O2/CO2气氛下煤焦燃烧实验研究

在热重分析仪上进行了不同气氛下徐州烟煤及其煤焦的燃烧实验，分析了O₂浓度、CO₂浓度和颗粒粒径等参数对其燃烧特性的影响；并对其进行了燃烧动力学分析。结果表明，气氛对煤和煤焦开始脱挥发分的时间影响不明显，但对其燃烧速率和燃尽时间影响很大；高浓度CO₂使煤焦的燃尽时间延长。气氛没有改变煤焦的燃烧反应动力学机理。O₂浓度提高、CO₂浓度降低和煤粉细化均可改善燃料的燃烧特性，但对煤焦的改善程度比对烟煤的小。扫描电镜（SEM）结果显示，同等O₂浓度下O₂/CO₂气氛较空气气氛煤灰表面孔隙结构更丰富。

Experimental investigation on coal and char combustion in O_2/CO_2 mixture

Thermogravimetric analyzer (TGA) was employed to evaluate the combustion behaviors of Xuzhou bituminous coal and its char in different atmospheres, and the effects of O_2 concentration, CO_2 concentration and particle size on the combustion characteristics were analyzed. Results show that the atmosphere does not affect the beginning time of devolatilization, but significantly affect the combustion rate and the burnout time. Higher concentration of CO_2 can increase the burnout time obviously. However, the atmosphere does not influence the combustion kinetics mechanism. Increasing the O_2 concentration, decreasing the CO_2 concentration and reducing the sample particle size are beneficial to the improvement of the combustion characteristic, while the improvement degree for coal is more obvious than that for char. SEM analysis indicates that the ash surface after O_2/CO_2 combustion is looser and more porous than that after air combustion.