Waste cooking oil transesterification by sulfonated polyphenylsulfone catalytic membrane: Characterization and biodiesel production yield

Abstract

A route to waste cooking oil (WCO) transesterification to produce biodiesel using sulfonated polyphenylsulfone (S-PPS) and blends of polyphenylsulfone (PPS) and sulfonated polyphenylsulfone (PPS:S-PPS) as catalytic membranes was tested. Thin catalytic membranes from S-PPS and PPS:S-PPS presented a good balance between their ion exchange capacity (IEC), swelling degree, and weight loss after crosslinking. In particular, the crosslinked dense membrane with 56% sulfonation degree PPS:S-PPS 56 (MD 3 C) that presents IEC value 1.00 ± 0.02 meq H+/g and 328.37% swelling degree in methanol, shows the best balance. MD 3 C membrane transesterification reaction using WCO reached 86% biodiesel conversion with a WCO feedstock containing 0.24% water, 68 g/100 g of iodine value and 93% triglycerides. The use of S-PPS membrane acid-catalyzed biodiesel production from WCO is a promising and cleaner solution for preventing water and soil pollution with an added value. Further test should be performed to determine catalytic membrane stability, number of catalytic activity cycles and evaluate the sustainability of the PPS:S-PPS catalytic membranes for biodiesel production.