摘要
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,n_(O)/n_(C)及n_(H)/n_(C)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69.56 kJ/mol降至40.55 kJ/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63.65 kJ/mol~105.02 kJ/mol;295℃~390℃主要是小分子挥发分主要燃烧阶段,其活化能为10.78 kJ/mol~35.76 kJ/mol;390℃~410℃主要是大分子挥发分析出与燃烧阶段,其活化能为117.08 kJ/mol~201.61 kJ/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22.18 kJ/mol~92.10 kJ/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1 g:15 mL且在220℃下水热1 h获得水解炭的燃烧性能较好,综合燃烧指数为3.55×10^(-10)/(min^(2)·℃^(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 content,but they have good prospects for application after thermal treatment.In the study,hydrochars made from Chinese medicinal residue were obtained by hydrothermal carbonization process.The effects of hydrothermal carbonization process on the characteristics of hydrochars were investigated through proximate and ultimate analyses,thermogravimetric analysis,and kinetic analysis.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,n_(O)/n_(C)and n_(H)/n_(C)gradually decrease to levels close to those of typical steam coal.The thermogravimetric analysis reveal that during the pyrolysis process,hydrochar formed at 280℃exhibits two significant peaks of weight loss at 160℃-300℃and 300℃-500℃,respectively,while other hydrochars exhibits only one significant weight loss peak at 275℃-400℃.With the hydrothermal carbonization 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 stages:from 180℃to 295℃,primarily the pyrolysis stage of small molecular volatiles,with activation energy of 63.65 kJ/mol to 105.02 kJ/mol;from 295℃to 390℃,primarily the combustion stage of small molecular volatiles,with an activation energy of 10.78 kJ/mol to 35.76 kJ/mol;from 390℃to 410℃,mainly the release and combustion stage of large molecular volatiles,with an activation energy of 117.08 kJ/mol to 201.61 kJ/mol;and from 410℃to 520℃,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
作者
况怡婷
黄芳
米铁
罗耀
刘玉婷
辛善志
刘晓烨
KUANG Yiting;HUANG Fang;MI Tie;LUO Yao;LIU Yuting;XIN Shanzhi;LIU Xiaoye(School of Environment and Health,Jianghan University,430056 Wuhan,China;Hubei Key Laboratory of Industrial Fume and Dust Pollution Control,430056 Wuhan,China;Hubei Gas Purification Enterprise-School Joint Innovation Center,430056 Wuhan,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2024年第3期45-58,共14页
Coal Conversion
基金
国家自然科学基金项目(51706085)
湖北省科技厅资助项目(2023AFB963)
湖北省教育厅高校中青年创新团队项目(T201420)
江汉大学校级科研项目资助计划项目(2022SXZX05).
关键词
中药渣
水热碳化
燃料特性
热解燃烧特性
动力学分析
Chinese herbal residue
hydrothermal carbonization
fuel characteristic
pyrolysis and combustion characteristics
kinetic analysis
