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Publication numberUS2383614 A
Publication typeGrant
Publication dateAug 28, 1945
Filing dateOct 17, 1942
Priority dateOct 17, 1942
Publication numberUS 2383614 A, US 2383614A, US-A-2383614, US2383614 A, US2383614A
InventorsHenry Percy Joseph
Original AssigneeColgate Palmolive Peet Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Treatment of fatty glycerides
US 2383614 A
Abstract  available in
Images(5)
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Claims  available in
Description  (OCR text may contain errors)

Aug. 28, 1945. PERCY 2,383,614

TREATMENT OF FATTY GLYCERIDES Filed 001;. 1'7, 1942 5 Sheets-Sheet 1 FATTY ALCOHOLYSIS GLYCERIDE METHANOL CATALYST V v v METHANOL SODIUM SOLUTION 0F CHLOR'DE ALCOHOLYSIS BED CATALYST J ESTERS RESIDUE if 't r CONTACTOR REACTOR J SETTLING TANK ALCOHOL SETTLING STlLL GLYCERINE TANK 1 .l. GLYCERINE INVENTOR JOSE-PH HENRY PERCY iORNE;

Aug. 28, 1945. J PERCY 2,383,614

TREATMENT OF FATTY GLYCERIDES Filed OCT,- 17, 1942 5 Sheets-Sheet 2 ETHYL ALCOHOL FATTY SOLUTION OF GLYCERIDE ALCOHOLYSIS CATALYST v ALCOHOL REACTOR STILL ESTERS w h T SETTLING sETTTklllbaG TANK GLYCERINE GLYCERINE RESlDuE 5 2? METHYL ALCOHOL OIL AND CATALYST CONTACTQR MIXER ESTEIRSF SETTLING 4 CTOR ALCOHOL TANK REA GLYCERINE TOR 1 JOSEPH HENRY PERCY Aug. 28, 1945. J. H. PERCY 2,383,614

TREATMENT OF FATTY GLYCERIDES Filed Oct. 17, 1942 5 Shegts-Sheet 3 OIL r METHANOL. ETHANOL gfifiggf w L L V METHANOL ALCOHOLIC EXTRACTION FREE FATTY ACIDS so u-nou 0F VESSEL AND WATER ALCOHOLYS|5 CATALYST REFINED ANHYDROUS OIL (some METHANOL.)

CONTACTOR TIME VESSEL MIXER SETTLING TAN K REACTOR ALCOHOL I- ESTERS A eLYCEmNs vAcuuM SETTLING STILL TANK v 1 GLYCERINE RESIDUE INVENTOR JOSEPH HENRY PERCY Aug. 28, 1945. J, H PERCY 2,383,614

TREATMENT OF FATTY GLYCERIDES Filed Oct. 17, 1942 5 Sheets-Sheet 4 on. ALCOHOL ALCOHOLYSIS CATALYST ALCOHOLIC SOLUTION OF ALCOHOLYSIS CATALYST t v CONTACTOR MIXER PARTIAL I REACTOR MIXER SETTLING TANK REAcToR ALCOHOL v 1 GLYCERINE 7 SETTLING STILL TANK ESTER FRACTIONS 1W GLYCERINE l 4 VACUUM SETTLING RES'DUE s'ru.| TANK GLYCERINE 5 INVENTOR T JOSEPH HENRY PERCY BY M4 R Y Aug. 28, 1945. PERCY 2,383,614

TREATMENT OF FATTY GLYCERIDES Filed Oct. 17, 1942 5 Sheets-Sheet 5 OH ETHYL ALCOHOLYSIS ALCOHOL CATALYST V ETHYL ALCOHOL AN D CATA LYST' CONTACTOR RESIDUE p ESTERS SETTL] N6 REACTOR AC1 D TANK GLYCERINE VACUUM M'XER STILL ALCOHOL SETTLING TANK STILL J GLYCERINE INVENTOR JOSEPH HENRY PERCY Patented Aug. 28, 1945 UNITED STATES PATENT OFFICE 21 Claims.

The present invention relates to a process for treating fatty materials and, more particularly,

to an improved process for preparing fatty acid resulting in considerable aqueous dilution of the glycerine, must be employed. The soap is put in a crutcher, where it is mixed with any desired adjuvant material, and may then be framed or dried, plodded and cut, or run in a plastic condition to steel rolls for flaking. The flakes may be left in this condition or may be ground. The plastic soap may also be forced through a nozzle in a spray tower to form beads or other finely divided particles. Continuous or semi-continuous processes of soap making have been provided, but high temperatures and/or numerous washings are also employed in these for removing glycerine from the soap.

Recently, it has been taught to split fats or oils by hydrolysis with water to obtain free fatty acids, and then to saponify these acids. Free acids react very quickly and vigorously with alkaline agents, as compared with the long process of saponif'ying fats and oils, but it is dimcult to control the reaction and the condition of the product at this speed. 4 Contact of unpurified free fatty acids, particularly unsaturated acids, with air, even at moderate temperatures, causes the formation of dark oxidation products which tend to discolor soaps. Furthermore, the use of free acids requires that expensive, corrosion-resistant equipment be employed.

In the prior art, it has been taught that these various disadvantages can be obviated by reacting a fat or fatty oil with an alcohol in the presence of a small amount of an alcoholysis catalyst to produce esters of the fatty acid and glycerine, separating the esters from the glyc-- erine, and reacting the esters with a saponifying agent. By the prior art processes employed, the glycerine can be recovered in a relatively concentrated and substantially anhydrous condition,

and soap can be produced from the fatty acid esters by a lower temperature process. However, it has been found-that the method of alcoholysis described by the prior art seldom gives more than about 94% of the theoretical amount of glycerine, the remaining glycerine being left behind as partially reacted glycerides. Moreover, distillation of the mixtures produced to recover all of the alkyl esters results in darkening and decomposition of the non-volatile glycerides. Another disadvantage of the prior art processes is that, in carrying out the alcoholysis with methyl alcohol, the alcohol is immiscible with the glyceride to be treated, and the final glycerine layer is immiscible with the methyl ester layer. Consequently, it has been necessary in these processes to mix the reaotants completely and thoroughly at once and to keep them well agitated in order to prevent premature saponification and separation of the glycerine layer and consequent removal of the alcoholysis catalyst from the reaction mixture before all of the methyl alcohol has been added. While this does not raise a difilcult problem in small batch operation, the difllculties increase in large scale production and constitute a real problem in operation with large tanks which require more than ten or fifteen minutes to fill.

It is an object of the present invention to provide an improved process for reacting fats and fatty oils with an alcohol to produce substantially quantitative yields of fatty esters and glycerine.

It is another object of this invention to provide a new method for treatment of fatty acid glycerides wherein the fatty acid radical is obtained in the form of a derivative containing only a single acyl radical per molecule.

It is also an object of the invention to provide a novel continuous alcoholysis process for treating fatty oils wherein only g ycerine and volatile alkyl esters are removed.

A further object of the invention is to provide a novel process for the alcoholysis of fatty oils wherein additions of the reactants can be made continuously or intermittently while maintaining a homogeneous phase.

Other objects and advantages of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, wherein:

Figs. 1 to 6 represent fiow diagrams illustrating the flow of materials in operative steps of various modifications of the invention.

According to this invention, fatty oils and/or fats are partially esterified with an alcohol, preferably in the presence of an alcoholysis catalyst, to form a pool of partially reacted material containing sumcient monoglycerides and diglycerides for the reaction mixture to be substantially homogeneous. Additional reactants, such as alcohol and alcoholysis catalyst either alone or with the fatty oil, can be added to this homogeneous mixture without immediately ail'ecting the homogeneity. The-reaction is then brought toward completion, and the mixture passes the point of homogeneity, whereby two phases appear. It may be preferred at this point, when using an alkaline catalyst, to add suflicient acid to decompose the soap formed from the catalyst, and in certain cases, especially where higher alcohols are employed in the process, the appearance of two phases does not occur until after acidification or removal of excess alcohol. The phases are separated, the denser or anhydrous glycerine layer containing some alcohol being removed for subsequent purification and the lighter layer, containing alkyl esters with alcohol and incompletely reacted glycerides, also being removed for further processing. With incompletely reacted glycerides present, the lighter layer is vacuum distilled to recover the esters in the distillate, and the distillation residue is returned to the reaction pool for reworking along with fresh materials. The separation 01' glycerine may be carried out stepwise, if desired, addingmore alcohol and alcoholysis catalyst to the lighter layer after removal thereof, again contacting the reactants in a mixing device, andagain separating and removing glycerine. This separation of glycerine may be repeated as many times as desired, the lighter layer from the final separation being removed and treated as aforesaid.

In converting the esters into soaps, the lighter layer may be treated in a variety of ways. It may be subjected to an intermediate water wash in batch, continuous concurrent or continuous countercurrent operation for the purpose of removing the alcoholysis catalyst, if desired. The lighter layer from the glycerine separation, with or without washing, is then subjected to distillation and/or solvent extraction and/or other separation and purification procedure. As mentioned supra, the distillation residue may be returned to the pool of partially reacted material for treatment, and the desired ester fractions from the distillation and/or extraction, etc., may be recovered. V

In one modification of the invention, the partial esterification may be accomplished by keeping the fatty oil and the alcohol in contact in a. pool for a time interval insufllcient tor the reaction to go to completion under the reaction conditions. According to this procedure, fatty oil, alcohol and alcoholysis catalyst are continuously run into the pool and a substantially equivalent amount of partially reacted material is continuously withdrawn at a rate designed to maintain uniform conditions in the pool and to maintain a sufiicient amount of monoglycerides and diglycerides therein for the mixture to be substantially homogeneous. The material withdrawn from the pool flows continuously through a reactor 01 such dimensions that, when a sufllcient proportion of methyl alcohol is used, the reaction proceeds past the point of homogeneity, whereby two phases appear. The mixture is then run into a settling tank to allow the glycerine layer to separate. When using an alcohol having at least two carbon atoms per molecule for the alcoholysis without suiilcient methanol present to provide final immiscibility, the reaction mixture is partially distilled, preferably at moved by distillation as aforesaid, also contains monoglycerides and diglycerides. The alkyl esters and alcohol can be removed irom this layer by vacuum distillation, and, according to ,this procedure, the distillation need not be carried to the end, since the distillation residue.

is returned to the pool of partially reacted material to be reworked. Thus, in this modification, nothing but glycerine and volatile alkyl esters are removed from the system, and the overall yield must be substantially quantitative. If any unsaponiflable matter is present in the fat or oil, this tends to increase in the recycle operation, and a small side stream can be bled from the recycle, ii desired.

The glycerine separation may also be carried out stepwise. After removal of the lower glycerine layer in the settling tank, additional alcohol and alcoholysis catalyst can be added to the upper layer containing alkyl esters and unreacted material. The liquid body thus formed is again thoroughly contacted and is passed to another settling tank. Glycerine again settles out and is removed, and the upper layer can be retreated with alcohol and catalyst as many times as desired before vacuum distillation.

In another modification, the partial esteriflcation is accomplished by employing an amount of alcohol (and catalyst) insuflicient for complete reaction with the quantity of fatty oil used. According to this procedure, the glyceride is treated with an amount of alcohol, such as methanol, insufiicient to cause separation of a glycerine layer and with an amount of alcoholysis catalyst not large enough to result in gelling in the low concentration of alcohol used. The reaction mixture is stirred until it becomes homogeneous, and the remainder of the alcohol, with additional catalyst if desired, can then be added. A homogeneous mixture immediately results, but, as the reaction proceeds, the glycerine phase separates. This procedure can be carried out in continuous operation by establishing a pool of partially reacted material having an excess of oil and continuously adding oil, alcohol and alcoholysis catalyst in such proportion that the exsess of oil is maintained in the pool. An approximately equivalent amount of material is continuously withdrawn from the pool and contacted with the balance of the alcohol (with or without additional alcoholysis catalyst), and the reactants are thoroughly mixed and passed to a settling tank from which the glycerine can be removed. As in the modification described supra, stepwise removal of glycerine and additions of further amounts of alcohol and catalyst can be made.

The two methods described of providing a pool of partially esterifled oil may be combined, if desired, or either or both may be combined with any other desired treatment. Thus, the oil and the alcohol are added to the contacting vessel in such proportion that. there is an insuflicient amount 01 alcohol present to esterify the glyceride completely, and the materials are contacted there for a timi insufllcient for complete reaction of the alcohol added. A quan: tity of the mixture approximately equivalent to the quantity of material added to the pool is withdrawn from the vessel and is run into a mixer, where additional alcohol is introduced. The mixture then passes to a reactor which allows sufiicient time for the reaction to go toward completion to such an extent that, after distillation or acidification if required, a separation into two phases results. It is then run into a settling tank, from which the glycerine layer can be withdrawn at the bottom thereof, The ester layer is then removed and treated as aforesaid. The stepwise separation of glycerine herein described with respect to each of the preceding modifications may also be" combined with a combination of both of these modifications, as will be apparent to those skilled in the art from the foregoing.

In an alternative alcoholysis procedure, the reaction mixture, after contacting of the oil and alcohol, is advantageously partially distilled to remove the unreacted alcohol (whether methyl or higher), and the residue is settled to separate glycerine therefrom. Thus, in a preferred procedure, the .fatty glyceride is passed together with alcohol and catalyst through a contactor coil with turbulent agitation, and the mixture is run over a bank of steam coils which heat it to a liquid temperature of about 120 C. to about 130 C., under reduced pressure if desired. The alcohol is volatilized, and the remainder of the mixture falls into a settling chamber where a lower mixture may \be contacted under superatmospheric pressure at about 120 C, or higher for av short period, say about ten minutes, and the pressure is then released to flash off the alcohol. Upon distilling off alcohol, the soap formed from the catalyst gels if the temperature is substantially decreased. The residue may therefore be treated before cooling with a brine solution to salt out the soap, or with substantially anhydrous acid to form free fatty acids and a substantially insoluble salt which may be separated by sedimentation or otherwise or may be removed with the glycerine, and the glycerine layer may be thereafter withdrawn, or, preferably, the residue may be settled while still hot and the glycerine layer withdrawn to be thereafter treated with brine or acid, as aforesaid. Glycerine may be removed from the soap-containing glycerine layer by heating in an inert atmosphere to a temperature above the melting point of the resulting anhydrous soap while passing steam or other inert gas therethrough or by flash distillation. The ester layer, containing partially reacted glycerides, may be vacuum distilled to remove the esters, and the residue is then reworked, preferably in a recycling operation.

In carrying out the alcoholysis procedures, the temperature may be regulated as desired. In general, however, an early increase in temperature tendsto accelerate the saponification of the glyceride by the alkaline catalyst before completion of the alcoholysis, which is an undesirable result. For this reason, temperatures of above 130 C. are usually to be avoided, and satisfactory results have been obtained when operating at about 40 C. to about 50 0., especially in ethanolysis. It is also possible to work at considerably higher temperatures than 130 0., say at about 175 C. and higher, in the absence of a catalyst and under superatmospheric pressure, say of the order of about 10 atmospheres. The employment of high pressures in substitution for the use of a catalyst usually results in considerably slower alcoholysis. In general, the operation may be carried out at reduced pressures, at atmospheric pressure or at superatmospheric pressures.

The fat and/or fatty oil treated may be any of those suitable for employment by the soap making art in any of the processes heretofore. known, especially those containing glycerides of fatty acids having about eight to about twentysix, and preferably about twelve to about twenty, carbon atoms per molecule. These include coconutoil, palm oil, olive oil, cottonseed oil, corn oil, tung oil, wool fat, tallow, whale and fish oils, soya bean oil, tall oil, etc. Although unrefined materials may be used, it is preferred to use a. refined oil containing substantially no moisture, as alcoholysis with an alkaline alcoholysis catalyst has its greatest effectiveness under anhydrous conditions. The presence of excessive free fatty acid is also deleterious, as it destroys an alkaline alcoholysis catalyst by converting it into soap. If sufiicient alkaline catalyst is added to give an excess of alkali above that destroyed by large amounts of free fatty acid present, a large amount of soap forms and gels, which interferes with the separation of the alcoholysis mixture. Even if the separation is accomplished, practically all of the soap goes to the glycerlne layer and must be recovered during the glycerine refining. Where an acidification step is included before separation into two phases, the fatty acid goes into the ester layer.

The refining cf the oil may be accomplished by any suitable process. However, economies can be effected by using unrefined oil and introducing a preliminary alcohol refining treatment before the alcoholysis. In a suitable procedure, the unrefined oil is extracted with methanol or ethanol containing, at most, only a small percentage of water, using either batch, continuous concurrent or continuous countercurrent methods. Free fatty acids and moisture present in the oil are extracted by the alcohol, and the refined dry oil saturated with the alcohol can be removed therefrom. The oil, thus refined, may be used directly for alcoholysis. The alcohol extract, containing fatty acids and moisture, is then treated with an acid esterification catalyst and is dehydrated. The free fatty acids and the alcohol are completely esterified to the methyl or ethyl esters.

' These esters may then .be worked up separately from the main body of esters formed in the alcoholysis of the refined glyceride, or they may be mixed with the main body of esters at any time before or during purification. In this way, acid and alkaline esterification catalysts can :be used to neutralize each other. After neutralization of the catalyst, if desired, the excess alcohol is distilled off, leaving lower alkyl esters which may be distilled, extracted with a selective solvent and/or otherwise purified before being converted to soap.

In carrying out the alcoholysis according to this invention, short chain aliphatic alcohols, including aryl-substituted aliphatic alcohols, are preferably employed, particularly the saturated, primary alcohols, especially alcohols having a boiling point in the presence of water in excess of the azeotropic composition of lower than C. at atmospheric pressure and, more particularly, the lower alcohols having one to about six carbon atoms per molecule. Thus, alcohols sat isfactory for use in forming esters with the fatty acid components of the glycerides treated include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, nbutyl alcohol, isobutyl alcohol, tertiary butyl alcohol, the amyl alcohols, benzyl alcohol, etc. It is preferred to employ an amount of alcohol at least about twice the calculated theoretical amount necessary for alcoholysis of the particular glycerides treated.

Separation of a glycerol layer is facilitated in the case of alcoholysis with an alcohol having at least two carbon atoms per molecule by introducing a small amount of methyl alcohol, say,.in the case of ethyl alcohol, about to about 20%. Aneven smaller amount of methanol can be used under suitable conditions; thus, alcoholysis with ethyl alcohol containing about 6% of methyl alcohol, about 1% of ethyl acetate and about 1% of gasoline gives a reaction mixture from which a glycerine phase readily separates. Thorough drying of oil and agents permits separation of a glycerine layer with about 6% or less of methanol alone.

In selecting an alcoholysis catalyst, an alkaline, a neutral or an acid catalyst may be employed. Among those which have been found suitable for use in the present process are sodium hydroxide, sodium methylate, sodium carbonate, lime, boron trifiuoride, aluminum chloride, glycerine sulphate, sulphuric acid, organic sulphonic acids, organic sulphonates, etc. In general, it is preferred to employ an alkaline catalyst, but the methods herein described are also applicable to acidic alcoholysis catalysts. The alcohol refining treatment discussed is equallyapplicable to acid alcoholysis, since free fatty acid tends to hinder such alcoholysis through the formation of water by ester'ification with the alcohol.

The esterified material may be treated in any of several ways as aforesaid. The ester layer from the last settling tank may be washed with water or treated with an agent for neutralizing the alcoholysis catalyst. This washing step may be accomplished by a batch method or may be done in a tower with concurrent or countercurrent contacting of the washing agent in continuous operation. The washing may be combined with any further treatment of the crude esters or may be omitted, or, if desired, the crude esters may be passed with or without washing and without subsequent treatment to a saponiflcation step. The crude esters, free of alcohols by washing, distillation and/or other methods, may be passed to a distillation apparatus, preferably a vacuum still, where most of the volatile matter is distilled off. The distillate is a colorless alkyl ester fraction and, if any glycerol remains in solution in the ester layer after removal from the settling tank, such glycerol also goes into the distillate and may be separated from the esters as a heavy lower layer. The distillation residue, containing unreacted triglycerides and partially reacted monoglycerides and diglycerides, can be returned to the alcoholysis reaction vessel, there to be reworked. If desired, the residue in the cases of alcoholysis of fish oils, palm oil and the like can first be subjected to extraction with selective solvents for removal of vitamins and other valuable by-products before reworking.

the esters of the Ca and C10 fatty acids are topped off in a fractionating column. The esters oi the C12, C14, C16 and 01a acids can be drawn of! at a lower point on the column and, if desired, can be further fractionated and recombined in preferred proportions of desired components. These can then be worked up to soap, with or without other preliminary treatment, as described infra.

Another method of purification of the ester layer which may be used either alone or in combination with the fractional distillation procedure just described, with or without washing, is a liquid-liquid extraction with a selective solvent which is at least partially immiscible with the esters. A polar solvent, such as furfural, sulphur dioxide, nitromethane, methyl alcohol, ethyl alcohol, ethylene glycol, allyl alcohol, ethyl sulphate, acetaldehyde, acetamide, dichlorodiethyl ether, methyl Carbitol, etc., is employed to extract the more polar components of the ester layer, that is, the esters of the lower chain fatty acids, the more unsaturated fatty acids and the fatty acids having the greater number of hydroxy groups. In this manner, by a suitable selection of solvents, the stearic acid esters may be separated, either with or without oleic acid esters, from linoleic and linolenic acid esters and from shorter chain acid esters. A solvent for the longer chain acid esters and/or for the more saturated acid esters may be employed in admixture with the polar solvent. Thus, aliphatic, cycloaliphatic and aromatic hydrocarbons, such as pentane, cetane, cyclohexane, and benzene, may be used for this purpose. It may also be advantageous to add water to the mixture, as certain of the solvents become more selective in the wet state than in the anhydrous state.

Where such solvent extraction purification step is combined with a fractional distillation purification step, either step may follow the other, as desired. The combination of these two modes of purification has been found to provide a more complete fractionation of the ester layer into its components than is possible with either method alone. Other suitable methods of separation and purification, such as fractional crystallization, may also be employed either alone or in combination with each other and/or with either or both of fractional distillation and solvent extraction.

The ester fractions obtained according to the present invention with or without washing and/or subsequent purification can be employed in many chemical processes and products, as in the paint, erfumery, lubricating oils, medicinals and other fields. They may be used in many chemical syntheses, and one of their great-' est outlets for volume consumption is in the soap making industry. In saponifying the esters, they may be mixed with monoesters of polyhydric alcohols, such as ethylene glycol monostearate, propylene glycol monolaurate, trimethylene glycol monoesters of olive oil fatty acids, glyceryl alpha- (or beta-) monostearate, mannitol monoesters of coconut oil fatty acids, sorbltol mono-palmitate, erythritol mono-oleate, etc. Any of these monoesters may also be admixed with di-, tri-, or poly-esters for saponiflcatiou, although such modification is not preferred.

The alkaline or saponifying agent which may be used for saponifying these esters includes sodium and potassium hydroxides, carbonates, silicates, etc., methyl morpholine, piperidine, alkyl amines, alkanolamines, and other organic and inorganic bases and alkaline materials. and mixtures of these. The alkaline agent may be introduced in aqueous solution, in alcoholic solution, or in solutions of other solvents, or may be substantially anhydrous and/or substantially undiluted. The amount of solvent introduced with the alkaline or saponifying agent has a bearing on the water or organic solvent content of the finished product.

The esters may be saponified by mixing with the alkaline agent in a soap kettle and boiling to remove the alcohol liberated, with or without recovery of the alcohol, as desired. The reaction may be completed in the kettle or the mixture may be run into frames to complete the reaction therein, without agitation, as a cold made soap, or the mixture may be continuously agitated during the reaction without substantial cooling to yield a granulated product or a floating soap.

In an alternative saponiflcation procedure, the

esters, with or without preliminary purification,

may be hydrolyzed to form the free fatty acid and an alcohol. The free fatty acid produced is then neutralized, preferably by a continuous neutralization procedure, to form soap.

In a preferred method of saponiflcation, the soap is prepared by mixing the ester with the saponifying agent and carrying out the reaction at atmospheric, superatmospheric, or reduced pressures. A reduced pressure may be employed to remove the alcohol from the product as the alcohol is liberated in the reaction. Alternatively, the materials may be reacted at somewhat elevated temperatures and then flashed into a lower pressure chamber to volatilize the alcohols, as well as some or all of any solvent (including water) employed. A subatmospheric pressure is advantageously employed .in the flash chamber to remove from the product alcohol liberated in the reaction. The reaction is preferably carried out as a continuous process, using a measuring or proportioning device for mixing the ingredients in such proportions as are determined by the operator, and then continuously passing them to a saponifler. An advantageous method of operation is to mix the esters and saponifying agents at an elevated temperature and under pressure and then to flash them into a separation chamber under reduced pressure, thereby vaporizing any solvent used and the alcohol formed in the reaction.

The moisture or solvent content of the finished product can be modified by regulating the heat supplied to the reaction mixture by preheating the reactants and/or externally heating the reaction vessel or otherwise. The temperature required is far below that necessary for glycerine recovery in saponifying lycerides, being of the order of about 50 C. to about 125 C. Therefore, although possible, it is unnecessary and less desirable to go to the temperature of molten anhydrous soap or higher in order to vaporize the monohydric alcohols liberated, as they or their aqueous azeotropes are lower boiling than water. Furthermore, it is possible to recover the soap in hydrated form, but free from the alcohol, without additional hydrating equipment, as required with anhydrous soap obtained in certain methods of saponifying glycerides. Moreover, shorter periods of heating, with consequent diminished danger of local overheating and decomposition, can be employed.

Soap builders, inert materials, antioxidants,

etc., may be added to the ester and/or to the saponifying agent before contacting. Since the soluble, are found in the product. Adjuvant materials may be admixed with the soaps by mixing them with the esters and/or the saponifying agents before flashing, by simultaneously flashing a second solution containing such adjuvant materials, and/or by mixing the final product therewith. Such adjuvant materials may include fatty acid soaps prepared by the same or other methods. resin acid soaps, naphthenic and alkvlated uaphthenic acid soa sulphated and sulphonated organic compounds; alkaline soap builders, water-soluble, water-softening,v acid compounds of phosphorus, and other salts, including sodium carbonate, sodium silicates, trisodium phosphates, borax, sodium tetraphosphate, sodium bicarbonate, sodium sulphate, sodium chloride, sodium acetate, sodium hypochlorite, sodium thiosulphate, sodium perborate, sodium tartrate, sodium citrate and sodium oxylate, and the corresponding ammonium, substipolyvinyl alcohols; liquids, such as ethyl alcohol,.

glycerol, cyclohexanol, naphtha, benzene, kerosene, turpentine, pine oil, decalin and tetralin and the like. The type of addition agent will depend upon the ultimate use of the new composition.

The soap may be recovered as a fluid, plastic or granular product and may be used in the form produced or may be forced through an extrusion outlet after flashing and cut in the form of bars and cakes, or it may be ejected through a spray nozzle or spinner bowl into a spray tower to give beads and spongy granules, It may also be passed to drum driers or, if drying is accomplished by other means, to chilling rolls to produce flakes and ribbons.- g

The following examples described herein are merely illustrative of the present invention, and it will be understood that the invention is not limited thereto.

Example I v About 215 pounds per minute of refined coconut oil is passed through a bed of sodium-chloride to complete its dehydration and is then run into a mixing vessel or contactor, as shown in Fig. 1. Solid sodium hydroxide is dissolved in anhydrous methyl alcohol in the proportion of about 1 part by weight of sodium hydroxide to 40 parts of methanol, and the alcoholic solution is run into the contactor at the rate of about 65.6 pounds per minute, a rate which is approximately twice that theoretically necessary for alcoholysis of the oil. The contactor is furnished with stirring means and has an overflow outlet located at a point which allows only five minutes' run of materials to be contained in the contactor. The mixture, only partially reacted in this time and containing monoglycerides and diglycerides, passes from the outlet into a time coil or reactor of such dimensions that it takes about twenty-five minutes for the material to pass therethrough. During this interval, the reaction proceeds to a point where two phases are present, and the mixture is then run into a settlingtank, where it is allowed to separate into two layers.

The lower glycerine layer is substantially continuously withdrawn at the bottom of the settling tank, and the upper layer'overflows into a conduit through which it passes to a still. The unreacted alcohol is removed by distillation and, being anhydrous, can be condensed and returned directly to the methyl alcohol supply tank for reuse in the process in dissolving sodium hydroxide. The bottoms from the still are run into a second settling tank, where a further amount of glycerine is settled out and withdrawn. The overflow from the second settling tank is run into a vacuum distillation apparatus, where the methyl esters are topped. The bottoms or residue containing unreacted and partially reacted oil are continuously run back into the mixing vessel or contactor for reworking along with fresh oil. The glycerine recovered is substantially anhydrous, and the methyl esters are obtained in a throughput yield of about 99% or higher of the calculated theoretical yield.

Example [1 Corn oil, refined and substantially anhydrous,

is run into a reactor, as shown in Fig. 2, at the rate of about 295 pounds per minute. Ethyl alcohol containing about 2% of sodium hydroxide is also run into the reaction vessel at a rate of about 94 pounds per minute. The material is contacted in the reactor for about forty minutes and is then run into a still where unreacted alcohol is removed by distillation. The residue is passed into a, settling tank, where it separates into two phases, and a glycerine layer is withdrawn from the bottom of the tank. The upper layer overflows into a conduit, through which it is run into a vacuum distillation apparatus. The ethyl esters are removed together with any glycerine remaining in solution in the upper layer, and the distillation residue containing mono-, di-, and tri-glycerides is passed back to the reaction vessel for further processing. The ethyl esters topped from the vacuum distillation apparatus are passed to a settling tank, where glycerine is separated and removed.

Example HI Referring again to Fig. 2, about 285 parts by weight per minute of cottonseed oil are treated according to the procedure described in Example II, using about 65.5 parts per minute of methyl alcohol containing about 2% sodium hydroxide as the treating agent. All other process steps are as set forth in Example If, methyl esters being recovered.

Example IV Coconut oil, reflned by extraction of free fatty acids with anhydrous methanol, is passed into a mixing vessel or contactor, as represented in Fig. 3, at a rate of about 1000 parts by weight per minute. About 7 parts of sodium methylate are dissolved in a mixture of about 225 parts of ethyl alcohol and about 35 parts of methyl alcohol, and the alcoholic solution is run into the contactor at a rate of about 267 parts per minute. The materials remain in contact in the vessel for about flve minutes and then overflow into a combined time vessel and settling tank, wherein the mixture separates into two phases and from which a glycerine layer can be withdrawn at the bottom thereof. The upper layer is passed into a mixer provided with stirring means and is there mixed with about 133 parts per minute of the methyl-ethyl alcoholic solution of sodium methylate described supra. The mixture thus formed passes through a, reactor during a time interval oiabout thirty minutes and ,removal of a glycerine layer.

Example V A mixture of about 285 parts by weight oi tallow with about 215 parts of coconut oil is dried and run into a contactor (see Fig. 4) at the rate of about 500 parts per minute. A methyl alcoholic solution containing about 2% of sodium hydroxide is prepared, and this solution is run into the contactor at a rate of about 87 parts per minute. The glycerides and the alcoholic solution are thoroughly mixed for about thirty minutes, and the mixture is then passed into a mixer where about 43 parts of the alcoholic solution of sodium hydroxide are added thereto. The mixture thus formed is passed into a reactor where it is turbulently agitated for about twenty minutes. During this time, the mixture separates into two phases, and it is then run into a settling tank for the two phases to settle where a furinto layers. A lower glycerine layer is with drawn from the tank, and the ester layer containing unreacted alcohol and partially reacted glycerides is removed from the top of the tank and is further processed in accordance with the procedure set forth in Example I.

Example VI About 215 parts by weight per minute of reflned anhydrous coconut oil are run into a mixing vessel or contactor, as illustrated in Fig. 5. A solution of about 4% sodium methylate in methyl alcohol is run into the contactor at a rate of about 28 parts per minute. The materials are thoroughly mixed in the contactor for about ten minutes and are then passed into a.mixer where about 14 parts per minute of the alcoholic solution of sodium methylate are added thereto. The material is thoroughly mixed and it is passed into a time coil or partial reactor through which it passes during a period of about twenty minutes. The mixture separates into two phases and is run into a settling tank for settling out and The upper layer overflows into a mixer, wher it is admixed with a further portion of the alcoholic solution of sodium methylate run into said mixer at a rate of about 25 parts per minute.

The material then passes into a reactor of such dimensions that it takes about twenty-five minutes for passage therethrough. The eiliuent from the reactor passes to a second settling tank, where a further glycerine layer is settled out and removed. The upper layer is run into a still, and the unreacted alcohol is removed by distillation.

The distillation residue is passed into a third settling tank, and a glycerine layer is again with tilled oil. The bottoms are returned to the con tactor for reprocessing.

Example VII phur dioxide is also introduced in an amount sufficient to neutralize the caustic and soap present. The acidified mass separates into two phases and flows to a. settling tank, from which a lower glycerine layer is withdrawn at the bottom. The overflow from the tank is run to a still which is operated at atmospheric pressure. Alcohol is vaporized and removed, and the bottoms pass to a va uum distillation apparatus. The ethyl esters and any remaining glycerine are topped off and separated in a second settling tank, and the distillation residue is run back into the contactor for reprocessing along with fresh cottonseed oil.

Example VIII Coconut oil and a methyl alcohol solution of about 1 part by weight of benzene sulphonic acid in about 16 parts of methanol are separately preheated to a temperature of about 60 C. andv are then run in confluence into a contactor at a. rate of about 215 parts per minute of the oil and about 45 parts per minute of the methyl alcohol solution The materials are thoroughly mixed for about thirty minutes, maintaining the. temperature at about 60 C. during the mixing. The mixture is then passed to a mixer where about 23 parts per minute of the hot methyl alcohol solution are introduced. The mixture thus formed is passed to a reactor and is turbulently agitated for about twenty minutes, maintaining the temperature at about 60 C. during this period.

'- partially reacted glycerides; removing alkyl esters monohydric alcohol liaving one to about six carbon atoms per molecule together with an alcoholysis catalyst into said liquid pool and partially reacting the introduced glyceride with alcohol; withdrawing a portion of said liquid pool; removing alcohol, esters and glycerine from said with- Sodium bicarbonate is then added in sufilcient amount to neutralize the catalyst. The mixture is then allowed to cool and is run into a settling tank, where it separates into two layers. A lower glycerine layer is withdrawn from the tank, and the ester layer containing unreacted alcohol and partially reacted glycerides overflows and is further processed in accordance with the procedure described in Example 1.

Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor without departing from the principles and true spirit of the invention. Such variations and modifications are believed to be within the scope of the present specification and within the purview of the appended claims.

I claim:

1. A process for the alcoholysis of fatty giycer-. ides which comprises reacting a fatty glyceride with a monohydric alcohol having one to about six carbon atoms per molecule to produce a liquid body containing esters, glycerine and partially reacted giycerides; removing esters and glycerine from said liquid body; and reworking the partially reacted giycerides.

2. A process for the alcoholysis of fatty glycerides which comprises reacting a fatty glyceride with an aliphatic alcohol having one to drawn portion to leave a residue containing partially reacted glycerides: and returning said residue to said liquid pool.

5. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, a monohydric alcohol having one to about six carbon atoms per molecule, esters. lycerine and partially reacted glycerides; continuously introducing a fatty glyceride and a monohydric alcohol having one to about six carbon atoms per molecule together with an alcoholysis catalyst into said liquid pool and partially reacting the introduced glyceride with alcohol; continuously withdrawing a portion of said liquid pool; removing alcohol, esters and glycerine from said withdrawn portion to leave a-residue containing partially reacted glycerides; and continuously returning said residue to said liquid pool.

6. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, an aliphatic alcohol having one to about six carbon atoms per molecule, alkyl esters, glycerine and partially reacted glycerides; continuously introducing a fatty glyceride and an aliphatic alcohol having one to about six carbon atoms per molecule together with an alkali metal base into said liquid pool and partially reacting the introduced glyceride with alcohol; continuously withdrawing a portion of said-liquid pool; removing alcohol, alkyl esters and glycerine from said withdrawn portion to leave a residue containing partially reacted glycerides; and continuously returning said residue to said liquid pool.

7. A process for the alcoholysis of fatty glycerides which comprises reacting a, fatty glyceride with methyl alcohol in the presence of an alcoholysis catalyst to produce a liquid body containing methyl esters, glycerine and partially reacted glycerides for a time at least sufllcient to form a separate glycerine phase; removing a lower glycerine layer from said body to leave an upper layer containing unreacted methyl alcohol, methyl esters and partially reacted glycerides; removing methyl alcohol and methyl esters from said upper layer to leave a residue containing par- I methyl esters and partially reacted glycerides;

'volatilizing methyl alcohol from said upper layer to leave an' unvolatilized remainder; removing residual glycerine from said remainder; distilling to remove methyl esters therefrom; and recycling the residue. e

9. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, an-aliphatic alcohol having one to about six carbon atoms per molecule, alkyl esters, glycerine and partially reacted glycerides; continuously introducing a fatty glyceride and an aliphatic alcohol having one to about six carbon atoms per molecule together with an alcoholysis catalyst into said liquid pool and partially reacting the introduced glyceride with alcohol; continuously withdrawing a portion of said liquid pool; maintaining a substantially homogeneous phase in said liquid pool and regulating the rates of said introduction and said withdrawal with respect to the size of the liquid pool to keep the fatty glyceride and the alcohol in contact in the pool in the presence of the alcoholysis catalyst for a time interval insufficient for the reaction to go to completion; further contacting the materials in the withdrawn portion; removing alcohol, alkyl esters and glycerine from said withdrawn portion to leave a residue containing partially reacted glycerides; and continuously returning said residue to said pool.

acted glycerides; removing unreacted alcohol from said liquid body; removing a lower glyce erine layer from said body to leave an upper layer 14. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, ethyl alcohol, ethyl esters of fatty acids, glycerine and partially reacted glycerides; continuously introducing a fatty glyceride and ethyl alcohol together with an alcoholysis catalyst into said liquid pool; continuously withdrawing a portion of said liquid pool; regulating the rates of said introduction and said withdrawal with respect to the size of the liquid pool to keep the fatty glycerides and the ethyl alcohol in contact in the pool in the presence of the alcoholysis catalyst for a time 10. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, methyl alcohol, methyl esters, glycerine and partially reacted glycerides; continuously introducing a fatty glyceride and methyl alcohol together with an alcoholysis catalyst into said liquid pool and partially reacting the introduced glyceride with alcohol; continuously withdrawing a portion of said liquid pool; maintaining a. substantially homogeneous phase in said liquid pool by regulating the rates of said introduction and said withdrawal with respect to the size of the liquid pool to keep the fatty glyceride and the methyl alcohol in contact in the pool in'the presence of the alcoholysis .catalyst for a time interval insufficient for the reaction to go to completion; further contacting the materials in the withdrawn portion for a time interval at least sufficient to form a separate glycerine phase; removing separated glycerine from said portion to leave a mass containing unreacted methyl alcohol, methyl esters and partially reacted glycerides; removing the methyl alcohol and the methyl esters from said mass to leave a residue containing partially reacted glyceridles; and returning said residue to said liquid poo 11. A process for the alcoholysis of fatty glycerides which comprises reacting a fatty glyceride with an aliphatic alcohol having one to about six carbon atoms per molecule in the presence of an alcoholysis catalyst to produce a liquid body containing alkyl esters, glycerine and partially rethe withdrawn portion;

interval insufficient for the reaction to go to completion whereby partially reacted glycerides are formed; further contacting the materials in removing unreacted ethyl alcohol from said portion to form a separate glycerine phase; removing separated glycerine therefrom to leave a mass containing ethyl esters of fatty acids and partially reacted glycerides; recovering ethyl esters from said mass to leave a residue containing partially reacted glycerides; and returning said residue to said liquid pool.

15. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, an aliphatic alcohol having one to about six carbon atoms per molecule, esters of the alcohol and fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and an aliphatic alcohol having one to about six carbon atoms per molecule together with an alcoholysis catalyst into said liquid pool, the amount of alcohol introduced in proportion to fatty glyceride being insuflicient for the reaction to go to completion; withdrawing a portion of said liquid pool; contacting said portion with further amounts of an alcohol under conditions preventing complete reaction whereby partially reacted glycerides are formed; removing alcohol, esters of the alcohol and fatty acids, and slycerine from said withdrawn portion to leave a residue containing partially reacted glycerides; and returning said residue to said liquid pool.

16. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, methyl alcohol, methyl esters of fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and methyl alcohol together with an alcoholysis catalyst into said liquid pool, the amount of methyl alcohol introduced in proportion to fatty glyceride being insufficient for the reaction to go to completion; withdrawing a portion of said liquid pool; contacting said portion with further amounts of methyl alcohol at least sufilcient to form a separate glycerine phase under conditions preventing complete reaction whereby partially reacted glycerides are formed; removing separated glycerine from said portion to leave a mass containing unreacted methyl alcohol, methyl esters of fatty acids and partially reacted glycerides; then removing methyl alcohol and methyl esters from said mass to leave a residue containing partially reacted glycerides; and returning said residue to said liquid pool.

17. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, methyl alcohol, methyl esters of fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and methyl alcohol together with an alkaline alcoholysis catalyst into said liquid pool, the amount of methyl alcohol introduced in proportion to fatty glyceride being insufficient for the reaction to go to completion; withdrawing a portion of said liquid pool; contacting said portion with further amounts of methyl alcohol under conditions preventing complete reaction whereby partially reacted glycerides are formed; removing unreacted methyl alcohol from said portion; then removing glycerine from said portion to leave a mass containing methyl esters of fatty acids and partially reacted glycerides; recovering methyl esters from said mass'to' leave a residue containing partially reacted glycerides; and returning said residue to said liquid pool.

18. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, ethyl alcohol, ethyl esters of fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and ethyl alcohol together with an alkaline alcoholysis catalyst into said liquid pool, the amount of ethyl alcohol introduced in proportion to fatty glyceride being insuflicient for the reaction to go to completion; withdrawing a portion of said liquid pool; contacting said portion with further amounts of ethyl alcohol under conditions preventing complete reaction whereby partially reacted glycerides are formed; removing unreacted ethyl alcohol from said portion to form a separate glycerine phase; then removing separated glycerine from said portion to leave a mass containing ethyl esters of fatty acids and partially reacted glycerides; recovering ethyl esters from said mass to leave a residue containing partially reacted glycerides; and returning said residue ot said liquid pool.

19. A process for the alcoholysis of fatty glycerides which comprises reacting a fatty glyceride with an aliphatic alcohol having one to about six carbon atoms per molecule in the presence of an alcoholysis catalyst to produce a liquid body containing esters of the alcohol and fatty acids, glycerine and partially reacted glycerides; removing unreacted alcohol from said liquid body to form a separate glycerine phase; removing separated glycerine from said body to leave a mass containing alkyl esters and partaining partially reacted glycerides; and recycling said residue.

20. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, an aliphatic alcohol having one to about six carbon atoms per molecule, esters of the alcohol and fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and an aliphatic alcohol having one to about six carbon atoms per molecule together with an alcoholysis catalyst into said liquid pool; withdrawing a portion of said liquid pool; maintaining a substantially homogeneous phase in said liquid pool by regulating the rates of said introduction and said withdrawal with respect to the size of the liquid pool to keep the fatty glyceride and the alcohol in contact in the pool in the presence of the alcoholysis catalyst for a time interval insufllcient for the reaction to go to completion whereby partially reacted glycerides are formed; and further contacting the materials in the withdrawn portion.

21. A process for the alcoholysis of fatty glycerides which comprises establishing a liquid pool containing a fatty glyceride, an aliphatic alcohol having one to about six carbon atoms per molecule, esters of the alcohol and fatty acids, glycerine and partially reacted glycerides; introducing a fatty glyceride and an aliphatic'alcohol having one to about six carbon atoms per molecule together with an alcoholysis catalyst intosaid liquid pool, the amount of alcohol introduced in proportion to fatty glyceride being ins'ufiicient for the reaction to go to completion whereby partially reacted glycerides are formed; withdrawing a portion of said liquid pool; and

contacting said portion with further amounts of an aliphatic alcohol having one to about six carbon atoms per molecule.

JOSEPH HENRY PERCY.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
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US4668439 *Jun 5, 1985May 26, 1987Hoechst AktiengesellschaftProcess for the preparation of fatty acid esters of short-chain alcohols
US5491226 *Apr 6, 1994Feb 13, 1996Procter & Gamble CompanyProcess for preparing polyol polyesters having low levels of triglycerides
US6127560 *Dec 29, 1998Oct 3, 2000West Central CooperativeEsterifying fatty acid glycerides of soybean oil derived from heat treatment of comminuted soybeans, by alcoholysis using alkali catalsyt to form fatty acid alcohol esters and glycerine, separating glycerine, purifying ester with water
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US7235183 *Jun 22, 2004Jun 26, 2007Crown Iron Works CompanyGlycerine foots salt separation system
US7619104Jul 8, 2005Nov 17, 2009Renewable Products Development Laboratories, Inc.Process for producing biodiesel or fatty acid esters from multiple triglyceride feedstocks
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Classifications
U.S. Classification554/167, 554/175
International ClassificationC11C3/04, C11C3/00
Cooperative ClassificationC11C3/003, C11C3/04
European ClassificationC11C3/04, C11C3/00B