Design of an industrial adsorption process with activated carbon for the removal of hexafluoropropylene from wet air

The design of an industrial gas adsorption column for the removal of hexafl uoropropylene (HFP) from wet air is reported. The column uses activated car bon and operates under the strongly fluctuating concentration conditions of an industrial plant. An important aspect of this study was to investigate the influence of water vapor in the feed on the performance of the adsorpti on column. During regeneration of the carbon, unforeseen reactions of HFP o n carbon occurred at elevated temperatures, imposing constraints on the reg eneration conditions. A two-dimensional mathematical model for the adsorber worked, well. Design calculations were performed on the basis of the exper imental results. The Dubinin-Radushkevich model described the adsorption eq uilibrium substantially better than did the Langmuir model. It is demonstra ted that a correct adsorption isotherm is more crucial than particle kineti cs in designing the adsorption column. Decoupling hydrodynamics from the ra te processes by filling the bed with fines of an inert material worked well , enabling the breakthrough experiments to be downscaled.