Desulfurization of High-temperature Coke Oven Gas by Using Zinc-bearing Dust Additive in Coking Process: Experimental and Simulation
炼焦过程利用含锌粉尘实现高温焦炉煤气脱硫的实验与模拟

Desulfurization of high temperature coke oven gas (COG) by mixing zinc-bearing dust into coking coal has been studied. For simplicity, a mixture of pure powered iron oxide and zinc oxide were used in the experiment to simulate the dust. Thermodynamic calculation and desulfurization experimental results show that in the plastic stage when metaphase is formed, the zinc-bearing dust additive could suppress the evolution of H2S into COG efficiently and in the subsequent contraction stage when coke is formed, zinc sulfide is decomposed to elemental zinc vapor and H2S because of high H2 atmosphere in COG. The elemental zinc vapor reacts homogeneously with H2S to form solid ZnS as COG leaves the carbonization room. Thus the concentration of H2S in COG does not increase and little zinc is left in the coke. Experimental results also disclose that iron oxide in the additive has the effect to retard the release of sulfur into COG and promote zinc to evolve from coke as zinc vapor in the contraction stage.