Emission profiling of diesel and gasoline cars at a city traffic junction

In congested urban roads, cars must stop at intersections because of city traffic lights. As a result, pedestri- ans and traffic police personnel are exposed to pollutants emanating from the tailpipe of various vehicles at such city trafficjunctions. In this study, various gasoline- and diesel-fueled cars complying with differ- ent emission standards were tested for their emissions in simulated city traffic junction conditions. The engine exhaust from these cars was subjected to physicochemical characterization at different engine speeds under no-load conditions. These engine conditions were chosen because the cars idle at differ- ent engine speeds at a city traffic junction. Gravimetric and real-time measurements were performed for the tailpipe exhaust sampled from these vehicles. Exhaust particles were collected on 47 mm diameter quartz filter papers and subjected to gravimetric analysis for determining the total particulate mass （TPM） and trace metals while the engines were operated at two different engine idling speeds, 1500 rpm （representing low idling） and 2500 rpm （representing high idling）. At similar engine operating condi- tions, TPM and trace metals were lower for the exhaust from gasoline engines compared to the exhaust from diesel engines. Real-time measurements were performed for particle-bound poly-aromatic hydro- carbons （PAHs）, particle number and size distribution, regulated gaseous emissions and smoke opacity of the exhaust at four different engine speeds, 1500, 2000, 2500, and 3000 rpm. Particle-bound PAHs showed a decreasing trend for the vehicles that complied with stricter vehicular emission standards. Higher particle peak number concentrations were observed for diesel exhausts compared to the results for gasoline exhaust. Regulated gaseous emissions were also comoared.

An evaluation of the emission profile for two-wheelers at a traffic junction

Two-wheeler vehicles are an important mode of transportation in developing countries. However, the emissions from two-wheeler vehicles are significant. Urban two-wheeler vehicles with gasoline-fueled engines produce NOx and particulate matter emissions that affect urban air quality. During traffic light stops and programmed stops, for instance, pollutants are emitted and are dangerous to human health. In this experimental study, two-wheeler vehicles with different makes, technologies and engine capacities were tested for exhaust emissions including gravimetric and online measurements at different engine speeds and a no load condition at a simulated traffic junction. Gravimetric measurements were performed by collecting the particulate mass （at two engine speeds： 1500 and 2500 rpm） from a diluted engine-out exhaust on quartz filter paper. Next, these collected particulates were used to determine the presence of metals, as well as the benzene soluble organic fraction （BSOF）. The total particulate mass, BSOF and trace elements were slightly higher at a higher engine speed （2500 rpm）. Online measurements were performed by sampling the engine exhaust （at four engine speeds： 1500, 2000, 2500, and 3000rpm） and using online instruments to determine the particle number and size distribution, the particle-bound polyaromatic hydrocarbons （PAHs）, the gaseous emissions and the smoke opacity. Engines with higher cubic capacity emitted a higher concentration of nano-particles. The particle-bound PAH concentration increased as the engine speed increased, but this concentration was notably low for the highest engine speed tested （3000 rpm）. The regulated gaseous emissions increased as the engine speed increased for all vehicles.

Development of port fuel injected methanol(M85)-fuelled two-wheeler for sustainable transport

Due to increasingly stringent environmental pollution norms,there is a need for alternate combustion techniques and alternate fuels to keep up with changing trends.One of the viable solutions for India is the adaptation of methanol as a fuel for automotive sector.Therefore,in this study a functional two-wheeler prototype was developed,which uses M85(85%v/v methanol and 15%v/v gasoline)in an electronic control unit(ECU)controlled port fuel injected(PFI)engine.This study included comparative investigations of simulated on-road two-wheeler performance on chassis dynamometer using a gasoline-fuelled motorcycle with stock ECU vis-a-vis M85-fuelled motorcycle using recalibrated ECU.ECU recalibration exhibited that M85-fuelled vehicle was operated at relatively more advanced spark timing compared to baseline gasoline-fuelled vehicle.Performance results showed that M85-fuelled motorcycle produced relatively higher engine power and higher maximum vehicle speed compared to gasoline-fuelled motorcycle.Relatively superior acceleration characteristics(especially at higher speeds)of M85-fuelled motorcycle was another important finding of this study,indicating that M85 provided superior throttle response compared to gasoline.Comparative analysis of raw tailpipe emissions showed that modified M85-fuelled motorcycle emitted relatively higher hydrocarbon(HC),carbon monoxide(CO)and oxides of nitrogen(NO_x)emissions compared to stock gasoline-fuelled motorcycle.However,these emissions can be controlled by using adaptation of suitable after-treatment systems.