Techno-economic analysis of integrated hydrogen and methanol production process by CO2 hydrogenation

Abstract

Global climate change is one of the major concerns of today's world. Indeed, the carbon capture and sequestration (CCS) has a great potential to abate global climate changes but the economic infeasibility of this process has motivated the researchers to develop methods for direct utilization of captured carbon dioxide (CO2) to value-added end products. For instance, the methanol production by hydrogenation of CO2 is extensively investigated for over two decades but the high operating cost of this process, especially for hydrogen production, has discouraged its commercial implementation. In this work, a high temperature solid oxide electrolyzer (SOE) as a source of hydrogen production (12.16 ton/hr) from steam is integrated with the CO2 hydrogenation process to reduce the cost of methanol production. Integration of SOE with methanol production process resulted into 22.3% reduction in the cost of hydrogen as compared to the alkaline water electrolyzer. Consequently, the cost of 63.5 ton/hr methanol production was reduced, from 1063 $/ton to 701.5 $/ton, by employing SOE and optimizing the process flowsheet (by considering seven different configurations of the flowsheet, along with heat and process integrations). It is anticipated that a further reduction in the cost of methanol production by aforementioned process is possible by the advancement of hydrogen production technology, especially the high performance materials development and commercialization of electrolyzers.