US2357352A - Process for hydrogenating edible oils - Google Patents

Description

Patented Sept. 5, 1944 PROCESS FOR HYDROGENATING EDIBLE OILS William J. Paterson, Newton Highlands, Mass.,

assignor to Lever Brothers Company, 'Cambridge, Mass, a corporation of Maine No Drawing. Application April 2, 1941,

"Serial No. 386,455

19 Claims.

The present invention relates to the preparation of improved products from glyceride oils which are susceptible to an improvement in stability against rancidity and color or odor, or both. More particularly, the invention relates to a novel treatment of glyceride oils with hydrogen in the presence of a catalyst to provide an improved product with respect to color, odor, plasticity, and stability.

The crude oils which are made available to the manufacturer of glyceride ,oil products and which have been prepared in accordance with the usual practice are generally dark in color and contain a substantial amount of undesirable impurities; such as free fatty acids, gums, mucilaginous material, and the like. Moreover, these oils are normally odoriferous and otherwise objectionable, particularly when the object is to use them as edible substances, for example, for culinary purposes. I

Heretofore, the crude oil generally has been subjected to a series, of refining, decolorizing, hydrogenating and deodorizin operations to remove objectionable constituents from the oil and to improve its stability, color, odor and flavor. The particular procedure followed and the severity of the treatment depends to a large extent I upon the type and initial purity of the crude oil as well as the desired characteristics of the final product.

In general, the initial refining of the oil is accomplished by subjecting the oil to a treatment with caustic alkali, which neutralizes and precipitates the free fatty acids as soaps. At the same time, a substantial proportion of the gums,

mucilaginous materials, and coloring matter is coagulated and removed along with .the fatty acid soaps.

To provide an oil of particularly good quality, it is not uncommon to subject the oil to a rerefining operation in which the refined oil is again subjected to the action of caustic alkali, generally in a more dilute solution. A further removal of foots, although smaller in amount, is thus effected which is highly beneficial in improving the quality of the finished product with respect to color and free fatty acid content. An inherent I disadvantage of the re-refining operation is a substantial further loss of neutral oil by saponification and entrainment. and therefore the use of the re-refining operation is undesirable from an economical standpoint.

Further, in accordance with the art of preparing glyceride oil products, the refined oil is bleaching treatment with a usual bleaching agent of the carbon or earth type. The bleach ng agents, it is believed, eifect a decolorizing action by absorbing coloring matter from the oil. The bleaching agents and the absorbed coloring matter are then removed from the oil by filtration.

It has been observed that bleaching agents also such as nickel and generally at elevated tempera-.

tures. Incidental to the hardening of the oil,

a further improvement in color generally takeslace.

p During such hydrogenation processes the esters of the unsaturated fatty acid components present in the oils are changed to the esters of corresponding saturated fatty acids. The consistency of the material progressively approaches that desired as hydrogenation is prolonged. If a plastic shortening is desired, it is essential that the more unsaturated glycerldes be saturated to a degree suflicient to decrease the fluidity of the oils and sufl'icient to improve the keeping qualities of the unsaturated components.

It is generally recognized that the instablity of glyceride oils is a result of the tendency of these oils to add on oxygen from the atmosphere at the points of unsaturation in their fatty acid components. It is understood, however, that complete saturation, characterized by the formation of a hard, brittle solid, is undesirable for most uses. In general, it is customary to hydro-. genate the oil, for example, a vegetable oil to be used in shortenings, to a degree which gives a product of substantially lard-like consistency at room temperatures.

The refined and bleached oil, either hydrogenated or unhardened, may then be deodorized by subjecting the oil to a treatment with steam under reduced pressure conditions.

It is an object or my invention to avoid the multiplicity of processing steps heretofore regarded as essential in the manufacture of good grade products from glyceride oils. I r

In particular, it is possible by the practice of my invention to dispense with the uneconomical nerally improved in color by a subsequent steps of re-reflning with alkali and decolorizing I such as distillation I edible oil products.

A particular object of my invention is to provide a method whereby unbleached oils may be bleached and hardened simultaneously tov at least the degree required in the production of good grade glyceride oil products.

It is another object of my invention to provide a method of hardening 'glyceride oils and fats whereby the oils exhibit a greater stability against oxidation and the development of rancidity as compared with oils hardened to the same iodine value or consistency in accordance with the prior art practice.

Another object of my invention is to provide a method of simultaneously decolor-izing and hardening edible oils whereby a product of improved color and odor having desirable plasticity charac teristics may be produced with a substantial saving in the time and amount of catalyst required.

The treatment of a prime cottonseed oil for the manufacture of edible oil products by the methods described above may be taken as typical and involves the problem of color removal. "A representative crude cottonseed oil ranges from dark reddish-brown to almost black in color when expressed from the seed. Upon being reflned'with alkali, a representative oil exhibits a color of approximately 5.0 red/35.0 yellow. All color values referred to herein are in Lovibondunits and have beenmeasured with a Lovibond tintometer provided with a 5% inch column. A subsequent bleach in accordance with the standard procedure approved by the American Oil Chemists Society using 6% of the official iullers earth and employing a temperature of 105-120 C. improves the color to approximately 2.0 red/20.0 yellow. Upon hydrogenation to shortening consistency. such an oil usually exhibits a color of 1.0 red/ 10.0 yellow.

A cottonseed oil which has been re-refined with alkali in addition to being subjected to the treatment outlined above, may sometimes, when choice oils are used, exhibit after bleaching a color of 1.5 red/ 5.0 yellow and after hydrogenation a color of 0.7 red/7.0 yellow. With respect to edible cottonseed oil, a color reduction below approximately 0.5 red previously has not been believed to be economically or practically possible by the prior methods of the industry even when the highest grade raw oil is treated.

Hydrogenated cottonseed oil is utilized principally as the major ingredient of shortening products. In this connection, it is to be observed that most commercial shortenings average about 2.0 red/20.0 yellow and seldom are below 1.5

red/15.0 yellow.

It is known in the art that special methods, and heat treatment of high temperature, will effect a high degree of color reduction in oils, but these methods, as a rule, are too severe as well as complex and expensive for general use, especially in the preparation of Therefore, it is an object of my invention to provide a methodior simultaneously hardening products made therewith.

and decolorizlng glyceride oils to eflect a greater improvement in color than has been possible heretofore without adversely affecting the desirable characteristics of the oil with respect to its use,

- for example, for edible purposes.

A particular object of my invention is to provide a method for simultaneously hardening and decolorizing cottonseed oil to form a plastic edible product which is characterized by an improved water-white appearance.

The problem of odor reversion in edible oils may be easily appreciated by a reference, for ex ample, to soybean oil. The characteristics of soybean oil in this connection are discussed in some detail in the Epstein, et al. Patent No. 2,l40,-'

794, issued December 20, 1938.

It is well known that soybean oil refined by prior methods and even after the usual hydrogenation to a lard-like consistency, undergoes a type of spoilage which is characterized as reversion, particularly when exposed to light and air and temperature conditions, such as 385 F., usually encountered when the shortening is used for deep frying. The reversion of soybean 'oil is characterized by the development of various oil? flavors and odors known as a beany" flavor or odor and sometimes described as fishy, which subsequently often become altered with the pro duction of other undesirable flavors and odors, classified as oleo and grassy.

One of the main objections to the use, for example, of hydrogenated soybean oil in shortenings is the reversion to a characteristic but undesirable odor of the oil at the elevated temperatures employed for deep-frying. In the commercial practice of deep-frying, the fat may be maintained at a temperature of about 385 F. for several days, any loss from the fat body being replaced by additions of further shortening. The objectionable odors and flavors which develop are not only undesirable during frying but also unfavorably affect the odor and flavor of the food The readily available supply of soybean oil makes its utilization attractive to the manufacturer. Nevertheless, the use of soybean oil has been greatly limited, particularly in high grade edible products, inasmuch as it has been impossible'to avoid the undesirable characteristics of soybean oil, particularly with respect to deepfrying, unless the oil is hydrogenated to the relatively high-titre of 51 C. which corresponds to an iodine value of about 50, and consequently hardened to such an extent that it can be used only in restricted amounts. In general, an iodine value in the range of '70 to and a penetration of 220 to 250 is desired in a hardened soybean oil when the object is to utilize the oil in shortenings. Even with the use of the most eiiective hydrogenation methods of the prior art, a sat isfactory shortening capable of meeting the high present-day commercial standards cannot be prepared having more than about 10% to 15% of hydrogenated soybean oil.

A particular object of my invention is to provide a method of simultaneously hardening and decolorizing glyceride oils such as soybean oil which imparts stability against reversion and good deep-fry characteristics to the oils at a desired plasticity whereby the same may be used 11:11 unlimited amounts, for example, in-shorten- ES. In accordance with my invention, I utilize a combination of catalysts comprising a metallic hydrogenating catalyst or its readily reducible minor sub-groups of groups V and VI, of the periodic classification. 0, of course, represents oxygen; that is, the metals are in the form of oxides. The minor sub-groups of groups I, II, V and VI of the periodic classification comprise divisions of the main groups as shown, for example, in the periodic chart appearing at page 46 of volume I of International Critical Tables. The minor sub-group of group I comprises copper, silver and gold. The minor sub-group of group II comprises zinc,'cadmium and mercury. The minor sub-group of, group V comprises vanadium, columbium, tantalum and protoactinium. The minor sub-group of group VI comprises chromium, molybdenum, tungsten and uranium.

It will be apparent that a great number of combinations or mixtures. of combinations of the above designated metals are possible in accordance with my invention. It is to be expected that the activities of the several species of catalysts will vary over a wide range and, accordingly, I have selected those metals from' the groups designated above which, in general, ex

hibit the greatest activity under the preferred copper-tungsten-oxide, copper uranium oxide and copper-vanadium-oxide.

The proportion of metals indicated by X and Y is not regarded as critical and may be varied under which the same is to be used, In general, a substantially atomic ratio of X and Y is preferred for effecting desirable results in accoijdance with our invention.

over a wide range depending upon the particular; metals selected and the conditions of operation) In general, it is preferred to stabilize the ccftalyst by the presence of an alkaline earth metal oxide, such as barium oxide or calcium oxide,-

although this is not essential. Substantially an atomic ratio of X and Y and of a -mole of alkaline earth metal has generally been found to p be preferable, but the proportions may be varied as desired and depending upon the particular metals selected as wellas upon the conditions under which the same is to be used.

The exact form of the metals ,or the oxygen in the catalyst is difficult to determine, and it is not intended that my invention shall be limited to any particular chemical or physical combination. It is possible that the catalyst may be a simple mixture of the separate oxides of the two metals present in the catalyst, but it is equally possible that the two metals and the oxygen may be combined to form a distinct and separate chemical compound. It is intended that the scope ofmy invention shall include-the use of two or more metals of the type described in combination with oxygen, regardless of the exact chemical or physical structure of the composition. It is possible that even as to those oxide catalysts which, at the present time, do not appear to have a preferred activity, a modification may be made in their physical form or struc-' ture which may make their use desirable.

Any of a number of varied methods may be employed in preparing the oxide portion of the catalyst, the simplest of which is possibly a direct combination produced by grinding together amixture of the selected oxidesand subsequently heating the mixture to an elevated temperature. Improved results are obtained by precipitating a mixed salt from a solution of coppernitrate and calcium nitrate by the addition thereto of a solution containing ammonium dichromate and ammonium hydroxide. The precipitate is dried,

pulverized, and decomposed at an elevated temperature to produce a black oxide mass.

A more-active catalyst as wellas one more uniform and capable of giving reproducible results, may be made by precipitating mixed carbonate from a solution containing the desired proportions of chromium nitrate, copper nitrate,

and barium nitrate by the addition thereto of a solution containing ammonium carbonate. The precipitate is washed, dried, pulverized, and decomposed at approximately 350 C.

The metallic hydrogenating catalyst which I prefer to use is nickel, although satisfactory results may be obtained with cobalt and, to a lesser degree, with platinum and palladium. It is intended that my invention shall include the use Of compounds of the above metals which are readily reducible during hydrogenation to form the metallic hydrogenating catalyst.

'.For convenience, the invention will be described more particularly by reference to the preferred use of active nickel. In general, the .conditions of operation efiective when active nickel is used will obtain for the other species except that a relatively larger proportion of such other species may be required for efiecting equivalent results.

The nickel component of the catalyst may be prepared in any convenient manner, for example, as set forth in the patent to Paterson, No. 2,123,342, issued July 12, 1938. A preferred method comprises the treatment of electrolytically precipitated nickel hydroxide which may be prepared by passing direct current through a cell using nickel as the anode and using a dilute solution of an alkali salt of a weak acid as an electrolyte. The nickel hydroxide so .preparedmay be reduced by means of pure hydrogen gas at a temperature of from 300 C. to 500 C.

The catalyst may be prepared by adding the nickel component to the metallic oxide component in suitable proportions.

However, for convenience, the components are separately added to the oil 'to be treated. The amount of the oxide component is preferably approximately .2 per cent based on the weight of the oil, while the nickel component is preferably approximately .001 per cent. It is to be understood that other proportions may be used in accordance with my invention, as will be discussed more fully hereinafter.

Oxide catalysts, of the kind disclosed above, have been used heretofore in the hydrogenation of various organic. compounds to produce alcohols, hydrocarbons, and similar unsaponifiable matter. In particular, in accordance with the prior art, the hydrogenation of glyceride oils using an oxide catalyst would result in the formation of unsaponifiable matter comprising higher ketones, such as palmitone and stearone;

matter.

Accordingly, in addition to providing for the simultaneous hardening and decolorizing of glyceride oils to effect an improvement in color and stability, having the advantages and ramifications discussed above, my invention further provides an operation durin the hydrobleaching process to effectively retard the formation of unsaponifiable matter. By my process, a decolorized and hardened product suitable after filtering, deodorizing, 'texturizing, and like finishing operations, for use as a shortening is obtainable. In addition as to oils, such as, for example, soybean oil, a product is obtained which is stable against reversion. These products hav unsaponifiable components but only in amounts comparable with that ordinarily present in good grade commercial shortenings. In fact, with my process, uniform products may be made with less than 1.0% unsaponifiable components.

It is an object of my invention to provide a method of using oxide catalysts in combination with metallic hydrogenating catalysts in which the formation of unsaponifiable matter is effectively retarded.

, I am aware that the use of metals, such as nickel as a catalyst in the hydrogenation of glyceride oils at elevated temperatures is well known in the art. The present invention relates to the discovery that the hardening of vegetable oils by the use of hydrogen gas may be more effectively accomplished by the simultaneous use of an active metal and metal oxide catalyst of the type described above, than is to be expected if the re,- sults obtained using theactive metal and the metal oxide type of catalyst, respectively, on separate samples, are added.

In other words, an unexpected synergistic action results in the simultaneous use of the metal catalyst and metal oxide catalyst described above, which permits the simultaneous decoloriza' ion,

stabil zation, and hardening of glyceride oils to produce products of improved characteristics and with a material saving in processing.

For convenience, the process is described in the specific examples as a batch operation, as by so doing-. simple and easily understood standard equipment may be used. However, it will be apparent. that the process may be carried outina continuous manner.

For example, the oil may be heated and maintained in contactwith hydrogen for a desired period of time in an elongated restricted passageway through which' the oil may be passed continuously or semi-continu-' erence is had to the following table of test results obtained with a representative refined prime cottonseed oil having a color of 14.7 red and 35 yellow and a standard bleach of 1.7 red/17 yellow, and an iodine value of 108.

Table I Catalyst I. V. No. Temp. Time Percent (6st) Cu-Cr-O asses:

Referring to the Table I, test No. 1, using ".5%

of CuCr--O catalyst yielded excellent color and adequate hydrogenation, but because of the relatively high amount of catalyst used, as well as the time required (sixty minutes), the unsaponiflable matter in the oil increased to 1.16%. In test No. 2-, with a reduction of oxide catalyst to .2%, and with a reduction in time to thirty minutes, the final color obtained was the equivalent of test No. 1, but the amount of hydrogenation was unsatisfactory. -In tests Nos. 3 and 4, in which the oxide catalyst contained .01% and .005% metallic nickel respectively, the oil became unduly hard before a sufficient temperature could be reached to obtain the best color removal. Test No. 5, using a preferred catalyst combination, gave sufficient hydrogenation in fifteen minutes with a satisfactory color reduction to .2 red/2 yellow. Test No. 6, showing the use of a nickel catalyst alone, indicates that for small amounts in the neighborhood of .001%, hydrogenation of the oil is negligible and color reduction is poor- By comparing the results obtained in test No. 5, using both nickel and oxide catalyst, with the results obtained in tests'Nos. 2 and 6, using the same amount of oxide or nickel catalyst alone, it will be apparent that a very pronounced synergistic eflect takes place .Whichwould not be expected from the results obtained with the oxide or nickel catalyst alone.

For more desirable results, it is preferred to carry out the invention at relatively high pressures in the neighborhood of 100 atmospheres or more, as set forth in Table I above. It is to be understood, however, that the pressure conditions are not critical and that desirabl results may also be obtained at pressures as low as atmospheric, although this requires the use of an increased amount of metallic nickel to obtain adequate hydrogenation.

The following is a table of test results at atmospheric pressures obtained with the prime cottonseed oil used in the experments at high pressures given above:

Table II Catalyst 0 Percent Percent Cu-Gr-O Ni Color onocamww ammon a-n In a period of sixty minutes, at atmospheric pressure, test No. 1 with 0.2% copper-chromiumoxide alone gave fair color but no hydrogenation and test No. 3 with 0.01% nickel alone gave poor hydrogenation and poor color. By reason of the synergistic effect described above, test No. 2 with identical amounts of both copper-chromiumoxide and nickel gave fair color and adequate hardening in thirty-two minutes. It will be noted are disclosed as effective when the entire catalyst is added to the oil prior to hydrogenolysis. Accordingly, it will be obviousto one skilled in the art that if one of the components of the catalyst, that is the nickel, is added to the oil subsequent to the beginning of hydrogenation, a proportionately higher amount of it may be used.

In such case the hydrogenating rate would be increased.

The temperatures under which my process may be carried out may be varied over a wide range. Temperatures of about 200 C. have been used with particular success, although satisfactory resultsmay be obtained at temperatures of, for example, 130-250" C. At lower temperatures, the synergistic effect described above is less marked and the reduction in color and iodine value tends to be less. In general, lower temperatures may be employed when higher pressures are utilized. 'At more elevated temperatures, the oil has a tendency to decompose and there is formed an undesirable amount of unsaponifiable material. In'general, an increase in temperature will cause a proportionately greater color and iodine reduction.

It has been found desirable to limit the tim of operation to not more'than substantially sixty minutes and, in some cases, to approximately thirty minutes or less subsequent to the heating of the oil to a sufllcient temperature for effective decolorization and stabilization. Successful op.- erations'may be carried out, for example, in as little as ten to fifteen minues. I Although the re-- duction in color and iodine value will be a function of the amount of time during which the oil is maintained at elevated temperatures, it will be found that the maintenance of the oil at elevated temperatures may cause the formation of relatively large amounts of ketones, alcohols and hydrocarbons. For satisfactory use in good grade shortenings, for example, it is desirable to reduce the iodine value of cottonseed oil to approximately 70-75 as quickly as possible with the least amount of unsaponifiable matter formed, and yet at the same time obtain the most complete color removal possible.

In addition to the improved effect with respect to color particularly noticeable in the case of cottonseed oil, it has been observed that this process is particularly effective forstabilizing glyceride oils against normal oxidationand the development of rancidity. A glyceride oil which has been treated with hydrogen in the presence of a catalyst containing metallic oxides and ac- I tive nickel in accordance with this invention, is

found to have a greater degree of stability than or saturation, or both, with a catalyst containing active nickel alone.

Furthermore, the present process is particularly effective for stabilizing glyceride oils such as soybean oil against reversion. which has been treated with hydrogen in accordance with this invention is found to be stable against reversion to the characteristic objectionable odor and flavor which normally develop in soybean oil products produced in accordance with the prior art, particularly when the oil is subjected to the elevated temperatures utilized in deep frying.

It is to be understood that a glyceride oil which has been hydrogenated in accordance with the invention, in addition to having an improved color and stability against reversion under deep frying conditions, will have upon further treatment in the conventional manner, such as by filtering, deodorizing, chilling, aerating, texturizing or otherwise finishing, the qualities requisite for conversion to and use in an all-purpose shortening. A shortening made from oils treated in accordance with this invention is plastic and workable over a reasonable range of temperature and may be readily creamed and when used for baking purposes, produces'cakes of good vol- .andto illustrate the novel results obtained. It

is to be understood that the process is applicable to the treatment of all glyceride oils and fats or mixtures thereof of animal, vegetable or marine origin which are susceptible to an improvement in color and stability. Among the oils which have been treated satisfactorily in accordance an oil hardened to the same degree of plasticity with my invention are, for example, palm oil, sesame oil, peanut oil, coconut oil and tallow.

The variations to which this invention is susceptible by one skilled in the art are intended to be included within the scopev of the invention.

I claim:

1. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oil at an elevated temperature'with hydrogen in the presence of a catalyst comprising nicked and a metallic oxide of the general formula XY-O, in which X represents at least one metal selected from the minor sub-groups of groups I and II, Y represents at least one metal selected from the minor subgroups of groups V and VI of the periodic classification, and 0 represents oxygen.

2. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oil at an elevated temperature with hydrogen in the presence of a catalyst comprising nickel and a metallic oxide of the general formula XY-O in which X rep- 1 resents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium, tungsten and uranium, and 0 represents oxygen.

3. A method of. simultaneously decolorizing, stabilizing and hardening glyceride oils which comprises treating the oil at'an elevatedtemperature with hydrogen in the presence of a catalyst comprising nickel and copper-chromiumoxide.

4. A method ofsimultaneously decolorizing, stabilizing and hardening glyceride oils, which A soybean oilv comprises treating'the oil at an elevated temperature with hydrogen in the presence of a catalyst comprising nickel and silver-chromiumoxide. e

5. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which .comprises treating the oil at an elevated temperature with hydrogen in the presence of .a catalyst comprising nickel and copper-vanadiumoxide. v

6.-A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treatingthe oil at an elevated temperatur with hydrogen in the presence of a catalyst comprising nickel and a metallic oxide of the general formula XY- in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium, tungsten and uranium, and 0 represents oxygen, said catalyst being stabilized by the presence of an oxide of an alkaline earth metal.

'7. A method of simultaneously decolorizing,,

' proportion of one atom of X to one atom of Y to one tenth mole of alkaline earth metal.

8. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils which comprises treating the oil at an elevated temperature with hydrogen in the presence of a catalyst comprising nickel and a metallic oxide of the general formula X--Y -O in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium, tungsten and uranium,

mium,vanadium, tungsten and uranium, and 0 represents oxygen, said nickel being present in amount not more than substantially 0.1% and said metallic oxides being present in amount not less than substantially 0.1%, based on the Weight of th oil.

11. A method of simultaneously decolorizing,

amount of substantially 0.001 to 0.01% nickel and 0.2% metallic oxide, based on the weight of the oil.

12. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oil at an elevated temperand 0 represents oxygen, said metals represented by X and Y being present in substantially equal atomic proportions, said nickel being present in amount not more than substantially 0.1% and said metallic oxides being present in amount not less than substantially 0.1%, based on the weight of the oil.

9. A method of simultaneously, decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oil at an elevated temperature with hydrogen in the presence of a catalyst comprising nickel and a major proportion of a metallic oxide of the general formula XYO in which X represents at least one of the metals of the group consisting of copper and silver, Y

ature under a pressure of not less than substantially 100 atmospheres with hydrogen in the presence of a catalyst comprising nickel and a metallic oxide of the general formula X--YO in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium, tungsten, and uranium, and 0 represents oxygen, said catalyst being present in amount of substantially 0.001% to, 0.01% nickel and 0.2% metallic oxide, based on the weight of the oil.

13. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises maintaining the oil at a temperature of not more than 250 C. while treating the oil with hydrogen gas and in the presence of a catalyst comprising nickel and a metallic oxide 01' the general formula XYO in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium, tungsten, and uranium, and 0 represents oxygen.

14. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises maintaining the oil at a temperature of not more than substantially 250 C."'while treating the oil with hydrogen under a pressure of not less than substantially 100 atmospheres and in the presence of a catalyst comprising nickel and a metallic oxide selected from the group consisting of metallic oxides of the general formula XYO inwhich X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, vanadium,

tungsten, and uranium, and 0 represents oxygen.

15. A method of simultaneously decolorizing,

stabilizing and hardening glyceride oils, which represents at least one of the metals of the group at least one of the metals of the group consisting of copper and silver, Y represents at least one of th metals of the group consistng of chrocomprises maintaining the oil at a temperature of not more than substantially 240 C. for a period of time of not less than substantially ten minutes while treating with hydrogen in the presence of a catalyst comprising nickel and a catalyst selectedv from the group consisting of metallic oxides of the general formula XY-O in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals of the group consisting of chromium, Vanadium, tungsten, and uranium, and 0 represents oxygen.

16. A method of simultaneously decolorizing, stabilizing and hardening ghrceride oils. which comprises maintaining the oil at a temperature of not more than substantially 250 C. while treating with hydrogen in the presence of a catalyst comprising nickel and a catalyst selected from the group consisting of metallic oxides of the general formula X-Y-O in which X represents at least one of the metals of the group consisting of coppar and silver, Y represents at least one oi the metals of the group consisting. of chromium, vanadium, tungsten, and uranium, and O represents oxygen, said nickel being present in amount lected from the group consisting of nickel, cobalt.

platinum and palladium and a metallic oxide of the general formula X-Y-O, in which X represents at least one metal selected from the minor sub-groups of Groups I and II, Y represents atleast one metal selected from the minor sub groups of Groups V and VI of the Periodic Classifications, and 0 represents oxygen.

'18. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oil at an elevated temperature with hydrogen in the presence of a catalyst comprising a catalytically active metal selected from the group consisting of nickel, cobalt, platinum and palladium and a metallic oxide of the general formula XYO in which X represents at least one or the metals of the group consisting of copper and silver. Y represents at least one of the metals oi the group consisting of chromium, vanadium, tungsten and uranium, and 0 represents oxygen.

19. A method of simultaneously decolorizing, stabilizing and hardening glyceride oils, which comprises treating the oii at an elevated temperature with hydrogen in the presence of a catalyst comprising a catalytically active metal selected from the group consisting of nickel, cobalt, platinum and palladium and a metallic oxide of the general formula X-Y-O in which X represents at least one of the metals of the group consisting of copper and silver, Y represents at least one of the metals or the group consisting of chromium,

vanadium, tungsten and uranium, and O represents oxygen, said catalyst being stabilized by the presence of an oxide of an alkaline earth metal.

' WILLIAM J; PATERSON.

1 CERTIFICATE OF coRR cmN-.- v

I Sep m 5. 9 m- WILLIAM J. 'PAmRsQN.

' It is hereby certified that error appears in the printed Specification of the above humberegl pateht I-equ:! 1:'1ng correctionas follows: Page 5, sec-- 0nd column, lirle, 50, 61-9111; 1, fof Ynieked" read --niEke1 page 6, second eolumn, line 611., cl aim 15, "for "214.0 C." read +25 O C.--; and that the said Letters Patent ehould'be read with this cor'rectien therein that the me m w 'coriform. t6- the recerdof the case in the Patent Office.

4 Signed and seaIeQ-thisfilst day ef October, .A; D. 191m" I Leslie Frazer (Seal) Actihg' Cpmnissioner of Patents.