As individual, business and society become more aware of environmental protection, the denitrification of biomass boilers will be implemented according to the ultra-low emission requirements. Biomass boiler is a new type of boiler using biomass energy as fuel, which has lower sulfur dioxide and nitrogen oxide content in the flue gas emission from the boiler and does not produce waste residue. Therefore, compared with coal-fired boilers, they are more energy-efficient and environmentally friendly. However, with the improvement of national environmental standards for boiler flue gas, coupled with the promotion and implementation of ultra-low emission of boiler flue gas. Biomass boiler denitrification catalyst will be widely used.

The boiler fuel type of biomass, low calorific value and poor feeding uniformity cause drastic temperature changes in the combustion zone, large fluctuations in the initial NOx emission concentration at the boiler outlet, low flue gas temperature, high alkali metal and fly ash content, and its outlet tail gas temperature is similar to the tail gas temperature in the waste incineration industry, which is also around 130~150℃.
The main denitrification catalysts are characterized by ① large differences in furnace chamber temperature, ② high hydrogen content in biomass, ④ low and fluctuating sulfur dioxide and nitrogen oxide concentrations, which are hazardous to SCR catalysts due to the high mass fraction of alkali metals in the soot and the presence of sparks in the dust at high temperatures. The current SNCR denitrification technology can meet the standard of 200mg/Nm3 NOx content in the export tail gas, now the biomass boiler emission standards according to the thermal power industry emission standards, requiring NOx emissions at 100 mg/Nm3 or even lower to 50 mg/Nm3, so the biomass boiler upgrading and retrofitting additional desulfurization and SCR denitrification device has become imperative
Biomass boiler tail gas denitrification process comparison
The current denitrification process is mainly to transform the boiler, take the gas from the coal economizer outlet at 200~240℃, and enter the SCR denitrification system after dry desulfurization and dust removal.