Effects of Catalyst Formulation on Vehicle Emissions With Respect to Gasoline Fuel Sulfur Level

Nitric oxide detection inside the cylinder of an SI engine by direct UV absorption spectroscopy

“…Then, doping the fresh mixture with some known quantities of NO molecules was an interesting way to check the lower detection limit of this technique. In spite of the broadband absorption, mainly due to hot CO 2 oxide in the cylinder may, however, disturb the combustion process via the NO reburn reactions and its diluting effect. It was found that, stoichiometric methane/air homogeneous load conditions result in 5% and 15% of NO reduction rate, respectively when 1000 and 2000 ppm are seeded.…”

Assessment of New Vehicles Emissions Certification Standards in the Metropolitan Area of Mexico City

“…The degree of sulfur's interference appears to depend on many factors, such as the specific design of the catalyst, the range of exhaust temperatures experienced by the catalyst, the materials used to store oxygen in the catalyst, and the range of air-fuel mixtures fed to the engine (Bartley et al, 1999;EPA, 1998EPA, , 2001. Figure 4 compares the calculated percent increase in emissions when data of exhaust emissions of the average fleet are related to the fuel of lowest sulfur content Scrappage is defined as the number of vehicles removed from circulation in any given year; this value is reported as percentage of the number of vehicles in use.…”