Increasing the recycling of plastic waste is a key priority within Europe and its circular economy initiatives. The benefits of recycling however decrease until a cut-off point is reached where recycling becomes environmentally and economically too expensive to achieve a net benefit compared to disposal. To identify this point, suitable indicators with a life cycle perspective are needed. In this study, we analysed the existing Recyclability Benefit Rate and the Recycled Content Benefit Rate indicators, which express the potential environmental benefits from recycling compared to disposal (e.g. incineration) taking into account life cycle thinking. However, improvements of these indicators are still needed. The aim of this research was to advance the existing indicators by introducing improved equations. More specifically, we further developed these indicators in four aspects, i.e. (i) by including the final step (e.g. incineration) in the cascaded use of the material, (ii) by accounting for the same basket of products in the denominator as the one in the nominator of the indicator, (iii) by eliminating confusion about the calculated result when the denominator is negative, and (iv) by introducing a new parameter ‘d’ to account for the lifetime of the product made from recycled material compared to the product made from virgin material. These adjustments clarify and advance the monitoring of the environmental benefits of material cascading. The indicators were applied to a case of mixed and contaminated plastic waste, which showed that recycling is more environmentally beneficial than incineration in this case. The impact of injection moulding of the new product was significant due to its energy consumption, and higher for the recycled material. Future research could focus on an economic cost-benefit analysis to complement this environmental analysis. Additionally, the practical implementation of accounting for the lifetime difference between the recycled and the virgin material needs further research.

在欧洲及其循环经济计划中，增加塑料废物的回收利用是一项重要的优先事项。但是，回收利用的利益会降低，直到达到一个临界点为止，在该临界点，回收利用在环境和经济上都变得过于昂贵，无法实现与处置相比的净收益。为了识别这一点，需要具有生命周期视角的合适指标。在这项研究中，我们分析了现有的“可回收性收益率”和“可回收成分收益率”指标，这些指标表示了考虑到生命周期的思想，与处理（例如焚烧）相比，回收带来的潜在环境效益。但是，仍然需要改进这些指标。这项研究的目的是通过引入改进的方程式来改进现有指标。进一步来说，我们从四个方面进一步开发了这些指标，即（i）通过在材料的级联使用中包括最终步骤（例如焚化），（ii）通过分母中与分母中相同的一篮子产品来说明（iii）通过消除分母为负值时对计算结果的混淆，以及（iv）引入新参数'd'来说明回收材料制成的产品与回收材料制成的产品的使用寿命原始材料。这些调整明确并推进了对材料级联的环境效益的监测。这些指标适用于混合和受污染的塑料废料，这表明在这种情况下，回收利用比焚化更具环境效益。由于新产品的能源消耗，对新产品的注塑成型影响很大，而对于回收材料而言，影响更大。未来的研究可能集中在经济成本效益分析上，以补充这种环境分析。此外，对回收材料与原始材料之间的寿命差异进行会计处理的实际实施还需要进一步研究。