화학공학소재연구정보센터
Chemical Engineering Science, Vol.51, No.19, 4489-4498, 1996
Use of the Laplace Transform Technique for Simple Kinetic-Parameters Evaluation - Application to the Adsorption of a Protein on Porous Beads
The kinetics of the adsorption of human serum albumin (HSA) onto spherical resin beads (Blue Sepharose CL-6B) in a closed stirred tank have been investigated. The differential equation with appropriate boundary conditions at the grain outer surface may be solved numerically or to various degrees of approximation. Using the Laplace transform technique to solve the equation of interest, we are able to obtain the exact solution to the problem, in the Laplace domain. We assume that equilibrium is described by a linear adsorption isotherm and that the adsorption rate is very rapid compared to diffusion in the adsorbent particles. A functional description of the experimental data in the time domain allows us to compute the corresponding Laplace transform and fit it to the exact solution, to obtain the film mass transfer coefficient, k(f), and the effective diffusion coefficient, D-e. The main advantage of this Laplace transform technique is that time-consuming numerical approaches are not needed, The two parameters are rapidly and easily found via two algebraic fits, one in the time domain followed by another in the Laplace domain. Using the parameters thus obtained, a numerical solution of the problem is in good agreement with the experimental data.