METHOD OF TREATING GAS CONTAINING NITROGEN OXIDE

摘要

A method of cutting down carbon monoxide and nitrogen oxides that is capable of easy realization of low NOx lowering the emitted NOx value to below 5 ppm and simultaneously realization of low CO. Further, there is provided a method of treating a gas containing nitrogen oxides that is capable of not only realizations of ultralow NOx and low CO but also realization of energy saving. There is provided a method of treating a gas containing carbon monoxide, nitrogen oxides and oxygen and not containing HC, characterized by including the steps of regulating the respective concentrations of carbon monoxide, nitrogen oxides and oxygen in the gas so that these satisfy the formula: ([NOx]+2[O2])/[CO] = 2.0 (2) (in the formula (2), [CO], [NOx] and [O2] respectively represent the concentration of carbon monoxide, the concentration of nitrogen oxides and the concentration of oxygen, provided that [O2]>0); and bringing the gas having the concentration ratios regulated into contact with a catalyst capable of reducing of nitrogen oxides.