How does the bio-diesel derived from castor oil rate on the above aspects?
Ash content: Castor oil has an ash content of about 0.02% Sulfur %: is less than 0.04% Potassium: Negligible Heating value: 39.5 GJ/T. At this number, it compares favourably with most vegetable oils. Petro-based diesel & gasoline have heating values of approximately 45 GJ/T. Hence, one could say that most biodiesel, including that from castor, have heating values that are about 10% lower than that for gasoline or petro diesel. Viscosity: Castor oil in its raw form is one of the most viscous of oils (9.5 10.0 dPa.s @ 20 degress C about 990 cP). The other plant oils, in themselves, have viscosities much higher than those for gasoline and petro-diesel. Castor oil has a viscosity of over 100 times that of petro-diesel! One can hence see that viscosity could be a major bottleneck in castor oil becoming a biodiesel. However, this high viscosity can be considerably reduced by subjecting the vegetable oils to the process of transesterification. Transesterification is the process most commonly
