Biodiesel as a transport fuel, advantages and disadvantages: review

World energy demand is increasing due to expanding economic activity, which in turn is driven by population growth and improving standards of living. Economic activity, in one way or another, requires mobility, and this is consuming most of the world oil supply. In this regard, energy consumption in the transport sector is becoming the determining factor in sustaining ever increasing economic activity. Meanwhile, it is very evident that the transport sector is responsible for about 29% of total energy-related CO2 emissions. The possible solution suggested by many scholars, to avert the negative environmental effect of using conventional transport fuels, entails shifting to renewable forms of energy like liquid biofuels and electricity. Among the liquid biofuels, biodiesel is receiving due recognition for its environmental and fuel benefits. The use of biodiesel as a transport fuel has many advantages and disadvantages. These are associated with a number of factors including the characteristics of the raw materials used, the type of processes applied for biodiesel production, and the blending/mixing ratio with other fuels and with additives. Accordingly, this paper reviews the research carried out in relation to biodiesel as transport fuel, emphasizing the technical and economic aspects of the advantages and disadvantages of using biodiesel as transport fuel. The various biodiesel fuel properties are reviewed and the major factors affecting these properties are indicated. The main drawbacks of biodiesel as transport fuel include its inferior oxidative stability and cold flow properties as well as its cost.