Investigation on effects of Na2CO3 on selective non-catalytic reduction of NOx
-
Graphical Abstract
-
Abstract
The effects of Na2CO3 addition on the selective non-catalytic reduction (SNCR) using ammonia solution or urea solution were investigated in a quartz tube reactor. The experimental results show that the addition of a little amount of Na2CO3 can improve the NOx reduction efficiency effectively in the low-temperature region, shift the NH3 slip curves to a lower temperature, and reduce the HNCO slip largely in the process of urea-SNCR. Also, the addition of a little amount of Na2CO3 can reduce N2O emission remarkably, especially for the course of urea-SNCR. It is found that the addition of Na2CO3 increases the conversion efficiency of HNCO to NH3 markedly in the thermal decomposition gases of urea, which is the main reason leading to the large reduction of HNCO slip and N2O emission in the process of urea-SNCR. Under the same Na2CO3 addition amount, the promoting effect on NOx reduction efficiency is more evident at lower ammonia-NOx ratio, and the promotion to the width of NOx reduction temperature window is more effective at higher ammonia-NOx ratio, and also the promoting effect on DeNOx efficiency is more obvious at lower oxygen content.
-
-
DownLoad: