American Journal of Mechanical Engineering. 2014, 2(6), 151-158DOI:
Abstract: The high energy demand in the industrial world and domestic sector as well as the pollution problems caused by emission from the use of fossil fuels as lead to an intensive research in alternative fuels sources with lesser environmental impact. One possible alternative to fossil fuel is biodiesel from vegetable oils which are currently being investigated in detail for application in compression ignition (CI) engines to increase energy security, reduce gas emissions and enhance its usage in diesel engines with little or no modifications. The objective of this study is to investigate the effects of biodiesel blends from Neem oil in CI engine and its corrosion rate in copper and mild steel samples. The corrosion rate of Neem biodiesel and diesel were both tested in copper and mild steel respectively. The test revealed that Neem biodiesel corrodes both test samples more than diesel. Combustion performance and emission characteristics of a single cylinder, four strokes and air-cooled diesel engine when fuelled with diesel and Neem-diesel blends at various loads was evaluated. The results showed that specific fuel consumption is better with diesel than the blends. Blends up to B20 showed higher torque, brake power and brake thermal efficiency than diesel at all loads. NOx emission increased with increase load in all the tested samples, with diesel having the least value. Fuel-Air ratio values of Neem oil biodiesel blends are less than diesel, it increases with increased load and decreased with increased blend ratio. However, there was an appreciable decrease in HC and CO emissions with increased load while there was variation in CO emissions with increased blend ratio and a decrease in HC emission. This behaviour is better with the blends than diesel due to higher oxygen content and lower carbon to hydrogen ratio in biodiesel compared to diesel.