Denitration waste heat boiler Desulfurization is followed by denitration, and then waste heat recovery is carried out. The content of SO2 in the flue gas after desulfurization is low, which is conducive to reducing the filling amount of denitration catalyst and extending the service life of the catalyst; Desulfurization products belong to conventional solid wastes, which are easy to treat and can also be used as resources.

In the actual engineering application, dry desulfurization was adopted in the early stage, and the temperature drop was very small, far lower than that of semi dry desulfurization and wet desulfurization, and there was no temperature drop in the whole set except for heat dissipation, which could ensure the temperature of flue gas during denitration and be conducive to the next step of waste heat recovery; The moving bed desulfurization process is adopted, and a special desulfurizer is developed, which has high desulfurization efficiency and low pressure; The moving bed dry desulfurization has excellent dust removal function, which can greatly reduce the dust content in the flue gas, meet the requirements of the national standard, and no additional dust removal device is necessary; The flue gas entering the waste heat boiler has been purified, which greatly reduces the boiler corrosion and extends the boiler life; Low temperature denitration is adopted, and imported porous excellent low temperature denitration catalyst is selected. The denitration efficiency of the same filling amount is about twice that of ordinary denitration catalyst, and the filling amount of denitration catalyst is small; The service life can reach more than 3-4 years. The ammonia injection system is designed by CFD simulation, which greatly improves the effectiveness of the catalyst and reduces the ammonia escape; The exhaust gas temperature after waste heat recovery is high, and the flue gas is returned to the original chimney after treatment, so that the original chimney is always in a hot standby state, and a large amount of white smoke is also avoided to be discharged at low altitude; The power off self opening system of underground original flue gate is set to ensure the safety of coke oven under special working conditions;

The whole unit has only three main equipment, namely, desulfurization tower, denitration reactor and waste heat boiler. The number of equipment is small, which can be flexibly arranged, greatly reducing the floor area and investment cost, making it feasible to build new integrated units or expand desulfurization and denitration under the original waste heat recovery.