Li Jie, Shang Yanchao, Wei Wei, Liu Zhengyi, Qiao Yingyun, Qin Song, Tian Yuanyu
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao, Shandong 266580, China.
ACS Omega. 2022 Mar 15;7(12):10144-10155. doi: 10.1021/acsomega.1c06363. eCollection 2022 Mar 29.
The pyrolysis characteristics of land biomass (corn stalks (Cs), pine sawdust (Ps)) and coastal zone biomass (Jerusalem artichoke stalks (JAs) and reed (Re)) were investigated based on thermogravimetric analysis (TGA) and products' analysis. The kinetic parameters were obtained by three isoconversional methods (Friedman, KAS, and FWO) and one model-fitting method (DAEM). The simultaneous effect of high temperature (700-900 °C) and high heating rate (1000 °C/s) on the pyrolysis product simulating the typical conditions of a fluidized bed gasifier was studied. TGA showed that high heating rates deepen the thermal cracking process of biomass. Compared with the land biomass, the initial decomposition temperature ( ) of the coastal biomass is reduced significantly owing to its higher proportion of hemicellulose. These methods agree with the trends shown by the activation energy ( ) distribution calculated, with fluctuations between 160 and 350 kJ/mol. The mean value activation energies of Re and JAs were higher than those of Cs and Ps between 10% and 90% conversion. The DAEM model showed that Cs and JAs have a good linear relationship between ln and during the main pyrolysis stage, while Ps and Re are relatively weaker. The kinetic compensation effect was evident for Cs and JAs during the main thermal cracking stage. Py-GC-MS results confirmed that phenols, hydrocarbons, PAHs, and oxygen heterocycle compounds were strongly present in the released volatile products. High-temperature fast pyrolysis of JAs produced a larger amount of PAH compounds than from Cs, Ps, and Re. A larger amount of hydrocarbons and phenols was generated from high-temperature fast pyrolysis of Ps. Some oxygen-containing volatiles are easily converted into aromatic products with higher stability under high temperature.
基于热重分析（TGA）和产物分析，研究了陆地生物质（玉米秸秆（Cs）、松木锯末（Ps））和沿海地区生物质（菊芋秸秆（JAs）和芦苇（Re））的热解特性。通过三种等转化率方法（弗里德曼法、KAS法和FWO法）和一种模型拟合方法（DAEM）获得了动力学参数。研究了高温（700 - 900℃）和高加热速率（1000℃/s）对模拟流化床气化炉典型条件下热解产物的协同影响。TGA表明，高加热速率加深了生物质的热裂解过程。与陆地生物质相比，沿海生物质的初始分解温度（ ）显著降低，这是由于其半纤维素比例较高。这些方法与计算得到的活化能（ ）分布趋势一致，波动范围在160至350 kJ/mol之间。在10%至90%转化率之间，Re和JAs的平均活化能高于Cs和Ps。DAEM模型表明，在主要热解阶段，Cs和JAs的ln 与 之间具有良好的线性关系，而Ps和Re的相对较弱。在主要热裂解阶段，Cs和JAs的动力学补偿效应明显。Py - GC - MS结果证实，释放的挥发性产物中大量存在酚类、烃类、多环芳烃和含氧杂环化合物。JAs的高温快速热解产生的多环芳烃化合物比Cs、Ps和Re更多。Ps的高温快速热解产生了大量的烃类和酚类。一些含氧挥发性物质在高温下容易转化为稳定性更高的芳香产物。
