低温热解提油-半焦燃烧可以实现低阶煤的梯级高效利用，是目前低阶煤高效利用的研究热点。由于热解半焦挥发分低，导致其燃点高、难燃尽，而添加助燃剂是改善低挥发分煤热解半焦燃烧特性的有效途径。采用热重法研究了碱金属（K2CO3）和碱土金属（CaCO3）添加剂对半焦燃烧特性的影响，并利用Kissinger-Akahira-Sunose （KAS）模型对不同条件下的燃烧活化能进行研究。结果表明，半焦着火温度高、燃烧性能差，半焦中碱性矿物质对其燃烧性能有一定催化作用；CaCO3的添加对半焦燃烧特征参数的影响不大，说明其对半焦燃烧性能的促进作用不明显；与碱土金属CaCO3不同，添加碱金属K2CO3能显著降低煤热解半焦的燃点、最大燃烧峰温及燃烧指数；同时随着K2CO3添加比例的增加，半焦表观燃烧活化能显著降低，说明其能明显促进半焦的燃烧反应性；在本研究试验条件下，添加2% K2CO3对改善半焦燃烧性能效果最好，同时采用浸渍法添加K2CO3的分散效果更好，因此相比机械混合方式，浸渍法添加K2CO3更能改善半焦的燃烧特性。

Pyrolysis to recover oil accompanied by semi-coke combustion can realize the high-efficiency and staged utilization of low-rank coal,which is the research hotspot of high-efficiency utilization of low rank coal. However,because of its low volatile,the ignition temperature of semi-coke is high,and it is hard to burn out as well. The addition of flux is a promising method to improve the combustion properties of the hard-to-burn semi-coke with low volatile. In this paper,the effects of alkali（K2CO3)and alkaline metal（CaCO3)on the combustion characteristics of semi-coke were studied by thermogravimetric analysis,and the activation energy of the semi-coke combustion were investigated by Kissinger-Akahira-Sunose（KAS)model. The results show that the semi-coke has the high ignition temperature and low combustion reactivity. The inherent mineral matters in semi-coke have some catalytic effects on its combustion performance. The addition of CaCO3 has little promotion effect on the characteristics of semi-coke combustion,which indicates that CaCO3 does not improve its combustion properties. However,compared with alkali earth metal CaCO3,the addition of K2CO3 obviously lowers the ignition temperature,the peak temperature of combustion and the combustion index. At the same time,with the increase of addition ratio of K2CO3,the apparent activation energy of semi-coke combustion decreases obviously,which means that the addition of K2CO3 can apparently improve the combustion reactivity of semi-coke. 2% addition of K2CO3 shows the best improvement for the combustion of semi-coke in this experiment,and the dispersion effect of adding K2CO3 by impregnation method is better. In addition,the addition of K2CO3 with impregnation is more favorable for the improvement of semi-coke combustion than physical mixture.

0 引言

1 试验

   1.1 试验材料

   1.2 燃烧试验

   1.3 燃烧特征参数的确定

   1.4 动力学参数的确定

2 结果与讨论

   2.1 半焦燃烧特性及内部矿物质的影响

   2.2 添加CaCO3和K2CO3对半焦燃烧特性的影响

   2.3 半焦燃烧反应动力学

3 结论