油泥焦流化床燃烧NO_x释放特性及控制

为无害化处理油泥焦,采用小型流化床反应器,研究了不同温度、不同颗粒粒径下油泥焦的燃烧氮氧化物释放特性,并借助空气分级燃烧技术降低NO_x排放。SEM电镜和物理吸附结果表明,油泥焦颗粒表面结构致密、孔道稀疏,不利于其内部有机质充分燃烧。燃烧实验结果表明,油泥焦燃烧产生的NO_x主要来源于焦炭氮,来自挥发性氮的较少。适当降低燃烧温度、减小颗粒粒径既能保证油泥焦充分燃烧,又能抑制氮氧化物排放。实施空气分级燃烧时,通过优化过量空气系数、二次风比例和二次风入口位置,能够获得显著的NO_x减排效果,同时可以有效抑制飞灰产生,有助于烟气终极处理。

Emission characteristics and control of NOx from oil sludge char fluidized bed combustion

To realize innocent treatment of oil sludge char, a lab-scale fluidized bed reactor was employed to study combustion of the oil sludge char in the term of nitrogen oxide emission characteristics at various different temperatures and particle sizes, as well as the reduction in the emission of NO_x by using air-staging combustion technology. According to the results of scanning electron microscope and physical adsorption analyses of oil sludge char, the surface structure of the sludge char is dense and its pores are sparse, which is not conducive to the full combustion of organic matter inside. The combustion experiments of oil sludge char show that the generated NO_x is mainly from coke-N and less from volatile-N. Reduction in the combustion temperature and the particle size to a proper extent can not only ensure full combustion of oil sludge char, but also inhibit NO_x emission. When conducting air-staging combustion, by optimizing the excess air ratio, proportion of secondary air and position of secondary air inlet, the NO_x emission is considerably reduced, and meanwhile the generation of fly ash is restrained, and these are beneficial for the ultimate treatment of the flue gas.