Scale-up and cost analysis of biodiesel production using liquid-liquid film reactors: Reduction in the methanol consumption and investment cost

Abstract

Biodiesel is an important renewable fuel industrially produced by transesterification of fats and oils. Conventional process productivity is limited by high residence time in the reaction and separation stages. Liquid-Liquid Film Reactor (LLFR) is a new technology able to overcome this limitation. This work presents the scale-up, cost analysis and process feasibility for the LLFR. The study was made using a complete mathematical model which includes fluid dynamics, kinetics, mass transfer resistance, liquid-liquid equilibria, and cost evaluation. This study recommended the construction of plants with capacities over 5 t/h (about 40,000 t/year) in order to avoid over costs in the process and also recommended the employ of multiple reaction stages to reduce until 32% the global methanol consumption. Results also shows that to get a profit in this biodiesel production, the vegetable oil price must be less than 830 US$/t. Finally, it was found that the use of LLFR technology permit a reduction up to 60% in the required volume when two LLFR stages are employed in comparison to the traditional use of continuous stirred tank reactors (CSTR), this reduction promotes a final cost reduction up to 0.6% per kg of biodiesel.