US1219485A - Process for decomposition of fats and oils. - Google Patents

Description

B. E. HE'UTER.

PROCESS FOR DECOMPOSITION 0F FATS AND OILS.

aid 2 7265566 APPLICATION FILED MAY 20. I912.

Patented Mar. 20, 1917.

BALTHASAB E. REUTEB, OF CHICAGO, ILLINOIS, ASSIGNOR 'IO REUTER PROCESS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Specification of Letters Patent.

Patented Mar. 20, 1917.

Application filed May 20, 1912. Serial No. 698,615,

To all whom it may concern:

Be it known that I, BALTHASAR E. REUTER, a citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented a new and Improved Process for Decomposition of Fats and Oils,

of which the following is a full, clear, concise, and exact description, reference being bad to the accompanying drawings, forming part of these specifications.

My invention relates to an improved process for the treatment offats or oils and'particularly to the decomposition of fats or oils, the recovery of glycerin therefrom, and the bleaching of the fatty acids resulting from the decomposition. By the use of my invention time is saved, acids of good appear ance, practically odorless are obtained very the fatsand oils in the presence of water as free from glycerin, the glycerin is're'covered in small volumes of water and the whole is accomplished in an, economical and simple manner.

In recovering theglycerin from soap lyes, the evaporation of very large quantities of very dilute glycerin solutions high in salt is necessary. Large amounts of water in three or four liberal washes have to be employed to wash out the glycerin after the fats and oils have been saponified by caustic soda. Correspondingly large amounts of salt have to be used to insure the separation of soap from lye. Therefore, the large volumes to be evaporated and the high salt content to be removed are a source of considerable expense and annoyance. It is not practical to remove all the glycerin in this Way, and so all settled soaps contain "3% to .6% glycerin figured on a wet soap basis, viz: 66% true soap, 33% water, 3% to .6% glycerin.

Several methods ofavoiding this trouble by the separation of glycerin from the fatty acids before making soap have been devised. The so-called Twitchell process is probably the most successful of those attempted prior to the invention of my improved process.

The Twitchell i ocess is described in U. S. Letters Patent 0. 601603 dated March 29, 1898. In carrying out the Twitchell process, a so-called Twitchell reagent acts upon a hydrolizing agent. The action is probably a catalytic one rather than a reaction between the fats and the Twitchell reagent.

An approximately complete decomposition of the fats in accordance with the to the prolonged oxidation. The time for completing the decomposition may be shortened simply by increasing the percentage of reagent but little is gained, as the increased percentage of reagent causes the fatty acids to be darkened practically to the same extent as would have been the case with the longer boil, using a less quantity of reagent. s

It may, therefore, be stated generally that the Twitchell process is carried on to complete decomposition only upon cheap products mostly cotton seed foots in this-country where the very black fatty acids resulting may be distilled and where the cost of distillation is offset to a certain extent by the recovery of a pitch, which is very highly prized by manufacturers of electrical insulators. When good grades of fats or oils, such as tallow, cocoanut oil, cotton seed oil and the various others entering into the manufacture of soap are decomposed to say 70% by the Twitchell'process the fatty acids become so darkthat they are not available for the manufacture of light colored soaps. These neutral fats or oils if saponified in the regular way of making settled soap in the kettle would have produced soaps of much better color than when subjected to the Twitchell process of decomposition. Some soap manufacturers have partly decomposed good grades of fat by use of the Twitchell process whereupon the stock is boiled in the regular way. It is doubtful if anything is gained by this procedure since the glycerin remaining'in the stock has to be separated from the soap, by a liberal water wash. And the same percentage of glycerin will be left in the finished soap as in the case when the neutral fats are saponified in the kettle.

It may be generally stated, therefore, that in none of the processes of the prior art has it been feasible to recover anything like the full glycerin content of the fats or oils undergoing treatment. It is well known to those skilled in the art that the glycerin has a high market value and it -has been recognized also that the full glycerln content has not been recovered by the use of the processes of the prior art but the recovery of a larger percentage. of glycer1n-has not I The details of my been economically feasible for the reasons" hereinbefore mentioned.

Since the Twitchell process provided a meansfor the recovery of a large percentage of the glycerin content subject to the controlling objection that the fatty acids were badly discolored, it was not unnatural that many efforts should have been made to bleach the fatty acids resulting from the use of the Twitchell process, but so far as I am aware no one has been able" to accomplish satisfactory results in this direction.

I have perfected a process which, in certain aspects, may be regarded as an improvement upon the Twitchell process by means of which it is entirely feasible to affect practically complete recovery. of the glycerin content of neutral fats and whereby the resulting fatty acids are sufliciently light in color to make them available for use in the manufacture of light colored soaps and indeed for the manufacture of white soaps.

improvement will perhaps be more easily followed if I outline the various steps before proceeding to a detailed description.

The fats or oils are first given a prelimi nary treatment with'concentrated sulfuric acid to free the stock from various non-saponifiable' matter "and to enable the reagent to start the hydrolysis readily. The clear fats or oils are then conveyed to an air-tight saponification tank in which they are treated with a reagent such as described in the Twitchell patent above mentioned and generally during the process of decomposltion they are subjected to heat and mechanical agitation to aid the hydrolytic action and to maintain a good emulsion of the tank contents. The emulsion is maintained also by controlling accurately the amount of free sulfuric acid present. The decomposition is conducted in successive 'steps, the glycerin water being settledout and drawn off after each intermittent treatment with the Twitchell reagent. Throughout this decomposition the air is almost perfectly excluded by suitable apparatus equipped with a water seal, the air bein excluded by steam in each instance also be ore attempting to draw the sweet water from the saponification tank. I add a small quantity of 60 deg. B. sulfuric acid to aid in breaking the emulsion and in causing the water to separate from and settle out of the fatty acids.

If the neutral fats are of good color to start with the fatty acids resulting after having carried out the details of the process above outlined will also be of good color and may be used in the manufacture of light colored soaps. If, however, it is desired to I improve the color of the fatty acids I proceed with a bleaching process in which the Badische Co.s decrolin is used in one or more treatments, the stock being washed with water before the bleaching treatment.

.. The free sulfuric acid is then neutralized, the

fatty acids not being allowed to come in contact with the air until they have been bleached and neutralized. In carrying out my process I find it desirable to treat the fats and oils to be decomposed in successive operations, only a small amount of reagent being used in connection with each treatment. At the same time, I employ a small percentage of sulfuric acid, just enough to make the mixture slightly acid. During each treatment the mixture is agitated or boiledor both to take the form of an emulfats or oils instead of bringing them into intimate contact to facilitate the decomposition. After any one stage of the decomposition has been completed additional sulfuric acid is added to the mixture to break up the emulsion and settle the glycerin wa' ter and reagent from the fattyacids.

The above outline is set forth simply in order to'give a comprehensive idea of the process before describing the details which in a large measure are responsible for the very successful results attained in the use of my invention.

Coming now to the detailed description reference may be had to the accompanying drawings:

Figure 1 is a diagrammatic representation of the apparatus employed, and

Fig. 2 is a detail sketch of steam heating coil, perhaps not clearly. shown in the main figure. 1

In the drawings, A indicates the acid treating or wash tank, B is a tank for the storage of wash water recovered from A, 0 represents the saponification tank with its agitator 0. D indicates the sweetwater or glycerin storage tank. E represents a tank the pipe 11 to the jets of the coil in the bottom of the tank. From .5% to 2% of sulfuric acid (GOdeg. B.) is added to the stock from matter which cannot be saponified, clarifies'the fats and oils and puts them in a condition such that the reagent may readily start the necessary hydrolysis.

,Thereupon the contents of the tank A are allowedto settle for from 1' to 12 hours as may be necessary, 1 or 2 hours settling generally being sufficient. When the settling is completed I draw off the acid water and settlings through the pipe 13 leading to the acid water storage tank B, from which any acid, glycerin, fats or fatty acids may be recovered, as subsequently explained.

The clear fats or oils left in the wash tank A are then run through the pipe 14. to the saponification tank C. It will be noted that this saponification tank is air-tight. A relief and exhaust pipe' 15 leads, however, from the top'of this tank first through the condensing coil 16 in the bottom of tank E and then below the surface of water in the overflow cup 17 located in the upper part of the water tank F. The coil 16 is formed as indicated in Fig. 2 and discharges through a vertical pipe connected at the central part of the coil which extends down- ,Wardly into the overflow cup 17 This arrangement permits the escape of steamfrom the top of tank C, thereby preventing the pressure from rising in tank C, and preventing also .a rise of temperature above 212 deg. F.

From 20 to 30% of condensed or distilled water is now added to the fats and oils which have been run into the saponification tank C and the mixture is brought to a boil by'the admission of live steam through the pipe 16. From .1% to .4% of the Twitchell ,or equivalent catalytic reagent is added through the funnel 17 whereupon the contents of this tank are kept at a temperature of '212 deg. F. while the agitator c is set in motion to mix thoroughly the contents of the tank, the agitator being kept in motion throughout the entire boil. Presently a sample is drawn through one or more of the cooks 18, 19 and 20 and a test ismade to determine the percentage of sulfuric acid in the water. If necessary 60 deg. B. sulfuric acid is added until the mixture shows a content of about .03% to 1%. It "is necessary to controlthe percentage of sulfuric acid but the percentage will vary with different fats and oils. There should be sufficient free sulfuric acid to tend to break up the fats and oils thereby permitting the agitator to maintain a good emulsion. If,

however, the percentage of sulfuric acid is too great for the particular fats and oils undergoing treatment, there is too much of a tendency to settle the contents of the tank whereby the intimate intermixture between the reagent and the particles of fats or oils is prevented. The mixture is boiled or agitated for from 12 to 18 hours, the length of time will vary with the nature of the fats or oils undergoing treatment. I avoid the volatilization of fatty acids and glycerin which at the higher temperature usually employed would go over by distillation into water tank F. Furthermore, the decomposition is more complete at the low temperature coupled with agitation as above described than would be the case at the high temperature. Anyv increase in pressure or temperature in the saponification tank would tend to effect a recombination amount of 60 deg. B. sulfuric acid is added to break up the emulsion. At the end of the boil the agitator is stopped and the live steam in pipe 16 is turned off and the contents of the saponification tank are allowed to settle'for from to 6 hours. During each settling operation it is necessary to prevent air coming in contact with the mixture in the tank C and to effectively accomplish this, steam maybe admitted to the top of the tank by the pipe 16 to seal the same. The additional sulfuric acid which was added at the end of the boil aids in carrying down the glycerin water and reagent so that they may be withdrawn from the saponification tank, leaving the fatty acids, fats and oils not yet fully decomposed for further treatment.

I If it were not for the effect of the sulfuric acid in breaking the emulsion the water would not readily percolate down through the fats and wash out all of the free glycerin and reagent.

.The glycerin and water are then drawn from the bottom of the tank C from which they run into the sweet water storage tank D.

In the above explanation I have given figures as closely as possible for average conditions but these figures may be varied somewhat depending upon the nature of the fats and oils undergoing treatment.

This first treatment of the clear fats and oils is twice repeated with or without such, variations and percentages of reagent and free sulfuric acid as may be found best suited for the particular fats or oils. which are undergoing treatment. That is to say 20% to 30% of distilled or condensed water is added to the fats or oils and fatty acids remaining after the first settling of glycerin water is drawn'ofi', and the contents of the saponification tank are again brought to a boil, the agitator is set in motion and from .17? to 4% of Twitchell or equivalent catalytic reagent is added. The mixture is allowed to boil under agitation for from 12 to 18 hours as before. By thus agitating the mixture during the entire boiling operation the decomposition is more eflectively performed than if the mixture were agitated but a portion of the time. Test of the acid of the water should show .03% to 1% of free sulfuric acid, the percentage of sulfuric acid being carefully controlled to maintain emulsion but so as to prevent separation or settling; at the end of the second bleaching the g ycerin water is again permitted to settle and is drawn off as before.

This same treatment is then repeated for the third time.

It will be understood, of course, that the gycerin water is evaporated or otherwise treated to recover and purify the glycerin content. This treatment will have removed almost the entire glycerin content of the fats or oils undergoing treatment.

The fatty acids remaining after the glycerin has been washed out are now subjected to the bleaching operation which may be carried on either in the saponfication tank or in the bleaching tank marked with reference letter E. In either case the bleaching is commenced and carried on without permitting the fatty acids to come into contact with the air.

A small proportion of water is added to the fatty acids whereupon the mixture is brought to a boil and the agitator is started. The fatty acids and water will, as a result of the prior treatment, be in good emulsion and should be boiled and agitated for from 3 to 6 hours, thereupon adding sufiicient sulfuric acid to break the emulsion, whereupon the water will settle out. The quantity of sulfuric acid necessary to be added will make the water test from .03% to 1% acid, the percentage being dependent upon the nature of the fats or oils undergoing treatment. After the additional sulfuric acid has been intermixed, the agitator is stopped and the steam turned off and the contents of the tank are allowed to settle for from to one hour. The water which settles out as a result of this washing is then drawn from the tank at the bottom. The fatty acids remaining are then subjected to heat and agitation whereupon a small quantity of distilled water is added together with from .1% to 2% of the Badische Co.s decrolin. This mixture is boiled from 15 to 30 minutes, if thereupon the water does not settle out, a small quantity of sulfuric acid sufficient to break the emulsion is added; this will cause the water to settle out in from 15 to 30 minutes, whereupon it is withdrawn from the bottom. a

The remaining fatty acids are then again boiledand agitated,-and a small quantity of water, from .1% to 2% of decrolin added as before; the boiling and agitation are continued for from 15 to 30 minutes. If again, the water does not settle out promptly upon turning off the heat and stopping the agitator, sulfuric acid sufficient to break the emulsion is added, whereupon the water will settle out in '15 to 30 minutes. This second water is drawn off as before.

Again the fatty acids are boiled and agitated with the addition of .1% to 2% decrolin, and the boil is continued for 15 to 30 minutes whereupon I add sufficient barium carbonate, sodium carbonate, or caustic soda to neutralize the sulfuric acid in the water; that is to say the neutralizing agent is added until the water in the mixture tests neutral to methyl orange. Thereupon the agitator is stopped and the steam turned off and the water allowed to settle to the bottom, the water which settles out is withdrawn from the bottom of the tank, whereupon the agitator is run for from 15 to 30 minutes. This finishes the fatty acids which will then be ready for the manufacture of soaps, stearic acids, candles, or for any other purposes to which high grade fatty acids of good color are adaptable.

I sometimes add from .1% to 2% decrolin to the mixture at the end'of each of the three decomposition boils and about 30 min utes before allowing the glycerin water to settle out. However, I prefer bleaching the fatty acids at the end of the last boil in the order hereinbefore described. I may bleach the fatty acids in one, treatment directly after drawing off the last glycerin water and without subjecting the fatty acids to the extra water and acid wash. In such case I add the required amount of decrolin at once or in three or more small quantities at intervals of 15 to 30 minutes. However by far best results are secured in the order hereinbefore described.

Just as in the matter of the quantities of Twitchell reagent and sulfuric acid necessary to be added in effecting the decomposition, so also in the matter of the bleaching operations the amount of decrolin will vary somewhat in accordance with the nature and quality of the fats or oils undergoing treatment. The figures above given will,

however, comprise the range which is ordinarily met in practice.

By the use of my process as hereinbefore described the time required to complete the manufacture .of soap may be reduced from 34 days to 8 days the color of the fatty acids entering into the soap manufacture will be equal to that of the neutral fats or oils which are subjected to decomposition.

While I have herein described the best manner of carrying on my invention so far as I am aware it is subject to minor variations, which, however, do not go to the essence of the new process of my invention; I do not, therefore, wish to be limited to the details herein stated. Q

What I claim as new and desire to secure by Letters Patent is:

1. The process of decomposing fats or oils which consists in forming. a mixture of the, fats or oils, catalytic reagent and water and simultaneously boiling and agitating the mixture with a portion of sulfuric acid sufiicient to break up the fats or oils to insure a good emulsion whereby intimate. intermixture between the reagent and fats or oils is attained.

2. The process of decomposing fats or oils which consists of forming a mixture of the fats or oils, catalytic reagent and water, agitating the mixture and simultaneously boiling the mixture with a portion of sulfuric acid sufficient to break up the fats or oils to insure an emulsion and intimate intermixture of the fats or oils and reagent, but insufiicient to settle the Water out 'of the fats or oils.

3. The process of decomposing fats or oils which consists in repeatedly subjecting the fats or oils to'the followin treatment: mixing the fats or oils with su furic acid, water and a portion of catalytic reagent too small to wholly decompose the fats or oils, boiling the mixture, and continuously agitating the mixture during the boiling operation.

' 4. The process of decomposing fats or oils and bleaching the resultant fatty acids consisting in subjecting the fats or oils to successive treatments each as follows: mixing the fats or oils with water, sulfuric acid and a quantity of catalytic reagent too small to wholly decompose the fats or oils under treatment, boiling the mixture and continuously agitating the mixture during the boiling operation, and after the successive decomposing treatments bleaching the fattyacids resulting from said decomposition.

5. The process of decomposing fats or oils consisting in subjecting the fats or oils to successive treatments each as follows: mixing the fats or oils with water from .03% to 1% of sulfuric acid and from .1% to .4;% of catalytic reagent, boiling the mixture from 12' to 18 hours, and continuously agitating the mixture during the boiling opera tion.

6. The process of decomposing fats or oils and bleaching the resultant fatty acids consisting in subjecting the fats or oils to suecessive treatments each as follows: mixing the fats or oils with water, from .03% to 1% of sulfuric acid, and from .1% to .i% of catalytic reagent, boiling the mixture from 12 to 18 hours, and continuously agitating the mixture during the boiling operation, and after the decomposition treatments bleaching the fatty acids resulting from said decomposition.

7. The process of decomposing fats or oils which consists in forming a mixture of the fats or oils, catalytic reagent and water, agitating the mixture, simultaneously boiling the mixture witha portion of sulfuric acid sufficient to break up the fats or oils to insure an emulsion and intimate intermixture of the fats or oils or reagent, but insufficient to settle the water out of the fats or oils, subsequently adding another portion of sulfuric acid to the mixture sufficient to settle the water out of the fats or oils and then withdrawing the aqueous solution of water and spent reagent.

8. The process of decomposing fats or oils which consists in forming a mixture of the fats or oils, catalytic reagent and water, mechanically agitating the mixture and simultaneously boiling the" mixture with a portion of sulfuric acid suiiicient to break up the fats or oils to secure a good emulsion whereby intimate intermixture of reagent and fats or oils is attained.

9. The process of decomposing fats or oils which consists in mixing the fats or oils with water, from .03% to 1% of sulfuric acid and from 1% to .4% of catalytic reagent, boiling the mixture from 12 to 18 hours and continuously agitating the mixture during the boiling operation.

10. The process of decomposing fats or oils which consists in forming a mixture of the fats or oils, catalytic reagent and water, and

agitating the mixture at a high temperature with a quantity of sulfuric acid sufiicient to break up the fats or oils to insure a good emulsion, whereby intimate intermixture between the reagent and fats or oils is attained.

.11. The process of decomposing fats or oils which consists in forming a mixture of fats or oils, catalytic reagent and water, agitating the mixture and simultaneously boiling the mixture with a quantity of sulfuric acid sufiicient to break up the fats or oils to insure an emulsion and intimate intermixture of the fats or oils and reagent, but insuflicient to settle the water out of the fats or oils.

In witness whereof, I hereunto subscribe my name this 17th day of May, A. D. 1912.

BALTHASAR E. REUTER. Witnesses:

ALBERT C. Bm, JOHN MALoNEY.

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