Katia C. P. Gabriel, Marcilio dos Santos, A. A. Chivanga Barros, Maria Joana Neiva Correia, Angola
Biodiesel can be used as a substitute for fossil diesel. However, its high price mainly due to the costs associated to feedstock and production process is still a problem. This work presents the study on the feasibility of using palm oil produced in Angola, with an acid index between 10 - 21mg KOH/g, for biodiesel production in batch reactors and in a reactive distillation column. To find the most favorable operating conditions for biodiesel production from crude and heated palm oil, esterification and transesterification experiments were first carried out in a batch stirred reactor. The methanol/oil molar ratio varied from 3:1 to 7:1 and the catalysts/oil weight percentage varied from 0.4 to 1.2%. Finally, the produced biodiesel was analysed for the density, viscosity, acid number and refractive index using the reference methods, whereas the FAME content was measured by near infrared spectroscopy. The results show that using a molar ratio methanol/oil of 6:1, 0.8
% H2SO4 and KOH, 63 +- 2 0C and 1 hour of reaction led to the production of a biodiesel that comply with international standards in terms of the density, viscosity, acid number and FAME content. A reactive distillation column for biodiesel production was also assembled. This column enables the realization of the esterification and transesterification reactions in series. In the experiments it was possible to obtain a 96% reduction of the initial fatty acids content of palm oil but the yield of the transesterification reaction was give good conversion but, it is necessary to adjust and optimize the operating conditions, such as the reagents and catalysts flow rates and their residence time.