废弃香菇菌糠的热重-红外分析及热解动力学研究

Thermal Pyrolysis Characteristics and Kinetics Study of Waste Mushroom Bran by TG-FTIR Technique

该文采用热重红外联用技术(thermogravimetry-Fourier transform infrared analysis,TG-FTIR)对废弃香菇菌糠的热失重特性和热解动力学进行分析,并监测热解过程中的气体释放行为。菌糠的热解过程中平均失重率为58%;随着升温速率的增加,最大失重速率及挥发分释放综合特性指数均逐渐加大,有利于挥发分的充分析出;菌糠热解过程中气体释放较多的是CO_(2)、芳香烃类以及醛酮酸类等有机组分,CH4释放量较低,呈现双峰释放特点。基于单一升温速率Coats-Redfern法的热解动力学分析表明F1.5级化学反应模型可较好地描述菌糠热解过程,活化能介于105.92 kJ/mol~106.93 kJ/mol之间;基于多升温速率的无模型法分析显示热解活化能随热解转化率升高而增大。

This paper analyze the thermal weightlessness properties and pyrolysis dynamics of waste mushroom bran by thermal heavy IR coupling technology(thermogravimetry-Fourier transform infrared analysis,TG-FTIR)and monitor the gas release behavior during pyrolysis.The average weight loss rate of bacterial bran was 58%during the pyrolysis process.Moreover,with the increasing heating rate,the maximum weight loss rate and volatile release index increased gradually,indicating a better release performance for the volatiles.The prominent volatile components produced during the pyrolysis process of mushroom bran were CO_(2),aromatic hydrocarbon,aldehydes,ketones,etc.The release content of CH_(4) was relatively low;it exhibited a bimodal form with temperature.The kinetic analysis of the pyrolysis process fitted by the Coats-Redfern method indicated that the F1.5 reaction model had the highest correlation coefficients under all three heating rates.The calculated activation energies based on this model were in the range of 105.92 kJ/mol-106.93 kJ/mol.Meanwhile,the activation energies calculated by an isoconversional model-free method increased with the conversion rate.