The energy saving and GHG mitigation benefits assessment of product remanufacturing from a multi-life cycle perspective: A case study of spark plug

As an advanced form of circular economy, remanufacturing can effectively reduce the energy and resource consumption, as well as environmental emission in the whole product life cycle. Life cycle assessment (LCA) is often used to evaluate the environmental benefits of product remanufacturing system, but no standard and guideline relating the system boundary and environmental burden allocation was established. This research proposed a new system boundary definition with a multi-life cycle perspective to quantify the energy saving and GHG mitigation benefits of product remanufacturing, based on a case of spark plug remanufacturing. The results show that remanufacturing exhibit significant energy saving and GHG mitigation benefits over the whole life cycle of spark plug, but the benefit value in multi-life cycle is lower than that in traditional waste life cycle. The energy saving and GHG mitigation benefits of spark plug remanufacturing in multi-life cycle are 18.5% and 18.0%, which are respectively 49.5% and 43.8% in traditional waste life cycle perspective. It is due to the fact that the remanufactured spark plug shared the environmental load of its original manufacturing in multi-life cycle, which are usually ignored in traditional waste life cycle. The system boundary delineation from the perspective of multi-life cycle takes into account of the residual function of retired product and the environ-mental load of its original manufacturing in the remanufacturing system, which is more reasonable for the environmental impact assessment of product remanufacturing system. The results also show that recovery rate of ceramic insulator, the key component of spark plug, exhibits significant effect on energy saving and GHG mitigation benefits, suggesting that increasing the recovery rate of ceramic insulator is helpful to improve the environmental benefits of spark plug remanufacturing.