Effect of additives on the compressive strength and denitrification performance of fly ash catalysts

Abstract

AbstractFly ash is a massive industrial waste. Owing to the abundance of oxides, such as SiO2 and Al2O3, fly ash is considered a high value material. In this study, we assessed its application in the industrial deoxidation of nitrogen oxides, a major environmental pollutant, using the selective catalytic reduction technology. Fly ash was used as the main raw material and bentonite was used as an auxiliary material in the catalyst. Silica sol, starch, and glycerol were added to improve the compressive strength and denitrification performance of the catalyst. The use of silica sol as a binder improved the compressive strength of the catalyst due to the production of Si–O–Si. In addition, the availability of acidic functional groups could improve the denitrification performance of the catalyst. The optimal dosages of the additives were as follows: 6% silica sol, 6% starch, and 5% glycerol. Under these conditions, the catalyst formation was the easiest, the cracks were the least, the compressive strength of the catalyst reached 1434 kPa, and the denitrification performance improved. The findings presented here are relevant for the development of an economical and practicable solution for tackling environmental pollution caused by nitrogen oxides.