Enhanced in situ ethanolysis of Jatropha curcas L. in the presence of cetyltrimethylammonium bromide as a phase transfer catalyst

Limited solubility of alcohols in vegetable oils hinders transesterification reaction process. Phase transfer catalysis can be of great advantage to enhance the reaction rates. Addition of cetyltrimethylammonium bromide as a phase transfer catalyst on in situ transesterification of Jatropha curcas L. with alkaline ethanol was investigated. Use of cetyltrimethylammonium bromide increased the yield of fatty acid ethyl esters. Optimum operating conditions were experimentally established. Yield of fatty acid ethyl esters increased from 89.2 wt% to 99.5 wt% with reduced requirement of ethanol by 16.7 v%, sodium hydroxide catalyst by 33.3 wt%, at a lower temperature of 30 °C and reduced mixing speed in shorter reaction time. The quality of fatty acid ethyl esters fuel conforms to the standards of ASTM D6751 and EN-14214.

► Cetyltrimethylammonium bromide increases yield of fatty acid ethyl esters.
► Cetyltrimethylammonium bromide reduced the consumption of NaOH and ethanol.
► Cetyltrimethylammonium bromide lowers reaction time, temperature and mixing speed.
► Reaction Mechanism of Cetyltrimethylammonium bromide catalyzed reaction is developed.