US2248373A - Process for solvent extraction of mineral oil - Google Patents

Description

y 194L' D. R. MERRILL ErAI. 2 ,373

PROCESS FOR SOLVENT EXTRACTION OF MINERAL OIL Filed Nov. 12, 1932 3 Sheets-Sheet 1 DICHLOR- OIL ETHYL CONTAINING ETHER wAx HEATING R R EXTRACTION 8? RAF'FINATE EXTRACTION I- a No. 1; 8 RAFFINATE v A RAFSINATE OIMWAX Q WAX No.1, 1N No.1,

ETI-IER NA ACETONE, NA WAX NOJ, PROPANE GT PROPANE GT PROPANE E E v RECOVERED EXTRACT PROPANE EXTRACT +1 ,LlQilD PROPANE DISTILLATION zx'I-IzAc'ruozA E SATION a; WAX No. 3A, ACETQNE RAFFINATE E5 ACETONE No.1 111mg v 83: I UID A L Q 355 PROPANE L D.- J n EXTRACTION R R 8% CA EXTRAGT No.1 F RAFFINATE 8; RAFFINATE No.2, u RAFFINATE No 2 WAX wAx NO 2 No.2, PROPANE ETHER, x AcE-rouEj I [5; WAX NO. 2, PROPANE, GT PROPANE E PROPANE v E Ls mum E EXTRACT PROPANE EXTRACT NO-SA, V DISTILLATION. ACETONE. j Y

[EXTRACTION r RAFFINATE WAX EXTRACT COOLIN e SI- 1:2

WAX RAFFINATE No.3,

ETHER' wAx No.3,

ACETONE PROPANE RAFSgIQTE PRoPANE EXTRACT RECOVERED I J ACETONE PROPANE I DISTILLATION g EITHER ACETONE. CONDENSATION CONDENSATION Y RAFFINATE Z) 'dRM 7/ Pfi l lt avz e r:

EXTRACT ETI-IER r g l ub ow NO. E & Ex'rRAc'r BY I, I i rfiiz I v r I I A ATTORNEY ,3 Sheets- Sheet 2 July 8, 1941. o. R. MERRlLL ETAL PROCESS FOR SOLVENT EXTRACTION 0F MINERAL OI L Filed Nov. 12, 1932 y 1941- D. R. MERRILL El AL .2 3

PROCESS FOR SOLVENT EXTRACTION OF MINERAL OIL Filed Nov. 12, 1932 3 Sheets-Sheet 3 QQN Am\ Mm 3w mmw \ww un MWN Pu (1.5a

MWN WMN www MN MN MPENEdmW mmN ms mm ATTORNEY. I

Patented July 8, 1941 UNITED STATES PATENT OFFICE P RtOCESS FOR SOLVENT EXTRACTION F 1 MINERAL 01L David B. Merrill, Long Beach, and Philip Subkow,

Los Angeles, Calif., assignors to Union Oil Com-- pany of California, Los Angeles, Calif., a cornotation of California Application November 12, 1932, Serial No. 642,371

13 Claims.

extracted in the next succeeding zone with a selective solvent and the extract phase coming The heavy oil fractions of many crude oils,

from which lubricating oils are produced, consist of a mixture of hydrocarbons some of which exhibit a low temperature viscosity susceptibility and some of which exhibit a high temperature viscosity susceptibility. In order to produce superior lubricating oil from such hydrocarbon mixtures, those oils present having a high viscosity temperature susceptibility are separated from the oils present which exhibit a low temperature viscosity susceptibility. Solvent extraction is one of the methods employed to separate the undesirable oil from the desirable oil. Solvents, such as aniline, furfural, nitrobenzene, selenium oxychloride, sulphur dioxide or dichlorethyl ether are capable, under the proper conditions of temperature and pressure, of dissolving the fractions present which are non-paraflinoid in character. These solvents form relatively heavy solutions with the nonparaflinoid oil fractions and can be separated from the insoluble parafflnoid oil fractions by settling. That portion insoluble in the extracting solvent is termed the railinate while the soluble portion is known as the extract.

In the following disclosure of our process, wherever dichlorethyl ether is mentioned it will be understood that the other solvents recited above may likewise be employed. B B dichlorethyl ether, ClCHzCHzOCHaCHzCl, has a preferential solvent action on aromatic or non-paraflinoid components of the oil. However, we have found that when extraction is accomplished using this solvent, not all of the paraflinoid components are removed in the insoluble raiiinate, nor are all of the non-paraiilnoid components dissolved in the extract. In other words, the solvent is selective as to a large proportion of parafl'lnoid and nonparafilnoid components but its selectivity is not entirely complete. We have found that after the primary separation .by extraction with dichlorethyl ether, the extract and raiiinate may be further classified separately whereby the ramnate will in turn be divided into a second rafilnate and a second extract and wherebythe primary extract may be divided into another extract and another raflinate.

We have found that in the operation of our process we are able to obtain a rafiinate of very high quality, 1. e., having a large'proportion of paraflinoid components and to obtain additional raliinates having successively smaller proportions of paraflinoid components as well as to obtain an extract high in the proportion of non-paraflinoid fractions. We have also found that temperature conditions during these extractions exert a great influence upon the character of the materials comprising the rafiinate and extract. For instance, when the primary extraction is carried out at a relatively high temperature we have found, upon reduction of temperature of the solution of dichlorethyl ether and extract obtained from said primary extraction, that this extract may in turn become separable into two phases, a raflinate and an extract. This latter extract may again be treated similarly after another reduction in temperature and this process can be continued to produce as many intermetract to produce fractions having various propor-' tions of paraflinoid components. 4

-When the primaryextraction with dichlorethyl ether is accomplished at relatively high temperatures, i. e., about 100 F. or more, the raflinate produced has a desirable large proportion of nonparaflinold hydrocarbons, but the yield of this raflinate is small. Commercial operation necessitates further extractions at lower temperatures.

1. e. 40 F. or 0 F., to obtain larger yields. In the extraction of certain oils with dichlorethyl ether, alone, it is sometimes found that the millnate is a viscid mass at the temperature necessary for extraction. This is particularly true when 'a wax-containing oil is subjected to' such treatment. We have found that the presence of a light hydrocarbon, such as a petroleum fraction obtained by the rectification of natural gasoline, reduces the viscosity of this mixture whereby more efiicient stratification and separation are accomplished.

As an example of such commercially available fractions, one composed of 6.72%, ethane, 72.2%

propane, 19.91% isobutane and 1.17% normal butane may be cited as satisfactory. It will be understood, however, that these merely illustrate the type of fractions which may be ,used and that the composition may vary. This fraction will hereafter be referred to as propane for purposes of simplicity. Also, in the operation of our process in which the raflinate from the primary extraction is further cooled in the presence of acetone for additional extraction, the viscidity of this rafllnate may likewise be reduced by the addition of liquid propane.

We have also found that the presence of seetone in the further dichlorethyl ether extraction at lower temperatures of the extract produced in the primary extraction at high temperatures is advantageous, not only for its own solvent effect, which is similar to that of the dichlorethyl ether, but also because of its diluent action and its property of inhibiting the presence of wax in the extract phase.

The pressure to be employed in the operation of our process depends upon a number of factors, notably the temperature used and the amount of solvents employed. However, the pressure should be sufiicient to accomplish the extraction while these solvents are liquid.

Therefore, it is an object of our invention to obtain by solvent extraction a number of fractions having varied proportions of paraflinoid components from mineral oil such as lubricating oil for example, which comprises parafllnoid and non-paraflinoid components.

Frequently such oil contains wax. It is a further object to dewax the oil in addition to treating it by successive extractions.

Another object is to correct for the lack of complete selectivity of the solvent by further selective extractions either of the raflinate or extract produced by the primary extraction, or by further selective extractions of both this rafiinate and extract.

In the drawings,

Fig. 1 is a flow sheet of the principal steps involved in the operation of our process.

Figs. 2 and 2A are one form of apparatus which we may employ to carry out our process. The diagrammatic embodiments in Figs. 2 and 2A has been divided along line 2-2.

Referring to Fig. 1 the flow of the material indicated by the legends is in the direction of the arrows. The raiflnate is that portion insoluble in the extracting solvent. The extract is that fraction soluble in the extracting medium. Figs. 2 and 2A show in. greater detail the process outlined in Fig. 1.

Referring more particularly to Figs. 2 and 2A,

oil containing wax to be subjected to treatment is stored in tank 5. It is removed therefrom by action of pump 6 in line 1 controlled by valve 8 and passes through calls 9 disposed in heater II]. From heater it this oil passes via line H into line Ir. Dichiorethyl ether stored in tank 12 is constricted apertures in diaphragms consecutively interposed between relatively large chambers whereby intimate contact of the liquids is insured. From the mixer I! the liquids pass via line l9 into primary sep'arator20 wherein the oil separates into two phases, a railinate substantially insoluble in dichlorethyl ether and an extract soluble therein. However, at the temperature employed, a. minor amount of the ether may also be dissolved in the railinate.

This raflinate in separator 20 is removed therefrom by pump 23 in line 2| controlled by valve 22. Acetone is introduced into line 2| by passage from acetone storage 25 through line 26, valve 21, pump 28, lines 29 and 30, and valve 3|. The mixture is then passed through orifice'mixer 35, line 38 and line 31 for cooling by heat exchange in heat exchanger II with the material to be described below flowing through line 69. The raflinate and acetone mixture then flows through line 39 into which is introduced a stream of liquid propane. Propane, under pressure sufficient to be maintained in the liquid state, is stored in tank ll and may be passed by action of pump ll into line 39 via lines l2 and 44 controlled by valves 42 and Ii, respectively. The cooled railinate-acetone-propane mixture containing a small amount of dichlorethyl ether then passes through orifice mixer II and line 41 into separator 5| in which this mixture again separates into two.

phases; a rafiinate solution in propane substantially insoluble in the solution of extract in aceeration of the ramnate containing wax. ,Jhe wax,

will precipitate from the oil at the low temperature produced. Propane vaporized in chamber 53 passes therefrom via line 5! controlled by valve 56 by action of pump l1 and thence into condenser coil 58 in which it is returned to liquid condition. Liquid propane is recycled to storage 40 by passage through line 59.

The mixture of rafiinate, precipitated wax and remaining propane in chamber 53 mayalso contain a relatively small proportion of dichlorethyl ether and acetone not removed in separators 2| and 50. This mixture in 53 passes therefrom by action of pump 82 in line .3 controlled by valve 64 into filter press 65 wherein the waxis retained on the filter plates, while the wax-free filtrate is removed via line 88 controlled by valve 61. The wax remaining in filter may be removed by any usual method.

The cold wax-free filtrate from F5 is next forced by pump '88 through a series of heat interchangers in order to raise its temperature before distillation of the remaining solvents from the oil. Accordingly, it passes via line 66 into line 69 disposed in heat exchanger 38 to absorb heat from the material passing through line 31;

- thence via line into line II situated in heat exchanger 12 to absorb heat from the material to be described below flowing through line I22, thence via line 13 into line 14 disposed in heat exchanger 15 to absorb heat-from the material to be described below flowing through line I40. The preheated wax-free filtrate from filter press 65 is then introduced into still 80 via line 16.

Distillation is eilected in 80 by introduction of additional heat; for instance, byfiow of steam through closed coil 8|. The solvents are thereby removed from the raflinate which remains undistilled. This wax-free raflinate, therefore, is

that portionof the oil which is substantially insoluble in dichlorethyl ether and acetone. From column still 80 the wax-free rafiinate is removed via line 82 and valve 93 by pump 84 into storage 65. Propane, together with any acetone and/or dichlorethyl ether present, vaporizes in still 60 and exits therefrom via line 86 controlled by valve 61. These vapors-pass into condenser coil 88 and thence into separator 90 via line 89. Condensation of the acetone and ether is effected in- 86 while the propane remains in vapor form. Propane vapors are removed from 98 by pump 9I via line 92 controlled by valve 93 to line 55 for return into liquid propane storage 80 in the manner above described.

Acetone and dichlorethyl ether are removed from separator 90 by pump 94 in line 95 controlled by valve 96, Line 95 connects with still I00 provided with closed steam coil IOI. Acetone vaporized in still I00 escapes via line I02 controlled by valve I03 into condenser coil I06 and the acetone is returned to storage 25 by action of pump I85 in line I06. Dichlorethyl ether, undistilled in still I00, passes to storage I2 via line I81 and valve I86 by action of pump I09.

Returning now to separator 50, the extract solution in acetone and dichlorethyl ether is removed by pump III through valve II2 via line IIO which connects with line 200 through which flows a mixture described below.

Again referring to primary separator 20, the extract soluble in dichlorethyl ether is removed by pump II6 through valve H1 in line H5. Acetone may be introduced at this point by flow from storage 25 through line 26, valve 21, pump 28, valve H8 and line H9. The mixture of extract, ether and acetone is then intermixed in orifice mixer I after which it passes via line I2I into line I22 situated in heat exchanger 12 for cooling by heat exchange with the material described above flowing through line 1|. From the heat exchanger 12 the mixture flows through line I23 into line I25 disposed in heat exchanger I24 to be cooled by heat exchange with the material described below flowing through line I52. The cooled mixture then passes through line I26 into separator I30 in which the mixture separates into two phases; a rafiinate substantially insoluble in dichlorethyl ether and acetone and an extract soluble therein. The rafiinate may, however, contain a minor proportion of the ether and acetone.

Following the course oi the ramnate from separator I30, it is removed by action of pump I3I into line I 32 controlled by' valve I33. Acetone may be introduced into this line from storage 25 via line 26, valve 21, pump 28, line I34 and valve I35. Liquid propanemay be sent into line I32 from storage 40 via line 42, pump 4|, valve 43, line I36 and valve I31. The mixture flowing through I32 is then intermingled by passage through orifice mixer I36 from which it passes by line I39 into line I40 situated in heat exchanger 15 in which it is cooled by heat exchange with the material above described flowing through line 14. From heat exchanger 15 the mixture passes into line I into which is also introduced cold liquid propane from line I53.

The manner in which this cold liquid propane is obtained is as follows: propane from storage 40 passes via pump 4|, line 42, valve 43 into line I42 through expansion valve I43 and into propane cooler I45 in which the pressure is sufiiciently reduced to partially vaporize the propane. This partial vaporization results in a drop in temperature in the liquid propane remaining in cooler I45. Propane vapors are removed by pump I46 via valve I41 in line I48 which connects with line 55 through which they pass for condensation and storage in 40 in the manner described above. Cold liquid propane is removed from cooler I45 by pump I49 through line I50 controlled by valve I5I. This cold propane then passes through line I52 disposed in heat exchanger I24. The material, previously described, flowing through line I25-is thus cooled by heat exchange with the cold liquid propane in line I52. The propane then flows through line I53 which connects with line I4I, described above.

The cold mixture of propane and raflinate from separator I30 then is intermingled in orifice mixer I54 and flows to separator I55 via line I56. Separation occurs therein into two phases; a raflinate'solution in propane substantially insoluble in the dichlorethyl ether and acetone and an extract soluble therein. The raffinate, however, may contain a small proportion of ether and acetone as well as some wax which was not removed in primary separator 20. This rafiinate is removed from separator I55 via line I51 controlled by valve I58 and is passed into.

expansion chamber I60. duced sufliciently therein to cause evaporation The pressure is reof at least part of thepropane with consequent internal refrigeration of the rafiinate containing wax. The wax will precipitate from the oil at the low temperatures attained.

Propane vaporized in chamber I68 passes therefrom via line I6I controlled by valve I62 by action of pump I63 and thence into lines 92 and 55 for condensation and return to liquid propane storage 40 as above described. The mixture of raifinate and precipitated wax and remaining propane in chamber I60 passes therefrom by action of pump I64 in line I65 controlled by valve I66 into filter press I 61 wherein the Wax is retained on the filter plates While the wax free filtrate is removed via line I68 controlled by valve I69. The wax remaining in filter I61 may be removed by any usual method.

The cold wax-free filtrate from I61 is next forced by pump "0- into line I1I disposed in heat exchanger I 12 to raise its temperature by heat exchange with the material tobe described passing through line 205. The filtrate then passes through line I13 into column still I 15 heated by closed steam coil I16. The raflinate is freed therein of acetone, ether and remaining propane by distillation. This rafiinate is removed by pump I11 in line I18 controlled by valve I19 and passes into storage I08.

The acetone, dichlorethyl ether and propane vapors in still I15 issue into line I83 controlled by valve I84 and thence pass into condenser coil I85. They are cooled sufficiently to condense the acetone and ether. These materials pass by line I86 into separator I81 from which the propane vapors issue via line I88, valve I89 and pump I90 into lines Nil, 92 and 55, as previously described, for liquefaction and recovery of the propane. The condensate in separator I 81 comprising acetone and dichlorethyl ether passes through line I9I, valve I92 and pump I93 for passage into line 95 and still I99, as previously described, for the separate recovery of these solvents.

pump 243 into lines 2I8, I48 and 55 for liquefaction and recovery of the propane as previously described. The condensate in separator 249 comprising acetone and dichlorethyl ether passes through line 244, valve 245 and pump 246 into line 95 and still I99 for the separate recovery of these solvents as previously described.

Again referring to separator -2I9, the extract solution in acetone and dichlorethyl ether is re- Returning now to separator I55, the extract solution in acetone and dichlorethyl ether is removed by pump I95 through valve I96 via line I9'I which connects with line 249 through which flows a mixture described below.

Again referring to the separator I39, the extract soluble in acetone and dichlorethyl ether is removed by pump I98 through valve I99 in line 299. Acetone from tank 25 is introduced into this line by passage through line 26, valve 21,

pump 28, line 29I and valve 292. Extract, previonsly described, from separator 59 is likewise introduced into this line via line 9, pump II I and valve II2.

. The mixture in line 299 is then intermingled in orifice mixer 293 and is passed via line 294 into line 295 disposed in heat exchanger "2 to be cooled by heat exchange with the medium described above flowing through line Ill. The cooled extract in line 295 then passes via line 296 into separator 2I9 in which a separation of phases is accomplished. The raflinate, i. e., insoluble portion containing wax not previously removed-in separators 29 and I39, exits from separator 2I9 by action of pump 2 in line 2I2 controlled by valve 2I3. Cold liquid propane, chilled in cooler I45 as previously described, 'is introduced into line 2I2 from propane cooler I45 via pump I49, line I59, valve I5I, line 2 and refrigeration whereby the wax will precipitate at the low temperatures attained. Propane vaporized in chamber 2II passes therefrom via line 2| 8 controlled by valve 2| 9 by action of pump 229 and thence into lines I48 and 55 for condensation and return to liquid propane storage 49 as above described.

The mixture of raflinate, remaining propane and precipitated wax in chamber 2" passes therefrom by action of pump 22I in line 222 controlled by valve 223 into filter press 225 wherein the wax is retained on the filter plates while the wax-free filtrate is removed via line 226 controlled by valve 221 by action of pump 228 into column still 239 heated by closed steam coil 23I. The raffinate is freed therein of acetone, dichlorethyl ether and remaining propane by distillation. This raflinate is removed by pump 232 in line 233 controlled by valv 234 into storage 235.

The acetone, dichlorethyl ether and propane vapors in still 239 issue into line 236 controlled by valve 231 and thence pass into condenser coil 238. They are cooled sufliciently to condense the acetone and ether. These materials pass via line 239 into separator 249 fromwhich the propane vapors issue via line 2, valve 242, and

moved by pump 24] through valve'248 via line 249 into which issues the previously described extract from separator I55 via line I9I. The mixed extracts then pass via line 249 into column still 259 heated by closed steam coil 25I. The extract is freed therein by distillation of acetone, dichlorethyl ether and any propane which may be present. This extract is removed by pump 252 in line 253 controlled by valve 254 into extract storage 255.

The acetone, dichlorethyl ether and propane vapors instill 259 issue into line 256 controlled by valve 251 and thence pass into condenser coil :58. They are cooled sufliciently to condense the acetone and ether. These materials pass via line 259 into separator 269 from which the propane vapors issue via line 25L valve 262, pump 263 into lines 2I8, I48 and 55 for liquefaction and recovery of the propane, as previously described. The condensate in separator 259 comprising acetone and dichlorethyl ether passes through line 264, valve 265 and pump 265 into line and still I09 for the separate recovery of these solvents, as described above. 7

It will be observed that in the operation of our process according to the exemplary method recited above and according to the flow sheet, Fig. 1, oil containing wax may be successively fractionated by solvent extraction whereby several fractions having varied characteristics may be obtained. For instance, if the oil to be treated is' a waxy lubricating oil containing paraffinoid and non-paraifinoid components, the extraction with dichlorethyl ether in separator 29 fractionates the oil into a railinate having a relatively large proportion of paraflinoid hydrocarbons and into an extract having a large proportion of nonparaflinoid fractions.

The paraifinoid content of this rafilnate is further increased by the extraction at a lower temperature in separator 59 in the presence of acetone, propane and any dichlorethyl ether which may pass with the raflinate from separator 29. r

The raflinate from 59, after wax removal in filter 65 and after'solventremoval in still 89, has

-the largest proportion of parailinoid components of any of the fractions obtained by ourprocess. It is stored in tank 85. v

The extract obtained by separation with dichlorethyl ether in separator 29 is then subjected to a series of extractions for further separation of paraflinoid from non-parafilnoid components in the presence of dichlorethyl ether, acetone and propane at successively lower temperatures in separators I39 and 2I9. For instance, the tem- The extract portions from separators 50 and I30 may be treated conjointly as described above,

.or separately. The rafilnate from the extraction in separator 2I|l,'after wax removal in filter 225 and after solvent removal in still 230 contains the third'largest proportion of parafilnoid components. It is stored in tank 235.

The extract phases from separators I55 and 2|!) may be treated together, as described, or separately. This extract, after removal of the solvents in still 250, contains theleast proportion of paraifinoid components and the largest proportion of non-paraflinoid fractions. It is stored in storage 255.

It is to be understood that while the foregoing example relates to successive solvent extraction of lubricating oil containing wax, our invention is not limited thereto because it is applicable to the treatment of mineral oils and hydrocarbons both heavier and lighter than lubricating oils. Furthermore, our invention is not limited to the same number of phase separations described but may be varied by omission of the extraction occurring in separator Zill or the number of separations may be increased if the need should arise. Many other variations may be made without departing from the spirit of our invention.

We claim:

1. A process of separating paraifinoid and nonparafiinoid components from mineral oil which comprises mixing said oil with dichlorethyl ether, separating the extract soluble therein from the raffinate insoluble in dichlorethyl ether, mixing said rafiinate with liquid propane, reducing the temperature of said ramnate to separate saidrafiinate into a second extract and rafiinate and separating said second extract from said raifinate.

2. A process of separating parafilnoid and nonparamnoid components from mineral oil which comprises mixing said oil with dichlorethyl ether, separating the extract soluble therein from the rafiinate insoluble in dichlorethyl ether, mixing said raflinate with acetone; and separating the extract soluble in said acetone from the ramnate insoluble therein.

3. A process of separating paraflinoid and nonparafiinoid components from mineral oil which comprises mixing said oil with dichlorethyl ether, separating the extract soluble therein from the rafilnate insoluble in dichlorethyl ether, mixing said rafiinate with acetone, reducing the temperature of said rafiinate, and separating the extract soluble in said acetone from the rafiinate insoluble therein.

-4. A process of separating paraffinoid and nonparamnoid components from mineral 011 comprising mixing said oil with dichlorethyl ether, separating the extract soluble therein from the ramnate insoluble in dichlorethyl ethenmixing said rafiinate with liquid propane and acetone, and separating the extract soluble in said acetone from the raflinate insoluble therein.

5. A process of separating paraflinoid and non parafi'inoid components from mineral oil comprising mixing said oil with dichlorethyl ether. separating the extract soluble therein from the ramnate insoluble in dichlorethyl ether, mixing said raflinate with liquid propane and acetone, cooling said raflinate and separating the extract soluble in said acetone from the Iafiinate insoluble therein. A v l .6. A process of separating parafiinoid and nonparafilnoid components from mineral oil comprising mixing said oil with dichlorethyl ether, separating the extract soluble therein from the rafiinate insoluble in dichlorethyl ether, mixing liquid propane with said extract and dichlorethyl ether, and separating an insoluble raflinate and a soluble extract from said mixture of propane,

dichlorethyl ether and extract from the first extraction.

7. A process of separating parafiinoid and nonparafiinoid components from mineral oil comprising mixing said oil with dichlorethyl ether,

separating the extract soluble therein from the rafiinate insoluble in dichlorethyl ether, mixing liquid propane with said extract and dichlorethyl ether, reducing the temperature of said extract, and separating an insoluble railinate and 'a soluble extract from said mixture of propane, dichlorethyl ether and extract from the first extraction.

8. A process of separating parafiinoid and nonparamnoid components from mineral oil which comprises extracting said oil in a first extraction stage with dichlorethyl ether, separating the rafiinate insoluble in said ether from the extract soluble therein, reducing the temperature of said extract, mixing liquid propane with said extract and dichlorethyl ether, separating the rafiinate insoluble in said second extraction stage from the extract remaining dissolved in said dichlorethyl ether, mixing acetone with the extract fromsaid second extraction stage dissolved in dichlorethyl ether, cooling said extract and separating the rafilnate insoluble in said solvents from the extract soluble therein.

9. A process of separating parafiinoid and nonparafilnoid components'from mineral oil which comprises extracting said oil in a first extraction stage with dichlorethyl ether, separating the rafllnate insoluble in said ether from the extract soluble therein, mixing acetone with said rafiinate, reducing the temperature of said rafiinate, separating rafiinate insoluble in said second railinate extraction from extract soluble in said acetone, mixing liquid propane with said extract and dichlorethyl ether from the first extraction stage, reducing the temperature of said extract, separating rafilnate insoluble in said second extract extraction from extract soluble in said dichlorethyl ether.

10. A process of separating parafiinoid and non-parafiinoid components from mineral oil which comprises mixing said oil with dichlorethyl ether, separating the extract soluble therein from the railinate insoluble in dichlorethyl ether, reducing the temperature of said extract to separate said extract into a second rafiinate and extract, separating said second rafiinate from said extract, cooling said second railinate, adding acetone to said second rafiinate, and separating the rafflnate insoluble in said acetone from the extract soluble therein.

11. A process of separating parafilncid and non-.paramnoid components from mineral oil which comprises mixing said oil with dichlorethyl ether, separating the extractsoluble therein from the raflinate insoluble in dichlorethyl ether, mixing liquid propane with said extract 'and dichlor ethyl ether, reducing the temperature of said extract, separating a second rafiinate dissolvedin said liquid propane from the extract dissolved in dichlorethyl ether, mixing acetone with said second raflinate dissolved in liquid propane, cooling said second raflinate, separating extract dissolved in said acetone from raiiinate undissolved therein.

12. A process of separating paraflinoid and non-parafllnoid components from mineral oil which comprises extracting said oil in a first extraction stage with dichlorethyl ether, separating the rafiinate insoluble in said ether from the extract soluble therein, mixing acetone with said raifinate, reducing the temperature of said ramnate, separating raflinate insoluble in said second ramnate extraction from extract soluble in said acetone, mixing liquid propane with said extract and dichlorethyl ether from the first extraction stage, reducing the temperature of said extract, separating railinate insoluble in said second extract extraction from extract soluble in said diincluding wax insoluble therein, cooling said rafli-.

nate to precipitate the wax and separating the wax from the rafiinate.

DAVID R. MERRILL. PHILIP SUBKOW.

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