**2.2 Use of ethanol in CI engine**

Ajav E. A. and Akingbehin O.A. (2002), have made a study on some of the fuel properties of ethanol blended with diesel fuel (six blends: 5, 10.15 . . .). Some properties have been experimentally determined to establish their suitability for use in CI engines. The results showed that both the relative density and viscosity of the blends decreased as the ethanol content in the blends has increased. Based on the findings of their report, blends with 5 &10% ethanol content are found to have acceptable fuel properties for use as supplementary fuels in diesel engines.

Alan.C.Hansen, et.al, (2004), have given a detailed review on ethanol-diesel fuel blends. They have stated that ethanol is an attractive alternative fuel because it is a renewable biobased resource and it is oxygenated, thereby providing the potential to reduce the emissions in CI engines. Also, the properties and specifications of ethanol blended with diesel fuel have been discussed. Special emphasis has been placed on the factor of commercial use of the blends. The effect of the fuel on engine performance, durability and emissions has also been considered.
