EXERGY ANALYSIS OF HYDROGEN PRODUCTION VIA BIOMASS STEAM GASIFICATION AND PARTIAL OXIDATION

Hydrogen production via biomass steam gasification and partial oxidation is analyzed from exergy aspect. Based on cypress sawdust gasified from 800 degrees C to 1200 degrees C, the exergy value of H(2) from steam gasification rises from 1410.80 kJ kg(-1) to 7922.89 kJ kg(-1), while that from partial oxidation increases from 988.30 kJ kg(-1) to 3097.81 kJ kg(-1). The exergy efficiency of H(2) from biomass also increases for both steam gasification (6.42-36.08%) and partial oxidation (4.50-14.11%). However, the exergy efficiencies of H(2) from syngas are not in accordance. For steam gasification, the exergy efficiency rises sharply from 14.67% to 47.39%, and then increases slightly to 48.90%. For partial oxidation, the efficiency increases from 15.50% to 29.91% first, and then decreases slightly to 28.26%.