US2084446A - Process for manufacturing soap and glycerine - Google Patents

Description

Patented June- 22, 193'! Process roa muvrlio'ruamoi soar m scream F, Lorenz, Jersey Cityfll. 1.. aleignor orfortypercenitoCharlesEWlllomN York, N. Y.

No Drawing. Befiled for abandoned application Serial No. 353,849, January 24, 1920.

This IP- plicatlon November 8, 1934, Serial No. 752,122

190laims.

This invention relates to the process of manufacturing soap and recovering glycerine from oils and fats by means of a vacuum. The object of the invention is to produce a process for decom- 5 posing saponiilable oils and fats including vegetable, animal, marine animal oils or, in fact, any fat or oilcontaining glycerine with alkali, primarily into soap and glycerine under reduced pressure, the general purpose being to render the process of soap making more expeditious and considerably cheaper.

In soap manufacture in the usual way the oil or fat is mixed with an excess of caustic alkali and boiled in an enclosed or open kettle until.

saponiilcation is complete, The soap lye is'salted out and the glycerine extracted and refined. By my process an excess of caustic alkali is not necessary, in fact, only the exact amount of alkali required for neutralizing the fatty acids need 26 be used, a neutral soap being obtained in one operation. Again, I obtain a. practically pure grade of glycerine, free from caustic alkali, including caustic soda, caustic potash and similar acting caustic bodies, salt, or other inorganic impurities. Also, practically all the glycerlne is nicely and smoothly separated from the soap residue.

The invention consists in the process to be more fully described hereinafter and particularly the heating of the soap making materials in such a. way that the water from the caustic solution, the glycerine liberated from the oil or fat, and a 45 small percentage of the volatile oily matter are drawn oil and collected. During the distilling operation a. vacuum is maintained in the system. Referring more particularly to the parts, and describing the process more fully, I may say that 50 one method of carrying out my process is to mix the oil or fat with a suitable quantity of alkali dissolved in an appropriate quantity of water (or mixing the oil or fat with finely divided alkali more or less in the dry state) in an enclosed 55 kettle or still connected with a condenser, condenser worm or coil (disposed within a condensing chamber in which the condensing operation is conducted in the usual way) and distillate receptacle or receiver, the whole being enclosed and forming a vacuum circuit. It is understood that the receiver is in turn connected by a pipe with a vacuum pump through the manipulation of whicha vacuum may be maintained or produced in the system.

Obviously the mixture of the oil or fat with the alkali can be-made in a separate vat or tank by agitation or otherwise and then drawn into the retort or distilling chamber. The retort is now heated in excess of 150 0., preferably up to 250 to 270 centigrade, in any suitable manner, with superheated steam coils, or otherwise, and the vacuum pump put in operation. The water, glycerine and a small percentage of volatile oil (usually 2 to 3%) will distill over, the soap formed remaining in the retort as a dry mass. During the cooling of the soap mass I have found it important not to admit any air into the retort, otherwise the soap will turn brown in color. To facilitate the distillation of the glycerine from the soapmixture, I may elect to pass steam preferably superheated, through the soap mixture in the retort. This operation will, of course, thoroughly agitate the mixture. The condensed water from the steam in this case will pass into the condensing receptacle that receives the glycerine and volatile oil.

During the distilling it will be self evident that as the water (unless dry alkali is used) in the mixture evaporates, the lye becomes highly concentrated, bringing about a complete saponiflcation with the production of a neutral soap, if the quantities of alkali and oil are present in equimolecular quantities. Inasmuch as the volatile impurities are removed, the soap will be a bland, sweet-smelling or practically odorless soap.

Before the distillation is begun-it is preferable to have the oil and alkali in intimate mixture. This can be accomplished by proper agitation with paddles or otherwise, by spraying the oil into the alkali or the alkali into the oil. Again, the oil and alkali can be sprayed separately in proper proportions, into the heating receptacle. Or, an emulsion or mixture of the oil and alkali can be first made and this sprayed into the heating receptacle or retort. While the spraying can be accomplished with air, or better with an inactive gas such as nitrogen or hydrogen, I prefer to use steam, ordinary or superheated, for

this purpose. For instance, to prepare soap and glycerine from cottonseed oil I may proceed as follows:-

Intimately mix or emulsify the oil and alkali. Spray this mixture with steam into a receptacle 5 or retort heated to 250 to 270 C:, said receptacle or retort being part of a vacuum distilling circuit. Said retort or receptacle may contain a mechanical scraper to scrape off the soap accumulated upon the hot surface walls, striking which the i0 oil-alkali mixture is instantly saponifled, the

water, glycerine and volatile oil distilling 01!.

Obviously, I can saponify an oil in the usual way, bring the mixture into the retort of the vacuum circuit and distill oi! the glycerine.

In the distillate, the volatile oil can readily be separated from the glycerine-water solution, the latter evaporated down to any concentration desired. It is also understood, that through suitable apparatus the glycerine can, in one and the same set of apparatus, be evaporated down to proper concentration. I prefer to use as high a vacuum as it is possible to maintain in carrying out my process.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

i. The process of making soap and glycerine which consists in heating a mixture of fat and a base to a temperature in excess of the melting point of the resulting anhydrous soap and thoroughly agitating the mixture in an atmosphere free of air while intimately contacting the mixture with a stream of water vapor.

2. The process of making soap with an unobjectionable odor and glycerine which consists in heating a mixture of low grade fat and a base to a temperature in excess of the melting point of the resulting anhydrous soap and thoroughly agitating the mixture in an atmosphere free of air, while intimately contacting the mixture with a stream of water vapor.

3. The process of making soap with an unobiectionable odor and glycerine which consists in heating a mixture of low grade fat and a base to a temperature in excess of the melting point of the resulting anhydrous soap and thoroughly agitating the mixture in an atmosphere free of air,

while intimately contacting the mixture under diminished pressure with a stream of water vapor.

4. The process of making light-colored soap with an unobjectionable odor and glycerine which consists in heating a mixture of low grade fat and a base to a temperathre in excess of the melting point of the resulting anhydrous soap and thoroughly agitating the mixture in an atmosphere free from air, while intimately contacting the mixture with a stream of water vapor.

5. The process of making light-colored soap with an unobjectionable odor and glycerine which consists in heating a mixture of low grade fat and a base to a temperature in excess of the melting point of the resulting anhydrous soap and thoroughly agitating the mixture in an atmosphere free from air, while intimately contacting the mixture under diminished pressure with a stream of water vapor.

6. The process of completely saponifying fat and of separating the resulting glycerine in vapor form from the soap which comprises uniformly heating a mixture of fat and an alkaline medium to a temperature in excess of the melting point of the resulting anhydrous soap while contacting the said mixture with a stream of water vapor at low pressure, excluding air, and condensing the glycerine.

7. The process of completely saponifying fat and of separating the resulting glycerine in vapor form from the soap which comprises uniformly heating a mixture of fat and an alkaline medium to a temperature above 150 degrees C. while contacting the said mixture with a stream of water vapor at low pressure, excluding air, and condensing the glycerine.

8. The process of manufacturing soap and glycerine, one from the other separated, which consists in maintaining a mixture of fat and alkali in a molten, substantially anhydrous state until the formation of soap is substantially complate and in removing glycerine therefrom in vapor state.

9. The process of manufacturing soap containing substantially no glycerine which comprises heating a soap and glycerine mixture uniformly to a temperature in excess of its melting point when anhydrous, excluding substantially all air from the melted mixture, intimately contacting the melted mixture with a current of steam and carrying the glycerine from the melted mixture by the current of steam.

10. The process of manufacturing soap containing substantially no glycerine which comprises heating a soap and glycerine mixture uniformly to a temperature in excess of its melting point when anhydrous, excluding substantially all air from the melted mixture, intimately contacting the melted mixture with a current of steam at a pressure less than atmospheric, and carrying the glycerine from the melted mixture by the current of steam.

11. A process for the manufacture of soap and glycerine consisting in the treatment of fats or fatty oils with an alkaline medium suiiicient to effect saponification, the subjection of the composition thus formed to heat, without local overheating, to a temperature in excess of 200 degrees C., with the aid of agitation, with the exclusion of air, with a current of steam, in a closed vessel with the aid of diminished pressure for the volatilization and recovery of the glycerine produced, and for the volatilization and removal of volatile impurities.

12.A process of making soap and glycerine consisting of mixing fats or fatty oils with an alkaline medium, heating the mixture thus formed, with the exclusion of air, with agitation, without local overheating, to a temperature in excess of the melting point of the anhydrous soap, with the employment of a current of steam, volatilizing, condensing and recovering the glycerine thus formed, and volatilizing and removing objectionable volatile impurities.

13. The process of making bland, sweet-smelling soap from fatty acids derived from marine animal oils consisting of mixing such fatty acids with an alkaline medium, heating the mixture thus formed with the exclusion of air, with agitation, without local overheating, to a temperature in excess of 250 degrees C., with the employment of a current of steam, in a closed vessel under diminished pressure, volatilizing and removing objectionable impurities.

14. The process of saponifying esters of fatty acids to produce soap and alcohol and of separating the resulting alcohol in vapor form from the soap, which comprises uniformly heating a mixture of esters of fatty acids and an alkaline medium to a temperature in excess of the meltin p int of the resulting anhydrous soap while contacting said mixture with a stream of water vapor at low pressure, excluding air, thoroughly agitating the whole, and condensing the alcohol so formed.

15. The process of saponifying esters of fatty acids to produce soap and alcohol and of separating the resulting alcohol in vapor form from the soap, which comprises uniformly heating a mixture of esters of fatty acids and an alkaline medium to a temperature above degrees C. while contacting said mixture with a stream of water vapor at low pressure, exc uding air, thoroughly agitating the whole, and condensing the alcohol so formed.

16. The'process of separating glycerine from a partially saponified and saponifying mixture of a fat and a base which consists in uniformly heating the mixture in the presence of water vapor to a temperature producing an appreciable vapor pressure of glycerine, continuously and thoroughly agitating said mixture to prevent local over-heating, excluding air, intimately contacting said mixture with a stream of water vapor, removing the mixed vapors of water and glycerine and condensing the glycerine.

1'7. The process of separating glycerine from a mixture of soap and glycerine which consists in heating said mixture uniformly without local overheating to a temperature producing an appreciable vapor pressure of glycerine, thoroughly agitating said mixture, excluding air, intimately contacting said mixture with a stream of water vapor, and removing the resulting mixed vapor of water and glycerine and condensing the same while carrying on the whole at diminished pressure.

18. The process of converting soap with an objectionable odor into soap without an objectionable odor which consists in heating said soap to a temperature above its meltingpoint when anhydrous thereby driving substantially all water therefrom, agitating to, maintain substantially uniform temperature throughout said soap regardless of heating means, and excluding air while contacting said soap with a flow of water vapor at a pressure low enough to prevent the existence of liquid water.

19. The process of converting soap with an objectionable odor into soap without an objectionable odor, which consists in heating said soap to a temperature in excess of 150 degrees C. thereby driving substantially all water therefrom, agitating to maintain substantially uniform temperature throughout said soap regardless of heating means, and excluding air while intimately contacting said soap with a flow of water vapor at a pressure low enough to prevent the existence of liquid water.

HENRY W. F. LORENZ.