Electrosynthesis of ethylene glycol with integrated CO2 capture

The authors (Northwestern University and collaborators, supported by Braskem) report an electrified process that oxidizes ethylene to ethylene glycol (EG) while integrating electrochemical CO2 capture to greatly reduce lifecycle carbon intensity.

• Main result: The integrated electrolytic system achieves 94% Faradaic efficiency for ethylene-to-EG conversion, 91% CO2 capture efficiency from a 10% CO2 stream, and sequesters 0.60 tonnes CO2 per tonne EG, yielding an estimated carbon intensity of 0.133 tCO2-eq/tonne EG versus the global average 1.2 tCO2-eq/tonne EG.
• Background and implementation details: The work identifies hydroxide counter-migration and an increased pH at the membrane–anode interface as challenges, introduces cathodic electrochemical carbon capture and RuSnOx catalysts favoring Cl over OH adsorption, is supported by Braskem, used NUANCE (EPIC, Keck-II, SPID) and Canadian Light Source facilities, and is associated with two US provisional patent applications (no. 63/607,143 and another titled ‘System for producing mono-EG and carbon dioxide and method for producing same’).