METHOD OF PRODUCING CARBOXYLIC ALKYL ESTERS Russian patent published in 2011 - IPC C07C67/03 C07C69/52 C11C3/00 C10L1/18 B01J23/02 C07C69/24 C07C69/58 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing carboxylic esters via esterification of carboxylic acids and/or re-esterification of carboxylic esters with methanol or ethanol in the presence of a metallic catalyst, in which the reaction takes place at temperature higher than 150°C, said metallic catalyst is an alkali-earth metal salt and an aliphatic carboxylic acid containing 10-24 carbon atoms, and at the end of esterification or re-esterification, respectively, the metallic catalyst is extracted and then reused as a liquid catalyst in the method of producing carboxylic esters via esterification of carboxylic acids and/or re-esterification of carboxylic esters with methanol or ethanol in the presence of a catalyst. The advantage of the method lies in that, in the initial mixture, free fatty acids can be present in any concentrations. These free fatty acids are also esterified in the said reaction to fatty acid alkyl esters. Hence, low-quality fat/oil can be processed. Another advantage of the method is that, the esterification/re-esterification reaction can also take place in the presence of water. Thus, water-containing material, particularly hydrous alcohol, can also be used. Unreacted free fatty acids or glycerides are returned for esterification/re-esterification, owing to which no losses occur. In contrast to processes without catalysts, the disclosed method has an advantage in that, the reaction can take place with amounts of alcohol which are a little higher than stoichiometric amounts, which markedly increases profitability of the method.

EFFECT: improved method of producing carboxylic esters.

5 cl, 4 tbl, 3 ex