中药渣因含水率高而处理困难,将中药渣经水热处理后有较好的应用前景。以中药渣为研究对象,采用水热处理获取中药渣水解炭,通过工业分析及元素分析、热重分析及动力学分析研究了水热处理对中药渣水解炭特性的影响。结果表明:随着水热处理温度升高,中药渣水解炭的固定碳及元素C含量、燃料比(水解炭的空气干燥无灰基固定碳与挥发分的质量比)及高位发热量增加,挥发分、元素H及元素O含量明显降低,nO/nC及nH/nC逐渐降低,水解炭性质接近一般动力煤性质。热重分析发现热解过程中,280℃下形成的水解炭在160℃~300℃和300℃~500℃出现较明显的双峰失重峰,其余水热处理温度下形成的水解炭仅在275℃~400℃出现一个极明显失重峰。随着水热处理温度的升高,水解炭热解活化能由69.56kJ/mol降至40.55kJ/mol。水解炭燃烧过程主要经历四个阶段,180℃~295℃主要是小分子挥发分热解阶段,其活化能为63.65kJ/mol~105.02kJ/mol;295℃~390℃主要是小分子挥发分主要燃烧阶段,其活化能为10.78kJ/mol~35.76kJ/mol;390℃~410℃主要是大分子挥发分析出与燃烧阶段,其活化能为117.08kJ/mol~201.61kJ/mol;410℃~520℃主要是固定碳与焦炭的燃烧以及少量矿物与无机化合物的热分解阶段,其活化能为22.18kJ/mol~92.10kJ/mol。随着水热处理温度升高,水解炭燃烧同一阶段的指前因子与活化能变化趋势一致。水解炭的可燃性指数、着火指数以及综合燃烧指数随着水热处理温度升高、水热时间增加以及固液比的增大而减小,固液比为1g∶15mL且在220℃下水热1h获得水解炭的燃烧性能较好,综合燃烧指数为3.55×10-10/(min2·℃3),可为高湿固废水热燃料化的应用提供参考。

Chinese herbal residues are difficult to handle due to their high moisture con-tent, but they have good prospects for application after thermal treatment. In the study, hydro-chars made from Chinese medicinal residue were obtained by hydrothermal carbonization process. The effects of hydrothermal carbonization process on the characteristics of hydrochars were inves-tigated through proximate and ultimate analyses, thermogravimetric analysis, and kinetic analy-sis. The results show that with the increasing of hydrothermal carbonization temperature, the contents of fixed carbon, element C, the fuel ratio and high calorific value of hydrochar increase with the increasing of hydrothermal carbonization temperature, while the contents of volatile matter, and element H and O in hydrochars decrease significantly. Additionally, nO/nC  and nH/nC  gradually decrease to levels close to those of typical steam coal. The thermogravimetric analysis reveal that during the pyrolysis process, hydrochar formed at ℃ exhibits two signifi-cant peaks of weight loss at ℃ and ℃, respectively, while other hydro-chars exhibits only one significant weight loss peak at ℃. With the hydrothermal car-bonization temperature rising, the activation energy of the hydrochars pyrolysis decreases from 69.56 kJ/mol to 40.55 kJ/mol. The combustion process of hydrochars mainly undergo four sta-ges: from ℃ to ℃, primarily the pyrolysis stage of small molecular volatiles, with acti-vation energy of 63.65 kJ/mol to 105.02 kJ/mol; from ℃ to ℃, primarily the combus-tion stage of small molecular volatiles, with an activation energy of 10.78 kJ/mol to 35.76 kJ/mol; from ℃ to ℃, mainly the release and combustion stage of large molecular vola-tiles, with an activation energy of 117.08 kJ/mol to 201.61 kJ/mol; and from ℃ to ℃, primarily the combustion of fixed carbon and char, along with the thermal decomposition of a small amount of minerals and inorganic compounds, with an activation energy of 22.18 kJ/mol to 92.10 kJ/mol. With the hydrothermal carbonization temperature rising, the varying trend of pre-exponential factor is consistent with that of activation energy at the same stage of hydrochars combustion. The flammability index, ignition index, and combustion index of Chinese herbal residue hydrochars decrease with increase in hydrothermal temperature, hydrothermal duration, and the solid-to-liquid ratio. The hydrochars obtained at solid-to-liquid ratio of g∶15 mL and hydrothermally treated at ℃ for h exhibit better combustion performance, with a compre-hensive combustion index of 3.55×10-10/(min2·℃3). It can provide a reference for the applica-tion of hydrothermal fuelization of high-moisture solid waste.