Development and validation of a two phase CFD model for tubular biodiesel reactors

• Detailed evaluation of mechanisms in the transesterification reaction medium.
• First time report of viscosity and density measurements for polar and non-polar phase in the biodiesel reaction medium.
• First time report of flow visualisation results of two phase flow in a tubular biodiesel reactor.
• Development of first multiphase CFD model for biodiesel reaction medium.

The use of biodiesel as an alternative to diesel has gained increasing momentum over the past 15 years. To meet this growing demand there is a need to optimise the transesterification reactor at the heart of the biodiesel production system. Assessing the performance of innovative reactors is difficult due to the liquid–liquid reaction mixture that is affected by mass transfer, reaction kinetics and component solubility. This paper presents a Computational Fluid Dynamic model of a tubular reactor developed in ANSYS CFX that can be used to predict the onset of mixing via turbulent flow. In developing the model an analysis of the reaction mixture is provided before the presentation of experimental data, which includes flow visualisation results and temperature dependant viscosity and density data for each phase. The detailed data and model development procedure represents an advancement in the modelling of the two phase transesterification reaction used in biodiesel production.