oil, including parain-base crudes, mixed-base crudes, and asphalt-base crudes. It may be used for producing any grade of oil, including such water, which passes overhead through conduit 58 to acid-rerun column 59, from hydrocarbons, which may be withdrawn through outlet B0. These hydrocarbons are liquid, of a clear color, have a low pour point, and are suitable for blending in small proportions with other lubricants.
  • Column 59 separates a constant-boiling mixture of water and hydrogenv fluoride, which may be withdrawn through outlet 6
  • Example I vhydrocarbon was equivalent to 84.8 per cent by weight of the original oil. Part of this material was tested by conventionall lubricating oil tests. Another part was clay-treated by agitating it with fullers earth and filtering; it was thenalso tested highly rened oils as transformer oil. It may be used advantageously in combination with older methods of reiining, such as solvent refining and sulfuric acid refining. It may be particularly advantageously combined with propane deasphalting and dewaxing steps, whereby the propane also serves as a diluent in steps for treating the oil with hydrouoric acid. It may be used in conjunction with alkylating agents to change appreciably thechemical constitution of the oil.
  • highly parailinic lubricating oil fractions such as petroleum waxes, may -be converted in the presence of concentrated hydroiiuoric acid and cyclic hydrocarbons to hydrocarbons of lower pour point and' better adaptability for ⁇ use as constituents in lubricating oil.
  • lubricating oil constituents which comprises reacting paraflin wax as such with a normally liquid cyclic hydrocarbon having at least one double bond in the ring in the presence of substantially anhydrous hydrotluoric acid at an elevated temperature and maintain liquid phase acid from refining crude lubricating oil with hydroiluoric acid.
  • the process of making lubricating oil constituents winch comprises reacting paraffin wax as such with a normally liquid cyclic hydrocarbon acid at a temperature ranging from 150 to 450 IF. and at a pressure sumcient to maintain lliquid means of substantially anhydrous hydroiiuoric acid at a temperature ranging from 250 to 350 F. and at a pressure suillcient to maintain liquid phase conditions.
  • lubricating oil constituents which comprises reacting paraffin wax as such with naphthalene by means of substantially anhydrous hydroiiuoric acid at a tempera-x ture ranging from 250 to 350 F. and under a l pressure sufcient to maintain liquid phase conditions.

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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)

Description

June 19, 1945. F. E. FREY 2,378,763
MAKING LUB-RICATING OIL CONSTITUENTS Original Filed Dec. 4, 1942 P'atented June 19,` 1945 LUBRICAIING OIL CONSTITUENTS Frederick E. Frey, Bartlesville, Okla., assigner to -Phillips Petroleum Company, a corporation of Delaware Original application December 4, 1942, Serial No. 467,875. Divided and this application October 4, 1943, Serial N0. 504,944
8 Claims.
This invention relates to the treatment oi'V hydrocarbons. More particularly it relates to the improvement of lubricating oil stocks by treatment with concentrated hydroiiuoric acid.
Lubricating oils of high quality have been manufactured from crude oil fractions having suitable boiling ranges by many processes, including sulfuric acid rening, aluminum chloride reilning, and solvent extraction. In sulfuric acid or aluminum chloride processes, the treating reagents are consumed by reaction with the'oil and are not economically recoverable from the resulting sludges. In solvent refining, the action is simply one of separating high-quality lubricating ingredients from the crude oil, or removing the undesirable or low-quality constituents; thus the yield of finished lubricating oil can be no greater than the proportion of lubricating oil-grade hydrocarbons in the raw material.
An object of this invention is to produce highquality lubricating oil in high yield by a chemical process in which the chemical reagent is recovarable.
Another object of this invention is to convert paraln wax to. normally liquid hydrocarbons suitable for blending in lubricating oil.
Another object of this invention is to improve cyclic materials for use as ingredients in lubricating oil.
Another object is to combine advantageously, into a process for manufacturing lubricating oil, steps for treating oil stocks with hydrofluoric acid with steps for solvent reiining of the oil stocks.
Other objects and advantages of this invention will be apparent to those skilled in the art from the following description, the accompanying drawing, and/or the appended claims;
According to this invention, a lubricating oil stock is treated with concentrated or substantially anhydrous liquid hydrofiuoric acid under conditions selected to improve or modify the properties of the oil. Properties which may be changed include one or more of the following: viscosity or viscosity index, flash and iire points, pour point, and carbon residue. These changes are preferentially promoted by carrying out the reaction in the presence of solvents or diluents such as low-boiling normally liquid hydrocarbons or halogenated hydrocarbons, in the `presence of added alkylating agents, such as olefins or polymers of olens having 2 to 5 carbon atoms per molecule, or in the presence of catalyst modiers, such as boron fluoride, sulfur trioxide, phosphoric anhydride, halides of antimony, arsenic or bismuth, or dissolved salts or colloidal suspensions of the following metals: silver, nickel, cobalt.
chromium, tin, zirconium, or other metals selected from the third and fourth periods of the periodic table.
The exact nature of the chemical changes which occur in the treatment are not known. It is presumed that a number of reactions occur simultaneously and that the nature and the extent of the predominating reactions are influenced appreciably by varying the conditions of temperature and pressure and by the use of solent as components in the oil being treated. Highboiling oleflnic hydrocarbons may undergo reactions such as cyclization to naphthenes, de-
polymerization, isomerization, or disproportionation to paraiiins and dioleiins or aromatics. Aromatics may undergo condensation reactions with added alkylating agents, such as ethylene, propylene, halogenated hydrocarbons, alcohols,
, and the like. Sulfur, nitrogen, and oxygen compounds in the lubricating oil may be simultaneously removed by absorption in, or formation of loose compounds with, the hydroiiuoric acid. The presence of boron fluoride, sulfur trioxide, phosphoric anhydride, or the like, appears to increase the catalytic activity and the selective solsolute viscosity greatly. Under relatively drastic conditions, such as at a temperature in the range of 300 to 450 F., or with a contact time of one ,or more hours, the absolute viscosity-decreases substantially. The extent of reaction is conthe oil.
trollable to some degree by limiting the proportion of hydrofiuoric acid used in the treatment. That is, hydrogen filoride tends to form molecular complexes and addition compounds with some of the more reactive or less stable hydrocarbons found in lubricating oil, and if the proportion of hydrofluoric acid is limited, say to from 5 to about 50 per cent by weight of the lubricating oil being treated, the reaction slows down or stops after the more reactive constituents have been removed by reaction with the acid. A low-temperature process may be controlled in this-manner to produce results similarto those obtained by solvent refining.
Crude lubricating oil stocks vary widely in composition. The various components may be classied in the following groups:
Asphalt Resins Naphthenes Cyclo-alkyl compounds Paraflins, including wax Color bodies Asphaltic constituents are tarry or pitchy materials of aromatic structure. Resins are similar but of lower molecular weight and more soluble in paraiin hydrocarbons. These constituents cause sludge and varnish formation in motor oils, and therefore must be removed by oil-refining processes.
By naphthenes is meant saturated liquid hyl drocarbons Ywhich are predominantly cyclic in having one or more cyclic nuclei with long ali-v phatic chains attached thereto.
These compounds are the preferred predominant constituents of lubricating motor-oils for general use. The Viscosityindex is high; the pour point is low;
extracts of progressively increasing paraillnicibons, or hydrocarbons of high hydrogen-to-carbon ratios, are substantially insoluble. As the temperature is increased, the solvent power of concentrated hydroiluoric acid increases until at about 350 F. and two thousand pounds per square inch pressure the acid is almost completely miscible with cyclics, and under these conditions 'it will dissolve substantial proportions of the paraiiins. Thus concentrated hydrofluoric acid may be used similarly to a single solvent in a series of solvent extraction steps at progressively higher temperatures to fractionate lubricating oil stocks into ty or hydrogen-to-carbon ratio. There are a1- ways some chemical reconstruction reactions of the more reactive of the ingredients, though if desired these may be retarded by the use of short contact times.
The eiiiciency of the extraction of cyclics and the like from lube oil stock by concentrated hydrouoric acid may be greatly increased by concurrently using a deasphalting diluent or selective solvent which is immiscible with hydrouoric acid. Liquid propane is a preferred diluent.
That is, at temperatures'in the range of aboutl 50 to 200 F., propane dissolves paraiilns and cycloalkyl hydrocarbons in lubricating oil, but precipitates substantial proportions of asphaltic and resinous materials. ,Thus the use of propane as a diluent for treating lube `oil stocks with hydrouoric acid greatly increases the selective solvent powerA of the acid for removing asphaltic, resi-v nous, and aromatic constituents from the oil.
Other low-boiling hydrocarbons such as ethane;V
butane, pentanes, or mixtures are alsol advanlower pressures may be used than with propane".
the carbon-forming tendency is low; and the oils are stable against oxidation.
The parailins have very high viscosity indices., and good lubricating properties. However, the carbon-forming tendency is greater than for c'yclo-alkyl compounds.- As many of the paraflins present in lubricatingl oil stocks have high melting points, the proportion of paraiiins which may be present in the final lubricating oil is limited mainly by the maximum permissible pour point of depressants. i
The structure of the color bodies is not fully known. They-are objectionable mainly because of consumer demand for oil of clear and standard appearance.
Concentrated hydrouoric acid has both a solvent eilect and a chemical eflect upon the lubricating oil. By its solvent effect, it dissolves vasphaltic, resin-forming, and other cyclic hydrocarbons preferentially to cycloalkyl and parafiinic hydrocarbons. The extent of the solvent effect is dependent upon the temperature, the pressure, the proportion of hydroluoric acid, and the The -allowable proportion of parafns may be increasedsomewhat by using pour point v alims.l Cyclo-alkyl compounds appear. t be con'i-` Next to propane, butane is preferred.
The chemical effect of hydroiluoricacid on asphaltic constituents appears to be slight. Resinforming substances are probably condensed to form resins and asphaltic compounds. Aromatics and naphthenes appear to be substantially 'unail'ex'stedl except in the presence of alkylating agents or u nder drastic conditions of time and temperature.
'and corresponding lower-molecularf-weight parparativelyl stable and unailected by hydroiiuoric acid, althoughv some; molecular rearrangements presence or absence of another solvent. For example, at; room temperature, asphaltic, aromatic,
unsaturated, and naphthenic hydrocarbons are vmay be formed in appreciable proportions.; The treatment givena specific lubricating oily vstock depends in large? measure upon the nature'. of the stock. Parain-base crudes,'such asare: 1 found'in Pennsylvania oils, requirefa treatment which removes parafn wax o rconverts part oi it s to lower-melting materials; that iaithe pour point `ofthe voil'must be decreased by the reilning proclIn the presence "of a1kylating" agents, they appear to .bei converted inlv part'tol compounds of greater paralnicity, v`presum ably by addition kof-aliphatic side chains tof/the s,
cyclic structures. yAt high temperatures some of Vthe cyclicsprobably react withhigh-"moleculary weight parains to form cyclo-alkyl h3`7d1 'oci a.rbons l and naphthenic components or converts them to materials of relatively higher paramnicity or-.hy-
ldrogen-to-carbon ratio; that is, the viscosity index oi the oil must be increased. Mixed-base crudes, such as are found in Oklahoma, Kansas, and Illinois, require treatment to remove unstable easily oxidizable or varnish-forming constituents and'to modify the pour point and viscosity index.
In treating paraffin-base crudes according to the principles or this invention, it is usually desirable to add some unsaturated cyclic materials, such as benzene, terpenes, and the like, to the oil prior to or during contacting with hydrofluoric acid. The added cyclic compounds react in the presence of hydroiiuoric acid with part of the y high-molecular-weight paralns or waxes of the oil to produce highly desirable cyclo-alkyl compounds and paraillns of relatvely low molecular weight. This decreases the pour point of the oil without excessively decreasing the viscosity index and produces a maximum yield of reilned lubricating oil.
In treating asphalt-base crudes according to the principles of` this invention, it is desirable to add aliphatic alkylating agents, such as olena.
cracked gasoline, alcohols, or alkyl halides, to the oil prior to or during contacting with hydrovof several per cent at temperatures only slightly above room temperature. This facilitates con tacting of the oil with the acid. 'I'he optimum temperature depends to some extent upon the nature Voi.' the feed stock but is usually in the range of about 50 to 200 F. In general. asphaltic and resinous constituents are less soluble in propane at high temperatures than at low. 'Ihe pressure should be sumcient to maintain substantially all the propane in the liquid phase and will generally be in the range of 100 to 600 pounds ing oil constituents except asphaltic and resinrluorlc acid. The added alkylating agents react in the presence of hydrofiuoric acid with naphthenic and aromatic constituents of the oil to produce compounds of increased paralnicity or hydrogen-to-carbon ratio. This increases the viscosity index of the oil and gives a much higher yield of refined oil than solvent extraction methods, which simply remove naphthenic components from the crude oil.
In treating mixed-base crudes, it may sometimes be desirable to add alkylating agents, depending upon whether the properties of the specific crude treated approach those of paraffinbase crudesor of asphalt-base crudes. In general, a-simple treatment with hydroiluoricA acid in the presence of a solvent, followed by a decolorizing, and in some cases a dewaxing, step gives very satisfactory results.
`Understanding of some aspects of my invention may be aided by referring to the accompanying drawing, which is a schematic flow diagram of onepreferred arrangement of apparatus for practicing my invention. In this specific embodir ment of my invention, propane is used to dilute the lubricating oil and to aid the acid in separating asphalt and wax from the oil. In some instances it is desirable to usean isoparailin such as isobutane or isopentane, for such isoparaflins at relatively low temperatures will react with unsaturates in the oil in the presence of hydro- V iluoric acid to produce saturates ,and at relatively Ah igh temperatures will react with high-melting parafilns to produce relatively low-melting paraiiins.
Liquid propane and crude lubricating oils are admitted, as through inlets i0 and il, respectively, to mixer I2, in which they are mixed together at a deasphalting temperature. In some modifications of this invention, especially for treating paraffin-base crudes, it will be desirable to use a cyclic hydrocarbon, such as benzene, as the solvent or as one component of the solvent; for treating most mixed-base and asphalt-base crudes, low-boiling parailins, Asuch as liquid propane, appear to be the most -suitable solvents. One distinct advantage in using propane as the solvent results from the fact that hydrogen iluoride is soluble in liquid propane to the extent ous substances.
From mixer l2 the mixture passes to asphalt settler i3, wherein asphaltlc and resinousv materials settle out and are removed through outlet it. The temperature may be reduced somewhat in settler I3 by allowing part of the propane to evaporate and to be removed as vapor through conduit IIS.
From settler lil the resulting deasphalted mixture is transferred by pump it through conduit ll to treater i8. In treater l0 it ls agitated with concentrated or substantially anhydrous hydrouoric acid which may be introduced through inlet i9 and/or recycle conduits 20 and 2l. Treater I8 may be operated at a temperature in the range of about to about 450 F. The exact temperature chosen in a particular instance Will depend upon the characteristics of the crude oil, the solvent effect desired, the chemical effect desired, and the proportion of hydrofluoric acid used. In most instances the preferred temperat ture is in the range of 100 to 300 F. In general,
at the lower temperatures Within the operative range, unstable constituents such as unsaturated compounds, organic acids, resinor sludgeforming materials are extracted by solution in,y
the hydrofluoric acid; in the absence of alkylating agents, the other constituents may undergov some molecular rearrangement and reconstruction reactions but, as a whole, are not greatly If an alkylating agent, such as an changed. olefin, a nonprimary alkyl halide, or a nonprimary alcohol, is present, considerable reaction rendering them more suitable -as constituents in matics, which act to decrease the pour point of the lubricating oil. For this reason it is advantageous in some instances, for example when the crude oill, contains relatively large proportions of wax or has a relatively high pourpoint, to add a low-boiling aromatic to the reaction mixture. At temperatures above about 200 F., ethylene, primary alcohols, and primary alkyl halides may be used as galkylating agents. f
The proportion of hydrofiuoric acid in the mixture may vary from about 0.1 to parts or more by weight per part of the crude oil, depending upon the nature of the crude oil and the desired characteristics of the refined oil. For producing high-grade motor lubricating oils from average lubricating oil stock, the optimum proportion of acid usually is in the range of about 0.5 to 4 parts by weight per part of the crude oil. small successive portions of hydrofluoric acid, the eiect is substantially that of a selective solvent; that is, the relatively unstable com.- pounds form complexes with the acid which dissolve in the acid phase, and the relatively stable constituents are substantially unaffected. When a large excess of 4hydrofiuoric acid over that re-y quired to tieup or remove, as compounds or molecular complexes, most of the unstable or undesired constituents is used, and when a sufficient reaction time is allowed, the relatively stable acid-insoluble lubricating oil constituents undergo considerable chemical change as already described.
The reacted mixture from treater 'I8 is passed through conduit 22 to cooler 23, wherein by iiash evaporation of part of the propane and hydrogen fluoride from the mixture, the remainder is cooled to the desired separating temperature. The separating temperature determines the extent of the solvent action of the acid. The optimum temperature is usually in the range of 50 to 300 F. though at times it may exceed this range in either direction. At low temperatures, such as 50 F., only the unsaturated compounds, aromatics, and nitrogen-, sulfur, and oxygen-containing compounds dissolve appreciably in the acid. At high temperatures, such as 300 F. and above, substantially all aromatics and substantial proportions of nonaromatic cyclic compounds are extracted-by, and removed in, the acid phase. i v
Vapors from cooler 23 are condensed andrecycled through conduit 24 and pump 25 to treater I8. Liquids are passed through conduit 26to separator 21, wherein they are separated by centrifugal or gravitational means at the Adesired separating temperature into two liquid phases. In instances when only a relatively minor 'proportion of hydrogen iluoride is used in treater I8, separator 21, may be by-passed-all hydrogen uoride being ashed or distilled overhead and recycled from cooler 23 and/or fractionator 23. Y The upper or hydrocarbon phase lfrom separator 21 is passed through conduit 28 to fractionating column 29.'- Substantially al1 the dissolved hydro-l gen iiuoride in the mixture is` withdrawn as anoverhead azeotropic mixture of propane and hydrofluoric acid and is condensed and recycled through conduit 24'and pump 25 to reactor I8.
The resulting hydrogen uoride-freed hydrocarbon mixture is passed through conduit 3|! to deasphalting unit 3 I vThe deasphalting unit consists essentially of ameans for adjusting the tem- By treating the oil with several relatively i n uv) ing temperature may be in the range o! about to 200 F. depending upon the degree of deasphalting desired. Asphaltic and resinous substances may be withdrawn through outlet 32, and the deasphalted hydrocarbon mixture is passed through conduit 33 to dewaxing unit 3.
In dewaxing unit 34, the propane-oil solution is chilled slowly to a temperature in the range of about -50 to 70 F., whereupon wax crystallizes out. The wax is then removed by known means,
vsuch as centrifugation or filtration. The purpose of dewaxing is mainly to reduce the pour point of the oil to adesired value. Experience has shown that, in order to obain an oil o1' given pour point, the dewaxing temperature should be inthe range of about 20 to 40 F. below the desired pour point. In order to obtain an easily separable wax, the chilling rate should not be more than about 3 F. per minute. Filter-aids may be added if desired. Cooling of the mixture is effected by evaporation of part of the propane, which may be recycled, as through conduit 35 and pump 36 to mixer I2. Wax may be withdrawn through out,- let31. The dewaxed'oil is passed through conduit 38 to decolorizer 39, in which it is subjected at a suitable temperature to the action of a contact mass having catalytic properties for hydrovgenation and/or dehydrogenation at relatively higher temperatures, such as nely divided nickel, bauxite, etc. l
Decolorizer 39 may consist of a conventional bauxite or clay treater such as is well-rknown in the art of reiining lubricating oil, Preferably it is a bauxite filter bed. The propane-oil mixture is allowed to percolate through the bauxite at a temperature in the range of about 50 to 500 F. The most eflicient decolorization usually occurs at temperatures in the range of to 300 F. In i the decolorizing step, organically combined iiuorine is also substantially completely removed.
The resulting' clear,` iiuorine-free,l dewaxed, and
deasphalted propane-oil mixture vlis passed through conduit 40 to depropanizer 4 I. In depropanizer 4I the oil is freed from propane by.dis
tillationithe propane is recycled through conduits 42 and 35 and pump 36 to mixer I2. Lubricating oil of high viscosity index, low pour point,
and low carbon-forming' qualities is-withdrawn through outlet 43. If desired, it may be fractionated, as by vacuum distillation, into several cuts of different viscosity, or it maybe blended with otherv oils to modify its properties.
The heavier or acid layer from separatorA 21-may be recycled in part through conduit 2-I to `treater I8;/pref erably a substantial proportionis passed throughvconduit 44 to column 45, and'aproportionof about 1 to 5 times the weightofwax available for the presently described conversiongto a is passed through conduit ,y
46 to reactor 41..
In reactor "petroleum `waxvsuch"as'that proi ducedinfdewaxing unit 34,' is agitated with subperature of the'propane-hydrocarbon mixture and i stantially anhydrous` hydrofluoric acid. (such vas the used .acid fromseparator 2l) j and one o'rfmore unsaturated'or aromatic compoundsgsuch as benzene, naphthalene',alkyllbenzenes alkyl naphtha- -v 4 lenes, cycloolen's.: terpenes, andv thelika; added through inlet 62. -The temperature-may be from about 150 to'a'bout- 450 F. Preferably itis in the. range of 250 to`35'0il3.,` At low temperatures the rate of reaction isflow, whereas at high temperatures excessive 'cracking' occurs. 1' fThe' mixture,
should be continuously .agitatesatc ,insure-mu QJPrEYEnFSBPeYii4 "".f i
me. sind asvavcs phases. The pressure should be sumcient to maintain liquidorv mixed-phase conditions; usually it will be in the range of about 50 to 2000 pounds per square inch. The contact time may Vary from l to 100 minutes or more. The optimum contact time varies inversely with the temperature. Under these conditions petroleum waxes, such as those obtained from lubricating oil `i'ractions, react with low-molecular-weight cyclic compounds having double bonds, such as aromatics, cyclooleiins, terpenes, and the like, to proyduce cyclo-alkyl compounds, consisting oi' cyclic nuclei with one or more attached alkyl groups', and Darafns of a molecular weight lower than that of the original wax. If desired a diluent or solvent, such as light naphtha or propane, may be used in reactor 41 to reduce the viscosity of the mixture and to facilitate handling it.
The mixture from reactor 41 passes through conduit 48 to separator 49, in which it is separated, by cooling and centrifugal or gravitational means. into two liquid phases. The lighter or hydrocarbon phase is passed through conduit 50 to fractionator l. From fractionator 5| an overhead fraction, comprising unreacted low-molecular-weight reactants, diluent or solvent, and hydrogen fluoride, is recycled via conduit 52 to reactor 41. The bottom fraction, which consists mainly of cyclo-alkyl'hydrocarbons having long alkyl groups, is withdrawn through outlet 53. This fraction is suitable for use as a pour-point depressant in lubricating oils.
The lower or acid layer from separator 49 is passed through conduit 54 to column 45. Column 45 is operated with a. high enough kettle bottom temperature, preferably in the range 300 to 500 F., to split out substantially all organically coma blned uorine as hydrogen uoride. This hydrogen iluoride, any water incidentally introduced into the process, and a, substantial proportion of the hydrocarbons present pass overhead through conduit 55 to column`56. A high-boiling residue oil is withdrawn through outlet 5l. y
Column 56 separates hydroiiuoric acid and by conventional lubricating oil tests. The following test data were obtained: Y
ment increased the viscosity index of the oil,
reduced the carbon-forming tendencies, and improved the color. The increase in pour point indicates an increase in paraiiin .content anda corresponding decrease in naphthenes.
This invention is broadly applicable to many modified processes for reiining oils. It may be applied to the refining of various grades of crude oil, including parain-base crudes, mixed-base crudes, and asphalt-base crudes. It may be used for producing any grade of oil, including such water, which passes overhead through conduit 58 to acid-rerun column 59, from hydrocarbons, which may be withdrawn through outlet B0. These hydrocarbons are liquid, of a clear color, have a low pour point, and are suitable for blending in small proportions with other lubricants.
Column 59 separates a constant-boiling mixture of water and hydrogenv fluoride, which may be withdrawn through outlet 6|, from substantially anhydrous hydrogen iiuoride, which is recycled through conduit 20 to treater I8.
To further illustrate some of the many aspects of this invention the followingI speciiic example is given:
Example I vhydrocarbon was equivalent to 84.8 per cent by weight of the original oil. Part of this material was tested by conventionall lubricating oil tests. Another part was clay-treated by agitating it with fullers earth and filtering; it was thenalso tested highly rened oils as transformer oil. It may be used advantageously in combination with older methods of reiining, such as solvent refining and sulfuric acid refining. It may be particularly advantageously combined with propane deasphalting and dewaxing steps, whereby the propane also serves as a diluent in steps for treating the oil with hydrouoric acid. It may be used in conjunction with alkylating agents to change appreciably thechemical constitution of the oil. Further, highly parailinic lubricating oil fractions, such as petroleum waxes, may -be converted in the presence of concentrated hydroiiuoric acid and cyclic hydrocarbons to hydrocarbons of lower pour point and' better adaptability for `use as constituents in lubricating oil.
Because the invention may be practiced other- Wise than as specifically described or illustrated, and because many modications and variations within the spirit and scope of it will be obvious to those skilled in the art of treating lubricating oil stocks, the invention should not be unduly restricted by the foregoing specincation and illustrative example, but it should be restricted only in accordance with the appended claims.
This application is a division of my copending application, Serial No. 467,875, filed December 4, 1942, which in turn is a continuation-impart of my copending application, Serial No. 426,627, led January 13, 1942.
I claim:
l. The process of manufacturing lubricating oil constituents which comprises reacting paraflin wax as such with a normally liquid cyclic hydrocarbon having at least one double bond in the ring in the presence of substantially anhydrous hydrotluoric acid at an elevated temperature and maintain liquid phase acid from refining crude lubricating oil with hydroiluoric acid.
3'. The process of claim 1, in which said cyclic hydrocarbon is benzene.
4. The process of making lubricating oil constituents winch comprises reacting paraffin wax as such with a normally liquid cyclic hydrocarbon acid at a temperature ranging from 150 to 450 IF. and at a pressure sumcient to maintain lliquid means of substantially anhydrous hydroiiuoric acid at a temperature ranging from 250 to 350 F. and at a pressure suillcient to maintain liquid phase conditions. a
6. The process of making lubricating oil constituents which comprises reacting parafiin wax as such with benzene by means of substantially anhydrous hydrofluoric acid at a temperature ranging from 250 to 350 F. and under a pressure suclent to maintain liquid phase conditions.
'7. The process of making lubricating oil constituents which comprises reacting paraffin wax as such with naphthalene by means of substantially anhydrous hydroiiuoric acid at a tempera-x ture ranging from 250 to 350 F. and under a l pressure sufcient to maintain liquid phase conditions.
8. The process of making a. material suitablev for use as a pour-point depressant'in lubricating oils which comprises reacting parailin wax as such with a low-molecular weight cyclic hydrocarbon having atleast one double bond by means of substantially anhydrous hydrouoric acid as the catalyst at a temperature ranging from 250 to 350 F. at a pressure sufficient to maintain liquid phase conditions, agitating the mixture continuously to insure intimatecontacting and I prevent separation of liquid phases, continuing the reaction until said wax has reacted with said cyclic hydrocarbon to produce cyclo-alkyl hydrocarbons consisting of cyclic nuclei with attached alkyl groups, separating the reaction mixture into two liquid phases, namely an acid phase and a hydrocarbon phase, separately withdrawing said phases, and recovering from the hydrocarbon phase said cyclo-alkyl hydrocarbons.
, FREDERICKVE. F'REY.
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2425559A (en) * 1943-03-11 1947-08-12 Kellogg M W Co Catalytic conversion of alkyl aromatic hydrocarbons
US2430724A (en) * 1944-11-29 1947-11-11 Socony Vacuum Oil Co Inc Catalytic conversion of hydrocarbons
US2430735A (en) * 1944-11-29 1947-11-11 Socony Vacuum Oil Co Inc Catalytic conversion of hydrocarbons
US2431715A (en) * 1944-01-14 1947-12-02 Shell Dev Prevention of corrosion in hydrogen fluoride catalytic organic reactions
US2452812A (en) * 1944-01-14 1948-11-02 Shell Dev Prevention of corrosion in hydrogen fluoride catalytic organic reactions
US2559818A (en) * 1948-12-31 1951-07-10 Phillips Petroleum Co Process for production of alkyl benzenes
US2681362A (en) * 1949-10-07 1954-06-15 Sun Oil Co Alkyl substituted benzene sulfonate
US4176044A (en) * 1977-08-15 1979-11-27 Exxon Research & Engineering Co. Process for alkylating waxy hydrocarbons with C3 -C5 carbon atom secondary alcohols as catalyst

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2425559A (en) * 1943-03-11 1947-08-12 Kellogg M W Co Catalytic conversion of alkyl aromatic hydrocarbons
US2431715A (en) * 1944-01-14 1947-12-02 Shell Dev Prevention of corrosion in hydrogen fluoride catalytic organic reactions
US2452812A (en) * 1944-01-14 1948-11-02 Shell Dev Prevention of corrosion in hydrogen fluoride catalytic organic reactions
US2430724A (en) * 1944-11-29 1947-11-11 Socony Vacuum Oil Co Inc Catalytic conversion of hydrocarbons
US2430735A (en) * 1944-11-29 1947-11-11 Socony Vacuum Oil Co Inc Catalytic conversion of hydrocarbons
US2559818A (en) * 1948-12-31 1951-07-10 Phillips Petroleum Co Process for production of alkyl benzenes
US2681362A (en) * 1949-10-07 1954-06-15 Sun Oil Co Alkyl substituted benzene sulfonate
US4176044A (en) * 1977-08-15 1979-11-27 Exxon Research & Engineering Co. Process for alkylating waxy hydrocarbons with C3 -C5 carbon atom secondary alcohols as catalyst

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