Adsorption inert-purge cycle

Regenerative adsorption units can be operated by a thermal-swing cycle, pressure-swing cycle, displacement-purge cycle, or inert-purge cycle. Combinations of these are frequently employed. 

Displacement-Purge Cycle This cycle, which is somewhat similar to the previous one, differs from it in that a gas or vapor which adsorbs about as strongly as the adsorbate is used to remove the adsorbate (see Figure 1) Removal is thus facilitated both by adsorbate partial-pressure reduction in the fluid around the particles and by competitive adsorption of the displacement medium. As with the inert-purge cycle, the maximum delta loading is the equilibrium loading ... 

The simplest cycle is the so-called inert-purge cycle, shown in Figure 14.19. It is basically a two-step process of a few minutes or hours duration. First is adsorption (often with heat evolution). 

Recently, a quite different use for an inert-purge cycle has emerged the removal of large amounts (up to and exceeding 20 wt. %) of water from organic streams. Thus, inert-purge adsorption can now compete directly with azeotropic and extractive distillation and other means for a number of azeotrope-breaking separations, the most common of which is the production of dry ethanol. The process, as depicted in Fig. 

Gas bulk-separation processes consist mostly of pressureswing adsorption (PSA) variations and displacement-purge and Inert-purge processes Recently, however, a chromatographic cycle has been commercialized Below, these cycles will be discussed ... 

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