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Preparation of rapeseed oil esters of lower aliphatic alcohols
Author(s) -
Nimcevic Dragan,
Puntigam Rupert,
Wörgetter Manfred,
Gapes J. Richard
Publication year - 2000
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-000-0045-1
Subject(s) - chemistry , transesterification , rapeseed , catalysis , organic chemistry , biodiesel , acetone , alkyl , alcohol , butanol , ethanol , food science
Rapeseed oil esters with lower aliphatic alcohols (C 1 −C 4 ) were prepared in simple batch mode using an alkali (KOH) or acid (H 2 SO 4 ) catalyst. The transesterification reaction conditions were optimized in order to obtain high yields of esters of the quality defined by standards for biodiesel fuels and for a short reaction time. Under these conditions it was possible to prepare only the methyl and ethyl esters catalyzed by KOH. Propyl and butyl esters were obtained only under acid catalysis conditions. The reaction catalyzed by H 2 SO 4 was successfully accelerated using slightly higher catalyst concentrations at the boiling points of the alcohols used. The branched‐chain alcohols reacted more slowly than their linear homologs, while t ‐butanol did not react at all. It was also possible to transesterify rapeseed oil using a mixture of alcohols characteristic of the end products of some fermentation processes (e.g., the acetone‐butanol fermentation). A simple calculation was made which showed that, because of the higher price of longer‐chain alcohols and because of the more intensive energy input during production the esters of these alcohols, they are economically unfavorable as biodiesel fuels when compared with the methyl ester.