Ali Reza Mahjoub
Tarbiat Modares University, Iran
Title: Investigation of 12-tungestophosphoric acid immobilized on zirconium modified SBA as catalyst for esterification of glycerol
Biography
Biography: Ali Reza Mahjoub
Abstract
Glycerol found in animal fat, vegetable oil, and crude oil is used as a raw material in various applications such as using in cosmetics, pharmaceuticals and food industries. In spite of such a wide range of applications, the price of glycerol is decreasing noticeably. This is due to commercialization of biodiesel which lead to large amount production of glycerol as a byproduct. So, Glycerol can be counted as biomass. Because of having three hydroxyl groups, Glycerol can be converted to many value added products via chemical reactions. Among all, one of the most interesting approaches is acetylation of glycerol by acetic acid. During this reaction di- (DAG) and tri- (TAG) acetyl glycerol are produced as valuable additives for biodiesel. It has been reported that solid acid catalysts promote the acetylation reaction of glycerol. In this study, we synthesized zirconium-modified mesoporous silica (Zr-SBA) and then immobilized tungestophosphoric acid into it (Zr-SBA-PWA). Both catalysts are used in acetylation reaction of glycerol by acetic acid at 100°C. DAG and TAG are characterized as main products of the reaction. Comparison of two catalysts showed our result is unlike of many reports which explain by increasing the acidity of the catalyst the conversion efficiency of glycerol to DAG and TAG is improved. While the NH3-TPD analysis showed weaker acid properties for Zr-SBA, it exhibited better performance than Zr-SBA-PWA in acetylation of glycerol. Zr-SBA converted 100% of total glycerol, while the selectivity of reaction to DAG and TAG is nearly 90% which is an impressive achievement.