Setting benchmarks for ethylene and propylene oxidation via electrochemical routes: a process design and technoeconomic analysis approach

Abstract

The chemical industry must reduce greenhouse gas emissions to align with the Paris Agreement. In this study, we assess the economic feasibility of electrochemical oxidations (i.e., using water and electricity to create reactive oxygen species) as an alternative to current energy- and emissions-intensive industrial methods for producing ethylene oxide (EO) and glycol (EG) and propylene oxide (PO) and glycol (PG). Technoeconomic analyses reveal ethylene electrooxidations in a gas diffusion electrode assembly reach economic viability at single-pass conversions above 70% for EO and 40% for EG with overall Faradaic efficiencies (FE) above 20% and high carbon selectivities toward the desired products. Propylene electrooxidation achieves economic feasibility at a minimum single-pass conversion of 10% and overall FE greater than 10% for both PO and PG, while allowing variance in carbon selectivity. These electrochemical methods require current densities of at least 0.1 A cm⁻² and lifetimes greater than 2 years for industrial scalability. We demonstrate that electrochemical oxidations can reduce emissions and operational hazards in the production of key chemical intermediates through benchmarking targets for the experimental advancement of alkene electrooxidations.