Hydrolysis of rapeseed oil to fatty acids using pyrrolidonium ionic liquids as catalysts

Abstract

ABSTRACTThis study aimed to evaluate the hydrolysis of rapeseed oil using pyrrolidonium ionic liquids as catalysts under atmospheric pressure. The process parameters were optimized using a sequence of experimental protocols to evaluate the effects of ionic liquid loading, dosage of emulsifier, weight ratios of substrates, temperature and time. The results demonstrated that the ranking of catalytic activity of ionic liquids is N-methyl-2-pyrrolidonium hydrogen sulfate salt ([HNMP]HSO4)>1-(3-sulfonic acid) propyl-2-pyrrolidonium hydrogen sulfate salt ([C3SO3Hnhp]HSO4)>2-pyrrolidonium hydrogen sulfate salt ([Hnhp]HSO4). In a batch reactor, the hydrolysis reaction conditions in the presence of [HNMP]HSO4 were investigated and optimized as follows: catalyst loading of 20% (based on the weight of oil), oil/water weight ratio of 1:2, emulsifier loading dosage of 4 wt % (based on the weight of oil), hydrolysis temperature of 100°C, and hydrolysis time of 30 h. The catalytic performance of this ionic liquid remained excellent even after reuse five times.