Recent advances in integrated CO2 capture and utilization: a review

CO2 is one of the most important greenhouse gases leading to severe environmental issues. The increase of CO2 emissions from the consumption of fossil fuels has received much research attention. One promising solution to reduce the impact of CO2 is to integrate CO2 capture and utilization (ICCU), which shows many advantages compared to traditional separate CO2 capture and utilization (CCU) processes. The ICCU process shortens the path of CO2 utilization such as CO2 transportation and storage, and further negates the need for purification of products owing to the high conversion of CO2. As an emerging integrated process, the improvement of ICCU performance is crucial for future applications. This review analyses and discusses the influence of the key process parameters of ICCU such as temperature, the presence of O2 or H2O in CO2, GHSV etc., to provide guidance for future investigation. The development and application of dual functional materials (DFMs) in ICCU are investigated and the roles and influence of interaction between adsorbents and catalysts are discussed. CaO showed superiority as an adsorbent to combine with CO2 utilization catalysts owing to its low cost and high CO2 capture capacity. The DFM system has opportunities to retard the deactivation of CaO owing to the presence of catalysts and the formed interaction. Nevertheless, there are several considerations from the industrial application perspective such as the reduction of overall cost and the possible post-processing requirements.