Analysis of biomass gasification in bubbling fluidized bed with two-fluid model

The framework of theoretical method is two-fluid model coupled with reaction process. The k-e model is used for gas phase, and the kinetic theory of granular flow is employed for solid phase. In the simulation, gasification process consists of three parts: pyrolysis, homogenous reaction, and heterogeneous reaction. In the first stage, biomass particles crack into carbon particles and volatile gases upon entering the reactor. Subsequently, the carbon particles and volatile gases react with oxygen, which includes both homogenous reaction and heterogeneous reaction. The effect of equivalence ratio (ER) is studied. It is found that all the products have same tendency with the increase of ER. H2 and CH4 change linearly with ER; CO and CO2 change cubically with ER. This is because the mechanism of formation of CO and CO2 is more complex than that of H2 and CH4. H2 and CH4 are consumed by O2, so they tend to decrease with the increase of ER, whose value corresponds to the amount of O2 fed. For CO and CO2, howeve...