Applications of Clay Based Composite Materials in Adsorptive Separation and Purification of Gases

Being versatile in nature the clays are being extensively explored for their use in developing selective adsorbent materials, which can be further applied for selective gas separation and purification. In this article, a small preface to different categories of clay based materials has been made and further some selected patents, involving the use of claybased materials for selective gas separation and purification have been reviewed. Amongst different applications clays have widely been used either as a binder, to support microporous active adsorbent in composite materials or as chemically modified selective adsorbent. A range of composite materials with zeolites, silica, activated carbon and modified clays as well as their corresponding applications has been detailed. These materials have gained much attention for their frequent use in the process of natural gas purification, O2 and N2 separation from air, and separation of toxic or valuable gases from exhaust. In most cases, the developed materials were employed with Pressure swing adsorption or Thermal swing adsorption techniques.