METHOD FOR REMOVING NITROGEN OXIDES FROM WASTE GAS

摘要

PURPOSE:To selectively reduce nitrogen oxides contained in a waste gas with gaseous ammonia and remove it from said gas, by bringing the gas into contact with a catalyst obtained by adding a substance contg. a transition-metal phosphate into a porous carrier at high temps. CONSTITUTION:A catalyst is prepared by adding a substance contg. at least one selected from phosphates of trasistion metals into a prorous carrier. A waste gas contg. nitrogen oxides is brought into cotact with this catalyst together with gaseous ammonia at high temps. to remove selectively nitorgen oxides from the waste gas independently of the presence or absence of sulfur oxides.