Removal of Hydrogen Sulfide from a Steam-Hydrogasifier Product Gas by Zinc Oxide Sorbent

Abstract

Removal of H2S by a commercially available zinc oxide sorbent was studied using a packed-bed reactor for desulfurizing the gas produced from steam-hydrogasification of carbonaceous materials. Experimental runs were conducted to monitor sulfur removal efficiency and H2S breakthrough time for the operation variables such as reaction temperature, steam content, space velocity, inlet H2S concentration, and sorbent particle size. For the inlet gas with 45 vol % steam content, the initial sulfur removal efficiency exhibited a maximum around 636 K. Varying the steam content of inlet gas affected the equilibrium of sorbent sulfidation in a reversible way, leading to the decrease of sulfur capture capacity of the sorbent as the steam content increased. Increasing the space velocity from 8 000 to 24000 h-1 decreased sulfur capture capacity significantly, indicating the deterioration of gas−solid contact in the reactor at the increased gas flow rates. Inlet H2S concentration was varied from 100 to 800 ppmv to reflec...