城市污水污泥与煤混烧的热重试验研究

Thermogravimetric Experiment on Co-firing Characteristics of Coal with Municipal Sewage Sludge

采用热重分析法对1种煤样(C)和2种城市污水污泥(S1和S2)及其混合试样进行了燃烧特性试验研究.结果表明:污泥的失重主要为挥发分的析出与燃烧,升温速率提高有助于污泥的快速处理及热能的利用,但总失重率较小,减量化较差;污泥与煤样的混烧特性从总体上表现为污泥和煤样共同作用的结果,随着污泥所占比例的增加,试样的着火温度逐渐降低;当污泥的掺烧比为25%左右时,综合燃烧性能最好.采用Freeman-Carroll微分法确定污泥与煤混烧过程中化学动力学参数,结果显示污泥在温度较低时更易于反应,而煤则表现出相反的性质.根据对不同掺烧比下污泥燃烧性能参数及化学动力学等方面的分析,得出污泥S2更适合燃烧处理.

Combustion characteristic experiments were respectively performed for one coal sample（C）, two municipal sewage sludge samples （$1, $2） and their mixtures using thermogravimetric analysis. Results show that the sludge weight loss mainly results from the separation and combustion of volatile compo- nents. Raising the heating rate may help to speed up the sludge disposal, but may decrease both the total weight loss rate and the quantity reduction effect. The co-firing performance of sludge with coal generally expresses the joint action of both the fuels; with the increase of sludge ratio, ignition temperature of the mixture reduces gradually; the comprehensive combustion performance index reaches the maximum at a sludge ratio of 25%. Besides, the kinetic parameters obtained by using the Freeman-Carroll differentiation prove the sludge to be more active at low temperatures, while the coal behaves in an opposite way, Based on analysis of combustion characteristics and chemical kinetics of sludge at different blending ratios, the combustion treatment is believed to be more suitable for sludge $2.