Finding appropriate operating conditions for hydrogen purification and recovery in supercritical water gasification of biomass

The gas product from biomass gasification in supercritical water contains about 55% H2 and 33% CO2 in mole fraction. Others like CH4 and CO exist in the gas product with less amounts. Hydrogen is the targeted product. Its purification is a very important step. Water is generally used as the solvent to purify the hydrogen by separating CO2 and other gases from the gas product. The hydrogen purification can be carried out through separators, generally a high-pressure separator followed by low-pressure separators. The operating conditions of temperature, pressure, and the amounts of water used have a significant effect on the efficiency of hydrogen purification. Simulation of hydrogen purification at a wide range of operating conditions has been carried out. The appropriate operating conditions have been indicated, at which, to the greatest extent, the hydrogen produced can be purified and recovered. The results of this work will have a significant contribution to the design of a process of supercritical water gasification of biomass.