Recent advances in renewable hydrogen production by thermo-catalytic conversion of biomass-derived glycerol: Overview of prospects and challenges

Abstract

Glycerol is the main by-products obtained from the transesterification of vegetable oils and animal fats to produce biodiesel which is an important biofuel used for transportation. The increase in the global energy demand has pushed up the production of biodiesel with a corresponding increase in glycerol production over the years. The thermo-catalytic process is gaining wide popularity as sustainable technical routes of converting glycerol to renewable hydrogen. There exists a great potential of utilizing hydrogen as a critical part of a more sustainable and secure energy mix. Hence, this study focusses on the review of the recent advances and development in the thermo-catalytic conversion of glycerol to renewable hydrogen in the last one decade. The analysis of the reviewed articles showed that substantial efforts had been made in the application of thermo-catalytic process for the conversion of glycerol to renewable hydrogen. Glycerol reforming using steam, carbon dioxide (CO2) and oxygen (O2) have received significant research attention and have been found to have great potential as technological routes for hydrogen production. Whereas, the use of the photocatalytic glycerol reforming has the advantages of energy-saving by utilizing the vast available solar resources and suitable photocatalysts. However, each of the thermo-catalytic processes exhibits inherent challenges which have been a bottleneck to the development of the process to industrial scales. Nevertheless, the prospect of employing each of the thermo-catalytic processes for hydrogen production via glycerol conversion was identified with the possible suggestion of strategies of overcoming the challenges. © 2019 Hydrogen Energy Publications LLC