The denitrification process in the cement industry is mainly used to reduce the emissions of nitrogen oxides (NOx) generated during cement production. Here are some common cement plant denitration processes:
Selective catalytic reduction (SCR) denitrification：
This is one of the most mature denitrification processes at present.
The catalyst is used to catalyze the reaction between ammonia water and NOx at high temperature, and NOx is reduced to nitrogen and water vapor.
SCR denitrification has the advantages of high efficiency, stability and low emission concentration, but requires the use of catalysts and large equipment investment.
SCR technology has been successfully operated in electric power, steel, chemical industry and other industries for many years, and is the main technology to achieve ultra-low emission of denitrification, and there are also successful application cases in cement industry.
Selective non-catalytic reduction (SNCR) denitrification：
By adding urea or ammonia into the cement combustion furnace, the nitrogen oxides react with the nitrogen oxides in the furnace, and the nitrogen oxides are reduced to nitrogen gas and water.
SNCR denitration efficiency is generally between 40% and 50%, and the cost is low, which is suitable for small and medium-sized cement enterprises.
However, due to its strict temperature requirement and no catalyst, the denitrification efficiency is lower than that of SCR.
Low nitrogen combustion technology：
The nitrogen oxides are reduced to N by chemical reduction reaction of reducing gases such as H2, CH4 and CO generated in the reduction combustion zone with nitrogen oxides generated during cement formation Class 2 non-polluting emissions.
The denitrification efficiency is generally between 10% and 20%, and the cost is low, but the requirements for reaction conditions and combustion equipment are high.
When selecting the denitrification process, it is necessary to make comprehensive consideration and selection according to the actual situation of the cement plant, such as equipment status, emission requirements, investment budget, etc. At the same time, all kinds of technologies have corresponding advantages and disadvantages, so it is necessary to choose the appropriate process route with more specific working conditions and on-site construction conditions of cement kiln.