SK11462000A3 - Method for producing higher fatty acid methyl esters by the re-esterification of triacylglycerols - Google Patents

Abstract

Method for producing higher fatty acid methyl esters by the re-esterification of triacylglycerols by methanol, in which the reaction is carried out in the reactor with turbine stirrer at the rotation speed from 150 to 250 per minute for a period of 0.5 to 4 hour at the temperature of from 15 to 40 °C at the present of alkali catalyst and methanol.

Description

Technical field;

The invention relates to the production of methyl esters of higher fatty acids by reesterification of triacylglycerols contained in vegetable or animal oils and fats.

BACKGROUND OF THE INVENTION:

The use of higher fatty acid methyl esters in organic fuel and their production process, including the production of rapeseed oil esters, is known from the patent literature, e.g. U.S. Pat. 277860, 277787, 279692.277856 ..

In these patents sodium hydroxide and its double addition with methanol at higher temperatures or potassium hydroxide are used as re-esterification catalysts, in both cases with additional chemical removal of residual inorganic fractions from the ester layer, which is a more complicated process over the present invention.

SUMMARY OF THE INVENTION

The process according to the invention solves more efficiently the production of higher fatty acid methyl esters, preferably by treating rapeseed oil, where a suspension of potassium carbonate catalyst, rapeseed oil and methanol is allowed to be regulated at a temperature of 15 to 40 ° C in a turbine stirrer reactor. Analysis by liquid chromatography showed that the degree of conversion of glyceryl esters to methyl esters was already greater than 94% as early as 30 min. The usual composition of methyl esters of higher fatty acids resulting from re-esterification depends on the proportion of individual fatty acids in triacylglycerols.

Unsaturated fatty acids predominate in vegetable oils, especially oleic, linoleic, linolenic, palmitooleate, myristoleic, erucic and others. Saturated fatty acids such as stearic, palmitic, myristic, lauric, arachic, behenic and others are less represented. After completion of the reaction, the reaction mixture was allowed to stand, the separated lower glycerol layer containing the catalyst and potassium salts of higher fatty acids. After separation of the glycerol layer for further use, methanol suitable for further re-esterification is distilled off from the upper ester layer under reduced pressure of 0.5 to 3 kPa at a temperature of 10 to 40 ° C.

In the following, the process according to the invention is illustrated by way of example without being limited thereto.

DETAILED DESCRIPTION OF THE INVENTION

4500 L of rapeseed oil, 750 L of methanol and 75 kg of potassium carbonate are charged to a 6000 L turbine mixer. The reaction mixture is stirred at 22 ° C for 2 hours, during which time the glyceryl esters are transformed into methyl esters of higher fatty acids.

The reaction mixture is allowed to settle for a further 2 hours, then a 500 L glycerol layer is separated through a glass separator for further use. The upper ester layer is degassed on a film evaporator from methanol at 30 ° C and 0.66 kPa. 50 l of methanol suitable for further re-esterification. The degassed rapeseed oil methyl ester is filtered on a pressure filter to give 4200 L of methyl ester with 6% unreacted higher fatty acid glyceryl esters.

The glyceride conversion is monitored by liquid chromatography using a column packed with reverse phase sorbent (RP-18), a mobile phase composed of tetrahydrofuran and acetonitrile (45:55) and an RI detector.

Industrial usability

The invention is applicable to the industrial production of higher fatty acid methyl esters, preferably rapeseed oil methyl esters as a suitable component of an ecological fuel.

Claims (4)

PATENT CLAIMS A process for the preparation of methyl esters of higher fatty acids by reesterification of triacylglycerols with methanol, characterized in that the reaction is carried out in a turbine stirrer reactor at a speed of 150 to 250 rpm for 0.5 to 4 hours at 15 to 40 ° C in the presence of an alkaline catalyst and methanol. Process according to claim 1, characterized in that powdered potassium carbonate in an amount of 1 to 6% with respect to triacylglycerols is used as the alkaline catalyst. The process of claim 1, wherein the volume ratio of triacylglycerol: methanol is 6: 0.8 to 1.2. The process according to claim 1, characterized in that after separation of the glycerol layer, unreacted methanol is distilled off from the methyl ester layer under a reduced pressure of 0.5 to 3 kPa at a temperature of 10 to 40 ° C and the product thus degassed is filtered.