Hydrogen production by supercritical water gasification

This chapter presents different aspects of supercritical water gasification for hydrogen production. In particular, it focuses on historical aspects, evolution of the technology, benefits, and disadvantages with a particular attention to the used reactors and involved reaction mechanisms. The main objective is to report and discuss the interest of the hydrothermal gasification process for the hydrogen production. The optimization of this process with respect to the effect of operating parameters including temperature, residence time, pressure, biomass/catalyst ratio is also considered. This present route is mainly assessed through comparison with conventional processes. In fact, in addition of being more efficient, hydrothermal gasification can also be a reliable and a sustainable alternative avoiding the release of CO2 into the atmosphere, hence reducing the important contribution to the global problem of climate change. Therefore, the production of hydrogen from biomass using hydrothermal gasification can be regarded as an important challenge and a promising technology able to lead to this energy vector development.