Techno-economical evaluations of decarbonized hydrogen production based on direct biogas conversion using thermo-chemical looping cycles

Hydrogen production by biogas conversion represent a promising solution for reduction of fossil CO2 emissions. In this work, a detailed techno-economic analysis was performed for decarbonized hydrogen production based on biogas conversion using calcium and chemical looping cycles. All evaluated concepts generate 100,000 Nm(3)/h high purity hydrogen. As reference cases, the biogas steam reforming design without decarbonization and with CO2 capture by gas-liquid chemical absorption were also considered. The results show that iron-based chemical looping design has higher energy efficiency compared with the gas-liquid absorption case by 2.3 net percentage points as well as a superior carbon capture rate (99% vs. 65%). The calcium looping case shows a lower efficiency than chemical scrubbing, with about 2.5 net percentage points, but the carbon capture rate is higher (95% vs. 65%). The hydrogen production cost increases with decarbonization, the calcium looping shows the most favourable situation (37.14 (sic)/MWh) compared to the non-capture steam reforming case (33 (sic)/MWh) and MDEA and iron looping cases (about 42 (sic)/MWh). The calcium looping case has the lowest CO2 avoidance cost (10 (sic)/t) followed by iron looping (20 (sic)/t) and MDEA (31 (sic)/t) cases. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.