Simulation of the Effects of the Equivalence Ratio on Hydrogen Production in Fluidized Bed Biomass Gasifiers

In recent years, hydrogen production from biomass has been optimized in fluidized bed conditions, and the steam gasification has become an area of growing interest because it produces a gaseous fuel with relatively higher H2 content which could be used in fuel cells, a new technology for the future to produce power in a much cleaner manner. The equivalence ratio is one of the most important operating variables in biomass gasification with air. In this work it is defined as the air-to-fuel weight ratio used, divided by the air-to-fuel weight ratio of stoichiometric combustion. The equivalence ratio shows two opposing effects on the gasification process. Increasing the amount of air favors gasification by increasing the temperature but, at the same time, produces more carbon dioxide. Gasification with a better level of efficiency produces more carbon monoxide and less carbon dioxide. From this point of view, in this study, the effects of the equivalence ratio on hydrogen production from an atmospheric biomass fluidized bed gasifier is simulated by developed 2D model. The model simulation results are also compared with and validated against experimental data given in the literature. The model predictions are in a good agreement with experimental data where the maximum error values do not exceed 0.17.