Kinetic Study of Paper Waste Thermal Degradation
Kinetic Study of Paper Waste Thermal Degradation
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DOI：
10.1016/j.polymdegradstab.2021.109681
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发表时间：
2021-09
影响因子：
5.9
通讯作者：
Zhuo Xu;S. Kolapkar;S. Zinchik;E. Bar-Ziv;J. Klinger;Eric P. Fillerup;K. Schaller;C. Pilgrim
中科院分区：
文献类型：
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作者：
Zhuo Xu;S. Kolapkar;S. Zinchik;E. Bar-Ziv;J. Klinger;Eric P. Fillerup;K. Schaller;C. Pilgrim
在过去几十年中，废纸的产生量一直在上升，大量的废纸被填埋。这些废纸在热处理后可以成为巨大的能源，因为它们被认为是碳中性的。这些废物主要含有纤维素、半纤维素、木质素和一些矿物质。纤维素、半纤维素和木质素的热分解已经得到了广泛的研究，然而，在较低温度下的废纸热降解的知识，这是更实际的工业应用仍然缺乏。在这项研究中，纸张废物进行了表征和热重分析，从200°C至400°C，并通过核磁共振（NMR）光谱和傅里叶变换红外（FTIR）光谱分析产生的焦炭。在建立废纸热降解动力学模型的过程中，采用了两种动力学方法：（1）利用纤维素、半纤维素和木质素的加和规律重构废纸热降解的热重分析结果;（2）将废纸作为一种材料，建立了一个多步连续反应机理，该机理关注不同温度下的固体产物。纤维素、半纤维素和木质素在废纸降解过程中存在着潜在的相互作用。因此，第二种方法更合理，并根据不同温度下的实验结果确定了一组动力学参数。这些结果为进一步研究废纸的降解动力学机制和固体产物分布提供了依据。结果表明，第一个反应是由于纤维素的脱水，第6和第7个反应是由于木质素的热降解。NMR和FTIR结果也证实了纤维素在较低温度下开始降解，而木质素在较高温度下降解变得更加明显。
Paper waste generation has been rising in the past decades, with a large amount being landfilled. These paper wastes can be great energy sources after thermal treatment since they are considered carbon neutral. These wastes contain mainly cellulose, hemicellulose, lignin, and some minerals. The thermal decomposition of cellulose, hemicellulose, and lignin have been extensively studied, however, the knowledge of thermal degradation of paper wastes at lower temperatures, which are more practical for industrial applications are still lacking. In this study, paper wastes have been characterized and thermogravimetric analyses were performed from 200°C to 400°C and the char produced were analyzed by nuclear magnetic resonance (NMR) spectroscopy and Fourier-transform infrared (FTIR) spectroscopy. Two kinetic approaches were taken while developing the kinetic model of paper waste thermal degradation: (i) reconstructing the TGA results of paper waste thermal degradation by an additive law of the degradation of cellulose, hemicellulose and lignin; (ii) considering paper waste as one material and develop a multi-step consecutive reaction mechanism that focuses on solid products at different temperatures. It was observed that there are potential interactions between cellulose, hemicellulose and lignin during paper waste degradation. Therefore, the second approach was concluded to be more plausible, and one set of kinetic parameters were determined according to the experimental results at different temperatures. These results provided insights into the degradation kinetic mechanism and solid product distribution of the paper waste. It was found that the first reaction was due to dehydration of cellulose and the 6thand 7threaction can be attributed to the thermal degradation of lignin. The NMR and FTIR results also validated that the cellulose started degrading at lower temperatures, and lignin degradation became more pronounced at higher temperatures.