焦油对生物质气化再燃还原NO的影响

采用配制含焦油模型化合物的生物质气的方法,实验研究了焦油的加入对生物质气化再燃还原NO的影响.模拟的生物质气化气由H2、CH4、CO、CO2、N2构成,并选择了苯、甲苯、苯酚和苯乙烯作为焦油模型化合物.实验在电加热的刚玉管流反应器中进行,实验温度在900～1,400,℃之间.研究了反应器入口焦油含量、氧气浓度、NO初始浓度、反应停留时间及反应温度等因素对还原NO的影响,分析了含焦油的生物质气化再燃特性.证实了焦油有助于提高生物质气化气还原NO的效率;含焦油的生物质气化再燃的最佳当量比在1.20～1.65之间,并且随着NO初始浓度的增加及停留时间的延长,NO还原效率逐渐增加;高温下,焦油含量较高时,有炭黑生成.

Effect of Tar on NO Reduction by Biomass Gasification Syngas Reburning

An experimental study on the effect of biomass gasification tar on NO reduction by biogas reburning has been performed in a ceramic flow reactor heated by an electric furnace. The biogas was composed of H_2,CH_4,CO,CO_2 and N_2,and the four tar model compounds were benzene,toluene,phenol and styrene. The reactor temperature was between 900 ℃ and 1 400 ℃. The influence of inlet content of tar,oxygen concentration,NO concentration,residence time and reactor temperature were studied to analyse the characteristics of biomass gasification-reburning. The results indicate that tar is helpful to increase NO reduction efficiency. Local equivalence ratio is an important parameter for NO reduction,and high NO reduction efficiency can be realized when bulk equivalence ratio varies between 1.20 and 1.65. NO reduction efficiency increases gradually with the rise of NO concentration and residence time. Soot forms at high temperature and high tar content.