CONICET | Buscador de Institutos y Recursos Humanos

The supercritical biodiesel production process has some disadvantages such as: high reaction temperature,large molar methanol-to-oil ratios (R) and large energy consumption. To mitigate these problems, an energyintegrated process inwhich biodiesel is obtained in a continuous tubular reactor operating at a reaction temperatureof 280 °C, R=20, a residence time of 1 h and a pressure of 110 bar, is proposed. A low-cost lipid feedstock(chicken oil) was used as raw material for testing the process. The enthalpy content of the stream exiting thesupercritical reactorwas used to eliminate the unreacted methanol in an adiabatic flash drum. The operating conditionsof the adiabatic flash were optimized to meet the specification of water and methanol content in the biodieselphase and minimize the ester and acid content in the vapor phase. These conditions were: P=0.1 bar andT=178 °C. For these conditions the methanol content is 88?90% in the vapor phase and lower than 0.2% in thebiodiesel phase. A scheme was developed for an energy integrated process maximizing the heat recovery. Composition,temperature and pressure of the streams were determined and also the amount of heat exchanged ineach unit. In order to fulfill the quality restrictions the final content of FFA in the biodiesel product had to befurther adjusted by adsorption over bleaching silica.