2. Production of biodiesel
Vegetable oils are chemically complex esters of fatty
acids. These are the fats naturally present in oil seeds, and known
as tri-glycerides of fatty acids. The molecular weight of these
tri-glycerides would be of order of 800 kg/m3
or more. Because
of their high molecular weights these fats have high viscosity
causing major problems in their use as fuels in CI engines.
These molecules have to be split into simpler molecules so that
they have viscosity and other properties comparable to standard
diesel oils. Modifying the vegetable oils (to make them lighter)
can be achieved in many ways, including; Pyrolysis, Micro
emulsification, Dilution and Transesterification. Among these,
transesterification is the most commonly used commercial
process to produce clean and environmentally friendly light
vegetable oil fuel i.e. biodiesel.