US 2548434 A
Description (OCR text may contain errors)
April 10, 1951 SELECTIVE EX'fRACTION AND FRACTIONATION Filed Aug. 1, 1945 W M. LEADERS 0F FATTY MATERIALS 5 Sheets-Sheet 1 75 ii & QLEAGlNOUs MATERIAL Q P ]%T E /76 6 Q Q. U Q 6 g 4 a ,2 17 5 20' z 47 A g I P PR i OP NE A E d m 21/ j S s, v Q q 23 i Q INVENTOR. WZ'ZZz'am MLeadez's A TTOIZNEY April 10, 1951 w LEADERS 2,548,434
SELECTIVE EXfRACTION AND FRACTIONATION OF FATTY MATERIALS Filed Aug. 1, 1945 3 Sheets-Sheet 2 Q INVENTOR. mZZzbmMLeaders .4 TTO'RNE Y April 10, 1951 w. M. LEADERS 2,543,434 SELECTIVE EXTRACTION AND FRACTIONATION OF FATTY MATERIALS Filed Aug. 1, 1945 3 Sheets-Sheet 3 OLEAGINOUS N MATERlAL 93 705' u 84 \l E k A 95 E I t g 96 8 o 708 i 5 E R 94 PROPANE. k g 700 4 91 85 86 [L a l] L 86 q E 98 I u 2 3 t 3 97 q a 99 89 o INVEN TOR. William M Leaders l atented Apr. 10, 1951 SELECTIVE EXTRACTION; ND FBACTlONA- TION F FATTY MATERIALS William M. Leaders Chicago, 111., assignor, by
mesne assignments, to Swift & Company, a corporation of Illinois Application August 1, 1945, Serial No. 608,186
This invention relates to the treatment of oleaginous materials and has to do more particularly with the selective extraction and fractiona n 9 fatty materials contained in fat bearing solids.
The invention has particular application to the solvent extraction of fatty materials such as seed meals, cracklings and used bleaching earth to selectively extract and fractionate oils and fats present'in such materials.
In the manufacture of vegetable oils such as cottonseed, and soybean oil, it is customary to dry and flake the seed material and then pressure expel or solvent extract the oil therefrom. The extraction is usually carried out in the presence of a hydrocarbon solvent such as hexane and under conditions whereby substantially all the soluble materials including gums, phosphatides, fatty oils and color bodies are removed with the solvent. Also the difference in density between the solution and the solid material is so slight ithat appreciable amounts of finely divided sus= pended solids are often carried over with the solvent. The resulting oil solution requires a considerable number of operations such as set-.-
'tling, refining, bleaching, etc., to obtain a light colored fat suitable for commercial purposes.
adsorptive materials used in the treatment of :animal and vegetable oils retain considerable .amounts of the oil treated. The major portion of such spent clays has been discarded heretofore. A certain amount of the clays has been treated to recover the oils by extraction withsol- "vents but the oil recovered is of poor grade due to :the extraction of the color bodies, resins, etc., :from the spent clay. g I
An object of the present inventionis to provide :an improved process for the separation of fatty material from oleaginous materials whereby a recovered fatty material of improved quality and yield is obtained.
Another object of the invention istoprovide a process for therecovery of fatty material from :so'lid 'oleaginous materials whereby the desired 2 fats and oils are extracted and the undesirable materials are rejected.
Another object of the invention is to provide a process for the treatment of oleaginous materials to extract therefrom high quality fats and oils and to produce a solid residue of increased value.
A further object of the invention is to provide a continuous process for the extraction of fatty materials from raw fat bearing'materials and to fractionate the extracted fatty materials to produce fractions of different chemical and physical properties.
A still further object of the invention is to provide a process for producing from raw materials edible fats of animalv and vegetable origin, in such a state that substantially no further treatment is required to produce a finished product.
The invention contemplates broadly the treatmerit of oleaginous materials with normally gasee ous hydrocarbons to selectively extract therefrom the desired materials while rejecting the undesired materials. then be further treated in a continuous opera.- tion to solvent fractionate such materials into the desired fractions. Such solvent fractionation may comprise a destearinizing operation wherein the stearin is separated as a solid fraction from the liquid oil or may comprise a high temperature fractionation operation wherein two liquid fractions of different iodine values are separated.
In accordance with the present invention the oleaginous material which may be solid or semisolid may be charged into the upper portion of an extraction zone wherein the material passes counter-current to a solvent introduced into the lower portion of the extraction zone. The solid material may be injected into the extractor in the form of apasteor slurry containing a suitable amount of fluid inaterial such as oil. The solvent may be a normally gaseous hydrocarbon vsuch as propane, butane, isobutane, propylene, butylene, ethane andmixturesthereof and preferably propane. The extraction apparatus may take the form of a tower containing rotating trays or plates over which the solid material is moved by a rake while the solvent is passing countere current thereto. A suitable extractiontower is shown in the Bonatto Patent No. 2,206,595.
The conditions in the tower will depend seme+ what on the oleaginons materials undergoing treatment. The temperatures may beenear the critical and will usually range between F. and 200 F. and preferably F. The res.- sures are sufficient to maintain the solvent in The extracted materials may the liquid phase and may range from 400 to 600 pounds and preferably about 500 pounds. Under these conditions the solvent selectively extracts property of causing a separation into two phases,
the lighter phase containing the light colored fats and oils and a heavier phase containing undesired materials such as color bodies, phosphatides, etc. the heavier phase are rejected by the solvent and remain with the solid materials undergoing extraction. By varying the temperature and pressure conditions the degree of separation between the light colored extracted materials and the rejected fractions may be varied as desired. Thus, by varying the temperature and pressure conditions a wide range of extraction and fractionation may be secured.
The amount of solvent may be varied according to the quantity of fatty material contained in the solids to be extracted and also according to the degree of fractionation desired following the extraction process. When a greater degree of fractionation of the extracted oil is desired the solvent ratio is increased and vice versa. The ratio of solvent to extracted oil will usually vary from about 15 to 1 to about 30 to 1. Substantially all of the solvent used is withdrawn from the top of the tower as a solution with the extracted oil. A small quantity of the solvent for example 1% on the basis of the weight of the solid extracted meal will be retained by the extracted solids, gums and color bodies.
According to one method of operation the solution of solvent and extracted oil may be flashed to remove the solvent and to produce an oil fraction. If the oil fraction is derived from vegetable seed meal the product would be suitable for hydrogenation in the manufacture of shortenings or to manufacture salad oils, margarine oils, etc. If the oil is derived from the extraction of cracklings the product may be suitable for the manufacture of lard or for oleo stockif the cracklings are edible. If the cracklings are not edible the oil may be suitable for choice white grease or choice tallow. The extracted material remaining in the tower may be drawn 011 and subjected to a vacuum flashing operation to remove the solvent. The resulting solid product may be a meal containing the residue from vegetable seeds or cracklings. Such a product is especially valuable for the production of poultry and cattle feeds. Such a feed material enriched with the ingredients. rejected by the solvent may show enhanced food value.
According to another method of operation the solution of the solvent and extracted oil may be subjected to further fractionation in a separate operation. According to one modification of the invention the fractionation may be carried out at low temperatures to separate a solid fraction and a liquid fraction. Thus a solution of propane and cottonseed oil may be subjected under reduced pressure to a vaporization to remove a In my process the materials in substantial amount of the solvent. In the latter operation the heat of vaporization of the solvent is utilized for chilling the oil to a sufficiently low temperature to crystallize stearin or other solid fraction desired to be removed. The resulting product comprising a solution of oil, solvent and crystallized solid is then subjected to filtration to remove the solid fraction.
According to another modification, the solution of solvent and oil removed from the extraction tower may be subjected to a high temperature fractionation operation to separate a liquid fraction of high iodine value from a liquid fraction of lower iodine value. The conditions contemplated in the fractionation tower are a solvent oil ratio of about 30 to 1, temperatures between about F. and 200 F., and pressures from about 500 to 650 pounds. Such high temperature fractionation is a liquid-liquid phase separation accomplished by altering the temperature and pressure conditions of the extracted solution in such a way as to carefully affect the solubility of a certain portion of the oil. Two liquid phasesare caused to develop, the lighter phase containing substantially all of the propane and themore saturated fatty material and the heavier phase consisting essentially of the more unsaturated fatty material with a very small amount of solvent. The two phases are removed from the top and the bottom of the fractionating tower and may be separately treated in strippers to remove the solvent.
In the fractionation operation substantially all of the sensible heat and pressure in the product from the extraction tower are utilized. The sensible pressure in the fatty material may be suificient to meet the requirements in the fractionation tower, but if insuincient the further small increment of pressure may be supplied by a pump. The heat requirements in the fractionation operation are usually in excess of the sensible heat in the fatty material from the extraction tower and accordingly additional heat is usually necessary to be supplied. This heat may be supplied by a suitable direct heat steam coil or by indirect heating electrical coils supplying heat to the outside of the tower.
The invention will be more fully understood by reference to the accompanying drawings in which:
Figure 1 shows digrammatically one form of apparatus for carrying out the process wherein the extraction and fractionation are obtained in a single tower.
. Figure 2 is a diagrammatical sketch of suitable apparatus for carrying out one embodiment of the invention wherein the extracted and decolorized oil is further subjected to low temperature fractionation to separate a solid fraction.
Figure 3 is a diagrammatical sketch of an apparatus adapted for carrying out a two step liquid-liquid phase extraction and fractionation process. 7
Referring to Figure 1, the fatty material to be extracted is charged through the line 5 by a pump 6'to an extraction tower l, which is equipped with means including a drive shaft 8 and pulley 9 for agitating the material in the tower. The details of the tower are notshown but a preferred form is'one containing a series of segmented baflies each equipped with a scraper to force the solids around a tray to the open section and causing them to fall to a succeedingly lower bafiie where the process is repeated.
Propane or equivalent solvent is introduced by the line It] and pump l2 into the lower portion of the extraction tower. In the tower the oleaginous material and solvent pass counter-current under high temperature andpressure conditions whereby the fatty material is selectively extracted from the oleaginous material, the desirable fatty material becoming dissolved in the solvent and the undesirable materials rejected and left in or with the residue. The solution of fatty material in the solvent is drawn from the upper portion of the tower through the line It to a stripper It. The pressure may be reduced on the solution by means of a valve I! to facilitate the flashing of the solvent from the fat in the stripper. The solvent is removed as vapors from the top of the stripper through the vapor line IS. The fatty material is drawn from the bottom of the stripper tower through the line 20.
While I have shown only one stripping tower [6 it is contemplated that a three stage stripping solvent recovery system may be used, the first stage being operated at pressures around 100 pounds and temperatures in the neighborhood of 100 F., the second stage being operated at substantially atmospheric pressure and the third stage being a vacuum steam stripping process.
The residue remaining in the extraction tower I is withdrawn from the bottom of the tower through the line 2| to a vacuum flasher 22. The pressure may be reduced on the material introduced into the flasher by means of a valve 23. Solvent flashed from the residue in the flasher 22 is removed as vapors through the line 24 from the top of the tower. The residual material is withdrawn from the bottom of the tower through the line 25.
In using the apparatus shown in Figure 2 the fatty material is introduced into the upper portion of the extraction tower 32 through the line 39 by the pump 3 I. re extraction tower is substantially the sameas that shown in Figure 1. Propane is introduced into the lower portion of the extraction tower through the line 33 by pump 34.
The temperature and pressure conditions maintained in the extraction tower are such as to obtain selective extraction including decolorization, the light colored fat becoming dissolved in the solvent while the dark colored bodies,
gums, phosphatides, etc. are rejected and remain pressure being partially released if desired by means of the valve 38. The solvent ratio is reduced in the flasher from to l to to 1, required for selective extraction, to approximately 4 or 5 to l. The temperature is reduced in the flasher from 175 F. to 190 F., maintained in the extraction tower, to around 120 F. which is desirable as a charging temperature for the next stage. The vapors of the solvent generated in the flasher 31 are withdrawn through the line 49 to a cooler 4| wherein the vapors condense under the prevailing pressure, the condensate being then collected in the receiver 42. The solution containing the fatty material and unvaporized solvent is drawn from the bottom of the flasher 31 through the line 44 and forced by the pump 45 alternately into the chillers 41 and 48 through the lines 49 and 50 which are equipped with valves 5| and 52. 7
Further vaporization of solvent takes place in chillers 41 and 48 by the gradual reduction of pressure, and as a result the temperature is re duced therein sufiiciently to crystallize a portion of the fatty material. The vapors are withdrawn through the lines 53 and 54, compressed by the pump 55 and passed to line 56. Chillers 41 and 43 are alternately charged so that the continuous operation of the flasher 31 and the filter can be maintained while the chilling operation is carried out intermittently. As one chiller is being charged and cooled the other is being discharged to the filter and made ready for a second charging of hot solution. The charging and discharging times are short in comparison to the time required for the chilling operation so that continuous operation can be maintained by the use of two vessels.
The chilled solution is withdrawn alternately through the lines BI and 62 to a rotary drum type pressure filter 69 which may be a pressure filter of the type shown in United States patent to Keith et al. 2,050,007 wherein the solid crystallized fraction is separated from the solution of fat and solvent. The solid portion is withdrawn through the line 64 to a stripper 65 wherein the solvent is substantially entirely removed, vapors-being withdrawn through the line 66 and the solvent free fat through the line 61. The liquid portion is discharged from the filter through the line 69 to a stripper 10 which is operated substantially the same as the stripper 6.5, vapors being withdrawn through the line H and the solvent free fat through the line 12. Strippers 95 and 19 are preferably three stage solvent recovery systems similar to the stripper l6 described in connection with Figure 1. The residue from the extraction tower 32 is withdrawn through the line 15 to a vacuum flasher 16 wherein the pressure may be reduced by operating the valve Tl. Substantially all of the solvent is vaporized in the flasher 16 and withdrawn through the line 18 for recovery and reuse in the system. The solvent free residue is withdrawn from the line 80.
In using the apparatus shown in Figure 3 the oleaginous material is introduced into the top of the tower 82 through the line 83 and pump 84. Propane is introduced into the lower portion of the tower through the line 85 by the pump 39. The construction and operation of the extraction tower 82 is substantially the same as heretofore described. The residual material is withdrawn from the bottom of the tower through the line 88 controlled by Valve 89 to stripper 90 which is equipped with vapor and solid outlet lines 9| and 92 respectively. The vacuum stripper 99 is operated substantially the same as described heretofore in connection with vacuum flashers 22 and 16 of Figures 1 and 2. The solvent oil solution is withdrawn from the extraction tower through the line 93 and is introduced into the fractionation tower 94 by the pump 95. Additional heat is generally required to accomplish the desired fractionation and such heat can be supplied by a, steam coil 96 or by electrical resistance coils .(not shown). The solvent oil solution is fractionated into two phases, the heavier phase which contains the more unsaturated fatty material is withdrawn through the line 91 and conducted to the stripper 98 wherein a reduced pressure is maintained by valve 99. The solvent vapors are withdrawn through the line 9! and conducted to the stripper 98 wherein a reduced pressure is maintained by valve 99. The solvent vapors are withdrawn through the 75 line I00 to be collected and reused in the system.
The solvent free oil is withdrawn through the line to storage. The lighter fraction obtained in the fractionating tower 94 which consists of essentially all of the propane solvent and the more saturated fraction of fatty material is withdrawn through the line I03 to the stripper I04 wherein a lower pressure is maintained by the valve I05. The operation of this stripper is essentially the same as that described for the stripper iii of Figure 1. The vapors are withdrawn from stripper I04 through the line I01 and the solvent free oil through the line I08 to storage.
As an example of the invention cooked flaked soybeans were slurried with about 10% soybean oil and introduced into the upper portion of an extraction tower which was flooded with propane at a pressure of about 550 pounds. The temperature in the tower was around 175 F. and about a 4 F. temperature gradient wa maintained throughout the column with the higher temperature being maintained at the top of the column. Under these conditions the soybean meal was selectively extracted, the gums, phosphatides and color bodies remaining with the extracted seed particles. The solvent oil solution containing about volumes of propane to 1 volume of oil was conducted to a three stage solvent recovery system, the first. stage being a high pressure flasher having a pressure of around 150 pounds and a temperature about 120 F. The second stage of the solvent recovery was substantially at atmospheric pressure and the temperature was maintained at about 150 F. The final stage of solvent recovery was a. vacuum steam stripping operation to remove final traces of solvent with a pressure of approximately 3 inches of mercury and a temperature of 150 F. The extracted meal was conducted to a vacuum flasher pressure being maintained around 3 inches of mercury to remove all of the solvent. The oil produced had a Lovibond color reading of about yellow, 1.9 red and a free fatty acid content of about .2%. The oil was found suitable for deodorization as a salad oil or for direct hydrogenation as a margarine oil without the normally required steps of caustic soda refining and bleaching. The extracted meal was found to be desirable as a stock feed, its value being slightly enhanced over the normal solvent extracted meal because of the presence of the phosphatides and fatty gums which increased its nutritive value.
As another example of this invention a flaked cooked cottonseed meal slurried with about 10% cottonseed oil was introduced into the upper portion of an extraction tower which was flooded with liquid propane and maintained at about 500 pounds pressure and temperature of around 170 F. A temperature gradient of about 6 F. was maintained throughout the length of the tower, the higher temperature being maintained at the top of the tower. Under these conditions the cottonseed oil is selectively extracted from the meal and a rectification takes place throughout the length of the tower by the gradual rejection of the color bodies, gums, resins and gossypol. The rejected material is withdrawn with the extracted meal which is withdrawn from the lower portion of the tower and subjected to a vacuum flashing operation to completely remove the solvent. This meal has been found desirable as a stock and poultry feed. The extracted oil solution containing around 16 volumes of propane to 1 volume of oil was introduced into a flasher which was maintained at approximately 250 pounds pressure and temperature of about F. The solvent ratio was reduced in this flashing operation to about 4 volumes of propane to 1 volume of oil. The solvent oil solution was then introduced into a large chilling vessel wherein the pressure was slowly reduced and the temperature of the solution lowered at a rate of 1 F. per minute by the gradual evaporation of a portion of the solvent. In the chilling operation the solvent ratio was reduced during the slow evaporation to approximately 4 volumes of solvent to 1 of oil. The final temperature of the solvent oil mixture was about 0 F. at which temperature the more saturated portion of the cottonseed oil, namely the stearin, had separated from the remainder of the solution as crystals. The cold slurry was then filtered in a continuous rotary pressure filter to remove the stearin from the oil solvent solution. The filtrate containing a majority of the solvent and about 92% of the extracted oil was introduced into a three stage stripper similar in operation to the three stage stripper described in the foregoing example. The solvent free oil obtained from the stripping operation was found suitable after deodorization as a salad oil, having a cold test of about 18 hours at 32 F., a Lovibond color of about 25 yellow and 2.5 red, and a free fatty acid content of 2%. The stearin separated in the filtering operation which amounted to 8% of the extracted oil was melted and subjected to a three stage solvent recovery system similar in its operation to that used for the filtrate. The solvent free stearin fraction had a Lovibond color of about 20 yellow and 2.1 red, a free fatty acid content of about .3%, an iodine value of about 63 and a melting point of about 115 F. This material was found desirable as an ingredient for compound shortening due to its light color and higher melting point than is normally obtained from a salad oil operation.
As afurther example of the invention cooked, flaked soybeans were slurried with about 10% soybean oil and introduced into the upper portion of an extraction tower flooded with liquid propane and maintained at about 520 pounds pressure and temperature of around F. Under these conditions a selective extraction of the oil from the beans was obtained and a rectification of the extracted oil was secured by maintaining a temperature gradient of around 5 F. throughout the length of the tower, the higher temperature being maintained in the top of the tower. The undesirable gums, phosphatides and color bodies are rejected from the solvent oil solution and descend through the column and are removed with the extracted meal. The extracted meal and the gums, resins, phosphatides and color bodies are removed from the lower portion of the column and subjected to a vacuum stripping operation to remove the small amount of solvent which is carried out with meal. The solvent free meal is a nutritious poultry and cattle feed due to containing the fatty type material which remains with the meal in this type of extraction process. The solvent oil solution containing around 20 volumes of propane to 1 volume of oil is pumped into a fractionating tower maintained at about 550 pounds pressure and at temperature of around F. A temperature gradient of around 6 F. is maintained in the fractionating tower, the lower portion of the tower being maintained around 172 F. and the upper portion of the tower around 178 F. The necessary heat to raise the temperature of the solvent oil solution and to maintain this temperature gradient was supplied by a series of electrical heating coils surrounding the fractionating tower. Under these conditions a separation of phases occurs, the lighter phase containing essentially all of the solvent and approximately half of the extracted oil rises to the top of the tower and is Withdrawn to a three stage solvent recovery sys tem as previously described. The heavier phase formed in the fractionating tower which contains the more highly unsaturated portion of the extracted oil and around 1% of solvent is withdrawn from the lower portion of the tower and subjected to a solvent recovery system similar in operation to that used for the overhead fraction. In this way the extracted soybean oil was fractionated into two approximately equal portions. The overhead fraction comprising the more saturated glyceride portion had an iodine value of about 121, a Lovibond color of about 17 yellow and 1.7 red, and a free fatty acid content of about 3%. This oil was found to be desirable as an ingredient in shortening products due to its lower iodine value and the lessened tendency towards a reversion in flavor after deodorization. The
more highly unsaturated fraction which was removed from the fractionating tower as the bottom fraction had an iodine value of around 150, a Lovibond color of about 30 yellow and 3.1 red, and a free fatty acid content of about .1%. was found to be suitable as an ingredient in paints and especially in alkyd resin type products due to its unsaturation.
As a still further example of the invention dry rendered pork cracklings were hashed and slurried with about prime steam lard and introduced into the upper portion of an extraction tower flooded with liquid propane at a pressure of about 500 pounds per square inch and a temperature of around 170 F. Under these conditions the cracklings were selectively extracted, the desired lard being dissolved by the solvent and the undesirable color bodies and oxidized fatty material remaining undissolved with the solid tissues. A small amount of rectification was found desirable and was obtained by maintaining about a 4 to 5 F. temperature gradient throughout the length of the extraction tower. This temperature gradient causes a further selective rejection of the undesirable materials. The extracted cracklings and the oxidized fatty material and rejected color bodies were withdrawn from the lower portion of the tower and subjected to a vacuum flashing operation to remove all of the solvent. The solvent free extracted material. was found to be useful as an ingredient in stock feed. The material is superior to the ordinary residue obtained from the de-greasing of cracklings because of its greater stability which is a result of the exclusion of air and the low temperature treatment during the extraction process. The solvent oil solution containing approximately volumes propane to 1 of oil is withdrawn from the upper portion of the extraction tower and subjected to a three stage solvent recovery system similar to solvent recovery units described heretofore. The solvent free fatty material is suitable for use in the compounding of lard. The product had a Lovibond color of about 15 yellow and 1.4 red, and a free fatty acid content of about 2%. It had a very mild and sweet flavor and odor.
The invention has the advantage of providing an extraction process wherein the desirable materials can be selectively extracted from the ole- This oil 10 aginous charge to obtain a highly refined extracted fatty material. The present invention has provided a process for the extraction of partially oxidized fatty material wherein a separation of the oxidized fatty matter from the desirable fats can be obtained during the extraction process. The present invention has an additional advantage of providing an extraction process wherein the color bodies normally present in the extracted fatty material can be rejected during the extraction. A still further advantage is that the present invention provides a process wherein a secondary fractionation of the extracted material can be accomplished without the necessity of removing the solvent used for the extraction. For example a selective extraction wherein the undesirable resins and color bodies are rejected can be immediately followed by a separation of the extracted fatty material into two fractions of high and low iodine number with one cycle of common solvent. The present invention, moreover provides a process wherein the extraction solvent can be partially evaporated under controlled conditions to accomplish a refrigeration of the extracted oil solvent solution to a sufficiently low temperature to cause a portion of the extracted fatty material to crystallize and to be readily separable by a filtration operation. In this manner oleaginous material may be selectively extracted to produce a light colored fatty material free from undesirable phosphatides and gums, and, without the necessity of removing the solvent, a destearinization of the extracted material can be accomplished. Also the present invention provides an extraction process wherein the undesirable material normally extracted is removed selectively in the extraction process eliminating the normally required operation of caustic refining. The present invention also provides a process for the treatment of a variety of crude materials to produce a high grade finished product in a simple and efficient type system.
The present invention provides a continuous process for the extraction, bleaching and fractionation of fatty materials to produce products which are suitable for direct usage after the simple step of deodorization.
Obviously, many modifications and variations of the invention hereinbefore set forth may be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated in the appended claims.
I claim: V
1. A process for the treatment of a material of the class consisting of seed meals, cracklings and bleaching earth to recover decolorized fatty material therefrom, which comprises, subjecting the material to the action of a liquefied normally gaseous hydrocarbon solvent in a solvent-oil ratio of between about 15 to 30 volumes of hydrocarbon to 1 volume of oil at temperatures of about 150 to 200 F. to dissolve the relatively light color fatty materials while leaving the undesirable dark color bodies undissolved with the nonfatty materials and under pressures sufficiently high to maintain the solvent in the liquid phase, and separating the solution of decolorized fatty material from the residual undissolved materials.
2. A process for the treatment of a material of the class consisting of seed meals, cracklings and bleaching earth to recover decolorized fatty material therefrom, which comprises, contacting the material with a liquefied normally gaseous hydrocarbon solvent, maintaining the temperature above about 150 F. and below the critical temperature of the hydrocarbon and under sufficient pressure to maintain the hydrocarbon in the liquid phase and maintaining a solvent-oil ratio of between about 15 to 30 volumes of hydrocarbon to 1 volume of oil to form a liquid fraction containing deco'lorized fatty materials and a solid fraction containing proteinaceous material, color bodies and other residual oleaginous material, and separating said fractions.
3. A process for the treatment of a material of the class consisting of seed meals, cracklings and bleaching earth to recover decolorized fatty material therefrom, which comprises, treating the material under liquid phase conditions with a liquefied normally gaseous hydrocarbon solvent in a solvent-oil ratio of between about 15 to 30 volumes of hydrocarbon to 1 volume of oil at temperatures within the range of about 150 to 200 F. While maintaining the solvent in the liquid phase whereby color bodies are rejected by the solvent and the fatty material is decolorized, separating the solution of decolorized fatty materials, promptly subjecting said solution to a fractionation operation under slightly higher temperature conditions than maintained in said firstmentioned treating operation, maintaining a solvent-oil ratio of approximately 30 volumes of hydrocarbon to 1 volume of oil while maintaining the hydrocarbon in the liquid phase whereby the solution separates into two phases, one phase being relatively rich in higher iodine value fatty materials and the other phase being relatively rich in lower iodine value fatty materials, and separating said phases.
4. A process for the treatment of a material of the class consisting of seed meals, cracklings and bleaching earth to recover decolorized fatty material therefrom, which comprises, contacting the material under liquid phase conditions with a liquefied normally gaseous hydrocarbon, regulating the temperature within the range of about 150 to 200 F. and the amount of solvent within the range of solvent to oil ratio between about 15 to 1 and 30 to 1 while maintaining the solvent in the liquid phase whereby color bodies are rejected by the solvent and the fatty material is decolorized, separating the solution of decolorized fatty materials, promptly vaporizing a major portion of the solvent by reducing the pressure thereby chilling the solution to slightly above the crystallizing temperature of the fatty materials, then further vaporizing solvent so as to reduce the solvent-oil ratio to approximately 4 volumes of hydrocarbon to 1 volume of oil thereby chilling the solution whereby a portion of the fatty materials crystallize, and separating the crystallized portion from the solution.
5. A process for the production of salad oil, which comprises contacting cottonseed meal with a liquefied normally gaseous hydrocarbon solvent in a solvent-oil ratio of between about 15 to volumes of hydrocarbon to 1 volume of oil, maintaining the pressure suiiiciently high to retain the hydrocarbon in the liquid phase and the temperature above about F. and below the critical temperature of the solvent to dissolve the cottonseed oil and to cause the color bodies, gums and phosphatides to remain undissolved with the meal, separating the solution of cottonseed oil and solvent, subjecting said solution to controlled evaporation of the hydrocarbon solvent thereby reducing the solvent-oil ratio to approximately 4 volumes of hydrocarbon to 1 volume of oil whereby the solution is chilled to approximately 0 F. by said evaporation and thestearin in said cottonseed oil is crystallized, separating said stearin and recovering the destearinized cottonseed oil.
6. A process for the production of a high iodine value fraction of soybean oil, which comprises contacting soybean meal with a liquefied normally gaseous hydrocarbon solvent in a solventoil ratio of between about 15 to 30 volumes of hydrocarbon to 1 volume of oil, maintaining the pressure sufficiently high to retain the hydrocarbon in the liquid phase and the temperature above about 150 F. and below the critical temperature of the solvent to dissolve the soybean oil and to leave the color bodies, gums and phosphatides with the seed meal, separating the solution of soybean oil and solvent, subjecting said solution to temperatures between about F. and 200 F. and pressures within the range of 500 to 650 pounds per square inch such as to cause the solution to separate into two liquid phases, one of said phases being rich in oil of lower iodine value and the other of said phases being rich in oil of higher iodine value, separating the phases and recovering the higher iodine value oil.
WILLIAM M. LEADERS.
REFERENCES orrnp The following references are of record in the file of this patent:
UNITED STATES PATENTS