Effect of Co-combustion of Multiple Additives with Coal on NO Removal

Abstract

Denitrification experiments of co-combustion of coal and additives were carried out in a horizontal tube furnace. The results showed that calcium acetate limited the production of NO 2 . The optimum calcination temperature of CTAB-Zr-TiO 2 was 673 K. The denitrification efficiency reached up to 72.27%, and desulfurization efficiency reached 83.03% when corncob, calcium acetate, and CTAB-Zr-TiO 2 were added. Corncob, calcium acetate, and CTAB-Zr-TiO 2 all promoted coal combustion. The specific surface area of CTAB-Zr-TiO 2 (55.50 m 2 /g) was the largest, which was more than 4.5 times that of pure TiO 2 (12.20 m 2 /g). The denitrification process in the co-combustion of coal with multiple additives included a homogeneous reaction and heterogeneous reaction. The homogeneous reaction was that NO and NO 2 were reduced to N 2 by reducing gases produced in combustion. The heterogeneous reaction involved the reduction of NO and NO 2 by coal char. The additives increased the specific surface area of the coal char and enhanced the activity of the heterogeneous reduction of NO and NO 2 . At the same time, the catalysis of alkali metal oxides in corncob and CTAB-Zr-TiO 2 promoted the heterogeneous reduction of NO and NO 2 by the coal char.