The early-stage design of plasma for the conversion of CO2 to chemicals: A prospective techno-economic assessment

Abstract

The persistent increase in CO2 emissions and the continued depletion of fossil resources are two major challenges of the 21st century. These challenges can be tackled with Carbon Capture and Utilization (CCU), fby capturing and using CO2 as a valuable feedstock. Plasma presents a reactive environment to convert the CO2 molecule efficiently into higher-value chemicals and is a promising CCU technology in an early development stage. This study translates the technical performance of the plasma, as observed in the laboratory, into economic cashflows on a pilot plant level. In this techno-economic assessment, the influence of three features of the plasma is analyzed: the type of feed, the space time and the type of packing material. The economic feasibility of the different plasma configurations for the conversion of CO2 and CH4 into higher-value chemicals is assessed by calculating the Net Present Value (NPV). This allows the identification of the major cost items and the prioritization of future R&D steps. Negative NPVs are observed for all configurations, due to high electricity expenses, high capital investments and insufficient revenues. Based on the NPV, the most promising reactor configuration is the unpacked reactor, supplied with pure CO2 in a short space time. However, to target higher-value chemicals and raise revenues, the presence of packing materials and a mixed feed of CO2 and CH4 is crucial. Indeed, the highest revenues are observed for the reactor filled with packing, supplied with CO2 & CH4 and at longer space time. To move forward, the right type of packing material should be found, enabling the targeted production of higher-value chemicals with higher conversion rates in a shorter space time.