Intensified and Flexible Flash Degassing in a Rotating Packed Bed

Abstract

Application of flash degassing in a rotating packed bed (RPB) has been experimentally studied using oxygen removal from water as a test system. It is shown that the process can be well described by two mass transfer steps in series: an initial flash and subsequent gas–liquid mass transfer in the rotating bed. Outlet oxygen concentrations close to the flash equilibrium concentration were obtained at high angular speeds, without requiring a large degree of superheat. The rotation of the bed enhances the gas–liquid mass transfer in the packing, up to a factor 10 by increasing the angular speed from 0 to 400 rad s–1. This leads to a reduction in the required packed bed volume and possibly to an energetically more efficient operation of degassing processes. Moreover, the angular speed yields an extra degree of freedom during operating, enabling fast-responding operation at a constant outlet concentration with varying inlet conditions.