Thermal degradation characteristics, kinetics, thermodynamic, and reaction mechanism analysis of pistachio shell pyrolysis for its bioenergy potential
Thermal degradation characteristics, kinetics, thermodynamic, and reaction mechanism analysis of pistachio shell pyrolysis for its bioenergy potential
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DOI：
10.1007/s13399-020-01104-2
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发表时间：
2020-10-25
影响因子：
4
通讯作者：
Mondal, Monoj Kumar
中科院分区：
文献类型：
--
作者：
Gupta, Supriya;Gupta, Goutam Kishore;Mondal, Monoj Kumar
研究工作旨在评估阿月浑子壳的生物能源潜力，并研究其降解动力学，这对于有效设计和优化生物能源产生的热化学过程是必要的。初步表征（近似，最终，较高的热值，和成分分析），动力学研究，热力学分析伴随着反应机理进行了研究。结果表明，阿月浑子壳具有较高的挥发性物质（约79.8wt%）和热值（16.85MJ/kg）。热重分析（TGA）在10、20、30和40 ° C/min的四种不同加热速率下在氮气流速下从环境温度至900 ° C进行。热重分析结果表明，热解反应分为三个阶段，即水分和轻挥发物的脱除、纤维素和半纤维素的降解以及木质素的分解。结果还表明，最大降解发生在200-400 ℃的温度范围内。为了计算动力学（活化能和指前因子）和热力学参数（焓、熵和吉布斯自由能），采用不同的等转化率模型，即Flynn-wall-Ozawa（FWO）、Kissinger-Akahira-Sunose（KAS）、Starink和Friedman，得到活化能的平均值分别为168.86，165.80，166.29，和190.10 kJ/mol，指前因子值在10（7）-10（21）s（-1）之间。FWO、KAS、Starink和Friedman方法计算的吉布斯自由能的平均值分别为182.09、182.15、182.13和181.42 kJ/mol。Criado法和Z图显示了复杂的反应机理。动力学和热力学研究结果表明，阿月浑子壳是一种高效的生物质能源生产原料。
The research work aims to estimate the bioenergy potential of pistachio shell and study its degradation kinetics which is necessary for the efficient design and optimization of thermochemical processes for bioenergy generation. Initial characterizations (proximate, ultimate, higher heating value, and compositional analysis), kinetic study, and thermodynamic analysis accompanied by reaction mechanism are investigated. Physicochemical characterization results confirmed high volatile matter (similar to 79.8 wt%) and high heating value (16.85 MJ/kg) of pistachio shell. Thermogravimetric analysis (TGA) is performed at four different heating rates of 10, 20, 30, and 40 degrees C/min under nitrogen gas flow rate from ambient temperature to 900 degrees C. TGA results show the three-stage pyrolysis reaction which involves removal of moisture and light volatiles, degradation of cellulose and hemicellulose, and decomposition of lignin. The result also reveals that maximum degradation occurred in the temperature range of 200-400 degrees C. For calculating the kinetic (activation energy and pre-exponential factor) and thermodynamic parameters (enthalpy, entropy, and Gibbs free energy), different iso-conversional models, i.e. Flynn-wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Starink, and Friedman, are employed which gives the average value of activation energy as 168.86, 165.80, 166.29, and 190.10 kJ/mol, respectively and the pre-exponential factor values lie in the range of 10(7)-10(21) s(-1). The average values of Gibbs free energy calculated for FWO, KAS, Starink, and Friedman methods are 182.09, 182.15, 182.13, and 181.42 kJ/mol, respectively. Criado method and Z plot are showing complex reaction mechanism. The results of kinetics and thermodynamic study reveal pistachio shell is an efficient biomass for bioenergy production.