Bypassing Energy Barriers in Fiber-Polymer Torrefaction
Bypassing Energy Barriers in Fiber-Polymer Torrefaction
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DOI：
10.3389/fenrg.2021.643371
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Zhuo Xu;S. Kolapkar;S. Zinchik;E. Bar-Ziv;Lucky I. Ewurum;A. McDonald;J. Klinger;Eric P. Fillerup;K. Schaller;C. Pilgrim
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文献类型：
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作者：
Zhuo Xu;S. Kolapkar;S. Zinchik;E. Bar-Ziv;Lucky I. Ewurum;A. McDonald;J. Klinger;Eric P. Fillerup;K. Schaller;C. Pilgrim
废物产生量一直在增加，其中大量被填埋。这些不可回收的废物中含有大量的纤维和塑料废物，由于它们具有高热值，数量丰富，通常需要支付处理费用，因此可以通过热处理将其转化为能源。本文通过热重分析（TGA）研究了不可回收纸（纤维）废弃物、混合塑料废弃物及其共混物在250 ~ 400℃温度范围内不同比例的焙烧。对实验后的固体残留物进行核磁共振（NMR）光谱分析。在250-300°C范围内，观察到纤维和MPW之间的显著协同作用，表明反应速率和总质量损失都有所增加。在250℃时，最大质量损失率提高了两倍以上，实验结束时的质量损失率也比预期的结果高得多。随着温度的升高，协同作用减弱，在400℃时完全消失。纤维和塑料废物之间的这种相互作用表明，在废纸或塑料废物的单独焙烧过程中，可以绕过天然能量障碍，在较低的温度和/或较短的停留时间内实现纤维和塑料共混物的焙烧。MPW和纤维废料也在220°C下以不同的混合比例进行挤压复合（生产球团）。通过红外光谱、流变学、热分析和弯曲性能对挤出制得的纤维- mpw球团进行了表征，发现在相同配比下，纤维- mpw球团与非挤出共混物相比有显著的化学变化。红外表征发现，由于羰基（C = O）和醚基（C-O-C）的存在，羟基（OH）基团显著增加。纸张与MPW之间的相互作用可归因于塑料聚合物在反应挤出过程中充当氢供体。在力学和流变性能方面也发现了协同效应。
The amount of waste generation has been increasing with a significant amount being landfilled. These non-recyclable wastes contain large number of fiber and plastic wastes which can be treated with thermal processes to turn them into energy sources since they have high calorific values, are abundant and usually tipping fees are paid to handle them. This paper studied the torrefaction of non-recyclable paper (fiber) wastes, mixed plastic wastes (MPW) and their blends at different ratios in the temperature range of 250–400°C through thermogravimetric analysis (TGA). The solid residues after the experiments were analyzed by nuclear magnetic resonance (NMR) spectroscopy. Significant synergy between fiber and MPW were observed at the range 250–300°C, showing both increase in the reaction rate as well as the overall mass loss. At 250°C, the maximum mass loss rate was more than two times higher and the mass loss at the end of the experiments were also much higher compared to the expected results. In addition, synergy was weakened with an increase of temperature, disappearing at 400°C. The existence of such interactions between fiber and plastic wastes indicates that the natural energy barriers during the individual torrefaction in paper waste or plastic waste could be bypassed, and the torrefaction of fiber and plastic blend can be achieved at lower temperatures and/or shorter residence times. The MPW and fiber wastes were also compounded by extrusion (to produce pellets) at 220°C with different blend ratios. The fiber-MPW pellets from extrusion were characterized by IR spectroscopy, rheology, thermal analysis and flexural properties and showed significant chemical changes from the non-extruded blends at the same ratios. From IR characterization, it was found that there was significant increase in hydroxyl (OH) group on account of the carbonyl (C = O) and etheric (C-O-C) groups. The interaction between paper and MPW can be attributed to the plastic polymers acting as a hydrogen donor during the reactive extrusion process. Synergistic effects were also found from mechanical and rheological properties.