城市污泥与煤或玉米秆混烧特性及动力学研究

利用热重分析法对城市污泥分别与煤或玉米秆混烧特性进行研究。结果表明:城市污泥燃烧过程存在挥发分析出和燃烧阶段及挥发分和固定碳燃尽阶段两个主要失重区间。城市污泥着火温度低,燃烧温度范围宽,失重速率低,燃尽性能特性指数Cb和综合燃烧特性指数SN性能均低于煤和玉米秆。掺混煤或玉米秆燃烧会改善城市污泥的燃尽特性和综合燃烧特性。采用积分法(Coats-Redfern方程)计算各阶段燃烧反应的动力学参数。混合试样中污泥含量增加,挥发分燃烧阶段活化能减小,固定碳燃烧阶段活化能增加。

THE CO-COMBUSTION CHARACTERISTICS AND KINETICS OF SEWAGE SLUDGE AND COAL OR CORN STALK

The co-combustion behaviors of sewage sludge and coal or corn stalk were studied by thermogarvimentic analysis.The results show that during the process of sewage sludge combustion,there are two obvious temperature zones that the sludge weight loses promptly,which correspond to two stages of volatilization and combustion of volatile and burn-out of residue volatile and fixed carbon.Sewage sludge has several characteristics such as low ignition temperature,wide range of burning temperature,low combustion rate.In addition,both the indexes of burn-out characteristics and combustion characteristics of sewage sludge are lower than those of coal and corn stalk.The addition of coal or corn stalk could remarkably improve the burnout and combustion performance of sewage sludge.Coats-Redfern equation was used to calculate the kinetic parameters of different stages.When the rate of sewage sludge in the blends increases,the activation energy decreases in the combustion stage of volatile,but increases in the combustion stage of fixed carbon.