Investigation On The Regulated And Unregulated Emission Characteristics Of Dedicated Methanol-fueled Vehicle

In order to investigate the emission charactertistics of regulated and unregulated pollutants from dedicated methanol-fueled vehicles,this paper collects data including regulated gaseous emissions,particulate mass and number,unregulated emissions,ozone forming potential and fuel economy,from several China-V certificated new models and China-IV certificated field-aged models by conducting chassis-level tests.The results show that,for China-V certificated new methanol vehicles,when methanol is consumed,CO emission measured over NEDC is far smaller than that measured in gasoline mode,but THC and NOx emissions indicate no evident change between the two fuels.Compared to gasoline,burning methanol is able to eliminate nearly two thirds of particulate matter from exhaust,however,carbonyl emissions surge.No matter gasoline or methanol is fed to the engine,formaldehyde is always the dominant species of carbonyls.Relative to gasoline baseline,ozone forming potential measured in methanol mode reduces by more than 50%.Additionally,burning methanol instead of gasoline could cause a decrease of over 8%in tailpipe CO₂ emission.Burning methanol also promotes fuel economy remarkably,but results in a shrinkage in range.In context to new models,China-IV certificated field-aged methanol vehicles emit much more CO,THC and NOx emissions,deterioration ratio for the three pollutants is 1.76,1.40 and 2.80 respectively.Very low level of particulate number can be achieved when methanol is burned.Compared to the baseline created by new models,unburned methanol and formaldehyde emissions from field-aged methanol vehicles increased by more than100%and 82%.Although all the field-aged methanol vehicles tested have run for at least160 thousand kilometers,CO₂ emission and fuel consumption data from the test crew self-accord well,while fuel economy of field-aged methanol vehicles is a little better than the new ones.