The local air quality districts in the Los Angeles area were the first to implement restrictions to require that NOx emissions on natural gas fired boilers be reduced to single digit levels. Now additional states are being required to develop State Implementation Plans (SIPs) to address bringing into compliance the areas that do not meet the ozone standards set forth in the Clean Air Act Amendm...

[1] We use a chemical transport model and its adjoint to examine the sensitivity of secondary inorganic aerosol formation to emissions of precursor trace gases from Asia. Sensitivity simulations indicate that secondary inorganic aerosol mass concentrations are most sensitive to ammonia (NH3) emissions in winter and to sulfur dioxide (SO2) emissions during the rest of the year. However, in the a...

If adopted by EPA, proposed new regulations on stack emissions will force many utilities with coalfired boilers to reduce their NOx emissions to levels which are substantially lower then can be achieved with current low NOx burner technology. To meet these requirements, some utilities are anticipating the need to use selective catalytic reduction (SCR) for NOx control. New SCR catalysts under d...

[1] Soil NOx emission from agricultural regions in the western United States has been investigated using satellite observations of NO2 from the SCIAMACHY instrument. We show that the SCIAMACHY observations over a 2 million hectare agricultural region in Montana capture the short intense NOx pulses following fertilizer application and subsequent precipitation and we demonstrate that these variat...

Pollutant emissions from combustion systems are a major area of concern with today’s energy needs. Numerical simulations have helped with the design of clean and efficient combustion strategies over the years. However, with the emergence of new fuels and combustion modes, it is necessary to improve the computational models. In this research, improved NOx and soot models are developed which uses...

Lightning NOx emissions calculated using the US National Lightning Detection Network data were found to account for 30% of the total NOx emissions for July–August 2004, a period chosen both for having higher lightning NOx production and high ozone levels, thus maximizing the likelihood that such emissions could impact peak ozone levels. Including such emissions led to modest, but sometimes sign...

Pollutant emissions from diesel engines are significantly affected by fuel injection strategies that could reduce NOx and Soot emissions. For the first time and in this study, numerical simulations were performed to consider the influences of changing the injection duration in each pulse of the double injection strategies on in-cylinder parameters and pollutant emissions. Results confirmed that...

In this study, we estimated the transportation-related emissions of nitrogen oxides (NOx) at an individual level for a sample of the Montreal population. Using linear regression, we quantified the associations between NOx emissions and selected individual attributes. We then investigated the relationship between individual emissions of NOx and exposure to nitrogen dioxide (NO2) concentrations d...

In this study, the efforts to reduce NOx and particulate matter (PM) emissions from a diesel engine using both ethanol-selective catalytic reduction (SCR) of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-diesel fuel blend (BE-diesel) on an engine bench test are discussed. Compared with diesel fuel, use of BE-diesel increased PM emissions by 14% due to the increase in the soluble organic...

One of the major technological challenges for the transport sector is to cut emissions of particulate matter (PM) and nitrogen oxides (NOx) simultaneously from diesel vehicles to meet future emission standards and to reduce their contribution to the pollution of ambient air. Installation of particle filters in all existing diesel vehicles (for new vehicles, the feasibility is proven) is an effi...