Effect of gas type on the fluidization and discharge characteristics of the pulverized coal

► Gas viscosity has a greater effect on fluidization properties than gas density. ► H2 can easily penetrate the coal bed and form a bubbling fluidization regime. ► CO2 can hardly fluidize the pulverized coal for its strong gas adsorption. ► The higher solid discharge rate corresponds to the more effective fluidization. ► The solid discharge rates can be predicted well by Nedderman's model.