Real-world key-process emission factors optimized environmental impact from passenger car tires' PM_2.5 and typical...

The reliability of partial emission factors (EFs) in current tire lifecycle database remains unclear. This study provided the real-world EFs for key processes (manufacturing, use phase) of passenger car tires that can be implemented to make the lifecycle evaluation more precise, and quantifies the impacts of PM_2.5 and its typical marker substances, benzothiazoles (BTHs). Manufacturing EFs determined by typical processes of vulcanization, compounding, and calendaring, were 3.09 × 10^-5 t/t rubber and 1.43 × 10^-9 t/t rubber for PM_2.5 and BTHs, respectively. The use-phase EFs from light-duty traffic fleet were averaged by peak and off-peak hours via urban tunnel, at 0.70 mg/km/veh and 479.58 ng/km/veh. With energy efficiency improvement and vehicle electrification, the use phase exceeds production and ELT phases, and serves as primary contributor for lifecycle PM_2.5 now and in the future, while production phase remains to dominate BTHs. The potential discrepancy for use-phase emission value via traditional method indicated an error of 56.5 % increase from the real-world level. Responding to vehicle electrification, the eco-tire solution to cope with the weight-induced emission increment could enhance the mitigation effect as electrification strengthens. It is estimated by 2035, tire lifecycle PM_2.5 probably reduce by 2.34 × 10³ t to 2.67 × 10³ t, and geographic distribution indicates the potential reduction rates for most provinces of 3.1∼28.3 % and 0.2∼19.7 %, for PM_2.5 and BTHs respectively. The results provide reliable data and indicate the vital role of tire use phase targeting to future mitigation measures.