Research Of Fuel Properties Effects On Vehicle Exhaust Emissions

Auto/Oil Programs have been initiated in the USA, Europe and Japan to establish correlations between fuel end engine technologies and their impact on vehicle emissions. They represent a remarkable cooperation of vehicle manufacturers, oil companies and government departments to establish a scientific basis for future emissions legislation and fuel quality regulations. One important aspect of these Auto/Oil Programs is to establish relationships between fuel variables and vehicle emissions, but at the present time China doesn't have done those researches. With the strictness of vehicle emission directives, the influence of fuel quality on vehicle emission becomes more important. There have been many differences between Chinese and other country gasoline (especially higher sulfur and olefin content), for the reason of characteristic of Chinese oil industry; on the other hand, the vehicle in china is much different from other countries. So the result of other country is don't appropriate to Chinese situation. This paper studies the effects of gasoline sulfur and olefin content on vehicle exhaust emissions.The effects of different physical and chemic character of gasoline on vehicle emissions are discussed firstly. Interaction of Sulfur with automotive catalysts and the impact on vehicle emissions was analyzed secondly. Sulfur interaction with platinum group metals and base metal components and the reversibility of sulfur inhibition was studied separately. The inhibition of fuel sulfur on vehicle catalysts was dependent on the condition of vehicle runs and the composition of platinum group metals. Effective reversal of sulfur inhibition maybe feasible, but the full reversibility will be difficult. The effect of fuel olefins on vehicle emissions also was analyzed.This dissertation mainly focuses on the effects of fuel sulfur and olefins content on vehicles emissions. The experiments design considers the all kinds of problem which could affect the precision of the test result. Reducing gasoline sulfur contents reduced composite cycle THC CO and NO_x emissions. Reduction gasoline olefins contents reduced composite THC and CO emissions, but increased NO_x emissions. Except the composite cycle, the response of ECE and EUDC cycles also wereanalyzed. Over the ECE and EUDC cycles, the response of vehicle exhaust emissions to the change of fuel quality was similar to composite cycle. The response of single vehicle to fuel quality changes is much different. At last advice was given to revise Chinese gasoline directive.