Synthesis of glycerol carbonate from biodiesel by-product glycerol over calcined dolomite

Glycerol, which threatens the viability of biodiesel industries, can be converted to valuable chemicals and chemical intermediates, such as glycerol carbonate (GC). GC was synthesized by glycerol transesterification with dimethyl carbonate (DMC) Cao-MgO mixed oxide catalyst prepared from natural dolomite. At calcination temperature of 800 degrees C, natural dolomite was converted to CaO-MgO mixed oxide to serve as catalyst in the conversion of glycerol to GC. Temperature changes and calcined dolomite surface and textural characteristics caused the glycerol transesterification with DMC to GC. The catalyst with 15< H_<18.4 basic strength yielded a maximum of 97% glycerol conversion and 94% yield of GC at 75 degrees C, 3 DMC/glycerol ratio, and 6 wt% catalyst dose. Calcined dolomite showed potential for a consecutive cycle of catalytic activity during glycerol transesterification with negligible yield of by-product glycidol. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.