Study on the decomposition of vehicle evaporative emissions

With the further tightening of light vehicle emission regulations, the emission limit of evaporative pollutants is reduced from 2.0g/test to 0.7g/test from the fifth stage to the sixth stage in China. The definition of evaporative pollutants in the regulation refers to the hydrocarbon loss from the fuel system of the vehicle. Through the actual evaporation test, it is found that the tested emissions include not only the hydrocarbon emissions from the fuel system, but also the hydrocarbon emissions from the non fuel system. In this study, an experimental study on evaporative pollutants was carried out for a vehicle and its components developed by Dongfeng Motor Company. The results show that the hydrocarbon emission from fuel system accounts for 21% of the total hydrocarbon emission. In order to reduce the emission of evaporative pollutants, we can start from two aspects: one is to improve the design of fuel system; the other is to carry out specific pretreatment for non fuel system