Volume 32: A Sustainable, Clean and Carbon-free Energy Future

Energy-Saving Hydrogen Harvesting from Ethylene oxide /Ethylene glycol (EO/EG) Process Waste Effluent by Electrochemical Reforming Hengwei Wang,Xue Wang,Bilian Zhu,Jianan Li,Jianheng Li,Xuejing Yang*

Abstract

Water electrolysis supported by sustainable electricity has been regarded as the promising method for large-scale hydrogen (H2) production, but the sluggish anodic oxygen evolution reaction with high-energy barriers to overcome much limited its broad development. Herein, by taking use of the EO/EG process waste effluent, we comprehensively demonstrated the feasibility of developing electrochemical reforming of glycols to simultaneously construct an energy-saving electrolysis H2 production system and degrade pollutants to purify the effluents. The cathodic H2 harvesting could retain nearly 100% Faradic efficiency, along with ~ 17.7% gain in electricity and its correlation with the COD removal in the effluent. Furthermore, the electrochemical oxidation of EG was studied in detail under real circumstances and compared with other EG-derived organic substances possibly present in the waste effluent to glean the possible oxidation mechanism. This work provides some new insights for designing both energy-effective electrochemical systems and sustainable water-energy nexus.

Keywords Hydrogen energy, ethylene glycol, waste effluent, electrochemical reforming, energy-saving