Halide compound removal from hot coal-derived gas with reusable sodium-based sorbent

The hydrogen chloride removal characteristics of molded sodium-based sorbents containing sodium aluminate (NaAlO2) were examined in simulated hot coal-derived gas. The reaction rate and absorbing capacity of the molded sorbent were lower in comparison to the particle sorbent, and the ability to remove hydrogen chloride to below 1 ppm lasted only a short time. For improved reactivity of molded sorbent, γ-alumina powder was added as supporting material in the process of NaAlO2 formation. This sorbent had a higher surface area, reaction rate and absorbing capacity, and the removal ability to below 1 ppm was improved. Reaction modeling of the sodium-based sorbents indicated that the cross-flow type reactor was suitable for continuous removal of hydrogen chloride in large-scale cleanup systems for coal-derived gas.