Synthesis of Ethyl Ester (Biodiesel) From Linseed Oil, Using Transesterification Double Step Process (TDSP)

Diminishing tendency of petroleum resources has led to find biodiesel (synthesized from renewable resources) as the best alternative and potential energy for current petrol-derived diesel. The aim of this investigation is to find ethanol as an alternative to methanol as a transesterification regent to produce biodiesel from linseed oil by using novel transesterification double step process (TDSP). The oil was transesterificated by using ethanol as regent and acid and basic homogeneous catalysts which added in two steps. The procedure was approximately performed during 4h, the alcohol/oil/catalyst molar ratio was 20:1:0.35, and the range of temperature was between 60-80 ˚C. The obtained yield for biodiesel was 96%. Ethyl ester was analyzed by standard physico-chemical techniques in addition of FT-IR spectroscopy. The quality of the synthesized biodiesel was tested according to ASTM. Some critical parameters like oxidation stability, cetane number, iodine value and cold flow properties which were correlated with the ethyl esters composition had been studied.