利用污水污泥煅烧水泥对氮氧化物排放的影响

Effect of Cement Calcination with Municipal Sewage Sludge on Nitrogen Oxide Emission

通过XPS、DSC-TG分析及NOx检测等方法,研究利用城市生活污水污泥煅烧水泥对NOx排放的影响.研究结果表明:挥发分含量及氮含量高于煤的污水污泥燃烧过程出现了两个明显的放热峰;相同氮含量的污水污泥与煤在900℃富氧条件下燃烧,前者产生的燃料型NOx的浓度低于后者;水泥生料会促进污水污泥和煤在900℃氧化气氛下燃烧生成燃料型NOx;煤掺入污水污泥后混烧,生成的燃料型NOx有所减少;掺入等量干基污泥煅烧水泥,含较高水分的污泥所生成的燃料型NOx较少;综合能耗等因素,煅烧污泥的含水率在10%左右为宜.

In this paper, the effect of cement calcination with municipal sewage sludge on the nitrogen oxide （NO＋） emission was investigated by means of XPS, DSC-TG and NOx monitoring. The results indicate that （ 1 ） two distinct exothermic peaks appear during the combustion of sewage sludge of which the volatiles and nitrogen contents are higher than those of coal ; （2） the fuel-NOx produced by the combustion of sewage sludge in oxidizing atmosphere at 900 ~C is less than that produced by the combustion of coal under the same conditions; （3） cement raw material accelerates the emission of fuel-NOx by the combustion of sewage sludge or coal in oxidizing atmosphere at 900 ℃ ; （3） the addition of sewage sludge in coal helps to reduce the emission of fuel-NOx ; （4） dry sludge with equal amount but higher moisture content helps to produce less fuel-NOx ; and （5） comprehensively speaking, the appropriate moisture content of sewage sludge is about 10%.