Waste incineration will produce a large amount of harmful gases during combustion, among which nitrogen oxides are the main pollutants in the atmosphere. Among various nitrogen oxides removal (denitrification) technologies, selective catalytic reduction (SCR) technology is the most widely used. Its core It is a denitration catalyst. In the waste incineration power generation industry, due to the particularity of its flue gas, the existing common medium and high temperature denitration catalysts in China cannot be applied, and it has been monopolized by foreign products for a long time.

In the waste incineration industry, the current nitrogen oxide emission standard is generally 200-250 mg/Nm3. The SNCR denitration process is generally used, and the reducing agent is directly injected into the furnace for selective non-catalytic reduction denitration, which can meet the emission requirements. With the increasingly stringent national environmental protection requirements, various local governments have also proposed more stringent exhaust emission standards. The current SNCR denitrification can no longer meet the requirements, and will cause the ammonia escape from the incinerator outlet to exceed the standard. At present, NOx in the exhaust gas of the waste incineration industry increases Standard transformation adopts SCR denitration technology.

Comparison of incinerator tail gas denitrification processes

The tail gas of the waste incinerator is reduced to 130~150℃ after dry/semi-dry deacidification (sulfur) and bag dust removal. At present, the activation temperature of medium and low temperature denitrification catalysts on the market is above 180℃, so it is necessary to supplement the exhaust gas. The denitrification can be carried out after the temperature rises. The general process route is to add a GGH heat exchanger, and then heat the heat source to increase the temperature of the flue gas to about 200 °C for denitrification. Therefore, the process is complicated, the investment in equipment engineering is large, and the operation cost of temperature rise is high. very high.

The temperature activity range of the ultra-low temperature denitrification catalyst is 130~180℃, which can be directly denitrified under the condition of 150℃ exhaust gas temperature after bag dust removal, no need for supplementary combustion heat exchange to heat up, the process is simple and no heating cost, and basically has no impact on the original system , and the flue gas resistance is low, which can meet the ultra-low and ultra-clean emission requirements.