Search Results

An experimental study was conducted on in-use and new, Indian two-wheelers to study the effect of gasoline composition (olefins, aromatics and benzene) on exhaust mass emissions. Exhaust emissions of benzene were also measured. The study was conducted on six makes of new and in-use, two-wheelers consisting of popular 2-stroke and 4-stroke, mopeds, scooters and motorcycles. Three test fuels, a high olefin gasoline, a high aromatic gasoline and a Euro-III equivalent gasoline were used for the study. High olefin test gasoline contained 26.5% olefins, 10.3% aromatics and 0.3% benzene. High aromatic test gasoline contained 0.9% olefins, 61.9% aromatics and 1.5% benzene. Euro-III test gasoline contained 15.9% olefins, 37.4% aromatics and 0.9% benzene. Intake system deposit study was also conducted on 4-stroke motorcycles and two-stroke scooters having separate lubrication, using two fuels, i.e. high olefin gasoline and Euro-III gasoline, with and without the use of multi-function additives.

Ceramic Hot tubes are developed as a cost effective substrates for 2 and 3 wheelers Catalytic Converter. These are used instead of ceramic honeycomb substrates for the applications where, lower conversion is enough to meet the emission norms. Ceramic hot tubes are more appropriate for 4-stroke two wheelers which are marginally failing to meet Indian emission norms for year 2000. The low thermal expansion cordierite based ceramic hot tubes offer very high thermal shock resistance, high temperature strength, very low back pressure and adequate geometrical surface area. The unique design of this product can withstand severe thermal stresses up to 1200°C. This is required for long durability against mechanical vibrations and extraordinary temperature rise expected in Indian two and three wheelers. Hence ceramic hot tubes have advantage over metallic hot tubes. Under the present work, two different configurations of ceramic hot tubes have been developed.

Available information in the literature has been reviewed to understand the effect of gasoline composition (olefins, aromatics and benzene) on the exhaust emissions from two and four wheeled vehicles. Studies show that isolating the effect of an individual compositional characteristics may be difficult. Aromatics in the exhaust could be correlated with the aromatics in the fuel. The benzene and toluene fractions in the exhaust were sometimes more than in the fuel because of dealkylation of higher alkyl aromatics. The olefins fraction in the exhaust were also observed to be more than in the fuel. The olefin fraction was noted to be directly proportional to the sum of olefins and paraffins in the fuel, and, inversely proportional to the aromatics. Exhaust emissions of benzene may be due to benzene content in the fuel or benzene formation during combustion or over the catalytic converter due to dehydroalkylation of the alkyl benzene.