Emission Inventory And Reduction Strategy Of Motor Vehicle Pollutants In Weinan

With the increasing of vehicle population in Weinan,the air pollution caused by vehicle emission has been widely concerned.Vehicle exhaust is one of the major contributors to air pollutants in the urban environment.Vehicle emission is not only an important source of particulate matter in autumn and winter,but also an important source of ozone precursors in summer.Clarifying the characteristics of vehicle pollution emissions and establishing the emission inventory in Weinan can provide the references for the reduction of regional air pollution,which is of great significance for improving urban air quality.Therefore,this paper estimated the emission inventory of vehicles in Weinan,analyzed the temporal and spatial distribution characteristics of pollutant emissions,and provided pollutant emission reduction strategies.The main conclusions are as follows:（1）Based on the vehicle population,vehicle type,activity level,mileage and meteorological parameters in Weinan,we obtained the motor vehicle emission inventory of2019 by using the MOVES model.The total annual emissions of PM_2.5,PM₁₀,SO₂,NO_X,VOCs,NH₃,CO,EC and OC were 633.6,690.8,25.7,13021,3780.8,165.3,28078.1,344.8and 201.2 t,respectively.（2）The population of heavy-duty trucks in Weinan accounted for 2%of the total number of vehicles,but its PM_2.5 and NO_X emissions accounted for 50%and 51%of the total emissions respectively;The number of small passenger vehicles accounted for 73%of the total,and its emissions contributed more than 41%to the total VOCs,NH₃,SO₂ and CO;Motorcycle population accounted for 15%of the total population,which contributed 25%to the total VOCs.Gasoline vehicle was the major source of CO,NH₃ and VOCs,which contributed more than to the pollutants emitted by vehicles;More than 86%of PM_2.5,NO_X,EC and OC emissions came from diesel vehicles.The number of vehicles with below China-III standard accounted for only 39%of the total vehicles,but which contributed more than 66%to the total emissions of PM_2.5,NO_X,EC and OC.（3）Vehicle emissions are also the main source of greenhouse gas（GHG）emissions.This paper further calculated the GHGs,naming CO₂,CH₄,and N₂O emitted by vehicles in Weinan in 2019.The total annual emissions were 424.3×10⁴,437.9 and 68.8 t,respectively.Small passenger vehicles are also the main source of greenhouse gases.Heavy-duty trucks account for 2%of the total number of vehicles,but contributed 26%and 22%to CO₂ and CH₄emissions.Natural gas vehicles only account for 0.3%of the total vehicles,but their CH₄emissions account for 61.9%of the total CH₄ emissions.（4）The emission reduction effect of eliminating old vehicles,using alternative fuels（compress natural gas）,and"road to railway transportation"in Weinan is evaluated.The results show that the elimination of old vehicles has a significant effect on the emission reduction of PM_2.5,PM₁₀ and NO_X.The emissions were reduced by 445.4,484.4 and 6189.8 t,respectively,and the reduction rates were 70.3%,70.1%and 47.5%,respectively.Vehicles powered by alternative fuels are effective at reducing CO and VOCs,the emissions were reduced by 5916.8 t and 529.9 t,respectively,and the reduction rates were 21.1%and 14%."Road transport changed to rail transport"greatly reduced PM_2.5,PM₁₀ and NO_X emissions,with the reduction rate reaching more than 21%.