Glycerol cuts energy use in CO2 conversion process

The team at the University of Illinois at Urbana-Champaign are said to have assessed the technical and economic feasibility of a new electrolysis technology that uses glycerol, a cheap biofuel byproduct, to reduce the energy consumption of the waste-to-value process by 53 per cent. The new findings are published in Nature Energy.

Conversion of CO2 to chemicals like ethylene for plastics is possible through electrochemical reduction, a process in which a stream of CO2 gas and a fluid electrolyte move through an electrolysis cell that breaks the CO2 down into molecules like ethylene on the cathode. It also produces oxygen from water on the anode, the researchers said.

"About 90 per cent of the energy required in conventional CO2 reduction is used up by the oxygen-producing, anode side of an electrolysis cell," said Paul Kenis, a chemical and biomolecular engineering professor, department chair and study co-author. "But there is no big market for the excess oxygen, so 90 per cent of the energy is essentially wasted."