Process intensification technologies for CO2 capture and conversion – a review

With the concentration of CO₂ in the atmosphere increasing beyond sustainable limits, much research is currently focused on developing solutions to mitigate this problem. Possible strategies involve sequestering the emitted CO₂ for long-term storage deep underground, and conversion of CO₂ into value-added products. Conventional processes for each of these solutions often have high-capital costs associated and kinetic limitations in different process steps. Additionally, CO₂ is thermodynamically a very stable molecule and difficult to activate. Despite such challenges, a number of methods for CO₂ capture and conversion have been investigated including absorption, photocatalysis, electrochemical and thermochemical methods. Conventional technologies employed in these processes often suffer from low selectivity and conversion, and lack energy efficiency. Therefore, suitable process intensification techniques based on equipment, material and process development strategies can play a key role at enabling the deployment of these processes. In this review paper, the cutting-edge intensification technologies being applied in CO₂ capture and conversion are reported and discussed, with the main focus on the chemical conversion methods.