Enviro-economic analysis of tandem and direct processes for ethylene electrosynthesis

Ethylene is the most important organic chemical in terms of global demand and production capacity. Of the sustainable alternatives to conventional ethylene production based on steam cracking of natural gas and naphtha, both direct electrochemical reduction of CO2 as well as a tandem process consisting of CO2 electro-reduction to CO followed by CO electro-reduction to ethylene have attracted attention. This conference paper presents a comparison between the tandem and direct CO2 electro-reduction processes both from an economic and environmental point of view, including a global sensitivity analysis of key process parameters on production cost and climate change impact. The results depict a clear trade-off between the economic and environmental performance of both electrochemical routes, although the tandem process remains more favorable at the current carbon price of the EU emission trading system (ETS).