Recent advances in processes and catalysts for glycerol carbonate production via direct and indirect use of CO2

Abstract

Glycerol can be utilised as a renewable feedstock in several chemical reactions, including carbonation, carbonylation, transesterification, and oxidation. Among the several conversions, the production of glycerol carbonate is environmentally most attractive, as it also utilises CO2 as the carbon source, as C1 feedstock, a key to accelerate the pursuit of decarbonization and the net-zero goals. The glycerol carbonate production can be divided into two main pathways i.e., direct and indirect route based on the utilisation of CO2. There has been much interest in the direct conversion of glycerol with molecular CO2, due to its potential for sustainability and ecological advantages. Moreover, this process could be directly minimising CO2 levels in atmosphere. The indirect pathways involve the utilisation of CO2 as a source for the synthesis of reactants, for instance organic carbonates and urea. These reactants are employed as raw materials in the process of glycerol carbonate production. It is important to note that each reaction route has its own set of advantages and drawbacks. However, the important factor for all processes lies in the high catalytic performance of the suitable catalyst and the optimal reaction conditions to enhance the yield of glycerol carbonate. This review aims to evaluate the recent progress made on the catalyst design and process conditions to produce glycerol carbonate via both the direct and indirect reaction pathways. In each route, the catalytic systems based on the heterogenous catalysts, the reaction condition and catalytic performance are considered. Finally, suggested perspectives for the future direction in glycerol carbonate production focusing on the utilisation of molecular CO2 are presented.

Keywords

• Carbon dioxide utilization
• CCUS
• Net zero
• Bio-fuels
• Glycerol
• Glycerol carbonate