| Abstract:Chemical recovery boiler is a key equipment of pulp production line, its main function is to produce Na2CO3 and Na2SO4 using in the kraft pulping through the reaction of carbon, sodium, and sulfur in the black liquor. It has to control the temperature strictly, therefore chemical recovery boiler can be considered as a chemical reaction device. Due to the lower furnace combustion temperature, there is little chance to generate “thermal” NOx by combustion of N in the air, therefore, the NOx emission in the flue gas is due to the combustion of the N in the fuel. At present, black liquor as fuel for biomass power generation has become a consensus, but under the current operation, it is impossible to meet 100 mg/m3 NOx emission specification of GB 13223—2011 Emission standard of air pollutants for thermal power plant for chemical recovery boiler. This will cause big confusing for getting new chemical pulping projects approval. From the point of view of encouraging cleaner production, recycle economy and fully utilization of the resources chemical recovery boiler should not be defined as biomass power generation boiler, it should follow the standard (2) of the coal-fired boilers in the standard of GB 13223—2011 or even slightly lower standard. |
