Sulfonic-Functionalized Carbon Catalyst for Esterification of High Free Fatty Acid

We report synthesis and characteristics of sulfonic-functionalized carbon catalyst in this work. The carbon soild acid was prepared through the sulfonation of the incomplete carbonized mung bean vermicelli and was used as a solid acid catalyst for esterification of high free fatty acid. The catalyst (SBET = 18.1 m2/g, acid site density of 1.53 mmol H+/gcat) could exhibit high esterification activity in the reaction of oleic acid with methanol due to the efficient accessibility of bulky substrate molecule to sulfonic active site during the reaction. This environmentally benign and ecofriendly C-SO3H catalyst could be suited to esterify high FFA feedstocks reducing the production cost of biodiesel.