Denitrification and catalysts
In dependence of the temperature profile thermal processes may cause the formation of nitrogen oxides from nitrogen contents in the combustion air. Apart from other substances, nitrogen oxides are responsible for acid rain which is a fair reason to take appropriate measures to reduce their content within flue gas flows. In this context, Envirotherm resorts to the selective catalytic reduction (SCR) technology. By the use of catalysts in conjunction with an added reduction agent (urea or ammonia) nitrogen oxide is converted into nitrogen, water and carbon dioxide at temperatures from 200 to 450 °C.
In dependence of the location of the denitrification unit (i.e. upstream or downstream of the dedusting stage) a difference is made between high-dust and low-dust applications.
Envirotherm does not only offer the SCR process chain as a complete solution but, if necessary, will even deliver the respectively required catalysts from China.
Depending on the defined task two products can be delivered:
SCR catalysts designed to eliminate nitrogen oxides will ensure a selective removal of NOx as a pollutant and a minimization of non-desired secondary reactions. Compared to non-catalytic technologies, the “ammonia slip“ level is significantly lower and, hence, causes less harm to the environment.
ZERONOX® D catalysts are mainly used for dioxin and furan reduction in conjunction with denitrification procedures. They have been applied at many waste incineration plants in Europe, Asia and North America.