Modelling and evaluation of a high-temperature integrated CO2 capture and conversion system via SrO-based biomass sorption-enhanced gasification coupling with methane reforming

A novel high-temperature integrated system for efficient CO2 capture and conversion via sorption-enhanced gasification of biomass (BSEG) coupled with methane reforming is proposed. Employing SrO as a superior sorbent alternative to conventional CaO, the system synergistically produces H2-rich syngas while converting captured CO2 into valuable syngas. Thermodynamic modeling reveals that SrO significantly outperforms CaO in CO2 capture capacity and H2 yield under optimal conditions. Coupled effects of the key operating parameters (αSrO/C and αG,s/C, reforming temperature and αR,s/C) on the performances of gasifier, reformer and integrated system are investigated and optmized. At αSrO/C = 1.0 and αG,s/C = 1.2, the system achieves 97.64 % carbon capture efficiency and 97.24 % effective carbon utilization. At αR,s/C = 0 and reforming temperature at 1050 °C, efficient carbon utilization reaches 97.24 %, while higher αR,s/C of 0.5 boosts H2 concentration to 60.70 % at 850 °C. For the first time, SrO is exploited as CO2 carrier that simultaneously captures biogenic CO2 at high temperatures and supplies CO2 for CH4 reforming within the same loop. This dual-function strategy achieves effective carbon utilization, yielding H2-rich syngas at negative carbon intensity.