Abstract The co-pyrolysis of Single-use low density polyethylene (LDPE) and Eucalyptus biomass (EuBm) can be considered as a sustainable waste management technique to produce viable byproducts. This study elucidates the effects of variable temperatures (300–600 °C), residence times (90–150 minutes), and proportions of LDPE (0.25, 0.33 (w/w)) on physicochemical characteristics of LDPE - EuBm char composites. The interference of liquified polymer coating on the surface with degradation of biomass could be the reason for low nutrient extractability of chars synthesized at 300 and 400 °C. These chars were rich in volatile matter (> 68 %) and their pores were filled with partially pyrolyzed products. Interestingly however, substantial changes in properties were observed at 500 °C due to the likely synergetic effect between the feeds. The highest plant-extractable concentrations of major nutrients (Na, K, Ca, Mg, NO3−, PO43-), electrical conductivity (4.73 mS/cm), and cation exchange capacity (50.5 Cmolc/kg) of char were observed at this temperature. The optimization through regression modeling identified 524 °C, 118 min, and 31 % (w/w) of LDPE as optimal process parameters to obtain char suitable for application in soil. Soil incubation test fortified the benefits of char to soil with 3.5 times improvement in soil fertility index at 5 % (w/w) rate of application.

中文翻译：

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共热解生产的一次性低密度聚乙烯-桉树生物质炭复合材料具有改善土壤质量的特性

摘要 一次性低密度聚乙烯 (LDPE) 和桉树生物质 (EuBm) 的共热解可被视为一种可持续的废物管理技术，以生产可行的副产品。本研究阐明了可变温度 (300–600 °C)、停留时间 (90–150 分钟) 和 LDPE 的比例 (0.25, 0.33 (w/w)) 对 LDPE - EuBm 炭复合材料物理化学特性的影响。表面液化聚合物涂层对生物质降解的干扰可能是在 300 和 400 °C 下合成的炭的养分可提取性低的原因。这些焦炭富含挥发性物质 (> 68 %)，它们的孔隙充满了部分热解的产物。然而，有趣的是，由于进料之间可能的协同效应，在 500 °C 时观察到了性质的重大变化。在此观察到炭的主要营养素（Na、K、Ca、Mg、NO3-、PO43-）、电导率（4.73 mS/cm）和阳离子交换容量（50.5 Cmolc/kg）的最高植物可提取浓度温度。通过回归建模的优化确定 524 °C、118 分钟和 31% (w/w) 的 LDPE 作为最佳工艺参数，以获得适合在土壤中应用的炭。土壤孵化试验加强了炭对土壤的益处，在 5% (w/w) 的施用率下，土壤肥力指数提高了 3.5 倍。和 31% (w/w) 的 LDPE 作为最佳工艺参数，以获得适用于土壤的炭。土壤孵化试验加强了炭对土壤的益处，在 5% (w/w) 的施用率下，土壤肥力指数提高了 3.5 倍。和 31% (w/w) 的 LDPE 作为最佳工艺参数，以获得适用于土壤的炭。土壤孵化试验加强了炭对土壤的益处，在 5% (w/w) 的施用率下，土壤肥力指数提高了 3.5 倍。