An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
A Thermodynamic and Time Course Study of the Lipase-Catalyzed Transesterification of Benzyl Alcohol and Butyl Acetate in Supercritical Carbon Dioxide Media
Published
Author(s)
Yadu D. Tewari, T. Ihara, Karen W. Phinney, M P. Mayhew
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.
Tewari, Y.
, Ihara, T.
, Phinney, K.
and Mayhew, M.
(2004),
A Thermodynamic and Time Course Study of the Lipase-Catalyzed Transesterification of Benzyl Alcohol and Butyl Acetate in Supercritical Carbon Dioxide Media, Journal of Molecular Catalysis B-Enzymatic
(Accessed November 6, 2024)