US2863890A - Refining glyceride oils with sulphonated phenol-aldehyde resin - Google Patents

Description

United States Patent-C REFINING GLYCERIDE OILS WITH SULPHO- NATED PHENOL-ALDEHY DE RESIN Samuel S. Gutkin, Plainfield, N. J., assignor to Falk & Company, Carnegie, Pa., a corporation of Pennsylvania N Drawing. Continuation of abandoned application Serial No. 274,497, March 1, 1952. This application June 28, 15956, Serial No. 594,378

3 Claims. (Cl. 260-424) This invention relates to the refining of glyceride oils, and particularly to crude oils which consist primarily of the triglyceride esters of long chain hydrocarbon acids.

In addition to their major components of triglyceride esters such oils comprise a number of minor constituents in varying proportions such as sterols, hydrocarbons, chlorophyll, carotenoid pigments, free fatty acids, phosphatides, carbohydrates, protein and nitrogen compounds, resins and ketones. Whereas some of the above impurities such as the sterols and ketones are unobjectionable and even beneficial in the sense that they retard oxidation of the oil, most of the other impurities are objectionable. When the oil is subjected to heat treatment as by kettling, some of such impurities and in particular the phosphatides produce a break with smoking and foaming of the oil and the formation of a precipitate. Their presence gives a dark colored oil and detracts from the enduring properties of a paint film in which the oil is included.

The method of this invention resides primarily in the step or steps of refining the oil prior to processing it with heat. Previously there have been various methods of refining the crude oils prior to heat treatment. One such method is by hydration or water washing in which treatment the oil is agitated with water to remove impurities such as the phosphatides, proteins and various mucilaginous substances. In many instances the efficacy of the water washing has been increased by using a weak water solution of a mineral acid or an alkali rather than plain I water. Another method has been treatment with relatively concentrated sulphuric acid which is well mixed with the oil and causes the impurities to settle in large particles. Another method which has been practiced is solvent refining with a suitable solvent such as ethanol, furfural or liquid propane. Also refining with a relatively strong alkali such as sodium hydroxide to convert the free fatty acids into oil insoluble soaps;

All of the above refining procedures require subsequent corrective steps to remove the treating materials which have been introduced for the refining. As for example, the oil must be dried carefully to' remove the water used for water washing or as diluent or solvent for the acid or alkali.

In distinction from such previous methods of refining glyceride oils my method does not require that there be introduced into the oil, water or other treating material which must subsequently be removed. It provides sim ple and convenient procedure which results in at least a partial elimination of undesirable constituent material from the oil in a single novel treating step and particularly removes constituents which cause dark coloration of the oil and the formation of break in subsequent refining steps. That is, the treatment both accomplishes an ultimate end and also places the oil in suitable condition for further treatment of conventional sort such as heat bleaching and agitation with decolorizing clays. The treatment is performable under approximately anhydrous conditions and thus need not introduce water into the oil.

; Briefly stated, my method consists in contacting the oil adequately with ion exchange material which is an ion exchange resin and desirably effecting such contact under approximately anhydrous conditions. According to all theories of ionization such phenomenon occurs only in solution, such as water solution and the effectiveness of the novel step of my method cannot therefore be attributed directly to preconceived theories of ion exchange processes. Contact can be had in any suitable manner which gives contact between the oil subjected to treatment and the surface of the ion exchange resin. Most desirably, however, contact is obtained by flow of the oil through a bed of such material.

I have found that the synthetic organic ion exchange resins are the materials best adapted to the purification of glyceride oils and that of these resins the most effective are sulphonated phenol-aldehyde condensation products and the polymeric alkali-treated amine resins. The sulfonated phenol-aldehyde resins are of two types, depending on whether the sulfonic acid group is on aside chain (CH SO H) or is attached directly to the aromaticnucleus. The first named type is made, for example, by heating together phenol, formaldehyde, and a mixture of sodium sulfite and metabisulfite, then adding more phenol and formaldehyde and heating to gelation, or is made by introducing the omega sulfonic groups into a pre-formed phenol-formaldehyde condensate. The second type is prepared by reacting paraphenol sulfonic acid with formaldehyde and phenol and heating the resin in drying pans to remove the excess water and form a cross-linkage. This resin has both SO H and OH groups attached to an aromatic ring, the SO H groups being effective in ion exchange.

In order to exemplify the method of my invention, it may be considered that the method is practiced in a treating tube which contains a bed of the ion exchange material, the treating tube being provided with suitable supply and delivery tanks and a pump and circulating connections so that the glyceride oil undergoing treatment can be caused to flow either upwardly or downwardly through the bed. The treatment may consist either of a single passage of the oil through the contact ed of ion'exchange material or the oil may be recirculated to pass two or more times through the bed. The rate of flow also can be regulated. The following specific exemplifications of the method were practiced in a treating tube 72" high with an internal diameter of about 3", this tube containing a 6" bed of pebbles carrying 6 pounds of a phenol-aldehyde resin having an SO H group attached to an aromatic ring. In order to check the length of useful life of the contact bed and the time of contact requisite for treatment, a run was made as follows, the oil being treated at atmospheric temperature:

EXAMPLE NO. 1

Table A Free Sample Time Flow Fatty Color Acid Crude-Un- 0.78 11+.

treated.

11. ll. 11. ll. 11. ll. .11. 11. ll. 11. ll. 11. 11. I ll. 11 hazy 11 hazy 11 cloudy.

It will be noted that when the contact bed is in fresh condition, contact time can be quite short while effecting a substantial reduction in the proportion of free fatty acids in the oil and, as will appear illustratively in connection with subsequent treatment, with substantial removal of other undesired constituents of the oil. As use of the contact bed continues the rate of flow desirably is decreased to increase the time of contact between the ion exchange material and the oil undergoing treatment. Ultimately a point is reached at which exhaustion of the contact bed renders the treatment relatively ineffective.

After treatment in accordance with my method, the properties of the various samples of the treated oil were checked. Each of such samples was divided into two parts. One part of each sample of the oil so treated was heat bleached for 5 minutes at a temperature of about 600 F. and the presence or absence of break was noted. The color of the oil also was noted. The other part of each sample of the oil was agitated for 8 minutes with 3% acidtreated bleaching clay at a temperature of 220 F., and after being treated with the clay, was filtered and was heat bleached at a temperature about 600 F. The color of the oil before and after filtration and heat bleaching was noted. A sample of the same initial oil which had, however, not been subjected to my contact treatment also was divided into two parts. One part Was checked for the effect of heat treatment on color and break without a preparatory clay treatment, and the other part was subjected to heat bleaching after agitation with clay and filtration. These check tests all are given in Table B which follows, each of the two part samples 1 to 17 inclusive being one of the corresponding numbered samples listed in Table A above.

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i l t I It will be noted that the novel treatment of the invention places the oil in condition to be acted upon with particular eitectiveness by the bleaching and adsorption treatment to which it is afterward subjected. Thus, it will be noted that the crude sample which had not been subjected to treatment in accordance with my method did not exhibit a reduction in color after heat bleaching and that heat treatment produced a relatively heavy break. After the adsorption treatment with clay, the color of the oil was slightly reduced and was slightly reduced further after heat bleaching. The samples which had been subjected to the treatment showed no break. The color was substantially reduced by heat bleaching, was reduced also in substantial order by the clay treatment. and was brought to an approximate minimum by heat bleaching which followed the clay treatment. The results immediately attendant on the contact treatment and the results of the subsequent colorreducing steps both show that the Contact bed became exhausted toward the end of the run and required reactivation.

It is to be noted that no undesirable side effects of my contact treatment have been observed but that on the contrary all of the film-forming properties of the oil are improved and the acid number of the oil is reduced in addition to the color improvement which has been specifically noted.

EXAMPLE NO. 2

The ion exchange resin used was the phenol-aldehyde resin used in Example No. 1. In the practice of this example, 10 pounds of raw soya bean oil was used for test and some of the extraneous matter was removed from the raw oil by filtration prior to the contact treatment. The same equipment used in Example No. l was used in this example and the oil was similarly caused to flow by gravity through the contact bed. The data of the treatment was as follows:

Table A Free Sample Time Flow Fatty Color Acid Crude e 0. 78 11+ Filtered Crude..- 1hour t), 551 11+ (1) 1}; qt. p r hour 0.301 It 1 qt. per hour. 0.391 ll 3) ,3 qt. per hour.. 0. 304 ll (4) 3 qt. per hour 0.301 ll It will be noted that by filtration the content of free fatty acids in the oil was reduced from 0.78% to 0.551% before treatment. By treatment, the content of free fatty acid was reduced from 0.551% to 0.394% but after treatment the color of the oil remained unchanged. The same conventional secondary steps were taken on the oil subjected to the preparatory treatment as were taken in Example No. 1. These steps and their result with respect to break and color reduction are shown in Table B as follows:

Table B 39'}, Color Color after 1st IIeat Bleach Break Filtrol alter 2nd Bleach Heat.

Bleach Med. heavy... 10 S Medium 8 7 1-5 It 1 3 3 3 4-'i 3 Because the contact bed becomes exhausted after a run of relatively great duration or after a succession of shorter runs, it is necessary from time to time to reactivate the contact bed. I have effected reactivation by recirculating a dilute water solution of hydrochloric acid through the contact bed until the bed is clean and otherwise in condition for further use. It is to be understood that the above specified reactivating agents need not be employed exclusively but that other reagents capable of cleaning the bed and restoring the ion exchange properties are similarly usable.

The contact treatment of the glyceridc oils is conducted at normal room temperature or if desired at slightly elevated temperature well below a point at which the properties of the oil are affected. Any increase in the effectiveness of the process by applied heat is. however, so slight that any heating is generally not to be considered worthwhile. As will be seen from the above, the treatment of my invention is unusually simple anct is particularly effective in its removal of undesirable initial constituents of the glyceride oils. It is important in the cffectiveness in which it removes such impurities because very small percentages of some impurities can exert a wholly disproportionate effect on the oil with respect to color, stability and the like.

Whereas in each instance soya bean oil has been treated in exemplification because of the fact that such oil has particular need of refining, it is to be understood that the other triglyceride oils such as linseed oil, sunflower seed oil and the like are equally susceptible to treatment and that diglyceride and monoglyceride oils similarly can be treated eflectively.

This application is a continuation of my prior application, Serial No. 274,497, filed March 1, 1952, for Method of Refining Glyceride Oils, now abandoned.

I claim:

1. The method of treating glyceride oils for the removal of free fatty acids and other organic impurities from such an oil by continuously flowing such oil through a bed of solid particulate synthetic organic cationic ion exchange resin which is a sulphonated phenol-aldehyde resin under approximately anhydrous conditions, and as the flow of glyceride oil continues regulating the rate of flow of the said oil in accordance with the relative freshness of the said resin and the exhaustion of the said resin by contact with oil flowing through the said bed in earlier stages of the said treatment, in substantial entirety to remove organic break impurities and in large measure to remove free fatty acids from the oil subjected to treatment.

2. The method of treating glyceride oils for the removal of free fatty acids and other organic impurities from such an oil by bringing the said glyceride oil into contact with a solid particulate synthetic organic ion exchange resin which is a sulphonated phenol-aldehyde resin under approximately anhydrous conditions and at approximately room temperature, in substantial entirety to remove organic break impurities and in large measure to remove free fatty acids from the oil subjected to treatment.

3. The method of treating glyceride oils for the removal of free fatty acids and other organic impurities from such an oil by continuously flowing the said glyceride oil through a bed of solid particulate synthetic organic ion exchange resin which is a sulphonated phenol-aldehyde resin under approximately anhydrous conditions, as the flow of glyceride oil continues regulating the rate of flow of the said oil in accordance with the freshness of the said resin and the exhaustion of the said resin by contact with oil flowing through the said bed in earlier stages of the said treatment, in substantial entirety to remove break impurities and in large measure to remove free fatty acids from the oil subjected to treatment, and after exhaustion of the said bed of sulphonated phenol-aldehyde resin to a stage of relative ineffectiveness reactivating the said resin bed by recirculating a dilute water solution of acid there through.

References Cited in the file of this patent UNITED STATES PATENTS 2,299,529 Crampton Oct. 20, 1942 2,456,428 Parker Dec. 14, 1948 2,771,480 Chasanov et a1 Nov. 20, 1956 OTHER REFERENCES Kunin: Ion Exchange, Analytical Chemistry, vol. 21, page 87, June 1949; Reprint available in Div. 63 Amberlite Book.

It You Use Water, by Rohm & Haas Company, the Resinous Products Division, Washington Square, Philadelphia 5, Pa., February 1955, 1 E-1-54a, page 3.

Claims (1)

1. 2. THE METHOD OF TREATING GLYCERIDE OILS FOR THE REMOVAL OF FREE FATTY ACIDS AND OTHER ORGANIC IMPURITIES FROM SUCH AN OIL BY BRINGING THE SAID GLYCERIEDE OIL INTO CONTACT WITH A SOLID PARTICULATE SYNTHETIC ORGANIC ION EXCHANGE RESIN WHICH IS SULPHONATED PHENOL-ALDEHYDE RESIN UNDER APPROXIMATELY ANHYDROUS CONDITIONS AND AT APPROXIMATELY ROOM TEMPERATURE, IN SUBSTANTIAL ENTIRETY TO REMOVE ORGANIC "BREAK" IMPURITIES AND IN LARGE MEASURE TO REMOVE FREE FATTY ACIDS FROM THE OIL SUBJECTED TO TREATMENT.