SULFONIC ACID-FUNCTIONALIZED MAGNETIC NANOPARTICLES AS EFFICIENT AND REUSABLE CATALYSTS FOR ESTERIFICATION OF FREE FATTY ACID IN GREASE IN TWO-STEP BIODIESEL PRODUCTION

摘要

Biodiesel is a renewable and clean fuel which is viewed as a viable alternative for petroleum-based diesel. It commonly composed of fatty acid methyl esters (FAME) produced from vegetable oils via base-catalyzed transesterification with methanol. Waste grease, which available cheaply and a non-edible resource, is an attractive feedstock that can help to improve the economic feasibility of biodiesel. However, technical challenge arises due to the high free fatty acid (FFA) content (15-40 wt%) present in grease, which interfere with the base-catalyzed transesterification. To solve this problem, grease may be firstly pretreated via an acid-catalyzed esterification to transform the FFA into FAME.