Energy in the form of biomass has been used to produce heat, electricity, steam and petrochemicals due to the zero net carbon emission. With regards to the environmental concerns, hydrogen offers a competitive edge over the fossil fuel as an alternative clean energy. Currently, production of hydrogen from biomass using a pressurized system is not being extensively analyzed and developed. Thus, process and flowsheet development of pressurized gasification process of biomass coupled with carbon dioxide adsorption for hydrogen production were investigated using a PETRONAS iCON simulation model. The effect of parameters such as pressure, temperature and steam/biomass ratio on the hydrogen yield was investigated. Hydrogen yield was predicted to be increasing with pressure, temperature and steam/biomass ratio in this high pressure gasification system. © 2011 Asian Network for Scientific Information.