Determination of critical conditions for the esterification of acetic acid with ethanol in the presence of carbon dioxide

Abstract

-In this work, we present the calculation of critical coordinates for the esterification of acetic acid with ethanol in compressed carbon dioxide. Determination of the critical pressure for this system is useful, since the conversion of this reaction increases with pressure in the two-phase region, reaching a maximum at the critical point. We used a calculation framework based on a coordinate transformation for molar fractions, producing a new compositional domain. For a system with five components (acetic acid + ethanol + ethyl acetate + water + carbon dioxide) and one equilibrium reaction, the compositional domain is entirely described by three independent transformed coordinates. The results obtained were compared with experimental observations presented in the literature. The results illustrate the capability of the framework used to determine critical coordinates for reactive systems, and thus its usefulness as a tool for pressure tuning for this esterification reaction in compressed carbon dioxide.

A Review on Global Optimization Methods for Phase Equilibrium Modeling and Calculations

“…Equations (24) and 25is a system of c + 2 non-linear equations in c + 2 variables: T, V and n = ( n 1 , n 2 ,…, n c ), where each element represents a nonzero perturbation in the component mole number. Note that Equations (23), (24) and (25) can be used for prediction of both homogeneous azeotropes and critical points in reactive systems if reaction invariant composition variables are used [14,17].…”