Catalytic pyrolysis offers a sustainable route to convert plastic wastes into fuel. We investigated the catalytic performance of coal ash (fly and bottom ash) at blending ratio of 5 wt%, and 15 wt% during pyrolysis of linear low-density polyethylene (LLDPE). The influence on activation energy and oil was characterized via thermogravimetric analyzer (TGA) and gas chromatography-mass spectrometry (GC-MS). Results have shown that 15 wt% bottom ash exhibited higher catalytic activity. The activation energy estimated by Coats-Redfern method decreased from 458.7 kJ·mol⁻¹ to 437.8 kJ·mol⁻¹, while the alicyclic hydrocarbon yield increased from 5.97% to 32.09%. This implies that CaO, which is abundant in bottom ash, could promote the conversion of LLDPE. Furthermore, a cradle-to-factory gate life cycle assessment was performed to investigate three scenarios (non-catalytic pyrolysis, 15 wt% fly ash, and 15 wt% bottom ash) of LLDPE conversion strategies via a normalization and weighting approach. It was found that LLDPE pyrolysis with 15 wt% bottom ash also showed the lowest normalized score of 2.83, implying the lowest environmental impact. This work has demonstrated that the recycling of coal ash, particularly bottom ash, as catalysts for LLDPE pyrolysis is effective.

催化热解提供了将塑料废物转化为燃料的可持续途径。我们研究了煤灰（飞灰和底灰）在混合比为 5 wt% 和 15 wt% 的线性低密度聚乙烯 (LLDPE) 热解过程中的催化性能。通过热重分析仪 (TGA) 和气相色谱-质谱 (GC-MS) 表征对活化能和油的影响。结果表明，15 wt% 的底灰表现出更高的催化活性。Coats-Redfern 方法估计的活化能从 458.7 kJ·mol ^-1降低到 437.8 kJ·mol ^-1, 而脂环烃收率从 5.97% 提高到 32.09%。这意味着底灰中丰富的 CaO 可以促进 LLDPE 的转化。此外，还进行了从摇篮到工厂的生命周期评估，以通过标准化和加权方法研究 LLDPE 转化策略的三种情景（非催化热解、15 wt% 飞灰和 15 wt% 底灰）。发现具有 15 wt% 底灰的 LLDPE 热解也显示出最低的标准化分数 2.83，这意味着对环境的影响最低。这项工作表明，煤灰，特别是底灰作为 LLDPE 热解催化剂的回收是有效的。