A STUDY OF PERFORMANCE AND EMISSIONS CHARACTERISTICS OF FUEL ADDITIVES USING THEIR BLENDS WITH DIESEL FUEL

Abstract

Fossil fuels are diminishing with each passing day and there are many emissions from the internal combustion engines. Diesel engines are widely used in many of the vehicles because of its fuel efficiency and lower fuel cost than petrol engines. They produce lower carbon mono-oxide and unburnt hydrocarbon emissions as compared to gasoline engine, but the presence of particulate matter (PM) in engine exhaust is more than that of gasoline engines. The Indian government has revised the restricted norms on the usage of the fuel keeping in mind the emissions and most of the people believe in being environmentally friendly. This research aims to reduce the emission from the diesel engine exhaust using different fuel additives, which promotes the ignition. Cetane improving substances, also known as ignition promoters added in the diesel fuel to enhance its cetane number and help in reducing overall emissions from the exhaust of the engine. Different ignition promoter additives can increase the cetane number of diesel fuel upto 12-15 and reduces carbon mono-oxide, nitrogen oxides and hydrocarbon emissions. Oxygen class cetane improvers such as Dipropylene glycol or diethyl ether, added in the diesel fuel in about 5~15% concentration increases the oxygen content of the fuel. In addition, Nitrogen class improvers such as 2-Ethylhexyl Nitrate or cyclo-hexyl nitrate are used in comparatively smaller concentration i.e. 0.1~0.3% in order to increase the cetane number of the fuel. The additives used in this work are Dipropylene Glycol, ethyl decaneperoxoate and 2- butoxyethanol. These were mixed with diesel fuel in the concentration of 10% by volume and were used to conduct experiments in a single cylinder diesel engine. The research work was divided into four stages. At first stage, diesel was analyzed for performance and emissions. At second stage, blend in diesel fuel was prepared with ethyl decaneperoxoate and Dipropylene glycol with 10% in concentration each. On third stage, 2-butoxyethanol and ethyl decaneperoxoate were used in 10% concentration each. At final stage Dipropylene glycol and 2-butoxyethanol were used in 10% concentration each. The results showed that by using these additives the percentage of smoke, carbon mono-oxide, oxides of nitrogen and hydrocarbons in the engine exhaust were reduced. Cetane number got improved upto 2-5%, Carbon mono-oxide emissions were reduced upto 20-25%, hydrocarbon emissions reduced upto 3-5%, and Oxides of nitrogen were reduced upto 4%. Generated brake power was 3-8% lower than that of mineral diesel, also brake specific fuel consumption increased by 6-8%. In addition, the efficiency of the engine was not much affected, but reduced a little bit as compared to mineral diesel. In India, cetane number of diesel fuel must be at least 48 in order to use in internal combustion engines.