Feasibility of diesel–biodiesel–ethanol/bioethanol blend as existing CI engine fuel: An assessment of properties, material compatibility, safety and combustion

The global fossil fuel crisis and emission problems lead to investigations on alternative fuels. In this quest, a successful finding is the partial substitution of diesel with ethanol/bioethanol rather than completely replacing it. These blends of diesel and ethanol/bioethanol can be used in the existing CI engines without any major modifications and the most significant result of using this blend is the lower emission with almost the same performance as of diesel fuel alone. Two major drawbacks of using this blend are low miscibility of ethanol/bioethanol in diesel and low temperature instability of produced blend. However, biodiesel can be successfully added to prevent the phase separation of diesel–ethanol/bioethanol blend. Thus, this blend becomes stable even at lower temperatures and more amount of ethanol/bioethanol can be added to them. It is found that a maximum of 25% biodiesel and 5% of ethanol/bioethanol can be added to the diesel fuel effectively. Adding ethanol/bioethanol to diesel fuel alters the properties of the blend, which does not meet some of the standards. Biodiesel addition to this blend helps in regaining the fuel properties to the standard values and thus the blend can be efficiently used in the existing diesel engines. From the review, it can be said that, the use of diesel–biodiesel–ethanol/bioethanol blend can minimize the use of diesel fuel by approximately 25–30%.