Kinetic analysis and safety implications in biodiesel transesterification process

Biodiesel is an alternative non-petroleum based fuel, consisting of alkyl esters obtained either by esterification of free fatty acids with low molecular weight alcohols, or by transesterification of triglycerides. The latter is the most common way and refers to a chemical reaction involving vegetable oil and alcohol, catalyzed by a strong base, to yield fatty acids alkyl esters and glycerol. The realization of a biodiesel unit can pose several safety issues and inherent safety application opportunities as the production involves the transport, use and storage of hazardous materials, either flammable or toxic. A key goal of inherent safety via substitution is the provision of a clear, unambiguous information on hazardous materials and how to properly select them. To this end, in the experimental phase, we studied different alkali catalysts and the relevant reaction parameters, at laboratory scale. A simple kinetic modelling approach was developed and applied to the transesterification process allowing to provide possible minimization and simplification plant options.