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New Perspectives into Cellulose Fast Pyrolysis Kinetics Using a Py-GC × GC-FID/MS System
ACS Engineering Au ( IF 4.3 ) Pub Date : 2022-04-05 , DOI: 10.1021/acsengineeringau.2c00006
Gorugantu SriBala 1, 2 , Diana C Vargas 1 , Pavlo Kostetskyy 2 , Ruben Van de Vijver 1 , Linda J Broadbelt 2 , Guy B Marin 1 , Kevin M Van Geem 1
Affiliation  

Cellulose pyrolysis is reportedly influenced by factors such as sample size, crystallinity, or different morphologies. However, there seems to be a lack of understanding of the mechanistic details that explain the observed differences in the pyrolysis yields. This study aims to investigate the influence of particle size and crystallinity of cellulose by performing pyrolysis reactions at temperatures of 673–873 K using a micropyrolyzer apparatus coupled to a GC × GC-FID/TOF-MS and a customized GC-TCD. Over 60 product species have been identified and quantified for the first time, including water. Crystalline cellulose with an average particle size of 30–50 × 10–6 m produced 50–60 wt % levoglucosan. Predominantly amorphous cellulose with an average particle size of 10–20 × 10–6 m resulted in remarkably low yields (10–15 wt %) of levoglucosan complemented by higher yields of water and glycolaldehyde. A detailed kinetic model for cellulose pyrolysis was used to obtain mechanistic insights into the different pyrolysis product compositions. The kinetics of the mid-chain dehydration and fragmentation reactions strongly influence the total yields of low-molecular weight products (LMWPs) and are affected by cellulose chain arrangement. Levoglucosan yields are very sensitive to the activation of parallel cellulose decomposition reactions. This can be attributed to the mid-chain reactions forming smaller chains with the levoglucosan ends, which remain in the solid phase and react further to form LMWPs. Direct quantification of water helped to improve the description of the dehydration, giving further indications of the dominant role of mid-chain reaction pathways in amorphous cellulose pyrolysis.

中文翻译:

使用 Py-GC × GC-FID/MS 系统对纤维素快速热解动力学的新观点

据报道,纤维素热解受样品大小、结晶度或不同形态等因素的影响。然而,似乎缺乏对解释所观察到的热解产率差异的机制细节的理解。本研究旨在通过使用与 GC × GC-FID/TOF-MS 和定制的 GC-TCD 耦合的微热解装置在 673-873 K 的温度下进行热解反应来研究纤维素的粒度和结晶度的影响。首次识别和量化了 60 多种产品,包括水。平均粒径为 30-50 × 10-6 m 的结晶纤维素产生50-60 wt% 的左旋葡聚糖。主要是无定形纤维素,平均粒径为 10–20 × 10 –6m 导致左旋葡聚糖的产量非常低(10-15 wt%),而水和乙醇醛的产量更高。纤维素热解的详细动力学模型用于获得对不同热解产物组成的机理见解。中链脱水和碎裂反应的动力学强烈影响低分子量产物 (LMWP) 的总产率,并受纤维素链排列的影响。左旋葡聚糖产率对平行纤维素分解反应的激活非常敏感。这可以归因于中间链反应与左旋葡聚糖末端形成较小的链,这些链保持在固相中并进一步反应形成LMWP。水的直接量化有助于改进对脱水的描述,
更新日期:2022-04-05
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