کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
71228 | 48888 | 2006 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The effect of water concentration on the activity and stability of CLECs in supercritical CO2 in continuous operation The effect of water concentration on the activity and stability of CLECs in supercritical CO2 in continuous operation](/preview/png/71228.png)
In this study the effect of the water concentration on a crystallized enzyme of Candida antarctica lipase B (ChiroCLEC™-CAB) in supercritical carbon dioxide (scCO2) is studied. The model reaction used is the enantioselective esterification of racemic 1-phenyl ethanol with vinyl acetate; the reaction is performed in scCO2 at 40 °C and 90 bar in batch and in continuous operation. Kinetic parameters have been derived from continuous experiments, leading to a catalytic turnover number of 0.95 s−1. The optimum activity is reached at low water concentrations (0.05 g L−1). At lower concentrations, CO2 is stripping water from the enzyme leading to deactivation. However, adding a small amount of water to the substrates can reverse this deactivation and the enzyme activity is restored.
Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 39, Issues 1–4, 2 May 2006, Pages 112–116