Desiccant Cooling and Dehumidification

This paper is concerned with identifying solid polymeric materials that might be used in desiccant cooling systems (DCS) that process water vapor in an atmosphere to produce cooling. Background information is presented that includes an introduction to DCS and the role of the desiccant as a system component. The experimental method for measuring water vapor sorption by desiccants is described for a quartz crystal microbalance (QCM). The water vapor sorption performance criteria are identified for narrowing the potential advanced desiccant materials (ADM) to a few candidate ADM. Measurements are presented for the sorption performance of 23 commercially available polymeric potential ADM materials with the QCM. The data include sorption isotherms, the rate of adsorption and desorption at each pressure increment or decrement, and cyclic stability. By applying the required performance criteria, the candidate polymers are: polystyrenesulfonic acid sodium salt, sodium polystyrene sulfonate, polyacrylamide-carboxyltmodified, polyaacrylic acid ammonium salt, poly (methacrylic acid) sodium salt, poly (n-vinyl-acetamide, vinyl sulfonate) sodium salt, polyacrylic acid sodium salt, cellulose sulfate sodium salt, and methyl cellulose.
This paper is concerned with solid materials used as desiccants for desiccant cooling systems (DCS) that process water vapor in an atmosphere to produce net cooling. Since mass transfer occurs between the system and its environment, these systems are commonly referred to as "open-cycle" systems (Collier et al. 1982). All these systems use a liquid or solid material called a desiccant to remove...