ADSORPTION OF CO2 IN A CONFINED FLUIDIZED BED OF A PELLETIZED 13X ZEOLITE: FLUIDIZATION VELOCITY AND PROCESS PERFORMANCE

Previous research has shown that when a bed of particles is fluidized in a confined environment like that provided by the voids of a fixed bed of coarser spheres, bubble flow is totally suppressed in favour of an increased ability of the bed to expand homogeneously. A "confined fluidized bed" (sometimes also termed “packed-fluidized bed”) seems therefore likely to improve the efficiency of gas-solid processes for which the by-pass effect associated to bubbling represents a major drawback. To check these potentialities, the paper presents the results of an investigation on CO2 adsorption by a fluidized bed of pellets of 13X zeolite.The performances of a confined fluidized bed and that of a conventional system are compared in terms of moles of CO2 adsorbed per unit mass of sorbent, breakthrough time and fraction of bed utilized at the breakpoint. The results obtained demonstrate that confinement of the bed allows exploiting fluidization technology in adsorption operations whose thermal control also results easier.