The effect of H2O on the use of ethanol as reductant in the SCR system

Abstract

In this experimental study, effects of H 2 O on the use of ethanol as reducing agents were investigated on the Ag-Pt-W-Ti/Cordierite catalyst. Ag-Pt-W-Ti/Cordierite catalyst was synthesized using the impregnation method for selective catalytic reduction (SCR) of NO x . To investigate the effects of H 2 O addition on the NO x conversion ratios, tests were carried out at 200-270 ° C under 30000 h -1 GHSV using three different reductants (ethanol, 5% H 2 O -95% ethanol, 10% H 2 O -90% ethanol). The catalytic activity of the catalyst increased with increase in exhaust gas temperature. The highest NO x conversion ratio was 89.9% at 270 o C with ethanol. The tests showed that when the H 2 O content of the reductant increased from 5% to 10%, the NO x conversion ratios significantly decreased at temperatures below 240 o C. NO x conversion ratios enhanced as engine load increased.