Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11C—FATTY ACIDS FROM FATS, OILS OR WAXES; CANDLES; FATS, OILS OR FATTY ACIDS BY CHEMICAL MODIFICATION OF FATS, OILS, OR FATTY ACIDS OBTAINED THEREFROM
  • C11C3/00—Fats, oils, or fatty acids by chemical modification of fats, oils, or fatty acids obtained therefrom
  • C11C3/12—Fats, oils, or fatty acids by chemical modification of fats, oils, or fatty acids obtained therefrom by hydrogenation
  • C11C3/126—Fats, oils, or fatty acids by chemical modification of fats, oils, or fatty acids obtained therefrom by hydrogenation using catalysts based principally on other metals or derivates

Definitions

• the present invention relates to a process for the selective hydrogenation of unsaturated fatty acid derivatives containing, in addition to fatty acids having two double bonds, fatty acids having more than two double bonds.
• fatty acids which consist mainly of a mixture of triglyceride esters of fatty acids.
• the fatty acids usually contain about 16 to about 22 carbon atoms and may be saturated, e.g. stearic acid; mono-unsaturated, e.g. oleic acid; di-unsaturated, e.g. linoleic acid; or tri-unsaturated, e.g., linolenic acid or may even be unsaturated to a greater degree.
• the selectivity values of the hydrogenation reactions are usually defined as follows:
• the selection of catalysts with which to perform the hydrogenation reaction can thus be important in order to ensure as far as possible that the desired hydrogenation reaction preferentially occurs and that only a minimum of isomerisation takes place.
• EP-A-0021528 A catalytic process which aims to hydrogenate selectively fatty acid derivatives containing more than two double bonds with a minimum of isomerisation is disclosed in European Patent Application No. 0021 528.
• EP-A-0021528 the selective hydrogenation of triglyceride oils such as soya bean oil, rapeseed oil, linseed oil and fish oils is described in which fatty acids having more than two double bonds are reduced to fatty acids having two double bonds in the presence of other fatty acids having two double bonds, so-called essential fatty acids, whose content in the oil remains high.
• a selectivity S II of at most about 10 is claimed for the process described in EP-A-0021528, which comprises hydrogenating at a temperature of from -20°C to 100°C in the presence of a catalyst comprising palladium, platinum, rhodium or iridium which has been treated with dry ammonia in a molar ratio of ammonia to catalytically active metal of at least 100:1. It is stated that with increasing levels of ammonia treatment the selectivity achieved in hydrogenation decreases and that when the mole ratios of ammonia to catalytically active metal are higher than 2000:1 no further increase in selectivity is achieved.
• a process for the selective hydrogenation of unsaturated fatty acid derivatives having fatty acid moieties containing more than two double bonds and fatty acid moieties containing two double bonds comprising catalytic hydrogenation at a temperature of from -20°C to 100°C in the presence of ammonia and a catalyst comprising at least one member selected from the group consisting of palladium, platinum, iridium and rhodium characterised in that ammonia is present at a level of at least 1.8 mol/I with respect to the said fatty acid derivative.
• the present invention extends to the fatty acid derivatives so hydrogenated and to products incorporating the separated hydrogenated fatty acid derivatives.
• the actual S ⁇ value achieved in a particular case depends on the fatty acid derivative, the catalyst and the reaction conditions employed. Employing for example a palladium catalyst we have found however that S ⁇ values of above about 10 can usually be achieved. In some instances even S " values of more than 14 have been found at an ammonia concentration of 4 mol/l with respect to the fatty acid derivative.
• the selectivity of platinum as a catalyst is in general known to be less than that of palladium. However by means of the present process the S II value is nonetheless increased even when platinum is employed.
• the amount of ammonia when calculated with respect to the amount of fatty acid derivative present gives a better correlation with selectivity S ⁇ , than when measured with respect to the amount of catalyst present.
• the present invention can thus provide a process that is easy to perform and that employs as a raw material dry ammonia which is not only readily available and relatively cheap, but which can also be removed readily from the hydrogenated fatty acid derivative.
• the present process can reduce the formation of trans-isomers to a low level. Unlike the process described in EP-A-0021528 however the present process can in addition give further increases in S II values.
• a fatty acid derivative which has been prepared by hydrogenation characterised in that the fatty acid derivative has an S II value (as hereinbefore defined) of at least 10.
• the fatty acid derivative has in addition a trans isomer content of less than 10 mol %.
• the actual amount will depend on the catalyst, the derivative and the reaction conditions employed.
• the fatty acid derivative contains a high percentage of fatty acid moieties having more than two double bonds such as for instance in linseed oil the opportunity for trans-isomerisation to occurs is greater and greater isomerisation may occur.
• the fatty acid derivative has a trans-isomer content of less than 5 mol %.
• the fatty acid derivative preferably has a S,, value of at least 14 to 15.
• the amount of ammonia present is preferably at least 2.5 mol/I with respect to the fatty acid derivative employed.
• a preferred upper limit for the ammonia concentration is 8 mol/I with respect to the fatty acid derivative employed. More preferably not more than 4 mol/I is employed.
• catalytically active metals of which Pd and Pt are preferred
• alloys of these metals can alternatively be used.
• Such catalytically active metals can contain so-called promoters, i.e. metals promoting the effect of the catalyst as far as its activity and/or selectivity are concerned, such as Cu, Ag, Au, Zn, Sn, Zr, Hf, V, Nb, Ta, Cr, Mo, W or Mn.
• the catalyst can be used in the form of a porous metal, preferably in the form of small particles suspended in the system, such as palladium powder or a metal sol, obtained by reduction of a soluble compound of the metal with a reducing organo-metal compound.
• the metallic constituent can alternatively be supplied on a carrier. Suitable carriers for the catalyst include carbon, silicon oxide, aluminium oxide, kieselguhr and an ion-exchanging resin.
• the amount of catalytically active metal which is employed in the hydrogenation is not critical and may vary from about 1 mg/kg to about 10 g/kg, preferably from 35 mg/kg to 1 g/kg, calculated on the basis of the metal catalyst with respect to the compound to be hydrogenated.
• the optimum amount depends inter alia on the form of the catalyst, whether the catalyst has been applied on a carrier or not, on the unsupported surface area of the catalyst, on the catalytic activity of the metal that is used and on the amount of ammonia that is to be added.
• the compound to be hydrogenated can be dissolved or dispersed in an organic liquid such as hydrocarbon, for instance hexane, or a ketone.
• an organic liquid such as hydrocarbon, for instance hexane, or a ketone.
• Good results can alternatively be obtained with alcohols, but in that case alcoholysis or in the case of oils and fats interesterification may take place; consequently, when alcoholysis or interesterification is desired, alcohols can be used.
• the ratio of organic liquid to fatty acid derivative is not critical but is preferably not higher than about 20:1.
• the hydrogenation can alternatively be carried out on the fatty acid derivative in the absence of an added solvent or the like.
• the hydrogenation can be carried out in any suitable apparatus such as a reaction vessel with a stirrer, or when done continuously in a series of reaction vessels with stirrers. Good results can also be obtained when hydrogenation takes place over a column of catalyst particles.
• the process is performed so that the catalyst is pre-treated with dry ammonia before hydrogenation commences.
• liquid ammonia can be employed.
• the hydrogenation is carried out by suspending the catalyst in the fatty acid derivative to be hydrogenated or a solution or suspension thereof and subsequently introducing dry ammonia, optionally under pressure, until the desired ammonia concentration has been reached, after which the hydrogenation is started by introducing hydrogen.
• the hydrogen supplied can contain still more ammonia.
• the temperature at which the hydrogenation is carried out should not exceed 100°C. Good results with active catalysts can be obtained at temperatures from -20°C.
• Preferably hydrogenation is arranged to take place at a temperature of from 10°C to 60°C.
• the reaction can be carried out under atmospheric pressure or at a higher pressure.
• the pressure will vary from 100 to 2500 kPa.
• a pressure above atmospheric pressure should be applied.
• the process can be controlled in a known manner, for example by stopping the hydrogenation when a previously calculated amount of hydrogen has been absorbed.
• Catalyst and ammonia removal can be performed in a conventional manner.
• the hydrogenated products can be used as frying oils, table oils, as raw material for margarine or as raw material for the preparation of stable products such as sdaps, esters, etc. Conventional techniques can be employed for their preparation.
• the sum of the amount of components is less than 100%, as less important fatty acid components such as C 14 -, C 17 -, C 20 - and C 22 fatty acids have not been mentioned.
• the composition of the substrates before and after hydrogenation is given in mol %. Other percentages have been calculated by weight.
• C18:3 means linolenic acid and isomers
• C18:2 linoleic acid and isomers
• Hydrogenations were carried out in an autoclave with a volume of 1 dm 3 and provided with a heating coil, through which thermostated water could be passed, a stirrer, an inlet for gases, a device for taking samples and a manometer.
• soya bean oil was hydrogenated at a temperature of 25°C and under a pressure up to 1200 kPa, the partial pressure of hydrogen of which amounted to 200 kPa.
• the autoclave was charged with 100 mg of palladium per kg of oil of a 5% Pd/C (5% of palladium on a carbon carrier) catalyst, 250 ml of soya bean oil and 250 ml of hexane.
• the reactor was degassed several times, flushed with argon and charged with different amounts of ammoniacal gas (see column I of Table I). Thereafter the reactor was charged with hydrogen and at intervals hydrogen was introduced to bring the pressure to 1200 kPa.
• the course of the hydrogenation was followed on the basis of the intake of hydrogen as indicated by the manometer. At certain intervals samples were taken to determine the fatty acid composition and the trans-isomer content as indicated in Table I.
• Example 1 The procedure of Example 1 was repeated, during which 975 mmol of ammonia were added and the partial pressure of hydrogen was increased to 1300 kPa.
• Linseed oil was hydrogenated according to the procedure described in Example I, but at a temperature of 25°C and under a pressure of 1050 kPa.
• the autoclave was charged with 200 mg palladium per kg of oil as a 5% Pd/C catalyst, 250 ml linseed oil and 250 ml hexane.
• the relatively high trans-isomer content arises from the high C18:3 content in unhydrogenated linseed oil.
• Example 1 The procedure of Example 1 was repeated with the exception that platinum was used as the catalyst. The temperature employed was 35°C and the pressure was 900 kPa. The autoclave was charged with 150 mg platinum per kg of oil as a 5% Pt/C catalyst and 500 ml soyabean oil. No organic liquid was added.
• the relatively low S ⁇ value is due to the use of a Pt catalyst.
• the S II value obtained is however substantially higher than that obtained in a similar experiment in which a lower amount of ammonia was employed.
• Example 7 from EP-A-0021528 is reproduced below.
• soyabean oil was carried out at a pressure of up to 1000 kPa using platinum as a catalyst at 20°C in an autoclave of 0.3 dm 3 volume, which was provided with an inlet for gases, a manometer, a stirrer and a sampling device.
• the reactor was charged with 200 mg of a 5% platinum-on-carbon catalyst, 25 ml soyabean oil and 75 ml hexane.
• the autoclave was degassed two or three times, flushed with nitrogen and charged with gaseous ammonia.
• the reactor was subsequently charged with hydrogen.
• the progress of the hydrogenation was followed on the basis of the hydrogen uptake as indicated by the manometer. At regular intervals samples were taken to determine the fatty acid composition and the transisomer content. The results are given in Table IVa.
• Soya bean oil was hydrogenated to a C18:3 content of 1 % to obtain an oil with good frying properties.
• the hydrogenation was performed by a procedure similar to that described in Example 1, but at a temperature of 35°C and under a pressure of 1050 kPa.
• An autoclave with a volume of 2 dm 3 was charged with 75 mg palladium per kg of oil at a 5% Pd/C catalyst and 1000 ml soya bean oil. No organic liquid was added.

Landscapes

• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Fats And Perfumes (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Medicines Containing Plant Substances (AREA)
• Junction Field-Effect Transistors (AREA)
• Logic Circuits (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Edible Oils And Fats (AREA)
• Catalysts (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=19837279

Family Applications (1)

Country Status (13)

Families Citing this family (2)

Family Cites Families (2)

• 1981
  • 1981-04-02 NL NL8101637A patent/NL8101637A/nl not_active Application Discontinuation
• 1982
  • 1982-03-30 AT AT82301663T patent/ATE15912T1/de not_active IP Right Cessation
  • 1982-03-30 EP EP82301663A patent/EP0063427B1/en not_active Expired
  • 1982-03-30 AU AU82163/82A patent/AU553083B2/en not_active Ceased
  • 1982-03-30 DE DE8282301663T patent/DE3266624D1/de not_active Expired
  • 1982-03-31 FI FI821126A patent/FI821126L/fi not_active Application Discontinuation
  • 1982-03-31 CA CA000400095A patent/CA1162563A/en not_active Expired
  • 1982-04-01 JP JP57054743A patent/JPS57177099A/ja active Pending
  • 1982-04-01 DK DK149982A patent/DK149982A/da not_active IP Right Cessation
  • 1982-04-01 NO NO821104A patent/NO153654C/no unknown
  • 1982-04-01 ZA ZA822261A patent/ZA822261B/xx unknown
  • 1982-04-01 ES ES511078A patent/ES511078A0/es active Granted
  • 1982-04-01 PT PT74688A patent/PT74688B/pt unknown

Also Published As

Similar Documents

Legal Events