Properties of alkyl esters base on castor oil

Castor oil is a non-traditional raw material for the preparation of methyl and ethyl esters of higher fatty acids as alternative fuels for diesel engines. Castor oil contains ricinoleic acid (12-hydroxy octadecene acid) with a major share of about 90%. The article presents the parameters of castor oil-based methyl esters (COME) and ethyl esters (COEE) defined by the standard EN 14 214. The densities of COME and COEE are higher than the limit defined by the standard EN 14 214. The viscosities are more than twice as high as the limit value. The cetane numbers are lower than defined by the standard EN 14 214. For the remaining parameters, COME and COEE meet, in principle, the standard EN 14 214. The presence of the free hydroxyl group has virtually no effect on the values of such parameters as carbon residue, filterability at low temperatures and oxidation stability, for which some influence was expected. The physicochemical parameters of the castor oil esters are discussed in comparison to the analogous esters of high-oleic sunflower oil, which contain about 80% of oleic acid. Both the methyl and ethyl esters of high-oleic sunflower oil meet the standard EN 14 214 in all prescribed parameters.