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Publication Citation: A Thermodynamic and Time Course Study of the Lipase-Catalyzed Transesterification of Benzyl Alcohol and Butyl Acetate in Supercritical Carbon Dioxide Media

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Author(s): Yadu D. Tewari; T. Ihara; Karen W. Phinney; M P. Mayhew;
Title: A Thermodynamic and Time Course Study of the Lipase-Catalyzed Transesterification of Benzyl Alcohol and Butyl Acetate in Supercritical Carbon Dioxide Media
Published: August 16, 2004
Abstract: The time course and thermodynamics of the lipase-catalyzed transesterification reaction (benzl alcohol + butyl acetate = benzyl acetate + 1-butanol) has been studied in supercritical carbon dioxide (SCCO2), n-hexane, toluene, and neat media (no solvent added) at the temperature T = 303.15 K. The time course data show that the rate of reaction in SCCO2 media is significantly higher than in the other solvents. In addition, the pressure dependence on the reaction quotient of the reaction was investigated over the pressure range p= 8 MPa to p = 20 MPa at T = 303.15 K. The equilibrium constant of the above reaction has been measured as a function of temperature (T=318.15 K) at p = 10.0 MPa. The equilibrium constant, standard molar gibbs energy {Δ}rG m, enthalpy {Δ}rH m, and entropy {Δ}rS ^ changes for the above reaction at the temperature T = 298.15 K are: K = 0.238 0.020, {Δ}rG m = (3.56 0.22) kJ mol-1, {Δ}rH m = (2.1 5.2) kJ mol-1, and {Δ}rS m = (4.9 17) J K-1 mol-1. The advantages of the use of supercritical carbon dioxide as a solvent for enzyme-catalyzed reactions are discussed.
Citation: Journal of Molecular Catalysis B-Enzymatic
Volume: 30
Issue: 3-4
Pages: pp. 131 - 136
Keywords: 1-Butanol;benzyl acetate;benzyl alcohol;butyl acetate;equilibrium constant;lipase;rate of reaction;supercritical carbon dioxide;thermodynamics
Research Areas: Thermodynamics, Bioscience & Health