Lemaire Romain, Wang Wei, Menanteau Sebastien
Department of Mechanical Engineering, École de technologie supérieure, Montreal, Quebec H3C 1K3, Canada.
Energy, Environment & Materials Engineering, Icam Lille, Hauts-de-France, Lille 59016, France.
ACS Omega. 2023 Jul 31;8(32):29455-29467. doi: 10.1021/acsomega.3c03110. eCollection 2023 Aug 15.
Devolatilization kinetics of coal, poplar wood, and blends containing 10 and 20 wt % of biomass were characterized. Measurements were carried out under inert atmosphere with heating rates between 10 K min and ∼10 K s using a thermogravimetric analyzer (TGA) and a flat flame reactor (FFR). Measured data were simulated using the chemical percolation devolatilization (CPD) model and a global kinetic scheme based on two competitive reactions integrating a refined differential reaction model. The CPD model failed to simulate TGA results but reproduced FFR data relatively well. As for the global model, selecting kinetic parameters from the literature turned out to lead to unsuitable predictions. Fitted values of the activation energies , pre-exponential factors , mass stoichiometric coefficients , and the reaction model factor were therefore inferred using a genetic algorithm-based optimization procedure, leading to obtain an excellent agreement between simulated and measured data. The assessed values were found to be lower for wood than for coal, which is consistent with the higher energy required to break the strong C-C bonds holding the highly cross-linked aromatic structures of coal. Besides, blending coal with 20 wt % of wood induced a decrease of values, which went from 99.79 to 86.1 kJ mol and from 186.72 to 171.57 kJ mol for the first and second reactions prevailing at low and high temperatures, respectively. Finally, the fact that the activation energy of the first devolatilization reaction was found to be lower with the blend containing 20% of wood than for wood illustrated the probable existence of synergies, as also exemplified by the characteristic devolatilization times for blended samples, which were found to be relatively similar to and even lower than that of wood.
对煤、杨木以及含有10 wt%和20 wt%生物质的混合物的热解动力学进行了表征。使用热重分析仪（TGA）和平板火焰反应器（FFR）在惰性气氛下进行测量，加热速率介于10 K/min和~10 K/s之间。使用化学渗流热解（CPD）模型和基于两个竞争反应并整合精细微分反应模型的全局动力学方案对测量数据进行模拟。CPD模型未能模拟TGA结果，但能较好地再现FFR数据。至于全局模型，从文献中选择动力学参数导致预测结果不合适。因此，使用基于遗传算法的优化程序推断活化能、指前因子、质量化学计量系数和反应模型因子的拟合值，从而使模拟数据与测量数据取得了极好的一致性。发现木材的评估值低于煤，这与破坏煤的高度交联芳香结构中强C-C键所需的更高能量一致。此外，将煤与20 wt%的木材混合导致评估值降低，对于分别在低温和高温下占主导的第一和第二反应，评估值分别从99.79 kJ/mol降至86.1 kJ/mol，从186.72 kJ/mol降至171.57 kJ/mol。最后，含20%木材的混合物的第一次热解反应活化能低于木材，这一事实表明可能存在协同作用，混合样品的特征热解时间也证明了这一点，其与木材的特征热解时间相对相似，甚至更低。
