Effect of Hydrogen Separation on Coal Char Gasification with Subcritical Steam Using a Calcium-Based CO(2) Sorbent

[Image: see text] Coal char was gasified using subcritical steam with/without a CO(2) sorbent (CaO) and/or a hydrogen separation membrane (palladium-23% silver) in a batch/semibatch autoclave reactor to investigate the kinetics in terms of the effect of hydrogen separation at 590–650 °C and 1.9–2.4 MPa in order to support a hydrogen production process of the HyPr-RING method. CO(2) sorption by CaO affects the production rate of H(2) but scarcely affected the carbon conversion to gas. Hydrogen separation promotes the hydrogen production in spite of the absence of CO(2) sorption. The effect of hydrogen separation on hydrogen yield and carbon conversion was higher than that of CO(2) sorption. A higher gasification temperature increased the hydrogen yield and carbon conversion. Using a first-order reaction form in parallel, the gasification reaction mechanism was explained for the components of the volatile matter and char in coal char. A higher reaction temperature results in an increase of the values of any kinetic constant for subcritical steam gasification of Adaro coal char with/without CaO and/or a hydrogen separation membrane. CO(2) sorption promoted hydrogen production due to the tar from volatiles with the catalytic effects of CaO, whereas hydrogen separation promoted hydrogen production due to char.