METHOD FOR PURIFYING NITROGEN OXIDE IN WASTE GAS

摘要

PURPOSE:To efficiently purify nitrogen oxide in waste combustion gas. CONSTITUTION:Nitrogen oxide in waste combustion gas is selectively reduced and purified by hydrocarbon under the presence of oxygen by using a selective reduction catalyst. In the method, the selective reduction catalytic layer is divided into >=2 in the flow direction of waste gas. Paraffin of >=3C or olefin of >=2C is introduced into the front flow sides of the respective catalytic layers as a selective reducing agent. Thereby the hydrocarbon being the selective reducing agent is made to low concentration with high denitrification effect in the whole region of the catalytic layer. The loadings of hydrocarbon are decreased and the degree of denitrification is enhanced.