Biomass gasification based on sorption-enhanced hydrogen production coupled with carbon utilization to produce tunable syngas for methanol synthesis

The production of methanol through biomass gasification is a hot topic in current research. However, the challenge lies in obtaining the correct H2/CO ratio, as the syngas generated from biomass gasification cannot be directly utilized for methanol synthesis. This paper proposed a biomass sorption-enhanced gasification coupled with carbon utilization to produce tunable syngas for methanol synthesis model in Aspen Plus. The effects of Steam/BBF, CaO/BBF and CO2 fraction on the composition and high heating value (HHV) of syngas were evaluated. This paper focused on the H2/CO ratio, the exergy efficiency and the global warming potential (GW). The study found that with the CO2 fraction of 0.6, the H2/CO ratio in the syngas approximated 2, with a yield of 257.19 kmol/h, making it suitable for methanol synthesis. The exergy efficiency of the system was ∼ 64 %, with the sorption enhanced water gas shift unit, gasification unit, power generation unit and methanol synthesis unit being the primary sources of exergy loss. Furthermore, in the global warming potential analysis, BBF gasification for methanol production stage and the biomass processing stage accounted for more than 97 % of the total GW. Improving the gasification for methanol production unit was crucial for enhancing the overall sustainability of the system. This study provides valuable insights into biomass sorption-enhanced H2 production and biomass-to-methanol conversion.