循环灰对N_2O热分解催化作用的研究

Catalytic Activity of Circulating Materials from CFB Boilers for the Thermal Decomposition of N_2O

N2O是循环流化床锅炉产生的主要污染物之一,在循环流化床中,高浓度的循环灰能促进N2O的热分解.本文利用固定床反应器研究了循环灰及其主要组分对N2O热分解的催化作用,实验结果表明,循环灰对N2O热分解的催化作用与循环灰的组成和比表面积分布有关.循环灰中的Al2O3,CaO,Fe2O3和Fe3O4是促进N2O热分解的活性成分,能促进N2O的热分解,循环灰的比表面积也是影响其对N2O热分解催化能力的重要因素.在循环灰作用下,N2O热分解会通过副反应生成少量的NO.

N2O is one of pollutants from circulating fluidized bed （CFB） combustion. In the freeboard of CFB boilers, the bed circulating materials of high concentration usually show catalytic activity for the thermal decomposition of N2O. The catalytic activity of bed circulating materials and its component for the thermal decomposition of N2O was investigated in a fix bed reactor. The N2O concentration of exhaust gas was compared with that of different bed materials. Results show that the catalytic activity mainly depends on the chemical composition and distribution of cumulative pore area. Al2O3, CaO, Fe2O3and Fe3O4are all active catalyst for the decomposition of N2O. A small quantity of NO is formed during this process.