Utilization of glycerol for the production of glycerol carbonate through greener route

Abstract

Availability of glycerol is increased in recent years due to production of biodiesel. Glycerol carbonate, an important compound, can be manufactured using glycerol as a raw material. This work describes the synthesis of glycerol carbonate from glycerol via an enzymatic transesterification reaction using dimethyl carbonate as co-substrate and in presence as well as in absence of solvent. It has been observed that the glycerol and methanol (generated during transesterification) showed an inhibitory effect on the enzyme activity. In presence of solvent i.e. tertiary butanol, the rate of reaction is increased due to higher solubility of glycerol in it. Methanol was removed using molecular sieves. After the optimization of various parameters affecting the reaction, 94.85% conversion of glycerol was achieved with 1.5:1 molar ratio of dimethyl carbonate to glycerol and catalyst amount of 22.02% Novozym 435 at 60°C in 14h.