High Quality Syngas Production with Supercritical Biomass Gasification Integrated with a Water-Gas Shift Reactor

A thermodynamic assessment is conducted for a new configuration of a supercritical water gasification plant with a water-gas shift reactor. The proposed configuration offers the potential for the production of syngas at different H-2:CO ratios for various applications such as the Fischer-Tropsch process or fuel cells, and it is a path for addressing the common challenges associated with conventional gasification plants such as nitrogen dilution and ash separation. The proposed concept consists of two reactors, R-1 and R-2, where the carbon containing fuel is gasified (in reactor R-1) and in reactor R-2, the quality of the syngas (H-2:CO ratio) is substantially improved. Reactor R-1 is a supercritical water gasifier and reactor R-2 is a water-gas shift reactor. The proposed concept was modelled using the Gibbs minimization method with HSC chemistry software. Our results show that the supercritical water to fuel ratio (SCW/C) is a key parameter for determining the quality of syngas (molar ratio of H-2:CO) and the carbon conversion reaches 100%, when the SWC/C ratio ranges between two and 2.5 at 500-1000 degrees C.