Techno-economic evaluation of the electrochemical production of renewable ethylene oxide from fluctuating power sources and CO2

Abstract

We present a techno-economic assessment of a novel ethylene oxide (EO) production process, which converts carbon dioxide (CO2) and water electrocatalytically to ethylene (C2H4) and hydrogen peroxide (H2O2), which are further synthesized into EO. To ensure environmental sustainability, the primary focus was on available CO2 from biogenic sources (biomethane and bioethanol plants) and renewable power sources (wind and photovoltaics) for decentralized applications. Accordingly, data on existing European CO2 and renewable power sources were compiled for spatial analysis to develop technology roll-out and exploitation scenarios: 175 suitable locations were identified. Focusing on three locations, the production costs of EO and the product mix were calculated, considering various energy sources and plant configurations (as of 2030 and 2040). For a generic scenario, considering CO2 to be available free of cost (existing biomethane upgrading) and electricity cost of 36€/MWh, the production cost of the product mix (EO, H2O2, methane, hydrogen) amount to 0.86 €/kg. This is at a similar order of magnitude as assessments on other Power-to-X value chains. Assuming that EO is the only utilizable product, the costs increase to 5.78 €/kg, which is significantly higher than for fossil alternatives. According to the sensitivity analysis, energy efficiency, electricity prices, and capital expenditure are the most relevant factors. Regarding the latter, an extended plant lifetime is a crucial factor.