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
  • C10G73/06—Recovery of petroleum waxes from hydrocarbon oils; Dewaxing of hydrocarbon oils with the use of solvents
• • 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
  • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
  • C10G21/06—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents characterised by the solvent used
  • C10G21/12—Organic compounds only
  • C10G21/20—Nitrogen-containing compounds

Definitions

• Patented Oct. 26, 1937 UNITED STATES 2,096,725 rnocnss F BEFINING menu. o ns Chester E. Andrews, bverbrook, and Men-ell It. Fenske, State College, Pa, assignors to Riihm & Haas Company, Philadelphia, Pa.
• the value of the more viscous fractions of these oils depends more on the physical than on the chemical properties of the oil, the latter being only important in that they more 'or less determine the former.
• One of the principal uses of such oils is .in the lubrication of all kinds of machinery and-the value of the oil for this purpose depends on its viscosity and particularly on the temperature coemcient of the viscosity.
• An oil having a high temperature coeflicie t is not so good a lubricant over a wide temperature range as is one having a lower coemci ent.
• the numerical'value of this coeflicient varies with 'oils of various composition and those which have the greatest proportion of parafflnic hydrocarbons have the lowest coeflicients.
• the less viscous fractions of vthese oils are believed to contain the same types of hydrocarbons as the more viscous fractions, but of lower molec-'- ular weight.
• the gasoline fractions from crude oils of different origins contain varying proportions of the various hydrocarbon types just as the lubricating oil fractions do. Due to the excess'ive knocking which they cause in'the internal combustion engine, the'normal paraiiins are the least desirable constituents of a fuel suitable for automotive use. No method has as yet been devised for the removal of normal paraflins from ,I a motor fuel, but it hasbeen necessary to add anti-knock agents to those gasolines which contain high percentages of these straight chain hydrocarbons. Manyorganic compounds, including low boiling fractions from cracking operations.
• a high grade kerosene fraction is one which contains a high per cent. of, paraflin' hydrocarbons.
• the process or treating kerosene fractions with liquid sulfur dioxide for removal of aromatics is well known to the petroleum indus- It has now been found that such hydrocarbon mixtures may be separated into fractions by treatment with certain solvents, and in so doing, mixtures having enhanced physical or chemical 40 properties may be obtained.
• the solvent used may be a pure amine, a mixture of amines, and mixtures of these with other liquids such as water, ammonia, methanol and other alcohols, monoethyl ether of ethylene glycol, aniline, aromatic hydrocarbons etc.
• the process is carried out in a closed system, if necessary under pressure, and at a temperature low enough to keep the solvent in the liquid state and to permit the formation of at least two phases.
• By lowering the pressure on the system a certain amount of the amines or ammonia will evaporate, thus causing a lowering of the temperature.
• the solvent thus evaporated can be condensed in a suitable apparatus and returned to the system or used in a subsequent treatment. This internal refrigerating action is advantageous in the procass for removal of wax.
• solvents also have the advantage that their selective solubility can be varied to fit any "hydrocarbon mixture by changing the percentage extraction apparatus, such as a series of mixing and settling tanks or in a, suitable contacting tower by a counter-current method.
• percentage extraction apparatus such as a series of mixing and settling tanks or in a, suitable contacting tower by a counter-current method.
• any of the conventional types of apparatus may be used with the amines .ous hydrocarbon producing a sharper and easier separation of oil from wax.
• the mixture of hydrocarbons and amines will separate into two liquid phases, one of which will contain a higher proportion of amines than the other. Likewise, one phase will contain a higher proportion of certain hydrocarbon types than the other because in no case is there a-sharp line of demarcation in the solubilities of the varitypes in the different amine mixtures.
• the two phases which appear are separated, and each is subjected to a distillation processor an equivalent process in order to remove the amines and-other solvent in case amixture is used.
• the amines with or without the other solvent'are 'then brought back to the liquid state in order to be available for later use with another batch of hydrocarbon. It may be necessary to warm the oil somewhat in order to completely remove the amines, and carrying out this step at reduced pressures also facilitates the complete removal.
• a suitable solvent such as water, methanol and the like, the removal of amine from the oil may also be effected. It is advantageous to remove the amines at somewhat elevated temperatures under pressures sufiicient to condense them at temperatures of ordinary cooling water in order to avoid the use of compressors or condensing liquids other than water.
• the proportion of solvent to oil used in this process may be varied within very wide limits and will depend on the nature of both solvent and oil, the proportion of material that isv to be removed, and the temperature. The same is true of the temperature, specific amine mixture or mixture of amine with other liquids.
• the composition of the solvent can also be changed so as to meet any desired operating conditions such as temperature, pressure, density etc., as well as to give a product of any predetermined characteristics.
• Liquids which may be used with the amines in order to bring about these results are ammonia, water, methanol, isopropanol, ethanol, and other alcohols, aniline, monoethyl ether of ethylene glycol etc.
• any solvent which in combination with amines and oil will produce two phases is more or less suitable. It is-immaterial whether the extracted oil exists as a separate phase containing a small percentage of solvent or whether a solvent mixture is used which is not completely miscible and the oil is added and I allowed to partition itself between the two solvents according to their selectivity for the various types.
• This method is applicable to the entire range of distillates and still residues obtained in the ordinary refining of Pennsylvania, Mid-Continent, California, Texas, Mexico etc. oils, and in every case fractions of varying composition and properties are obtained.
• Vol. means the ratio of the volumes of amine solvent used per volume of oil being treated.
• fV. I. indicates Viscosity Index.
• the original oils had'the following characteristics:
• Viscosity 45. l 185. 5 95 55. 3 577 15. 2 157. 2 2692 95. 4 Residual 011 B"; 107.4 1820 72. 5
• a sample of. gasoline from which the light naphthahad been removed was extracted with a water-monomethylamine mixture containing 50 volume per cent. amine
• the extract portion had a refractive index of 1.4554, and the rafllnate of 1.4388. Since it is generally known that the straight chain parafiins are the most undesirable constituents of a superior or high knock rating motor fuel,- and further, that for a given boiling point the normal .paraffins are among the compounds having the lowest refractive index it is obvious that a motor fuel of improved knock rating has been produced in the extract portion.
• gasoline is a relatively volatile hydrocarbon,mixture
• an amine-ammonia solvent mixture in order to facilitate the removal of solvent by distillation at low temperatures thus preventing the loss of gasoline.
• the presence of the methylamines, particularly dimethylamine'and monomethylamine in gasoline in small quantities greatly increases or improves the knock rating of the fuel.
• butand 51% methylcyclohexane was extracted with an 87 volume per cent monon'iethylamine-l3% water mixture.
• the extract portion was 63.5% toluene and the rafiinate portion was 46% toluene.
• a normal heptane-toluene mixture containing 42 mol. per cent of theformer on extraction with a mixed methylamine-water mixture, yielded an extract containing 10.5 mol. per cent heptane and a rafiinate containing 43.3 mol. per cent heptane.
• the amine solvent mixtures have a selective'solubility for olefins over parafilns.
• the amine solvent mixtures also produce separation according to molecular weight or viscosity.
• separation is brought about according to molecular weight or viscosity. This v is because, in general, the higher the boiling point, the higher is the viscosity and molecular weight.
• separation according to type does not usually occur to any degree by distilla tion in the case of an extremely complex hydrocarbon mixture such as a lubricating oil. This fact is shown by measuring the viscosity index of a Pennsylvania neutral and bright stock. It will be found that they are practically identical.
• a mixture of normal parafllns in the range of approximately 16-18 carbon atoms permolecule, and an equal volume of normal heptane was extracted with a mixed amine-water solvent.
• the extract portion contained 35% of the high molecular weight paraflins, and the raflinate 55% of the high molecular weight. compounds. This property of the amine solvent mixtures to produce separation according to molecular-weight we have termed a fractionating process.
• the first two solvents have been used for dewaxing purposes cormnercially.
• the wax was found to be six times as soluble in the naphtha and three times as soluble in the benzene-acetone solution as it was in the dimethylamine.
• the methylamines also possess the advantage of being less dense so that when they are added to the oil, the specific gravity of the solution is greatly reduced and the Wax can settle out more easily.
• the cooling was brought about by the use of externalrefrigerants, but with the dimethylamine its internal refrigerating action caused by evaporation was used to maintain the desired temperature.
• a sample of Pennsylvania cylinder stock having a pour point of 70 F. yielded oils on treatment with dimethylamine having pour points of 45 F., 35 F., 25 F., and 15 F., depending on the amount of dimethylamine present and the temperature to which the mixture was cooled.
• methylamine is employed to include monomethylamine, dimethylamine and trimethylamine, mixtures of any two of. them or mixtures of all three or mixtures of these andsuitable proportions of other liquids.
• suitable proportions we mean the addition of quantities of other liquids to the methylamines to obtain the desired operating conditions, such as temperature, solvent to hydrocarbon ratio,- density, pressure, etc., and to obtain products with the desired properties, such as hydrocarbon type or molecular weight, viscosity, volatility, gravity, viscosity index, carbon residue, oxidation characteristics, color, knock rating, fagur point, melting point, penetration and the
• the liquids used with the methylamine consist of a variety of substances, which, mixed together with the amines and the mixture to.be treated,
• methylamine solvents have many other desirable properties, such as low boiling point, low freezing point, low density, low viscosity, solubility in organic as well as in inorganic substances, availability, chemical stability, non-corrosive to ordinary materials of construction, easy detection and estimation, etc.
• the process of separating kerosene into fractions having different chemical and physical properties which comprises mixing said kerosene with methylamine so that at least two phases form, separating the phases and removing the methylamine from said phases.

Landscapes

• 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)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=21831658

Family Applications (1)

Country Status (4)

Cited By (3)

• 0
  • NL NL43043D patent/NL43043C/xx active
• 1935
  • 1935-06-13 US US26408A patent/US2096725A/en not_active Expired - Lifetime
• 1936
  • 1936-06-05 GB GB15728/36A patent/GB477888A/en not_active Expired
  • 1936-06-12 FR FR807663D patent/FR807663A/fr not_active Expired

Also Published As

Similar Documents