Low-density polyethylene (LDPE) is the second most prevalent waste plastic globally, followed by polypropylene. The pyrolytic conditions required to obtain light oil(≤C12) from LDPE are more stringent than those for polypropylene, water plastics, acrylonitrile, butadiene, styrene, and other materials. Consequently, numerous researchers have underscored the necessity of employing catalysts in LDPE pyrolysis. This study explored the pyrolysis characteristics of LDPE at various temperatures in a non-catalytic fluidized bed reactor. The experiments employed a mixture of sand + kaolin, one of the Si-Al catalysts, to investigate the pyrolysis of LDPE in a fluidized bed reactor at different temperatures. The findings demonstrated that using sand + kaolin as a fluidized bed material significantly enhances the yield of pyrolysis oil while concurrently reducing the gas yield compared to using sand alone. Moreover, a higher light oil fraction was obtained using kaolin (16.67 wt%) at 560 °C compared with 8.6 wt%. In addition, the study revealed that elevated temperatures (520 °C, 560 °C, and 600 °C) led to a reduction in olefins and paraffin, coupled with an increase in the formation of naphthenes, aromatics, and ketones in the pyrolysis oil. Overall, the findings underscore the promising potential of kaolin as an alternative to sand, facilitating the enhanced production of valuable light oil fractions. The insights garnered from this study are invaluable for devising effective waste management strategies.

中文翻译：

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LDPE 热解技术实现两倍进步：提高轻油产量并在流化床系统中用高岭土替代沙子

低密度聚乙烯（LDPE）是全球第二大常见的废塑料，其次是聚丙烯。从LDPE获得轻油（≤C12）所需的热解条件比聚丙烯、水塑料、丙烯腈、丁二烯、苯乙烯等材料更严格。因此，许多研究人员强调了在 LDPE 热解中使用催化剂的必要性。本研究探讨了 LDPE 在非催化流化床反应器中不同温度下的热解特性。实验采用沙子+高岭土（硅铝催化剂之一）的混合物，研究 LDPE 在流化床反应器中不同温度下的热解情况。研究结果表明，与单独使用砂子相比，使用砂子+高岭土作为流化床材料可显着提高热解油的产量，同时降低气体产量。此外，在 560 °C 下使用高岭土获得了更高的轻油馏分（16.67 wt%），而轻油馏分为 8.6 wt%。此外，研究表明，升高温度（520°C、560°C 和 600°C）会导致烯烃和石蜡减少，同时热解油中环烷烃、芳烃和酮的形成增加。总体而言，这些发现强调了高岭土作为沙子替代品的巨大潜力，有助于提高有价值的轻质油馏分的产量。这项研究获得的见解对于制定有效的废物管理策略非常宝贵。