Numerical Simulation And Experimental Study On Biomass Gasification For Hydrogen Production

The excessive consumption of fossil resource is not only bad for continuable development of society, and also will lead to the exhaustion of the resourse. With the problem of greenhouse effect becoming serious, hydrogen is hoped to be an important carrier of energy in the future continuable energy system. The prospective future of rich hydrogen gas from biomass gasification makes it a common concern of researchers all around the world.In this study, a new method of hydrogen production from biomass has been provided. The interconnected fluidized beds are choosed as the platform, which consist of a circulating fluidized bed and a bubbling fluidized bed. The two fluidized beds are connected by cyclone and bed inventory. The circulating fluidized bed is used to provide the heat needed by gasification process. The catalyst can be regenerated in the circulating fluidized bed due to the combustion of carbon deposit on the surface of catalyst particle. The bubbling fluidized bed is used to produce hydrogen from biomass steam gasification.In order to study the performance of interconnected fluidized beds gasifier, a mathematical model is established by the"cell model"method. The main processes in detail are considered, such as hydrodynamics, devolatilization of biomass, combustion and gasification of char, heat transfer. The influences of broad size distribution of bed inventory and core shrinking model of carbon on hydrodynamics and chemical reactions are also taken into account.Simulation results indicate that the established model can reflect the feature of the interconnected beds gasifier in detail and reveal the rule of hydrogen production deeply. The establishment of such a model provides theoretical instruction for designing, debugging and operation of interconnected fluidized beds gasifier.