Effect of gasoline/methanol blends on motorcycle emissions: Exhaust and evaporative emissions

The emission characteristics of motorcycles using gasoline and M15 (consisting of 85% gasoline and 15% methanol by volume) were investigated in this article. Exhaust and evaporative emissions, including regulated and unregulated emissions, of three motorcycles were investigated on the chassis dynamometer over the Urban Driving Cycle (UDC) and in the Sealed Housing for Evaporative Determination (SHED), respectively. The regulated emissions were detected by an exhaust gas analyzer directly. The unregulated emissions, including carbonyls, volatile organic compounds (VOCs) and methanol, were sampled through battery-operated air pumps using tubes coated with 2,4-dintrophenylhydrazine (DNPH), Tenax TA and silica gel, respectively. The experimental results showed that, for exhaust emission, compared with those from gasoline fueled motorcycles, the concentration of total hydrocarbons (THC) and CO from motorcycles fueled with M15 decreased by 11%e34.5% and 63%e84% respectively, while the concentration of NOx increased by 76.9%e107.7%. Compared with those from gasoline fueled motorcycles, BTEX from motorcycles fueled with M15 decreased by 16%e60% while formaldehyde increased by 16.4%e52.5%. For evaporative emission, diurnal losses were more than hot soak losses and turned out to be dominated in evaporative emissions. In addition, compared with gasoline fueling motorcycles, the evaporative emissions of THC, carbonyls and VOCs from motorcycles fueled with M15 increased by 11.7%e37%, 38%e45% and 16%e42%, respectively. It should be noted that the growth rate of methanol was as high as 297%e1429%. It is important to reduce the evaporative emissions of methanol fueling motorcycles.