Environmental techno-economic assessment of an electrocatalytic conversion process of carbon dioxide into ethylene: towards more sustainable chemistry

Abstract

In order to mediate climate change due to CO2 emissions, alternative technologies should be looked at across sectors. One such sector is the chemical industry in which 30% of all end products have ethylene (C2H4) as an intermediary. Therefore, the traditional cracking of naphtha will be reevaluated and more sustainable processes based on CCU can be suggested. Through the execution of an ‘Environmental Techno Economic Assessment’ (ETEA), the alternative process of producing C2H4 via electrocatalysis will be evaluated on both the economic and environmental aspects. These analysis showed a base case negative NPV of - €188 million, with different scenarios showing values between - 316.8 and -91.3 million euros. Main contributors to this NPV are the selectivity level (FE), electricity price and the applied potential. A business currently importing ethylene could however benefit from this technology, providing import cost savings and pushing the NPV up towards in the most optimistic scenario € 167 million. The environmental aspect showed that, when green electricity can be used, lower carbon emissions of 1 tonne CO2 per tonne C2H4 can be achieved by using electrocatalysis as a production method. However, water consumption will be higher, causing the overall environmental impact score to be worse. It will be important to increase technological development on both the economic and environmental aspects and to search for sustainable sources for both electricity and water in order to make electrocatalysis for ethylene a viable route.