Production of glycerol carbonate from glycerol over modified sodium-aluminate-doped calcium oxide catalysts

Glycerol is a low-cost coproduct from the biodiesel production process. Currently, production of value-added products from glycerol is still of great interest. This research studied the production of glycerol carbonate (GLC) from the transesterification reaction of glycerol and dimethyl carbonate (DMC) using modified sodium aluminate catalysts. Sodium aluminate was modified with CaO to increase its basicity and glycerol was also used as a template during catalyst preparation to increase its surface area. The results showed that sodium aluminate modified with CaO at 5 % by weight (NA5Ca) and using 45 % glycerol template by weight of NA5Ca (NA5Ca45 G) produced the most active catalyst among those prepared. By varying the operational parameters, the maximum GLC yield of NA5Ca-45 G was 90.5 % with 100 % selectivity, a catalyst content of 30 % by weight of glycerol reactant, a glycerol:DMC molar ratio of 1:4, a reaction temperature of 70 degrees C, and a reaction time of 3 h. The study of catalyst reusability revealed that NA5Ca-45 G has problems with agglomeration and a small amount of leaching, which require further study for their prevention.