Hydrogen is a potential alternative energy source over fossil fuels when produced from biomass via thermal conversion process. This is indeed very attractive as Malaysia is having abundant biomass resources. In this paper, a mathematical model is developed to predict the maximum possible attainable composition of the product gas from a thermal conversion process, i.e. gasification, of palm kernel shell for hydrogen production. The work is motivated by the need to study the technical feasibility of the process under different operating conditions, i.e., temperature and Steam/Biomass ratio. The model predicts a maximum hydrogen production of approximately 50 mol at system pressure and temperature of 1 atm and 1200 K and steam/biomass ratio of 1. Generally, the model is capable to capture the thermodynamic limit of the process, which is an essential knowledge on accessing the feasibility of the process. In addition, such information is also vital in designing the gasifier and for selection of materials for construction as well. © 2011 IEEE.