Comparison of Combustion, Performance, and Emissions of HSDI Diesel Engine Operating on Blends of Diesel Fuel with Ethanol, n-Butanol, or Butanol Isomer Ether DEE

摘要

The present investigation evaluates the combustion, performance, and exhaust emissions of diesel fuel in blends with either 5, 10, and 15% ethanol, or with 8, 16, and 24% n-butanol, or lastly with 8, 16, and 24% diethyl ether (DEE, an isomer ether of butanol) by volume, fueling a standard, experimental, single-cylinder, four-stroke, high-speed direct injection (HSDI), Hydra diesel engine. The tests were conducted using each of the above fuel blends, with the engine operating at three different loads. Fuel consumption, exhaust gas temperature, and exhaust smoke, nitrogen oxides (NOx), carbon monoxide (CO), and total unburned hydrocarbons (HC) were measured. The differences in combustion, performance, and exhaust emissions of those biofuel blends from the baseline operation of the diesel engine (when working with neat diesel fuel) and among themselves are compared. Fuel injection diagrams, combustion chamber pressure diagrams, and heat release rate (HRR) diagrams obtained thereof, reveal some interesting features of the combustion mechanisms. These results and the differing physical and chemical properties of those biofuels among themselves and against those for the neat diesel fuel are used to aid the correct interpretation of the observed engine behavior. With increasing percentage of all biofuels in the blends, significant reduction of smoke opacity (higher for the n-butanol case) is observed, reduction of NOx (higher for the diethyl ether case), decrease of CO, and increase of HC emissions, against the corresponding neat diesel fuel case.