Biodiesel production in a counter-current reactive extraction column: modelling, parametric identification and optimisation
Résumé
Reactive extraction is a potential alternative for biodiesel production, in which reaction and glycerol separation are simultaneous, increasing conversion, yield and process productivity. This paper presents a stepwise reaction-separation model for a counter-current reactive extraction column, used in homogeneous-base-catalyzed palm oil methanolysis, and the models' parameters are identified from the results of a set of experimental tests. In addition, multi-criteria optimisation of the process conditions was performed using an evolutionary algorithm. The optimum conditions provide for palm oil conversion of 97.7%, a yield to FAME of 99.5% and a process productivity of 1.4 m3 FAME h−1 m−3 in a single reaction step. Finally, a comparison of the process productivity with co-current and batch processes was made. As the counter-current reactive extraction process does not require the intermediate separation stages required in co-current and batch processes, its productivity is 1.5 and 6.9 times higher than those processes, respectively.