Sustainable Assessment of Glycerol to Monoglycerides by Heterogeneous Catalysis

Abstract

Biofuels are renewable solutions to replace the ever dwindling energy reserves and environmentally pollutant fossil fuels. Therefore, large surpluses of glycerol, biodiesel byproduct, are generated. Glycerol is used as an ingredient in cosmetics, foods and pharmaceutical products. Heterogeneous catalysts are potentially low cost and can solve many of the problems encountered in homogeneous catalysts. In this paper, mixed metal oxides as transesterification catalysts are studied. Especially the relationship between physicochemical properties and catalytic activity was revised. Mixed metal oxides obtained by thermal decomposition of Layered Double Hydroxides have been studied in the transesterification of methyl stearate to monoglycerides production. To increase the basic property of the Mg-Al oxide a third metal (Ca or Ba) was incorporated. The catalytic results showed that conversion and selectivity to monoglyceride increased, specially, with the basic sites density. The oxide with Ba incorporated by impregnation showed most medium basic sites density and the highest catalytic performance.