Equilibrium Constants for the Liquid-Phase Synthesis of Isopropyl tert-Butyl Ether from 2-Propanol and Isobutene

• Published in: Industrial & engineering chemistry research Vol. 36; no. 3; pp. 896 - 902
• Main Authors: Calderón, Adela, Tejero, Javier, Izquierdo, José Felipe, Iborra, Montserrat, Cunill, Fidel
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-03-1997
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Isobutene; Catalytic reaction; Enthalpy; Activity coefficient; Alcohol; Entropy; Experimental study; Etherification; Free energy; Thermodynamic equilibrium; Thermodynamic model; Heat of reaction; Thermodynamic properties; Heat of formation; Ion exchange resin; Ethylenic compound
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie960492h

Equilibrium constants for the liquid-phase addition of 2-propanol to isobutene to give isopropyl tert-butyl ether (IPTBE) were determined experimentally in the temperature range 303−353 K and at 1.6 MPa. To reach etherification equilibrium, the macroporous sulfonic resin Bayer K-2631 was used as the catalyst. The UNIFAC estimates of activity coefficients were used to describe the liquid-phase nonideality. The thermodynamic equilibrium constants and the enthalpy, free energy, and entropy changes of the reaction were given as a function of temperature. At 298.15 K, the standard molar reaction enthalpy Δr H°m(298.15 K) is −(22.9 ± 1.3) kJ·mol-1, in agreement with literature data, and the standard molar reaction entropy Δr S°m(298.15 K) and free energy Δr G°m(298.15 K) are −(60.3 ± 0.5) J·(mol·K)-1 and −(4.9 ± 1.4) kJ·mol-1, respectively. Finally, at 298.15 K the standard molar enthalpy of formation Δf H°m(l, 298.15 K) and the standard molar entropy of IPTBE S°m(l, 298.15 K) were estimated to be −(378.5 ± 2.7) kJ·mol-1 and 337.6 ± 1.5 J·(mol·K)-1, respectively.