US2292027A - Oil treatment - Google Patents

Description

Patented Aug. ,4, 1942 on. murmur Eddie C.

Glenn, Westfleld, N. 1., assignor to Inustrial Patents Got-notation, Chicago, 111., a

corporation of Delaware Application June 23, 1939, erial No. 2895M No Drawings.

1% Claims. (CL ZBMOW This invention relates to the treatment of fats and oils.

One of the objects of this invention is to provide an improved method, of bleaching fats and oils.

Other objects and advantages of this invention will become apparent irom the description and claims which follow.

Vegetable oils, for example, cottonseed oil, cocoanut oil, soya bean oil, corn oil, rape seed oil, peanut oil, palm oil, and the like, are generally subjected to three steps in the preparation of edible compositions, namely, a refining step, a bleaching step, and a deodorization step. In many cases a hydrogenation step is introduced between the bleaching step and the deodorization step. The reg step. is generally carried out by treating the oil with caustic which reacts with the free fatty acids to form soaps, and the soaps and roots are removed to produce a refined oil.

The refined oil is then treated with from'two per cent to three per cent of a solid adsorbent, such as fullers earth, activated earths, activated carbon, or mixtures of these materials, to bleach or decolorize the oil. After removal of the solid adsorbents from the oil, the oil may be hydrogenated or may be passed directly to the deodorization chambers. Deodorization is generally effected by treating the oil at elevated tempera tures and under a reduced pressure by passing steam through the body of the oil.

a1 rats and oils, for example, lard, oleo stearine, and tallow, may also be refined, bleached and deodorized or hydrogenated and deodorized. In the claims, the term oils is employed in its broad sense to include animal and vegetable tats and oils regardless of the melting point or the particular material.

The use oi solid adsorbents for complete bleaching of oils results in an oil loss which is dependent upon the amount of adsorbent employed in thebleaching step and upon the individual adsorbent,

The present invention contemplates a partial bleaching of oils by treatment with a solid adsorbent followed by a final or complete bleaching of the oil during hydrogenation or deodorization.

earth, is mixed thoroughly with the heated oil. I have discovered that generally less than one halt the usual quantities of fullers earth may be employed in partially bleaching dark colored oils and smaller quantities may be employed in partially bleaching light colored oils in accordance with my invention. Generally, from about 0.1 per cent to one per cent fullers earth is satisfactory. For example, in bleaching a refined oil having a color of 7.6 red, from two per cent to three per cent iullers earth is generally employed in the conventional bleaching process to bleach the oil to a coloroi from 2.0 red to 2.5 red. In accordance with my invention, 1 may employ about up to one per cent iullers earth, which is sumcient to eflect a per cent reduction in the color, or to reduce the color to about 5.0 red. The adsorbent is then removed by passing the mixture of adsorbent and oil through a filter press.

The partially bleached oil is then deodorized at a temperature of from 350 degrees F. to 470 degrees F, under a vacuum of about 28 inches and steam is passed through the body of the oil for about five hours to remove volatile compounds which impart undesirable odors to the oil. I havediscovered that bleaching of the oil may be completed simultaneously with the deodorization. 'An oil, previously partially bleached to a color of about 5.0 red, will be reduced to a color as low as that obtained by standard bleaching with six per cent fullers earth, namely, to a color of from 2.0 red to 2.5 red, during the deodorization step or other heat treatment step.

If the oil is to be hydrogenated, the hydrogenation step precedes the deodorization step. In general, hydrogenation may be carried out at a temperature of from 365 degrees F. to 385 degrees F. in the presence of a catalyst such as nickel. Hydrogenation may be efiected under a vacuum or at atmospheric pressure. During hydrogena- In the practice of my invention, crude oil, for

example, cotton'seed oil, may first be refined, for example, with caustic at a temperature of from degrees F. to degrees F. The refined oil is then heated to a temperature of from degrees F. to 220 degrees F., for example, to a temperature of about degrees F., and a small proportion of solid adsorbent, such as iullers tion the oil may be bleached, the rate and degree of bleaching being dependent upon the degree of heat maintained durin i'drogenation. I have found that substantially the same amount of bleaching may be accomplished during hydrogenation as is effected during deodorization. Where the hydrogenation step is to be followed by a deodorization step it is not necessary to closely control the hydrogenation step to efiect a complete bleaching since the bleaching may be completed in the deodorization step.

I have discovered that bleaching of the oil may also be completed by heating the oil under atmospheric pressure or increased pressure, with or without passing steam through the body of the oil or in the presence or absence of hydrogen.

Animal fats and oils may be treated in the same manner as described for the treatment of fullers earth. It will be noted that in eachof the cottonseed oil samples, the red color was reduced about 50 per cent with respect to the reduction obtained by the standard bleach emtated for a short period, for example, from ten to fifteen minutes, was then passed through a filter press to free the oil of the earth. The fourth column of data represents the red color vegetable oils, 5 ploying six per cent fullers earth.

My process has been applied satisfactorily on In each case, a portion of the refined, partially a large scale in bleaching cottonseed oil, cocoableached oil was deodorized by heating the oil nut oil, rape seed oil, corn oil, soya bean oil, to a temperature of from 350 degrees F. to 400 peanut oil, palm oil, tallow, and oleo stearine. degrees F. under a vacuum of about 28 inches, In large scale operations on these oils and fats, and steam was passed through the oil for a period I have found that from about 0.3 per cent to 0.6 of about five hours. The data in the fifth colper cent solid adsorbent, such as fullers earth, umn represents the color reading of the deodorand that deodorization temperatures between ized oil sample. 350 degrees F. and 400 degrees F. are quite satis- A portion of certain of the main samples of factory. I have found that a highly satisfactory refined, partially bleached oil was hydrogenated bleach may be obtained by effecting a bleach in the presence of a nickel catalyst at a temperawith asolid adsorbent equivalent to about 50 per ture of from 365 degrees F. to 385 degrees F. cent of the standard bleach for the particular under a pressure of about 40 pounds per square oil and completing the bleaching by heat treatinch for from five to twelve hours. The data in ment, the sixth column represents the color reading Table A represents data which was obtained of the hydrogenated material. in semi-commercial practice of my invention in A portion of certain of the samples of refined, 'the treatment of 326,000 pounds of cottonseed partially bleached oil was hydrogenated in the oil and 212,000 pounds of soya bean oil. I have presence of a nickel catalyst at a temperature found that the use of about one third of one per of from 365 degrees F. to 385 degrees F. under a cent fullers earth is generally satisfactory in pressure of about pounds per square inch. the treatment of cottonseed oil, and that about The cottonseed oil so treated was subjected to one half of one per cent fullers earth is generally the action of hydrogen for from fifty minutes satisfactory in the treatment of soya bean oil. to one hundred thirty-five minutesl The soya In Table A, the first column of data represents 30 bean oil so treated was subjected to the action the color reading of the refined oil. The second of hydrogen for from ninety minutes to one huncolumn of data represents the red color reading dred fifty minutes. The hydrogenated material of a small sample of each of the samples of the was then deodorized by heating the material to refined oil which has been subjected to the standa temperature of from 350 degrees F. to 400 deard bleach wherein the oil is bleached by treatgrees F. under a vacuum of about 28 inches, and ment with six per cent standard fullersearth steam was passed through the material for a in accordance with the specifications of the period of about five hours. The data in the ,American Oil Chemists Society, published in seventh column represents the color reading of American Oil Chemists Societys Methods," the hydrogenated, deodorized oil.

' Table A 00191. Hydrogenated on Color readmg s git Per cent Color fifig i af n? z l r ri g g g g ggigg g g Sample uller'a earth reading g 7 8103; used red Yellow Red red Yellow Red Yellow Red Yellow Red OOTIONSEED OIL a5 7.1 1.4 0.411 3.2 15 1.4 10 1 5 35 7.3 1.5 0.222 4.0 15 1.8 12 1.4 35 as 1.0 0.203 4.2 15 1.2 12 1.0 35 0.5 1.5 0.300 4.3 20 1.0 14 1.5 14 1.3 35 0.7 1.0 0.273 4.1 15 1.3 12 1.3 15 1.4 J

SOYA BEAN OIL page 17. It willbe noted that samples of soya The use of my method of bleaching fats and bean oil were not treated with six per cent fullers oils results in a substantial reduction in the cost of earth. bleaching since much smaller quantities of solid In each case, the refined oil was heated to a adsorbent are required than in the conventional temperature of from 160 degrees F. to 220 debleaching method. Bleaching to 50 per cent of grees F. and fullers earth then added and thorthe total standard bleaching results in more than oughly. mixed with the oil. The third column a 50 per cent saving in the solid adsorbent since of data represents the percentage of earth added. the last full point of color which is,remo'ved by The mixture of oil and earth after being agisolid adsorbents requires about six times the quantity of solid adsorbent required in the removal of the first full point of color. My method also effects a savings in the cost of filter press cloths and of cleaning the filter press since larger reading of the 011 after partial bleaching with quantities of oil may be run through the filter press before sumcient solid adsorbent has been collected to require the replacement of the cloths and cleaning of the filter press. It is apparent that a reduction in the quantities of adsorbent employed in treating the oil also reduces the oil loss resulting from retention of oil by the earth, since about one pound of oil is lost 'for each ten pounds of earth employed.

I claim:

1. The method oi bleaching glyceride oils which comprises treating a refined glyceride oil with up 8. The method of bleaching refined cottonseed oil which comprises heating the oil to a tem-' perature of from 160 F. to 220 F., adding thereto up to one per cent iuller's earth to eflect a partial bleach oi the oil, agitating the mixture of tullers earth and oil, separating the iullers earth from the oil, heating the'oil to a temperature'oi to about 1 per cent of an activated adsorbent earth to effect a partial decolorization oi the oil,

separating the activated earth adsorbent from the oil, and thereafter heating the oil to a higher temperature of about 350 to 400 degrees F. in order to eflect more complete decolorization.

2. The method bleaching refined glyceride oils which comprises adding to the oil up to one per cent of a solid adsorbent to eflect a partial decolorization oi the oil, agitating the mixture of oil and adsorbent, separating the solid adsorbent from the oil, and thereafter heating the oil to a higher temperature of from 350 degrees F. to 400 degrees F. v

3. The method of bleaching refined glyceride oils which comprises adding to the oil up to one per cent 0! a solid adsorbent to eilect a partial decolorization oi the oil, agitating the mixture of oil and adsorbent, separating the solid adsorbent from the oil, heating the oil to a higher temperature 0! from 350 degrees F. to 400 degrees F. under a vacuum, and subjecting the oil to the action of steam.

4. The method of bleaching refined glyceride oils which comprises adding to the oil up to one per cent of a solid adsorbent to effect a partial decolorization of the oil, agitating the mixture of oil and adsorbent, separating the solid adsorbent from the oil, and thereafter hydrogenating the oil at a higher temperature oi from 350 degrees F. to 400' degrees F.

5. The method of bleaching refined glyceride oils which comprises heating the oil to a tern-- perature of from 160 degrees F. to 220 degrees F., adding thereto from 0.1 per cent to one per cent of a solid adsorbent, agitating the mixture 01 adsorbent and oil, separating the adsorbent from the oil, heating the oil to a temperature of from 365 degrees F. to 400 degrees F. under a vacuum, and treating the oil with steam.

6. The method 01 bleaching refined vegetable oils which comprises heating the oil to a temperature of from 160 F. to 220 F., adding thereto up to one per cent iullers earth to effect a partial bleach oi the oil, agitating the mixture at iuller's earth and oil, separating the iullers earth from the oil, heating the oil to a temperature of from 350 F.-to 400 F. under a vacuum of about 28 inches, and passing steam through the oil under the vacuum for a period of about 5 hours.

7. The method of bleaching refined cottonseed oil which comprises heating the oil to a temperature of from 160 degrees F. to 220 degrees F., adding thereto up to one per cent of a solid adsorbent to eii'ect a partial decolorization of the oil, agitating the mixture of adsorbent and oil, separating the adsorbent from the oil, heating the oil to a temperature of from 350 degrees F.

to 400 degrees F., and subjecting the oil under 70 from 365 degrees F. to 400 reduced pressure to the action of steam.

from 350 F. to 400 F. under a vacuum of about 28 inches, and passing steam through the oil under the vacuum for a period of about 5 hours.

9. The method of bleaching refined cottonseed oil which comprises heating the oil to a temperature of from degrees F. to 220 degrees F., adding thereto from 0.1 per cent to one per cent tullers earth to effect a partial decolorization of the oil, agitating the mixture of oil and iullers earth, separating the tullers earth from the oil, heating the oil to a temperature 0! from 350 degrees F. to 400 degrees F., and subjecting the oil under vacuum to the action of steam for about five hours. 1

10. The method of bleaching refined cottonseed oil which comprises heating the oil to a temperature of from 160 degrees F. to 220 degrees F.. adding thereto from 0.1 per cent to one per cent iuller's earth to eflect a partial decolorization oi the oil, agitating the mixture of oil and iuller's earth, removing the fuller's earth from the oil, and hydrogenating the oil at a temperature of from 365 degrees F. to 400 degrees F.

11. The method of bleaching refined soya bean oil which comprises heating the oil to a temperature of from 160 degrees F. to 220 degrees F., adding thereto up to one per cent of a solid adsorbent to eifect a partial decolorization oi the oil, agitating the mixture of adsorbent'and oil, separating the adsorbent from the oil, heating the oil to a temperature of from 350 degrees F. to 400 degrees F., and subjecting the oil under reduced pressure to the action of steam.

12. The method of bleaching refined soya bean oil which comprises heating the oil to a temperature of from 160 F. to 220 F.. adding thereto up to one per cent tullers earth to eiIect a partial bleach of the oil, agitating the mixture of iullers earth and oil, separating the iullers earth from the oil, heating the oil to a temperature 01 from 350 F. to400 F. under a vacuum of about 28 inches, and passing steam through the oil under the vacuum for a period of about 5 hours.

13. The method of bleaching refined soya bean oil which comprises heating the oil to a temperature of from 160 degrees F. to 220 degrees F., adding thereto from 0.1 per cent to one per cent i'ullers earth to effect-a partial decolorization oi the oil, agitating the mixture of oil and iullers earth, separating the iullers earth from the oil, heating the oil to a temperature of from 350 degrees F. to 410 degrees F., and subjecting the oil under vacuum to the action 01 steam for about five hours.

14. The method of bleaching refined soya bean oil which comprises heating the oil to a temperature of from 160 degrees F. to 220 degrees F., adding thereto from 0.1 per cent to one per cent iuller's earth to effect a partial decolorization oi the oil, agitating the mixture of oil and iullers earth, separating the iuller's earth from the oil, and hydrogenating the oil at a temperature of degrees F.

EDDIE C. GLENN.

emu-Imam OF comqmon; e Patent li -.1 2,292,027. am 1;,

" EDDIE 0. am,

It is hereby certified that: error appears in the printed afieei ricat ion of the above nuinbered patent requiring correctien a: fallen; Page 5, I sec-2 0nd colum'n, line '59, for 11.19 degrees reed ."hOO degrees"; and that the said Letters Patent 'ahould be read with this correction therein that the same may conform to the recerd of the casein the Patent .prrglee- I signed ehdeealed this 8th day'ef September, L. Di 1%.21.

Ha vm-mma; (Seal) Aetirg Commissioner of Patents.