Production of high-quality biodiesel fuels from various vegetable oils over Ti-incorporated SBA-15 mesoporous silica

Ti-incorporated SBA-15 mesoporous silica (shortly termed Ti-SBA-15) was a highly efficient and recyclable solid acid to synthesize high-quality biodiesel fuel (BDF) derived from various vegetable oils at moderate reaction condition, in comparison to siliceous SBA-15 and commercial TiO2 catalysts with different anatase sizes, where the catalytically active sites mainly related to the tetrahedral-coordinated Ti(IV) species with weak Lewis acid nature. The TOF values of Ti-SBA-15 catalysts were around 18-166 h(-1), an order of magnitude larger than those of commercial TiO2 catalysts. A high-quality BDF containing more than 98.4 mass% of fatty acid methyl ester (FAME), which met with international fuel standard, was obtained over 3Ti-SBA-15 catalyst at 200 degrees C using a methanol/oil ratio of 108. Most importantly, the 3Ti-SBA-15 catalyst showed extremely high water and free fatty acid (FFA) tolerance levels, which were several ten times better than homogeneous and heterogeneous catalysts in conventional BDF production technology. (c) 2013 The Authors. Published by Elsevier B.V. All rights reserved.