煤炭转化2024，Vol.47Issue(3)：45-58,14.DOI:10.19726/j.cnki.ebcc.202403005
中药渣水解炭燃料特性及热解燃烧动力学分析
Fuel characteristics and kinetics analysis of pyrolysis and combustion of Chinese herbal residue hydrochars
摘要
Abstract
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 280℃exhibits two signifi-cant peaks of weight loss at 160℃-300℃and 300℃-500℃,respectively,while other hydro-chars exhibits only one significant weight loss peak at 275℃-400℃.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 180℃to 295℃,primarily the pyrolysis stage of small molecular volatiles,with acti-vation energy of 63.65 kJ/mol to 105.02 kJ/mol;from 295℃to 390℃,primarily the combus-tion 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 vola-tiles,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 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 1 g∶15 mL and hydrothermally treated at 220℃for 1 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.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Key words
Chinese herbal residue/hydrothermal carbonization/fuel characteristic/py-rolysis and combustion characteristics/kinetic analysis分类
环境科学引用本文复制引用
况怡婷,黄芳,米铁,罗耀,刘玉婷,辛善志,刘晓烨..中药渣水解炭燃料特性及热解燃烧动力学分析[J].煤炭转化,2024,47(3):45-58,14.基金项目
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)和江汉大学校级科研项目资助计划项目(2022SXZX05). （51706085）
