Thermodynamic Modeling and Simulation of Biodiesel Systems at Supercritical Conditions

Abstract

Biodiesel is becoming a promising fuel in many markets in the world for being a renewable energy source and for not requiring significant adaptation in existing diesel engines. It is biodegradable and its polluting gas emissions are less harmful to the environment. Transesterification is used for the biodiesel synthesis at supercritical conditions using triacylglycerols and solvents in a heterogeneous reaction. The Peng–Robinson (PR), the volume-translated Peng–Robinson (VT-PR), and the perturbed chain statistical associating fluid theory (PC-SAFT) equations of state were using to predict the fluid phase behavior of systems containing solvents and components present in the synthesis of biodiesel at supercritical conditions. Two pure component parameters for the VT-PR equation, N and k3, and the five pure component parameters for the PC-SAFT equation, m, σ, and e as well as the associating parameters κAiBj and eAiBj, were predicted based on the vapor pressures and the saturated liquid volumes. Results were...