3种炭供热体材料的燃烧特性及反应动力学分析

Investigation on combustion characteristics and reaction kinetics of charcoal-fueled heating units

为了考察加热非燃烧型烟草制品用潜在炭供热体材料的燃烧特性，分别以淀粉基水热炭、竹炭和松木炭为研究对象，利用扫描电镜、元素分析、X射线衍射和热重分析等方法研究了3种炭供热体材料的微观形貌、元素组成、碳微晶结构以及空气气氛下燃烧特性和动力学参数等。结果表明：①3种炭材料中淀粉水热炭石墨化程度最小，竹炭次之，木炭最高；随着石墨化程度的增大，炭材料的热失重温度区间向高温偏移。②淀粉水热炭着火点温度（270℃）和燃尽温度（535℃）较低，可以作为供热体引燃用炭材料；松木炭着火点温度和燃尽温度最高，竹炭次之，两者持续燃烧性较好。③淀粉水热炭在200℃～350℃温度范围内有明显的质量损失，该段燃烧动力学属于1.5级化学反应控制；在温度高于350℃以后，3种炭材料的燃烧过程符合三维扩散控制模型。

In order to find potential heating sources for heat-not-burn tobacco products, starch-based hydrothermal carbon （HTC-S）, bamboo charcoal and pine wood charcoal were experimented. Their surface microstructures, chemical compositions, micro-crystallite structure, combustion characteristics and kinetic parameters at the presence of air were studied with scanning electron microscopy, elemental analysis, X-ray diffraction spectroscopy and thermogravimetric analysis separately. The results indicated that： 1） HTC-S had the lowest graphitization degree, wood charcoal had the highest. With the increase of graphitization degree, the thermal mass loss of charcoal shifted towards a higher temperature region. 2） The ignition point （270 ℃） and burnout point （535 ℃） of HTC-S were relatively lower, which enabled it to be used as an ignition fuel in a heating unit. With higher ignition and burnout temperatures, pine wood charcoal and bamboo charcoal showed better burning retention. 3） For HTC-S, significant mass loss happened in the region of 200 ℃-350 ℃, where the combustion reaction kinetic was dominated by chemical reaction order of 1.5. However, above 350 ℃, the combustion processes were in compliance with the 3-D diffusion model.