A thermodynamic view on the in-situ carbon dioxide reduction by biomass-derived hydrogen during calcium carbonate decomposition

Abstract

In the carbonate industry, deep decarbonization strategies are necessary to effectively remediate CO2. These strategies mainly include both sustainable energy supplies and the conversion of CO2 in downstream processes. This study developed a coupled process of biomass chemical looping H2 production and reductive calcination of CaCO3. Firstly, a mass and energy balance of the coupled process was established in Aspen Plus. Following this, process optimization and energy integration were implemented to provide optimized operation conditions. Lastly, a life cycle assessment was carried out to assess the carbon footprint of the coupled process. Results reveal that the decomposition temperature of CaCO3 in an H2 atmosphere can be reduced to 780 oC (generally around 900 oC), and the conversion of CO2 from CaCO3 decomposition reached 81.33% with an H2:CO ratio of 2.49 in gaseous products. By optimizing systemic energy through heat integration, an energy efficiency of 86.30% was achieved. Additionally, the carbon footprint analysis revealed that the process with energy integration had a low GWP of -2.624 kgCO2-eq·kg-CaO-1. Conclusively, this work performed a systematic analysis of introducing biomass-derived H2 into CaCO3 calcination and demonstrated the positive role of reductive calcination using green H2 in mitigating CO2 emissions within the carbonate industry.