Characterization of mass transfer coefficients and pressure drops for packed towers with Mellapak 250.X

This paper presents an experimental procedure and an extended modelling analysis aimed to characterize the mass transfer coefficients and the pressure drops of structured packings to support the design of packed absorption columns. The study is applied to Hastelloy C-22 Mellapak 250.X, an effective packing for distillation and absorption processes. The experimental campaign is performed with model aqueous solutions to separately address the mass transfer coefficients in the gas and liquid films and to evaluate the column pressure drops in the operating conditions typically adopted for absorption processes. An extensive analysis of the main available models for mass transfer coefficients and pressure drops available in the open literature is presented. Subsequently, the experiments are used to calibrate the models for the investigated packing and to select the most reliable for its thorough characterization. The predictive capacity of the calibrated mass transfer models is implemented in an ASPEN PLUS® simulation and successfully tested through a set of new desulphurization experimental data carried out on a model flue-gas at different SO2 concentrations and temperatures and with different sorbents. The calibrated simulations accurately predict the experimental SO2 removal efficiency, the wash water pH and temperature.