Laboratory evaluation of NH3 injection technology to reduce HCl emissions from incinerators

A laboratory-scale experimental study is conducted to investigate the fundamental properties of NH3-HCl reaction in a simulated incinerator duct system. The NH3 injection technology is a dry HCl removal process which produces solid products. The test results showed that under typical incineration operation conditions, the outlet concentration of HCl can meet the emission standards for incinerators in Taiwan. An excessive injection of NH3 above stoichiometric requirement may not lead to the NH3 slip problem. This is because that the excessive amount of NH3 would probably diffuse onto the product particles. However, the enhancement of NH3 utilization is economically not feasible. The outlet concentrations of HCl and NH3 are almost independent of their inlet concentrations for residence time longer than I second. Moisture content and the NH3/HCl injection ratio are two of the most important factors which affect the HCl removal and NH3 utilization.