Basic fuel properties of rapeseed oil-higher alcohols blends

Vegetable oils are becoming a promising alternative to diesel fuel because they are renewable in nature, can be produced locally and are environmentally friendly. But the major disadvantage of vegetable oils is their inherently high viscosity. There are different approaches to handling this problem. In this study, rapeseed oil (RSO) was blended with the higher alcohols (1-propanol, 2-propanol, isobutanol, 1-butanol and 2-butanol). The blends were prepared at proportions of 10% and 20% alcohol on the basis of volume. The key fuel properties such as density, heating value, viscosity, volatility characteristics (flashpoint and evaporation behaviour) and cetane number (CN) of the blends were measured using the International Standard methods. The results indicate that the viscosity, cold filter plugging point (CFPP), CN and heating value of the blends decrease with an increase in concentration of alcohols in the blends. The viscosity of RSO blends is also shown to be temperature-dependent and approaches that of diesel fuel at higher temperatures. These blends are much safer than diesel fuel in terms of safety for storage and transportation as they possess higher flash points than those of diesel fuel.