Estimation Of Air Pollutant Emission Factors For Motorcycle

While increased use of motor cycles in the recent years for various demands could worsen air quality, only few studies have been conducted on estimation of emission factors and characterization of emissions from motorcycle. In this study, emissions from selected six models of motorcycle based on largest market share and production rate were investigated. To investigate gaseous and carbonaceous air pollutants, such as carbon monoxide ( CO), total hydrocarbon (THC), nitrogen oxide (NOx), elemental carbon (EC) and organic carbon (OC), total 124 motorcycles between 2003 and 2007 model year were tested with regulatory driving conditions, such as CVS-40 and CVS-47 mode. These motorcycles were further sub-categorized based on their displacement (<50 cc, 50 similar to 150 cc, and >= 150 cc), type of stroke (2-and 4 strokes) and model year (2003 similar to 2005 and 2006 similar to 2007).Tested motorcycles with recent model year (2006 similar to 2007) exhibited less emissions of regulatory gaseous and carbonaceous air pollutants compared to old model year (2003 similar to 2005). Chemical analysis showed that CO present in highest concentration followed by THC and NOx for all tested motorcycles. Interestingly, two strokes motorcycle produced higher THC emission but less CO and NOx than those of four strokes. For all types of displacement and stroke, emission factors (gram per kilometer) of THC and CO except NOx with recent model year (2006 similar to 2007) showed decreased trend compared to old model year (2003 similar to 2005). In addition to this, due to mixed combustion between gasoline fuel and lubricant, two strokes motorcycle showed OC>EC emission trend.