Kristanto Jonas, Azis Muhammad Mufti, Purwono Suryo
Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.
Professional Engineering Program, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.
Heliyon. 2021 Jul 26;7(7):e07669. doi: 10.1016/j.heliyon.2021.e07669. eCollection 2021 Jul.
Developing a kinetic model to analyze the multi-step reaction of biomass pyrolysis is pivotal to elucidate the mechanism of the pyrolysis. For this purpose, a model-fitting method such as multi-distribution the Distributed Activation Energy Model (DAEM) is one of the most reliable methods. DAEM with 4 different distribution functions of Gaussian, Logarithmic, Gumbel, and Cauchy was utilized to characterize the pyrolysis of cellulose and lignin during Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC) instrumentation. By comparing Derivative Thermogravimetry (DTG) and DSC profiles, determination of pseudo-components can be done more accurately. A kinetics analysis on the pyrolysis of cellulose with a single Gaussian distribution DAEM yielded a single activation energy of 178 kJ mol with a narrow standard deviation. This result was justified by a single and dominant endothermic peak followed by minor exothermic peaks in the DSC result. For lignin pyrolysis, the presence of multiple peaks is characterized by four pseudo-components in DAEM with activation energies of 157, 174, 194, and 200 kJ mol. These pseudo-components were confirmed by the DSC result which indicated the occurrences of two exothermic peaks with two lesser exothermic or possibly endothermic peaks at the same temperature range. These findings imply the importance of DSC to support a kinetics study of thermogravimetric pyrolysis.
建立动力学模型以分析生物质热解的多步反应对于阐明热解机理至关重要。为此，诸如多分布的分布式活化能模型（DAEM）之类的模型拟合方法是最可靠的方法之一。利用具有高斯、对数、冈贝尔和柯西4种不同分布函数的DAEM来表征热重分析/差示扫描量热法（TGA/DSC）仪器中纤维素和木质素的热解。通过比较微商热重曲线（DTG）和DSC曲线，可以更准确地确定假组分。用单高斯分布DAEM对纤维素热解进行动力学分析，得到单一活化能为178 kJ/mol，标准偏差较窄。DSC结果中出现一个单一且占主导地位的吸热峰，随后是较小的放热峰，证明了该结果的合理性。对于木质素热解，DAEM中的四个假组分表征了多个峰的存在，其活化能分别为157、174、194和200 kJ/mol。DSC结果证实了这些假组分，该结果表明在相同温度范围内出现了两个放热峰以及两个较小的放热峰或可能的吸热峰。这些发现表明DSC对于支持热重热解动力学研究的重要性。
