Experimental study on underground coal gasification as multicomponent reducing gas for denitrification

In order to reveal the NO reduction behavior of underground coal gasification as multicomponent reducing gas (H₂, CO) in the reburning process, systematic experiments were conducted on the gas reactor test-system. The results show that with the increase of stoichiometric ratio, the denitrification efficiency decreased at the isothermal high temperature. The higher temperature of reburning atmosphere, the higher NO reduction can be achieved with the less stoichiometric ratio. But when the stoichiometric ratio is higher, there exists an optimum temperature for multicomponent gas reburning. The effect of residence time on NO reduction shows that in order to get the optimum denitrification efficiency, it should guarantee enough long residence time as much as possible in the design process of the boilers. The increment of reburning fuel ratio is more beneficial to improve the denitrification efficiency. Experimental results not only are beneficial to the understanding of the characteristics of NO reduction and the organization of good combustion conditions, but also provide a basis for theoretical study.