Mass-transfer limitations for immobilized enzyme-catalyzed kinetic resolution of racemate in a fixed-bed reactor.
A mathematical model has been developed for immobilized enzyme-catalyzed kinetic resolution of racemate in a fixed-bed reactor in which the enzyme-catalyzed reaction (the irreversible uni-uni competitive Michaelis-Menten kinetics is chosen as an example) was coupled with intraparticle diffusion, external mass transfer, and axial dispersion. The effects of mass-transfer limitations, competitive inhibition of substrates, deactivation on the enzyme effective enantioselectivity, and the optical purity and yield of the desired product are examined quantitatively over a wide range of parameters using the orthogonal collocation method. For a first-order reaction, an analytical solution is derived from the mathematical model for slab-, cylindrical-, and spherical-enzyme supports. Based on the analytical solution for the steady-state resolution process, a new concise formulation is presented to predict quantitatively the mass-transfer limitations on enzyme effective enantioselectivity and optical purity and yield of the desired product for a continuous steady-state kinetic resolution process in a fixed-bed reactor.
Xiu
G H
GH
Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, P.R. China. ghxiu@hotmail.com
Jiang
L
L
Li
P
P
D019149:Bioreactors; D002384:Catalysis; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D007536:Isomerism; D007700:Kinetics; D008433:Mathematics; D008956:Models, Chemical
D004800:Enzymes, Immobilized