Energy consumption and pollutant emission of diesel-fired combustion from 2009 to 2018 in Beijing, China.

Diesel-fired combustion is one of the main sources of air pollution in the world. In this study, to better understand the energy consumption and main air pollutant emissions of diesel-fired combustion, a practical investigation and historical data analyses were conducted to determine the variations and driving forces of diesel consumption, the distribution of diesel consumption, and the contribution of emissions among various industries. Based on the results of this study, future control measures can be proposed for diesel-fired combustion. The results show that economic development led to an increase in the total volume of passengers and freight transportation, and the number of diesel vehicles increased from 0.16 million in 2009 to 0.25 million in 2018. However, diesel consumption in Beijing decreased from 2.4 Mt in 2009 to 1.8 Mt in 2018 due to the dominant driving forces, such as structural optimization of the diesel vehicle fleet and stricter limit standards for single-vehicle fuel consumption. The use of diesel vehicles in the logistics and transportation industries and the use of diesel-fired machinery in the construction industry were the two main sources of diesel consumption, accounting for 55% and 23% of the total, respectively. The main air pollutant emissions from diesel-fired combustion from 2009 to 2018 first increased and then decreased, while the NO emissions peaked at 74,800 tons in 2014, which was affected by the structural optimization of the vehicle fleet and the elimination of old diesel trucks. The emissions finally decreased to 54,000 tons in 2018, which was approximately 89% of the amount in 2009. However, the continuously increasing contribution of diesel combustion to the total emissions requires more attention. The electrification of diesel vehicles and the structural upgrading of diesel vehicles have played important roles in mitigating the emissions of diesel combustion. Our study suggests that consumption control targets should be set, reduction plans for key industries such as the logistics and transportation, construction, and tourism industries should be developed, and low-emission zones should be created to promote the elimination and updating of low-emission diesel vehicles and machinery.