石灰石脱硫对循环流化床中N_2O排放浓度的影响  

Limestone Effects on N_2O Emission in CFB Combustors

作　　者：侯祥松[1] 李金平[1] 张海[1] 吕俊复[1] 岳光溪[1] 

机构地区：[1]清华大学

出　　处：《电站系统工程》2005年第3期1-3,共3页Power System Engineering

摘　　要：N_2O是循环流化床锅炉运行时主要的污染物之一,石灰石脱硫会影响循环流化床锅炉中N_2O的生成和排放。石灰石脱硫过程中由于CaO对N_2O的分解的催化作用;能促进HCN向NH_3转化,减少N2O的生成;同时石灰石脱硫生成的CaS可以直接还原N_2O,减少烟气中N_2O的排放浓度。此外,石灰石脱硫产生的床料对喷氨脱氮有催化作用,可使N_2O脱氮后的残留量降低三分之二左右。因而石灰石脱硫能同时降低循环流化床中SO_2和N_2O的排放。N2O is one of the major pollutants emitted from a coal-fired circulating fluidized bed (CFB) boiler and its formation is significantly influenced by the addition of limestone, which is used for desulphurization. During the desulphurization, due to the catalytic effect on N2O destruction played by CaO, which is decomposed from the limestone, HCN is converted into NH3, preventing the formation of N2O. In the same time, the product CaS formed in desulphurization reduces N2O directly in the flue gas. Furthermore, the bed material formed in desulphurization has a catalytic effect on N2O reduction as well when NH3 is injected for NOx reduction, resulting in 2/3 reduction of total N2O emission. Therefore, limestone can be used for simultaneous reduction of SO2 and N2O in a CFB boiler.

关 键 词：石灰石脱硫 N2O 排放浓度 循环流化床锅炉 催化作用 锅炉运行 脱硫过程 直接还原 污染物 CaO NH3 HCN CaS 残留量 SO2 脱氮 烟气 

分 类 号：X511[环境科学与工程—环境工程] TK229.66[动力工程及工程热物理—动力机械及工程]