Techno-economic feasibility of electrochemical CO2 conversion to high-value circular chemicals

Abstract

Low-temperature electrochemical CO₂ conversion has gained growing attention as a potential route towards a more circular and electrified chemical industry, particularly for producing carbon-based chemicals under mild operating conditions. Most progress remains focused on electrochemical reactor performance or lower-order products, while industrial feasibility also depends on process integration, separation, recycle design, purification, and economic performance. It therefore remains unclear whether coupling CO₂ electrolysis with electrocarboxylation can provide feasible pathways to higher-value circular chemicals at industrial scale.

This study assessed the techno-economic feasibility of producing ethylene carbonate (EC) and succinic acid (SA) via direct and tandem low-temperature electrochemical CO₂ conversion pathways in an industrial-scale plant in North-West Europe. A structured screening framework compared CO₂-derived products and pathway concepts using complete CO₂ utilisation, technological readiness, continuous operation, electricity demand, economic attractiveness, strategic fit, and sustainability by design. This led to the selection of EC as the strongest near-term product candidate and SA as a complementary high-value case, with ethylene and carbon monoxide (CO) retained as key intermediates. Four routes were then defined: direct and tandem pathways to EC, and direct and tandem pathways to SA.

The routes were developed as process flow diagrams and implemented as steady-state Aspen Plus models, including electrolysers, electrocarboxylation cells, gas and liquid separation sections, recycle structures, and final purification. The resulting mass and energy balances were used in a techno-economic assessment (TEA), with net present value (NPV) as the main feasibility indicator. Under the base-case assumptions, none of the four routes reached economic feasibility, as expected for early-stage low-temperature CO₂ electrolysis and electrocarboxylation at industrial scale. This result should be interpreted as a current feasibility benchmark rather than as a rejection of the route concepts. Route 1, the direct pathway to EC, showed the strongest process-design and mass-balance performance, while Route 2, the tandem pathway to EC, was the strongest near-term techno-economic option. The SA routes showed higher product-revenue potential and the strongest optimistic-case upside, but were constrained by dry-solvent operation and losses, raw material demand, product purification, and downstream separation uncertainty.

The case analysis showed that technology improvements alone were insufficient, whereas improved economic conditions had a stronger effect and the combined optimistic case made all four routes economically feasible. Overall, the selected routes are technically credible early-stage pathways, but not yet techno-economically feasible under current base-case assumptions in North-West Europe. The main bottlenecks were electrochemical cost, economic exposure, dry-solvent demand, product purification uncertainty, and separation and recycle uncertainty. Future research and development should therefore prioritise integrated electrochemical and separation improvements, focusing on lower stack cost, lower cell voltage, stable high-current operation, dry-solvent recovery, electrolyte-compatible product purification, recycle validation, and realistic North-West European market conditions.