Novel design of in-situ hydrogen sorption/storage integrated enhanced hydrogen production in supercritical CO2 gasification, air gasification, and steam gasification from biomass

The novel process on in-situ hydrogen sorption/storage during water gas shift (WGS) was proposed and the enhanced hydrogen production in supercritical CO2 gasification (CG), air gasification (AG), and steam gasification (SG) from biomass was integrated. Pure hydrogen was obtained by regeneration from the material (Mg2Ni) used for in-situ H2 absorption during WGS. The effects of temperature, pressure, steam-to-carbon (S/C) ratio, and the quantity of adsorbent for the enhanced hydrogen production with in-situ hydrogen sorption/storage were determined. When Mg2Ni was added as the in-situ H2 adsorbent, the hydrogen conversion in WGS reaction was improved. The increase of temperature reduced the hydrogen yield. SG presented the highest hydrogen yield and AG showed the highest hydrogen conversion. The steam-to-carbon (S/C) had a positive effect on the hydrogen production for all the processes and the methanation reaction was greatly inhibited by AG. The energy efficiencies reached 22.98 %, 26.31 %, and 27.149.51 %, and the exergy efficiencies reached 61.66 %, 64.19 %, and 83.62 %, for CG, AG and SG, respectively. The system energy can be supplied by in-situ hydrogen sorption/storage and the energy requirement order was SG > CG > AG.