Alternative Diesel Fuel : Microemulsion Phase Behavior and Combustion Properties

The phase behavior of water, diesel, limonene, and ethanol was investigated at ambient temperature using single nonionic alkyl polyglycol ethers (C14E3). Visual inspection as well as crosspolarizers was used to detect transparency and anisotropy. Ternary phase diagrams were determined. Combustion experiments using a four-cylinder diesel engine were carried out. Isotropic water in diesel microemulsion region (L2) and anisotropic liquid crystalline region (LC) were found with all combinations. Increasing the ratio of limonene to diesel reduced the microemulsion region while the presence of ethanol increased it on the expense of the LC region. Combustion tests performed on a selected formulation from the ternary phase diagram of water, diesel, ethanol, and C14E3 revealed substantial reduction of soot, NOx, and CO2 emissions compared to neat diesel