Electrochemical conversion of carbon dioxide to ethylene: Plant design, evaluation and prospects for the future.

In support of the energy and feedstock transition, new concepts of producing chemical building blocks are necessary. While currently ethylene is mainly produced from fossil feedstocks, this paper explores its production via the electrochemical conversion of CO 2. Different process routes were reviewed and a most promising route was selected based on Faradaic efficiency, current density, overpotential, and material availability. In this preferred route, syngas is produced electrochemically from CO 2 , which is then converted into methanol before the final conversion into ethylene and other high-value chemicals. On this preferred route, a design has been made which includes process design, unit design and a techno-economic evaluation, with CAPEX and OPEX included. Also the CO 2 emission is evaluated and it was found that a net consumption of 2.5 ton CO 2 per ton high-value chemical can be achieved. As expected, the investment and operational costs are very high with the applied price sets. However, when the electricity price decreases due to developments in renewable energy and a tax is implemented on CO 2 emissions, this process can become economically viable and can contribute to CO 2 emission reduction in view of climate change. [Display omitted] • Electrochemical CO 2 reduction could play a key role in reducing greenhouse gases. • Route was chosen based on carbon efficiency, electricity requirements and complexity. • Electrochemical syngas production, methanol formation and olefin production. • The electrolyzer is a stacked-cell system with a Nafion-424 cation exchange membrane. • Price of ethylene mainly dependent on CO 2 price, current density and electricity price. [ABSTRACT FROM AUTHOR]