LAUSR

Abstract To prevent global warming and climate change caused by CO2 emissions, the Intergovernmental Panel on Climate Change (IPCC) recommends lowering CO2 emissions to limit the global temperature to 1.5 °C. In addition to carbon capture and storage (CCS) technologies, there is a growing interest to explore CO2 utilisation. Several review papers exist in the literature either focusing on one or two CO2 transformation technologies or covering only experimental studies. This review paper addresses the gap by classifying CO2 transformation technologies and looking at products from CO2 conversion. It reviews experiment and modelling/simulation-based studies for CO2 biological and chemical conversion processes to assess their technical barriers. A detailed analysis of their technology readiness level, cost, market and environmental benefits are also elaborated. Finally, the research trend and projects for CO2 transformation technologies worldwide as well as the key challenges hindering their commercial deployments are carefully outlined. The analysis of the research trend shows a significant increase in research for CO2 utilisation with hydrogenation and electrochemical reduction being the most studied technologies since 2016. 53% of the projects are laboratory projects whereas, only 14% account for commercial projects. There is currently no commercial project for plasma catalysis, photochemical, electrochemical and non-photosynthetic technologies. The USA holds the highest number of 45 projects including 8, 6, 10 and 21 commercial, demonstration, pilot and laboratory projects, respectively. The development of improved catalysts and process intensification techniques are highly needed for successful scale-up of CO2 transformation technologies.