US2292822A

US2292822A - Refining of animal and vegetable oils

Info

Publication number: US2292822A
Application number: US406062A
Authority: US
Inventors: Clayton Benjamin
Original assignee: REFINING Inc
Current assignee: REFINING Inc
Priority date: 1941-08-08
Filing date: 1941-08-08
Publication date: 1942-08-11
Anticipated expiration: 1959-08-11

Description

Aug. 1l, 1942. B, CLAYTON v 2,292,822

` REFINING oF ANIMAL AND VEGETABLEQILS Filed'Aug. a,v 1941 Berg/amm Ulayon,

a 74m, mavwum www Patented Aug. 11, 1942 Benjamin Clayton, Houston, Tex., assignor to Rening, Inc., Reno, Nev., a corporation of Nevada Application August 8, 1941, Serial No. 406,062

14 Claims. (Cl. 26o-425) This invention relates to a process of refining glyceride oils, and more particularly to a process in which the color of the oil is reduced prior to neutralization of the free fatty acids in order to enable neutralization to be carried out in a manner'which does not causek saponification of neutral oil.

This invention is particularly adaptable to highly colored oils, such as cottonseed oil, but is advantageous for refining various other oils, such as soya bean oil, corn oil, sesame oil, rapeseed oil,

etc., and may be employed in refining other glycl eride or fatty oilssuch as animal and ilsh` oils. Many oils, particularly cottonseed oil, are highly colored. and this color must be reduced to produce a commercially acceptable oil. It has been Vthe practice in refining such oils to'empl'oy a ried on so as to assist in removing color from the oil.` Thus, degumming agents having bleaching properties such` as oxygen liberating materials,

caustic alkali., usually caustic soda, as a reiiningv reagent and use a considerable excess of such reagent for reaction with color impurities in the oil. However, caustic alkalies saponify neutral oil and, when employed in the necessary excess, cause substantial refining losses due to saponication of neutral oil. Other neutralizing reagents, such as sodium carbonate, trisodium phosphate, sodium silicate, etc., or equivalent potassium salts, will neutralize the free fatty acids,

Abut will not substantially reduce the color of the oil. The same is` true of such neutralizing agentsas ammonia or amines, for example, methylamine, ethylamine, or triethanolainine. vIn general, neutralizing reagents other than caustic alkalies have the advantage ofnot attacking neutral oil, but have not been extensively employed because they do not substantially reduce the color of the oil. Bleaching agents, or color adsorbents. such as acid treated clay, iullers earth, activated carbon, etc., when employed in bleaching processes subsequent to treating with neutralizing re.. agents other than caustic alkalles, are also no It has been foundv that the color adsorbents ljust referred to are eilective to" reduce the color of the oil to within commercial limits,'if employed prior to neutralization treatments. Vegetable oils" in general, however, contain substantial'.

quantities of gummy materials, such as phosl'- phatides, proteins, resins, etc., which interfere with fthe'employment of the bleaching. materials referred to.A In the presence of such gums, large amounts of color adsorbents are necessary. Also,

the 'gums interfere .with the separation of the adsorbents from the oil and cause a. large-amount of valuable oil to be retainedtherein. Itis possible to recover a portion of this oil from the adsorbent,

butin the presence of the gums referred the oil 1s `o1' poor quality. By treating an oil which has been denuded of gums with a color adsorbent, it has been found that the color of the oil issubstantially reduced, and that the amount of adsorbent necessary and the amount of oil retained in the adsorbent are markedly reduced.

Also, a major portion of this oil can be recovered.

as high quality oil by treating the lter cake with an oil solvent. The present invention, therefore, contemplates removing gums from the oil prior to the employment of color adsorbents or starting with an oil which is substantially free of gums and treating this oil with a color adsorbent.

In addition, the degumming step may be car'- Afor example, solutions of hydrogen peroxide, organic peroxides, alkali metal or alkaline earth` metal peroxides, hypochlorites, Aperborates, per-- carbonates, persulphates, etc., may be yemployed as part or all of the Adegumming agent to produce` a degummed oil of lighter color so as to reduce the amount of color adsorbent necessary to be used in the following step. Furthermore, certain degumming agents which do not liberate oxygen, for example, boric acid, have color removing properties whenthe mixture of crude oil and degumming agent is subjected to relatively high temperatures. With some oils suiiicient color re-V duction may be accomplished by solutions of ther v abovementioned forming part or all of the degumming agents so that treatment with an adsorbent after degumming is rendered unnecessary.

As indicated above, effective color reduction can thus be produced, and the oil conditioned for treatment with neutralizing agents which do not substantially-reduce color. It is preferred to employ a non-saponifyingneutralizing agent* which will not lattack neutral oil. However, caustic alkalies in amounts substantially equivalentto the free fatty vacids can be Aemployed with or without additional non-saponifying neutralizing agent without substantial attack on neutral oil. Also, the soap stock resulting from neutralization'is relatively free from gums and coloring materials, so that entrainment of neutral oil' therein is lessened and such'entrained oil can be recovered as high quality oil.

It is, therefore, an object of the present invention to 'provide a process of refining animal and vegetable Oils in which oils substantially free of gums are treated with bleaching agents prior to neutralizing the free vfatty acids thereof.

Another object of the invention is to provide a process of refining glyceride oils in which refining losses are minimized by preventing saponiflcation of neutral oil in the neutralizing step while produoingaq oil ofaocoptable color.; A furthenobiect of e inventionlis tovprovide a process of refining fatty oils in which the oil is bleached in a manner avoiding substantial losses of neutral oil and then subjected to neutralization and separation of resultin'g'soapstbc; in"

which steps saponiiication of neutral oil and entrainment of oil in the soap..stock can,be largely prevented.

Other objects and advantages of the invention will appear in the following deecription of the invention given in connection with 'the attached drawing which is a diagrammatic showing of'an apparatus suitable for carrying out a preferred process.' f -The l`apparatus riisclosedfis' capable of' being usedto carry out ay process in which the oil vis continuously degummed," treating with a color adsorbent-to reducethe color thereof, then 'continuously treated ywith e; neutralizing agent,'and the resulting soap stock continuously separated from the 011:' --As will appearbelow, certain' of the steps referred` to'maybe carried on as'batch operations, and' still provide an improved process..

"Referring more'particularly to the drawing, crude bilis withdrawnfroma source of supply shownas aftank HJ by a pump II and forced through a'heat 'exchanger 'I2 to a'mixlng device It` The heatexchangedevice I2 may include afooil -I4- through-which-theoil' is passed and erasing" I5'surrounding the' coil I4. Any suitable'lr'eating medium may be circulated through the casing` I5 inorder to heat the' oil. A de'- gummingreagent is withdrawn from asource of supply'shown as a tank' I6 'by apump I1 and delivered to themixing' device I3." The pumps lHani'l: I1 are shownas being driven by a varia- 'blespeed eiectricmotor-'with' a variable speed device-18' positioned between' the motor and the pump -I I: .'Ihis'provides for delivering accurately proportiohed'streams' of" oil' and degumming reagent'under pressure to'the' mixer I3, but any other suitable type of proportioning mechanism Lmay be employed in lieu thereof; "I'he mixer I3 is 'preferably "closed -from the -'atmosphere and ofthe flow type in' which a'streambf degummin'g reagent is iniectedatright angles into a flowing stream of-oiL-'but may-be many-suitable type of flow mixer'such as' a"closed'mechanical' 'agitator. The degumming reagent, when admixed 'with the oilin the mixer I3 precipitates the gummy materials 'contained inthe 'oil and the agent is preferably passedthrough a -second heat exchange device 20, which maybe similar to the heat exchange device l2-and delivered to a continuous eentrifugalseparator 2l. 'I'he separator 3l ispreferablyof the heated type similar to that disclosedinPatent No., 2,100,277., granted Novem'- ber 2 3, 1937, butzmay be of any type of separator `capable'pf sc eparatingl gums from oil. 'I'he gums are dischargedl from thecentrifugal separator as the heavy eilluent, through a spout 22 into a receiver23, and refined oil i's discharged as the iight 'emeht 'through epipe za.

'I'he oil discharged'frox'n the centrifugal separator 2i' is'subs'tantia'lly free of gummy mate- 4rials and may-'be' d'irectly'di's'charged into a mixing tank 25 iii wlch it is mixed with 'a bleaching or color reducing agent such as an adsorbent earth. A second tank 28 is shown so that the oil may be delivered into one of these tanks, while another body of oil is being mixed with the bleaching agent in the other tank and discharged therefrom. Thus, by opening the valve in the pip e21 connected to the tank 25 and closing the v`alvein the pipe 28co'nnected tothe tank 25, oil may be delivered from lthe centrifugal separator 2| into the tank 25. Conversely, by closing the valve on the pipe 21 and opening the Valveon the pipe 2 8, oil may be discharged into the tank 28. Each olf the

tanks

25 and 28 may beipiovlded with an agitator 28 driven from any 15..'suitable source of power through a pulley or Asprocket 20. Tanks 25 and 2l may also be provided with heat exchange coils 2I through which any'deslrable heating or cooling medium may be circulated in order to maintain the oil in the tanks at a desired temperature. The tanks 25 andv 28 are preferably closed to the atmosphere in order-toprevent contact between the atmosphere and the heated oil in the tanks and also prevent air from being stirred into the oil during agitation thereof. 'Adsorbent earth or other bleaching agents may be introduced into. the

tanks through a hopper 32 for each tank. Thus, mixing with the bleaching agent and withdrawal of oil from one tank may take place simultaneously with introduction of oil into the other tank. Alternatively, mixing and introduction of oil may take place simultaneously in one tank while oil is being withdrawn from the other tank.

'i The oil can be withdrawn from the

tanks

25 and 26 b'y means of a pump 82 driven by a motor 84.v1 By opening the valve in the pipe 25 connected to the tank 25 and closing the valve in the pipe"'36 connected to the pipe 28,' oil is withdrawn'from the tank 25; and conversely, closing the valve'in the pipe 85 and opening the valve in the pipe .36 allows oil to be withdrawn from the tank'26. 'Ihe agitator 29 in the tank from which the oil is being withdrawn is preferably maintained in motion during withdrawal so as to maintain the bleaching agent in substantially uniform admixture with the oil.

'The mixture of oil and bleaching material is then'delivered to a filter press 51 or a lter .press 38. vTwo filter presses have been shown, in' order to provide for filtration in one filter press while the other is being cleaned. As many filter presses as necessary to provide for continuous filtration of oil or a continuous filtration system may be employed. The filtered 'oil from either of the filter presses 31 or 38 is discharged therefrom through a pipe 39 into a container 40 which is preferably a. closed tank provided .with a -vent 4I. The ltered oil collected in thel tank 40 is'free of gummy materials and is of reduced color, but still contains free fatty acids. The filtered oil may be withdrawn from the tank 40 by a pump 42 and passed through `a heat exchanger 43 to a mixer 44. A neutralizing'agen't' is'withd'rawn from a source of supply shown as a tank 45 by a pump 46 and delivered to' the mixer 44. The pumps 42 and 46 may be driven by a variable speed electric motor 41 with` a variable speed device V48 positioned between the motor and the pump 42, although any other apparatus capable of delivering accurately proportioned streams to the mixer 44 may be employed. 'I'he mixer 44 is also preferably 'of the flow type in which a stream of the neutralizing reagent is injected at right angles into a flowing stream of the oil, but, as in the case of vacuum y from the vacuum chamber 50 by mixer I3, may be any type of now mixer such as a closed mechanical agitator. The neutrallz' ing agent reacts with the free fatty acids of the oil to produce soap stock, and the mixture of oil and soap stock is preferably passed through another heat exchanger 49 and delivered into a vacuum chamber 50.

The vacuum chamber 50 is preferably provided with a heating jacket through which any desired heating medium may be circulated and with a steam distributor positioned in the lower portion of the tank to enable steam, preferably superheated, to be passed through a body of oil contained in the. vacuum chamber 50. The chamber 50 is employed to remove vaporizable material, including at least a portion y of the water in admixture therewith, and any gases such as air or carbon dioxide occluded in amount of water, it is many times advantageous to dry this oil before delivering it to the mixing

tanks

25 or 26. This may be accomplished by delivering the oilto a dehydrating chamber through a pipe 16 by closing the valve 11 in the pipe 2l and opening the valve 18 in the pipe 15. The chamber 15 may be provided with a heating coil 19 and a vacuum pump 8| connected to the chamber through a condenser 82 and a receiver 83 lfor removing moisture from the oil. The dried degummed oil 'may be continuously removed from the dehydrating chamber 15 by a pump 54 and returned tothe pipe 24 for delivery to the mix the soap stock particles. Vapors and gases are l 'vaporizable' materials including water are con` densed material may be withdrawn from the receiver 51, for example, by means of a pump (not shown) through a pipe 58'. A vacuum pump 59 connected to the receiver 51 is provided for withdrawing uncondensed 1gases and maintainingja vacuum in the vacuum chamber 50. The mixture of oil andsoap stock is preferably delivered linto the vacuum chamber 50 through nozzles SII positioned so as to direct the mixture against the heated walls of the vacuum chamber so that the 40 mixtureilows` down the walls as a thin film.

This provides for eflicient separation of gases and vapors from the mixture-and further provides for unobstructed passage for thel gases and vapors inwardly and \upwardly through the vacuum chamber to the pipe 53 so asto minimize en` trainment in said gases and vapors. y

The dehydrated mixture of oil and soap stock, which is substantially free of gases, is withdrawn stock therein. Alternatively, the weighting liquid ,and bases.

ing tanks

25 and 26.

In the preferred process carried out in the above described apparatus, effective degumming with most oils is produced by preheating the oil from thevtank I0 in the heat exchanger l2 tor a temperature between 110 and 160 F.,prior to admixture with a a degumming reagent. With other oils, it has been found most eifective to mix at lower temperatures, for example, temperatures from 70 to 100 F., 'and then heat lto a desired y temperature of separation in the heat exchanger 20, in which case the heat exchanger v I2 may be eliminated for the lower temperatures of mixing. As isclosed in the copending application of Benjamin H. Thurman, Serial No. 2l3,700,.iiled June 14, v1938, there is an optimum temperature and treating time between mlxing'and separation for eachoil being degummed, such that no definite range of temperatures vorltreating Atimes ca'n be "given for all oils contemplated -by the present process. The temperature of separation and treatment and-time of treatment will not only dependupon the particular oilbeing treated but- Y also upon the type of degumming reagent employed. The degumming reagentmay be water.

alone,aqueous solutions of neutral salts or weak acids or bases or dilute solutions of strong acidsV The degumming reagent also preferably includes a soluble alkali thiosulfate or thiocyanate, asdisclosed in the copending application of Benjamin H. Thurman, Serial No. 248,355, filed December 29, 1938, as more liquid gums are thereby produced and less oil is entrained in the gums separated from the. oil in the separator 2l. Thel `continuousdegumming operation disclosed 'above is preferable, as a substantially complete'sepaapump 5I and 50 Vdelivered through a pipe 62, heat exchanger 53 y may be delivered into the pipe 52 between Ithe g pump 6I and the vheat exchanger 63 through a pipe 69 or centrifugalseparator 65 mayhave prothe tankSB ,directly into thecentrifugal bowl. `In any case, the separator is preferably of the heated/typel disclosed in the patent above referred to, although any type of centrifugal sepa-l rator capable of separating the'soapstockfrcmthe oil may'beemployed, Soap stock, along-withl vision'for denvering the weighting liquid from 959 ratiorrofy the gums from the oil is effected, and the entrainment of neutral oil in the `gums is markedly reduced., However, it is possible to produce a degummed oil in which either-the mixing or separation steps, or both, are batch operations. Thus, the oil and-degumming reagent, such as ,water, may be yadmixed in a tank and the gums allowed to settle from the oil,A or ya continuous, mixing step maybe combined 'with a gravity settling steplor a continuous centrifugalsepal i' ration step combined with a batch mixing step.-

Such batch operations, however, tend to 'set greater losses due to entrainment ofo'il in the dependy upon the process employed, the type of oil.`

weighting liquid, is` discharged as the heavy eillu- 'l foots. The amount of degumming -reagent will being treated, and the nature of the rdegumming reagent, andmay range between `wide limits,A for example, from` 1% 'to 50%.

chloritesabo've-mentioned, in whichcas'e it may be possible` to eliminate a subsequent step -of- The degumming agent mayv include -a soluble bleaching agent such as the peroxides or yhypohigh temperature treatment in the presence of boric acid as the degumming agent has a marked eilect in reducing color so as to reduce the amount of subsequently used color adsorbent or to make it possible to eliminate such a subsequent step. Ordinarily, any high temperature treatment of oils containing gums and coloring matter tends to "set the color in the oil so as to render its subsequent removal more diiiicult. However, the reverse is true when employing a solution of boric acid as a degumming agent alone or in combination with other degumming agents. The high temperature referred to will usually range between 200 and 550 F., depending upon the amount of color it is necessary or desired to remove, and may be secured by preheating the oil in the heat'exchanger I2 or heating the mixture in the heat exchanger 20. Separation may in some cases be performed at the high temperature, but the mixture may be cooled before separation, if desired. l

The color -adsorbent employed as a bleaching agent to bleach the substantially gum-free oils prior to alkali refining will also depend upon the nature of the oil being treated. For example, with highly colored cottonseed oil an extremely active bleaching agent, such as acid treated clay,

temperatures. so as to assist in vaporizing water and other vaporizable vmaterials from the mixture of oil and soap stock and also to assist in may be required, while with oils containing less I colors, such as corn oil, a less -drastic bleaching agent such as fullers earth or even activated carbon may be suflicient. Other examples of adsorbents which may be employed depending upon the nature and amount of color to be removed are aluminum oxide, aluminum silicates. diatomaceous earth, etc. 'I'he temperature of treatment of the oil with thesolid bleaching agent will also vary with the oil being treated and the amount of color reduction necessary. Certain of the oxygen liberating bleaching agents may likewise be employed with the color adsorbents, if the color is dimcult to remove. Thus, temperatures from substantially room temperatureVi. e., 70 F. for light colored oils, up to as high as 200 to 400 F. for extremely dark colored oils may be required. This temperature may be adjusted by means of the heat exchange coils 3| located in the tanks 26, or, alternatively, a heat exchange device may be employed between the centrifugal separator 2| and the tanks and 26. The oil may be a1- ternately mixed with the bleaching agent in the

tanks

25 and 26 and delivered to the filter` presses 31 and 38 or a continuous mixing step may be,

employed. The iilter presses may be of any conventional type capable of separating the bleachlng agents along with adsorbed color from the oil. Also, it is possible to separate the bleaching agent from the oil by continuous ltering devices or by centrifugal separation, for example, continuous centrifugal separation with a iiushing liquid for continuously washing the separated bleaching agent along with adsorbed color impurities from the centrifuge.

The heat exchanger 43 is employed to provide' an optimum temperature of mixing between the neutralizing agent and the oil. This temperature will depend upon the oil being treated and the neutralizing agent. Preheatingis desirable in some cases, in which case mixing may take place at temperatures between approximately 110 and 160 F., while in other cases mixing at relatively low temperatures, for example, between and 100 F. produces best results. The heat exchanger 49 may be employed to add heat to the mixture, particularly if mixing is at low driving oi! gases such as air occluded in the oil or carbon dioxide produced during neutralization. If preheating is employed, the heat exchanger 49 may be eliminated, and,the mixer M positioned closely adjacent the vacuum chamber 50. By positioning the mixer 44 closely adjacent the vacuum chamber 50. the vacuum may extend into the mixer 4Iv such that mixing is under vacuum conditions. Alternatively, the oil and neutralizing agent may be delivered as separate streams directly into the vacuum chamber Il so as to provide for mixing therein. The heating jacket 5! for the vacuum chamber 50 may be employed to maintain a desired treating temperature in lthe vacuum chamber 50, and also superheated steam may be passed through a body of oil and soap stock in the chamber 50 to assist in carrying ofi the gases and vaporizing materials and supply additional heat to the mixture.

It is difficult to separate soap stock produced by neutralizing degummed oil from the oil without leaving a large amount of soap stock in the oil or a large amount of oil entrained in the soap stock. By dehydrating the mixture of oil and soap stock in accordance with the preferred process and then introducing a weighting liquid into the mixture shortly before it is delivered to the separating zone of the continuous centrifugal separator, an effective separation of the oil and soap stock can be obtained to produce a clean oil and a soap stock containing very little entrained oil. In this process, the heat exchanger 63 may be employed to adjust the temperature of the oil-soap stock mixture to that found most effective for separation of the oil being treated. This temperature will ordinarily vary from to 160 F. If the oil withdrawn from the vacuum chamber 50 is at the most effective temperature for separation for the particular oil being treated, the heat exchanger 83 may be eliminated, although with certain oils it has been found more effective to introduce the water into the oil-soap stock mixture through the pipe 69 so that the mixture of oil-soap stock with the weighting liquid is passed through the heat exchanger 63, irrespective of whether this heat exchanger is employed to produce a change in temperature of the mixture. Although the vacuum treatment followed by continuous centrifugal separation in the presence of a weighting liquid is preferred, it is possible to settle the soap stock from the oil. This settling step may be combined with continuous mixing. as above described, or both the mixing and settling steps may be carried on as batch operations. Since non-saponifying neutralizing reagents or no substantial excess of saponifying neutralizing reagents are employed, no substantial attack on the neutral oil is produced, even in batch alkali refining operations. If sodium carbonate is employed as the neutralizing reagent in a batch operation, it is preferred to mix under vacuum conditions, or at least subject the resulting mixture of oil and soap stock to vacuum conditions prior to settling, in order to eliminate carbon dioxide. The presence of a vweighting liquid is also desirable in batch settling steps, in which case the weighting liquid is usually a relatively concentrated aqueous solution of sodium chloride or other alkali metal salt. The soap stock separated by a settling operation usually contains a large amount of entrained neutral oil,

escasas but because of the absence of substantial amounts of gums or coloring material in the soap stock, this oil may be recovered as high quality oil from the soap stock by diluting the same with water and again settling or centrifugally separating or by solvent extraction with an oil solvent..

It is also possible to employ with advantage vaporizable neutralizing reagents which do not attack neutral oil, for example, ammonia or amines such as referred to above. With such neutralizing agents, the soap stock produced is ordinarily flowable and no weighting liquid is usually necessary. Also. vacuum treatment of the mixture is omitted, as such treatment would remove the neutralizing reagent to again leave free fatty acids in the oil. 'Ijhe soap stock produced by ammonia, amines or other vaporizable neutralizing reagents is preferably continuously centrifugally separated from the oil, but may valso be settled therefrom. When employing such vaporizable neutralizing reagents in the process, the mixing and separating is preferably carried on in a closed system under pressure to prevent loss of neutralizing agent. One advantage of such neutralizing agents 'is that the soap stock produced may be subjected to vacuum treatment to remove the neutralizing agent for reuse in the process and also to produce fatty acids.

It will be seen that I have provided a process wherein the oil is neutralized under conditions in which there is no substantial attack on the neutral oil so as to reduce refining losses due to saponification of neutral oil. Thus refining reagents which will not attack neutral oil can beemployed. and also caustic alkalies can be employed in amounts substantially chemically equivalent to the free fatty acids contained in ceride, thereafter neutralizing the free fatty acids of said glyceride under conditions preventing substantial saponification of neutralglyceride, adding a solution of an ,alkali metal salt to the resulting mixture of oil and soap stock, and

thereafter neutralizing the free fatty acids of said glyceride under conditions preventing substantial saponication of neutral glyceride, adding a solution of an alkali metal salt to the resulting mixture of oil and soap stock,land thereafter` continuously centrifugally separating the soap stock from said glyceride in the presence l of said added solution.

3. The process of rellning glyceride oils and fats .containing gums, color impurities and free a solution of an alkali metal salt to the resultthe ons. The neutralizing without substantial attack on the neutral oil is made possible by removing color impurities from the oil prior to neutralization. Thus, it is unnecessary to employ caustic alkalies in excess to reduce color. The removal of color impurities prior to neutralization by treatment with color adsorbents `my co-pending application, Serial No. 248,330,

filed December 29, 1938.

While, I have disclosed the preferred embodiment of my invention, it is understood that the details thereof maybe varied within the scope of the following claims.

I claim:

l. A process of refining glyceride oils and fats containing gums, color impurities and free fatty acids, which comprises, admixing a stream of an aqueous degumming reagent with a stream of said glyceride to precipitate gums therein, delivering the resulting stream to a centrifugal separator and continuously centrifugally separating the precipitated gums from said glyceride, treating said glyceride with an adsorbent material for color impurities and removing said adsorbent along with said color impurities from said glying mixture of oil and soap stock, and thereafter separating the soap stock from Isaid glyf ceride by difference in specific gravity in the v presence of said added solution.

4. 'Ihe process of refining glyceride oils and fats containing gums, color impurities and free fatty acids, which comprises, removing said gums` from said glyceride, thereafter treating said glyceride with an adsorbent material for color impurities and removing said adsorbent along with said color impurities from said glyceride, thereafter neutralizing the free fatty acids of said glyceride with an aqueous solution ofV sodium carbonate to prevent substantial saponiiication of neutral g1yceride,.adding a solution of an alkali metal salt lto the resulting mixture o f oil and soap stock, and thereafter separating the soap stock from said glycerides by difference in specific gravity in the presence of said added solution.

5. The 4process of refining glyceride oils and fats containing gums, color impurities and free fatty acids, which comprises. removing said gums from said glyceride, thereafter treating said glyceride with an adsorbent material for color impurities and removing said adsorbent along with Said color impurities from said glyceride. thereafterneutralizing the free fatty acids of said glyceride with a non-saponifying alkali, adding a solution of an alkali metal salt to the resulting mixture of soap stock, and thereafter separating the soap stock from Said glyceride by difference in specific gravity in the presence of said added solution.

6. The process of refining glyceride oils and fats containing gums, color impurities and free fatty acids, which comprises, removing said gums from said glyceride, thereafter treating said glyceride with an adsorbent material for fcolor -stock while preventing substantial saponification of neutral glyceride, rehydrating said mixture of glyceride and soap stock and separating said soap stock from said glyceride by difference in specific gravity.

7. The process of refining glyceride oils and fats containing gums, color impurities. and free fatty acids, which comprises. removing said gums from said glyceride, thereafter treating said Y glyceridewith an adsorbent materiab for color impurities and removing said adsorbent along with said color impurities from said glyceride, thereafter neutralizing the free fatty acids of said glyceride with sodium carbonate, adding a solution of an alkali metal salt to theresulting mixture of oil and soap stock, and thereafter continuously centrifugally separating said soap stock from said glyceride in the presence of said added solution for causing said soap stock to separate from .said glyceride and iow continuously from the centrifugal separator employed.

8. The process of refining glyceride oils and fats containing free fatty acids and color impurities, which comprises, treating a glyceride substantially free of gummy materials with a color adsorbing material, separating said adsorbing madioxide and other vaporizable and gaseous materials to be separated from the resulting mixture to produce a substantially dehydrated mixture of glyceride and soap stock, thereafter mixing a stream of said mixture with a stream of rehydrating liquid for said soap stock -and continuously centrifugally separating said soap stock from said glyceride in the presence of said rehydrating liquid.

11. The process of refining glyceride oils and fats containing free fatty acids and color impurities. which comprises. treating a glyceride substantially free of gummy materials with a color adsorbing material, separating said adsorbing material from said glyceride along with color impurities, thereafter neutralizing the free fatty acids of said glyceride under conditions preterial from said glyceride along with color impurities, thereafter neutralizing the free fattyA acids of said glyceride with a non-saponifying neutralizing agent, subjecting the resulting mixture of glyceride and soap stock to vacuum treatment sufficient to remove water and other volatile materials from said mixture, and continuously centrifugally separating said soap stock from said glyceride in the presence of a rehydrating medium for said soap stock.

9. The process of refining glyceride oils and fats containing free fatty acids and color impurities, which comprises, treating a glyceride substantially free of gummy materials with a color adsorbing material, separating said adsorbing material from said glyceride along with color impurities, thereafter neutralizing the free fatty acids in said glyceride with sodium carbonate, subjecting the resulting mixture of glyceride and soap stock to vacuum treatment suihcient to remove water and other volatile materials from said mixture, and continuously centrifugally separating said soap stock from said glyceride in the presence of a rehydrating medium for said soap stock.

10. The process of refining glyceride oils and fats containing free fatty acids and color impurities, which comprises, treating a glyceride substantially free of gummy materials with a color adsorbing material, separating said adsorbing material from said glyceride along with color impurities, thereafter mixing an aqueous solution of sodium carbonate with said glyceride under suicient vacuum to cause water, carbon venting substantial saponiilcation of neutral glyceride, adding a solution of an alkali metal salt to the resulting mixture of oil and soap stock, and thereafter separating the soap stock from said glyceride by difference in specic gravity, in the presence of said added solution.

12. The process of refining glyceride oils and fats containing gums. color impurities and free fatty acids, which comprises, removing said gums from said glyceride, thereafter treating said glyceride with an adsorbent material for color impurities and removing said adsorbent along with said color impurities from said glyceride, thereafter neutralizing the free fatty acids of said glyceride under conditions preventing substantial saponiflcation of netural glyceride, adding a solution of an alkali metal salt to the resulting mixture of oil and soap stock, and thereafter separating the soap stock from said glyceride by difference in specific gravity, in the presence of said added solution.

13. The process ofreilning glyceride oils and fats containing gums, color impurities and free -fatty acids, which comprises, removing said gums and substantially all of said coloring matter from said glyceride oil, thereafter neutralizing the free fatty acids of said glyceride under conditions preventing substantial saponiflcation of neutral glyceride, adding a solution of an alkali metal salt to the resulting mixture of oil and soap stock, and thereafter separating the soap stock from said glyceride by difference in specific gravity, in the presence of said added solution.

14. 'Ihe process of refining glyceride oils and fats containing gums, color impurities and free fatty acids, which comprises, admixing a degumming agent containing a color reducing agent with said oil, separating the precipitated gums and coloring matter from said oil, thereafter neui tralizing the free fatty acids of said glyceride under conditions preventing substantial saponiflcation of neutral glyceride, adding a solution of an alkali metal salt to the resulting mixture of oil and soap stock, and thereafter separating the soap stock from said glyceride by difference in specific gravity, in the presence of said added solution.

BENJAMIN CLAYTON.