Effect of mixing on NO removal in the selective noncatalytic reduction reaction process

Abstract

The effect of mixing of NH 3 and NO on the selective noncatalytic reduction (SNCR) reaction was investigated using a bench-scale reactor. Three different experimental conditions were compared for the removal of NO in the bulk gas with NH 3 , a reducing agent, by means of mixing and contacting. The temperature that gave the highest NO removal effi ciency was about 800°C when NH 3 was injected with air or NH 3 was premixed and air was injected. It is suggested that control of mixing of the reducing agent and the injection conditions could be a good way to increase NO removal effi ciency as well as to lower the reaction temperature. When NH 3 was injected with air, the NO removal effi ciency increased with increasing injected air fl ow if the initial NO concentration was low, whereas for high NO concentrations, the NO removal effi ciency slightly increased up to an injected air fl ow rate of 100 ml/min. A proposed mixed-fl ow model can be used as a prediction tool for the NO removal effi ciency covering various conditions of the real SNCR process.