4. Pilot plant process and equipment
4.1. Biodiesel production and characterization
Biodiesel was produced from 100 L of used frying oil in the pilot
plant using the optimum conditions. A simplified process flow
schematic for biodiesel production is shown in Fig. 10. The main
reaction unit has been described in detail in a previous work
[17]. Used frying oil is stored in a 1000 kg cone-bottom tank at
room temperature. For the transesterification reaction the oil is
transferred to the main reaction tank. The main transesterification
reaction takes place in a 200 L glass steel tank with a turbine agitator.
A load cell mounted on one leg of the reaction tank measures
the reactant amounts. After preparing the alcohol solution with the
catalyst, it is added to the reaction tank. The stirred speed is fixed
at 0.02 Np. The reactants are agitated for 30 min, and then the
reaction mixture is transferred to a 400 L decanter for glycerin separation
and ester washing.