燃煤固硫剂的燃烧特性及动力学研究

Combustion Characteristic and Kinetic Parameter of Sulfur-fixing Agent in Coal Combustion

以太原烟煤为研究对象,考察电石渣、赤泥单独作主固硫剂时固硫率的差异,结果表明,电石渣较赤泥好。并以电石渣为主固硫剂,比较4种单一助剂对固硫效果的影响,其中添加助剂C为8%时固硫效率提高的幅度最大,高达15%。以电石渣、电石渣+赤泥复配为主固硫剂,添加正交试验所确定的最佳助剂配比,均不同程度的提高了固硫效率,固硫率分别为73.77%、64.87%。最后利用热重分析仪考察了不同固硫剂对固硫效果的影响,重点从煤样的燃烧特性和动力学参数进行研究。研究结果表明:添加不同主固硫剂和助剂的煤样其热重曲线的趋势走向与原煤基本一致。添加固硫剂后着火点并没有太大的变化,燃烧过程均变为两段燃烧,且第二段燃烧均在较高温度下,燃烬温度较高,燃烬时间明显延长。从动力学角度分析,在低温区域内,不管掺入何种固硫剂其活化能均比原煤低温段的活化能明显降低,说明固硫剂的加入使反应向着有利的方向进行。

Taiyuan bituminous coal is selected as the research object. The difference of the carbide slag and red mud are studied when they are chosen as the main sulfur-fixing agent, the result shows that carbide slag has an advantage over red mud. With carbide slag as the main sulfur-fixing agent, the influences of four kinds of additives on sulfur-fixing efficiency are compared. 8% of additive C has the greatest efficiency, with sulfur-fixing efficiency increased by 15%. Carbide slag as well as the compound of carbide slag and red mud is used as the main sulfur-fixing agent, adding the best fertilizer ratio of additives which determined by the orthogonal experiment can improve sulfur-fixing efficiency, which are up to 73.77% and 64.87%. The effects of various sulfur-fixing agents are investigated by thermogravimetric analysis with focus on combustion characteristic and kinetic parameter. It finds out that the thermogravimetric cures of samples which are added different sulfur- fixing agents and additives almost keep the same with raw coal＇s. Ignition .temperature is not changed so much even if adding sulfur-fixing agent. While the combustion process becomes into two-section combustion, the second combustion process of them are under higher temperature. At the same time, the burnout temperature is higher and the burning time is prolonged clearly. From the point of kinetics, in low temperature area, no matter which kind of sulfur-fixing agent is mixed into, its activation energy is significantly lower than the raw coal＇s, indicating that sulfur-fixing agents drive the reaction toward favorable direction.