CO2 capture and utilization from supercritical coal direct chemical looping combustion power plant – Comprehensive analysis of different case studies

Abstract

Carbon dioxide utilization has gained much attention as a greenhouse gas (GHG) abatement strategy complementary to carbon dioxide storage. Fossil fuel (including coal) based power plants are the large emitters of carbon dioxide as a single sector. Chemical looping combustion is an inherent CO2 capture technology and can also be used for hydrogen production. The captured CO2 and H2 can be used as reactants for synthesis of various products. Present study explores the carbon dioxide utilization (CDU) from the coal direct chemical looping (CDCL) combustion plant with power and hydrogen co-generation to produce four valuable products as four different cases. These case studies include formic acid (FA), methane, methanol, and dimethyl ether (DME) synthesis plants. The performance of these integrated plants is evaluated based on a comprehensive assessment including energy, exergy, ecological, economic and life cycle (4-E&L) analyses. Levelised cost of the products (LCOP) of CDU plants are estimated and compared. Results of 4-E&L analyses show that the CDCL plant with formic acid synthesis is the most favourable option with 100% CO2 utilization efficiency. At the end, the LCOPs estimated from the proposed CDU integrated CLC based power plant are compared against the LCOPs obtained from two different approaches using hydrogen production from solid oxide electrolysis cell (SOEC). The proposed approach is found to be resulting in less LCOP compared to the other approaches.