In the carbonate industry

deep decarbonization strategies are necessary to effectively remediate CO

2

. These strategies mainly include both sustainable energy supplies and the conversion of CO

2

in downstream processes. This study developed a coupled process of biomass chemical looping H

2

production and reductive calcination of CaCO

3

. 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 CaCO

3

in an H

2

atmosphere can be reduced to 780 ℃ (generally around 900 ℃)

and the conversion of CO

2

from CaCO

3

decomposition reached 81.33% with an H

2

: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 kg·kg

-1

(CO

2

/CaO). Conclusively

this work performed a systematic analysis of introducing biomass-derived H

2

into CaCO

3

calcination and demonstrated the positive role of reductive calcination

using green H

2

in mitigating CO

2

emissions within the carbonate industry.