Properties of Nonwoven Fabrics Containing Immobilized Superabsorbent Polymer Particles for Air Conditioning in Grain Dryers

Abstract

HighlightsThe SAP fabric adsorbed up to 1.05 times its dry weight, at room temperature SAP fabric had up to three times more adsorption capacity compared with silica gel.SAP fabric moisture adsorption rate trends are best predicted using logarithmic models.The fabric maintains high permeability in comparison with other desiccants, an average pressure drop of 0.10 millibar for 10 layers of SAP was recorded at 0.5 m/s air velocity.SAP fabric adsorption capacity remained unchanged after several cycles of regeneration by oven drying at 105°C.Abstract.In sub-Saharan Africa, maize and other cereal grains are normally sun-dried after harvesting. Post-harvest preservation techniques and conditions greatly contribute to the loss of the produce mainly due to mycotoxins infestation. There is lack of affordable and adequate technical facilities for post-harvest preservation of the produce. This research presents the findings of Superabsorbent Polymer (SAP) fabric properties, a material that is proposed for use in hybrid solar drying technology. The objective of the study was to determine the moisture adsorption capacity of SAP fabric. The experiments were carried out in an air conditioning unit, in each experiment the inlet air temperatures were maintained at a constant level of 20°C, 30°C, and 40°C, the inlet air relative humidity was varied between 50% and 90% in 10 unit intervals. It was found that the SAP Fabric had a high adsorption capacity of up to 105% of its dry weight at an air temperature of 20°C and 90% relative humidity. The adsorption rate trends are best predicted using logarithmic models which showed high initial moisture adsorption decreasing gradually to the equilibrium moisture content. The pressure drop across 3, 6, 10, and 15 layers was between 0.09 to 0.12 millibars, which showed that SAP fabric is a highly porous desiccant. There was no noticeable change in moisture adsorption capacity of the SAP when oven-dried at 105°C to regenerate it. It was established that SAP fabric is effective for use in drying air. Keywords: Air conditioning, Desiccant, Grain drying, Non-woven fabric, Superabsorbent Polymer (SAP).