The transient response of bubble columns

Abstract

A two-phase model that incorporates axial dispersion in both phases, as well as interphase mass transfer, is used to simulate the transient response of bubble columns. The time-domain solution is obtained by inverting the Laplace domain solution via a Fourier series approximation technique. Using the solution obtained, the validity of model simplifications that have appeared in the literature is evaluated by comparing the predictions of those models. These simplifications are found to give low errors only under special conditions. A parametric study of proposed pulse experiments in bubble columns simulating Fischer-Tropsch slurry reactors showed that model simplifications are invalid for these experimental conditions. Both the interphase mass transfer and the gas-phase axial dispersion affect the pulse response of the gas phase significantly.