PSA method using a composite adsorption bed comprising an adsorbent and PCM agglomerates

A PSA process for separating and/or purifying a gas mixture containing several constituents by adsorption, using one or more adsorbers that each contain at least one bed of adsorbent particles to adsorb at least one of the constituents of said gas mixture onto said adsorbent particles, each adsorber being subjected to adsorption/desorption cycles comprising steps of adsorption and of desorption, said at least one adsorbent bed contained in each adsorber comprises, in addition, particles of at least one phase change material (PCM), said PCM particles are in the form of agglomerates of several PCM microcapsules, said agglomerates being mixed with the adsorbent particles so as to form a composite bed comprising said adsorbent particles and said micro-encapsulated PCM agglomerates, wherein:

• the density of the PCM agglomerates is different from the density of said at least one adsorbent with which they are mixed in the composite bed;
• and
• the ratio of the densities of the PCM agglomerates and of the adsorbent particles (Rdensity) in the composite bed is such that:
• Rdensity≦5.5−(2·Rdiameter)
• where:
• Rdensity is the ratio of the densities of the PCM agglomerates and of the adsorbent particles;
• Rdiameter is the ratio of the equivalent diameters of the PCM agglomerates and of the adsorbent particles;
• and
• the numerators and denominators of said Rdensity and Rdiameter ratios being chosen in order to have:
• 1≦Rdensity≦3.5 and 1.0≦Rdiameter≦2.25.