Direct use of crude glycerol in synthesis of glycerol carbonate via transesterification

Driven by high energy consumption and environmental concerns, biodiesel as an alternative substitute for non-renewable energy is recognized to be promising clean and renewable energy. The tremendous growth of biodiesel industry has led to large surplus of its by-product crude glycerol. The surplus of crude glycerol has great impact in financial and environmental issues in biodiesel industry. Hence, research efforts in finding a new application is necessary to transform the crude glycerol to marketable and valuable products. Therefore, this study aimed to synthesize glycerol carbonate (GC) by transesterification of direct use of crude glycerol (C.GLY) with dimethyl carbonate (DMC) using calcined calcium oxide (CaO) as the catalyst. Factors for optimization on synthesis GC via transesterification included reaction temperatures, reaction time, molar ratios of (DMC:C.GLY) and (Catalyst:C:GLY) ratios. Reaction optimization was performed by using response surface methodology with Central Composite Design (CCD). Finally, the optimum condition for GC production obtained was 80 °C reaction temperature, 105 minutes reaction time, molar ratio (DMC:C.GLY) fixed at 3:1 and (Catalyst:C.GLY) ratio maintained at 8.35 wt%:1 wt% gave the highest conversion and yield. Under the optimum condition, C.GLY conversion and GC yield achieved were 97.3% and 79.2% respectively. As conclusion, C.GLY can be direct utilized as reactant without any further purification in synthesis of GC via transesterification approach.