BIODIESEL PRODUCTION USING SUPERCRITICAL METHANOL

P. VALLE; A. VELEZ; P. HEGEL; G. MABE; E. A. BRIGNOLE

Arcachon, France

Simposio; 9th International Symposium on Supercritical Fluids; 2009

Biodiesel is an alternative fuel for diesel engines that is gaining attention in the world. Its primary advantages are that it is one of the most renewable fuels currently available and it is also non-toxic and biodegradable. It can also be used directly in most diesel engines without requiring extensive engine modifications. The purpose of thiswork is to describe and explain the processes  involved in producing this new fuel from a non-commercial vegetable oil (Raphanus sativus L. oil) with supercritical methanol without the presence of catalyst.  In this work the transesterification of raphanus sativus L. Oil (non-commercial vegetable oil) by supercritical methanol is studied. The optimization of the process conditions was carried out based on a statistical design of experiments where the key process variables were studied over different ranges to obtain a reliable model for the efficiency of the reaction as a function of reactants residence time and temperature. The initial molar ratio was fixed at 39 of methanol to oil. The present results indicate that high conversions can be obtained at pressures of 15 Mpa at temperatures between 590 K and 610 K using a molar ratio of 39 and 20 to 25 minutes of residence time. From direct observations and the modeling of the phase behavior, a better understanding of the supercritical methanol transesterification process is obtained as well as the confirmation of the phase equilibrium predictions based on the GCA-EOS model.