Analysis of real-world diesel sulphur in diesel engines in China's key regions

To reduce vehicle pollutant emissions at the source, from 2019 to 2022, four key regions encompassing 60 cities in 9 provinces were investigated. Notably, 25,777 diesel samples from gas stations and oil tanks of diesel trucks, non-road mobile machinery, and illegal refuelling vehicles were collected and subjected to on-site rapid and laboratory detection methods. The results showed that, due to strengthening supervision, the qualification rate of the sulphur content in diesel samples from the gas stations increased from 95.7% to 98.1%. However, unqualified diesel fuel is still used in diesel trucks and non-road mobile machinery, and illegal refuelling vehicles remain widespread. The effect of the sulphur content on particulate emissions was estimated. The results indicated that heavy-duty diesel trucks produce notable emissions during long-distance transport. This research enhances the understanding of the impact of the real-world diesel sulphur content on emissions and can help supervision departments clarify the regulation direction.