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

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 °C (generally around 900 °C), 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 global warming potential (GWP) of −2.624 kgCO₂·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.