Biodiesel Production by Esterification of Hydrolyzed Soybean Oil with Ethanol in Reactive Distillation Columns: Simulation Studies

Abstract

Biodiesel conventional production process, by alkaline transesterification reaction, have disadvantages such as complex products separation and high feedstock costs. In this regard, production of biodiesel by esterification of fatty acids into a reactive distillation column has proved to be promising for overcoming some of these drawbacks. However, only simulation works that consider only one type of fatty acid reagent are available in the literature, and not simulations based on a real fatty material for this process. In this way, this work presents steady-state computational simulations of fatty acid esters (biodiesel) production in a reactive distillation column by esterification reaction of a new feedstock that represents the fatty acids composition of the soybean oil (hydrolyzed soybean oil) with anhydrous ethanol. Sensitivity analyses showed that the best operating conditions were the minimum reflux ratio of 0.001 and 15 theoretical stages. As to thermal analysis, it was noted that the process is optimized by increasing the energy consumption of reagent instead of the reboiler. The low thermal load on this equipment can be used in order to avoid exposure of the bottom product at elevated temperatures. Conversions close to 99% were possible with the proper choice of these operating conditions. The results show the technical feasibility of this process, and such data can be useful for the design of biodiesel processes.