The escalating accumulation of plastic waste presents a critical environmental challenge due to its resistance to degradation. Liquefaction, a thermochemical conversion process, emerges as a promising solution to convert plastic waste into valuable resources like fuel. The objective of this study was to investigate the behaviour of plastic polymer degradation in solvothermal liquefaction. This study comprehensively examines the liquefaction processes HDPE, LDPE, PS, and PP under 350–400 °C conditions and 30–90 min reaction times, using toluene as a solvent in an autoclave batch reactor. The results indicate that temperature significantly impacts liquefaction efficiency, with the following sequence: PS > PP > LDPE > HDPE. The liquefied products exhibit high heating values (HHV) of 40–44 MJ/kg, with viscosity and density comparable to gasoline and diesel. GC–MS and FTIR analyses reveal a composition rich in olefins, paraffins, and aromatics, producing carbon chain lengths from C6 to C20, aligning with conventional fuel. Finally, the mechanism of liquefaction for the polymers is proposed based on the chemical components found.

中文翻译：

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使用甲苯将热塑性塑料热化学液化成燃料：产品分布和行为


由于其抗降解性，塑料垃圾的不断积累带来了严峻的环境挑战。液化是一种热化学转化过程，是将塑料废物转化为燃料等宝贵资源的有前途的解决方案。本研究的目的是研究溶剂热液化中塑料聚合物降解的行为。本研究在高压釜间歇式反应器中使用甲苯作为溶剂，在 350-400 °C 条件下和 30-90 分钟反应时间内，全面研究了液化过程 HDPE、LDPE、PS 和 PP。结果表明，温度对液化效率有显著影响，顺序如下： PS > PP > LDPE > HDPE。液化产品表现出 40-44 MJ/kg 的高热值 （HHV），其粘度和密度与汽油和柴油相当。GC-MS 和 FTIR 分析揭示了富含烯烃、石蜡和芳烃的成分，产生的碳链长度从 C6 到 C20，与传统燃料一致。最后，根据发现的化学成分提出了聚合物的液化机理。