Review on nanoporous inorganic desiccant materials in the context of application in rotary dehumidifiers

Desiccants play a major role in dehumidifiers operated using desiccant wheels. Performance improvement of desiccant wheels is mostly depending on the desiccants. Good desiccant materials should have high adsorption capacity and low regeneration temperature. Researchers in the past have made several attempts to review desiccant materials that possess good adsorption capacities and low regeneration temperature but not many have reviewed the class of nanoporous inorganic desiccant materials. This class of desiccants covers three novel types – Aluminosilicate zeolites, Aluminophosphate-based molecular sieves, and Aerogels. Detail review of nanoporous inorganic desiccants is presented in this paper in the context of the applicability of desiccants in the dehumidifiers operated using desiccant wheels. Authors have attempted to cover a work of researchers who have synthesized and utilized this novel class of desiccants for dehumidification. It is important to note that nanoporous inorganic desiccants have high adsorption capacity than conventional desiccants such as Silica-gel, activated carbon, zeolites, etc., and also, it possesses regeneration temperatures in the range of 50 to 90 °C which can be easy to achieve using low-grade energy or waste heat.