Techno-economic analysis of integrated carbon capture and utilisation compared with carbon capture and utilisation with syngas production

Abstract

Currently, excessive CO2 emissions have become a global challenge due to their influence on the climate. According to the Paris Agreement, global warming should be limited to 1.5 °C by 2100. Carbon capture and utilisation (CCU) are attractive as they can both reduce CO2 content and utilise CO2 as a carbon resource. However, in conventional CCU processes, CO2 needs first to be extracted and purified for the following utilisation. In contrast, the recently reported Integrated Carbon Capture and Utilisation (ICCU) was designed to realise the overall process in one reactor, where CO2 is captured by adsorbents (e.g., CaO) and utilised in-situ with the introduction of a reducing agent (e.g., H2). This ICCU technology can promote CO2 conversion with fewer intermediate steps, leading to a reduction in overall cost. Energy and economic analysis of ICCU are thus urgently required. According to several recent research, the operational cost of ICCU has been reported to be cheaper than that of CCU. However, a comprehensive view of ICCU is still expected due to further application. This paper focuses on comparing ICCU and conventional CCU processes based on Aspen simulations covering mass balance (i.e., CaCO3 consumption, purge production, annual CO production), energy balance, the total annual cost and the CO cost, etc. Analysis shows that the ICCU process can produce more CO (1.20 Mt year−1), less purge (0.21 Mt year−1), and less consumption of CaCO3 (0.62 Mt year−1) with higher energy efficiency (37.1 %) than the CCU process. The results also show that the total annual cost of ICCU is $867.07 million, corresponding to a total cost of CO of $720.25 per tonne. In contrast, CCU has higher costs, with a total annual cost of $1027.61 million and a total cost of CO of $1004.53 per tonne. The Cost of CO2 Avoided of ICCU (317.11$/ton) is much lower than that CCU (1230.27 $/ton). Therefore, ICCU was confirmed as a better choice for further industrial applications. In addition, H2 is shown to have a significant influence on economic performance, which remains a challenge for further application.