Impact of Common Plastics on Cellulose Pyrolysis
Impact of Common Plastics on Cellulose Pyrolysis
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DOI：
10.1021/acs.energyfuels.9b01376
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发表时间：
2019-07-01
期刊：
影响因子：
5.3
通讯作者：
Yoshioka, Toshiaki
中科院分区：
文献类型：
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作者：
Kumagai, Shogo;Yamamoto, Miki;Yoshioka, Toshiaki
在热解过程中，单独的热量可以同时裂解聚合物材料中的几个化学键。1− 3这种方法对于处理不能物理分离和回收的混合物是有利的。4，5因此，在这项研究中，我们专注于纤维素/塑料混合物。研究了纤维素与塑料（如聚乙烯（PE）、聚丙烯（PP）、聚苯乙烯（PS）、聚氯乙烯（PVC）和聚对苯二甲酸乙二醇酯（PET））的二元混合物在500 ℃快速共热解期间的协同相互作用。PS的加入使纤维素转化为左旋葡聚糖（LG）的产率提高了3.5倍; PVC催化LG脱水生成左旋葡糖酮;纤维素促进PE和PP转化为气态和液态脂肪烃以及PS转化为液态芳烃。这些协同效应有助于阐明互补的共热解机制，允许热解产物的预测和有用的燃料和化学原料从纤维素和塑料复合材料的回收的最大化。最近，含有富含纤维素的植物纤维的轻质增强树脂作为建筑和汽车材料受到了研究关注。6，7 2020年欧盟（EU）天然纤维复合材料的预测产量几乎是2012年的四倍。在木质纤维素生物质和塑料的共热解过程中，热解相互作用（通常称为协同作用）具有广泛的重要性。最近的研究表明，在木材与PE、PP和PS的共热解过程中，木质纤维素生物质和塑料热解产物之间发生氢交换。8− 11由于这些塑料通过自由基链机制分解，最近通过使用具有新型加热单元的电子自旋共振光谱仪研究了共热解过程中的12− 14自由基相互作用。然而，氢交换能力和自由基相互作用机制取决于塑料类型，各种塑料对纤维素热解的影响以及纤维素热解对塑料的影响仍然不清楚。其他聚合物（如PVC和PET）的热解通过自由基和离子反应进行。15，16产生的酸，即来自PVC的氯化氢（HCl）和来自PET的苯甲酸（BA）和对苯二甲酸（TPA），应强烈影响纤维素热解。虽然这些聚合物的影响已经通过热重分析17，18进行了研究，并使用配备热解器的气相色谱/质谱（Py-GC/MS）进行了半定量，18，19纤维素和塑料之间的热解相互作用的阐明仍然是不完整的。进一步的机理研究将有助于理解共热解系统的性质和共热解在实际燃料和化学原料生产中的应用。等
During pyrolysis, heat alone can simultaneously cleave several chemical bonds in polymeric materials. 1− 3 This method is advantageous for the treatment of mixtures that cannot be physically separated and recycled. 4, 5 Therefore, in this study, we focused on cellulose/plastic mixtures. Synergistic interactions were investigated during fast co-pyrolysis at 500 C of binary mixtures of cellulose with plastics, such as polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). PS addition increased the yield of levoglucosan (LG) from cellulose by 3.5 times; PVC catalyzed LG dehydration to produce levoglucosenone; and cellulose enhanced the production of gaseous and liquid aliphatic hydrocarbons from PE and PP and liquid aromatic hydrocarbons from PS. These synergistic effects facilitate the elucidation of the complemental co-pyrolysis mechanism, allowing for the prediction of pyrolysis products and maximization of the recovery of useful fuel and chemical feedstock from cellulose and plastic composite materials. Recently, lightweight reinforced resins containing cellulose-rich plant fibers have received research attention as construction and automotive materials. 6, 7 The forecasted production of natural fiber composites in the European Union (EU) in 2020 has almost quadrupled that in 2012. 7Pyrolytic interactions, often called synergies, during the copyrolysis of lignocellulosic biomass and plastic are of widely recognized importance. Recent studies have suggested that hydrogen exchange occurs between lignocellulosic biomass and plastic pyrolysates during the co-pyrolysis of wood with PE, PP, and PS. 8− 11 Because these plastics decompose through radical chain mechanisms, 12− 14 radical interactions during copyrolysis have recently been studied by employing an electron spin resonance spectrometer featuring a novel heating unit. 11 However, the hydrogen exchange ability and the radical interaction mechanism depend upon the plastic type, and the influence of various plastics on cellulose pyrolysis and vice versa remain unclear. The pyrolysis of other polymers, such as PVC and PET, progresses via radical and ionic reactions. 15, 16 The produced acids, ie, hydrogen chloride (HCl) from PVC and benzoic acid (BA) and terephthalic acid (TPA) from PET, should strongly influence cellulose pyrolysis. Although the impact of these polymers has been investigated by thermogravimetric analysis 17, 18 and semi-quantified using pyrolyzer-equipped gas chromatography/mass spectrometry (Py− GC/MS), 18, 19 elucidation of the pyrolytic interactions between cellulose and plastics is still incomplete. Further mechanistic studies will aid the understanding of the nature of co-pyrolysis systems and the application of co-pyrolysis to practical fuel and chemical feedstock production. Such