Industrial & Engineering Chemistry Research, Vol.43, No.13, 3242-3250, 2004
Effect of adsorption on residue curve maps for heterogeneous catalytic distillation systems
Heterogeneous catalytic distallation has seen in the last few years an increase in interest from both academic and industrial researchers as a means of obtaining higher product yields in otherwise equilibrium-limited processes. One of the first steps toward the design of a reactive distillation column is the study of the system's residue curve maps (RCMs), which are normally obtained through simulation of a simple batch distillation in a heated still. Although this process always works in an unsteady state, unsteady-state phenomena, such as adsorption, are usually not considered when deriving a model. In this paper, a four-component reactive system, comprised of 2-methyl-1-butene, 2-methyl-2-butene, methanol, and tert-amyl methyl ether, is studied to determine the effects of adsorption in the RCMs. To do so, two new models that take into account Langmuir mono- and multicomponent isotherms were derived and used for the construction of the RCMs. These RCMs were then compared to those of the nonadsorptive model, and it was found that adsorption can play an important role in the process. Also, a study of the influence of two parameters and one variable, the Damkohler number (Da), the ratio of vapor flow rate to liquid holdup (R-V/L), and the temperature, on the adsorptive models was carried out, and it was found that the effects of adsorption increase for systems operating at higher Da, R-V/L, and temperature.