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Vehicular emissions limits have been reduced throughout the world in compliance with environmental legislations. With the rapid increase in the number of flex-fuel vehicles on the market, the consumption of ethanol has also increased. As a result, there is expected to be a large abundance of unburned alcohol from tailpipe gas emissions. Another important factor arising from the use of ethanol is the formation of tropospheric ozone. The objective of this study was to measure the amount of unburned alcohol and legislated emissions as well as the ozone formation potential of a passenger (light-duty) vehicle fueled with gasoline containing different concentrations of ethanol. The main conclusion is that unburned alcohol emissions increase in direct proportion to the ethanol content in the fuel. The unburned alcohol was measured by two techniques: gas chromatography and FTIR.

Some chemical characteristics and natural impurities of diesel fuel used in diesel engines may damage the operation of emission control devices as well as contribute to the formation of secondary pollutants in the atmosphere. Sulfur is one of the natural impurities of diesel fuel, which upon burning, combines with oxygen to form SO2, creating emissions that adversely affect both the environment and human health. Many countries around the world have adopted stringent diesel emission standards to drastically reduce the sulfur content in diesel fuel and thereby improve air quality. Many authors have addressed the need to regulate transportation fuel emissions from pollutants, including sulfur (S), carbon monoxide (CO), particulate matter (PM), nitrogen oxides (NOx) and hydrocarbons (HC). This paper addresses both regulated and non-regulated emissions from four types of diesel fuels, each with a different sulfur concentration.

In order to comply with the introduction of new emission limits, motorcycles have been equipped with electronic injection systems and three-way catalytic converters for emissions abatement. However, these converters produce unwanted reactions, such as the formation of ammonia. This paper was focused on ammonia emission reduction in motorcycles. To provide ammonia abatement, one SCR (Selective Catalytic Reduction) catalyst has been developed and installed in a fourstroke motorcycle in addition to the original one, a three way catalyst (TWC). SCR systems work by chemically reducing NOx (NO and NO2) to nitrogen (N2). This is an experimental research work conducted by the Research and Development Institute (Lactec) and the Umicore Automotive Catalysts. Regulated and unregulated emissions have been measured in a chassis dynamometer test cell.