PHASE AND REACTION EQUILIBRIA OF ACETIC-ACID 1-PENTANOL WATER N-AMYL ACETATE SYSTEM AT 760 MM HG

The esterification reaction of acetic acid and alcohol is one of the p rocesses applying reactive distillation technology. It is known that t he thermodynamic properties are essential to chemical process design. In this study, the thermodynamic behaviors of vapor-liquid equilibrium (VLE) and reaction equilibrium of acetic acid, I-pentanol, n-amyl ace tate, and water mixture were determined experimentally. Since the pres ent esterification reaction is very slow, thus, a sulfuric-aluminum ox ide catalyst prepared in our laboratory was used to accelerate reactio n rate such that the chemical reaction equilibrium will be reached ahe ad of phase equilibrium. Then this complicated problem was simplified and readily to be solved. The reaction equilibrium constants at differ ent temperatures were calculated with experimental VLE data and the re action and phase equilibrium equations. We found that the reaction equ ilibrium constant was slightly dependent on temperature. The experimen tal VLE data were correlated by the models of UNIQUAC and NRTL with th e consideration of vapor molecular association of acetic acid. Figures showing the experimental data and the calculated composition surfaces were plotted against temperature. From these figures, we observed tha t reactive azeotropy as described by Barbosa and Doherty [D. Barbosa, M.F. Doherty, 1987. Proc. R. Sec. London Ser. A, 413, 443-459.] does n ot exist for this quaternary mixture. (C) 1998 Elsevier Science B.V. A ll rights reserved.