Abstract:
In the present work the ultrasonicator parameters, such as amplitude ratio, recycle ratio and reaction time, have been optimized for transesterification reaction for both edible and non-edible oils. The soybean oil was used an edible oil while jatropha oil was used as a non-edible oil. The transesterification reaction was carried out at atmospheric pressure and the temperature was maintained in between 35–40 0C. The reaction was carried out in the presence of a basic catalyst (CH3ONa) and the amount of catalyst was constant for all the experiments. The methanol was used as another reactant. The vegetable to alcohol ratio was maintained as 1:6 on mole basis. For soybean single step reaction was carried out and the optimized conditions for a 90% FAME yield are as follows: amplitude ratio as 30 %, cycle ratio as 0.4 and reaction time 10 min. In case of jatropha oil the two step reaction was carried out due to high FFA contents present in the crude jatropha oil. The optimized parameters for transesterification of jatropha oil to obtain 86% yield are as follows: amplitude ratio as 80%, cycle ratio as 0.4 and reactions time as10 minutes.
Further the numerical modelling of oil dispersion in water has been carried out using a SMX mixer, which is a motionless mixer. The SMX mixer was considered as they are generally used for the production of biodiesel. SMX mixers are comprised of cross-link elements, which create turbulence at low Reynolds numbers. The oil dispersion in water studies has been carried out at low Reynolds numbers, i.e. 100 – 400. To trace the interface between the oil and water phase volume of fraction approach was used. The pressure drop results for single phase flow, predicted using numerical model were in good agreement with the experimental data reported in the literature. A fairly well dispersion of oil was observed in water after 6 SMX elements.
