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Item Sorption–desorption characteristics of dried cow dung with PVP and clay as composite desiccants: Experimental and exergetic analysis(Elsevier Ltd, 2023) Dasar, S.R.; Boche, A.M.; Yadav, A.K.; Anish, S.The present study investigates the sorption and desorption characteristics of a natural composite desiccant based on dried cow dung (DCD). Polyvinyl Pyrrolidone (PVP) and clay are used as binders with DCD. The moisture uptake capacity of composite desiccants is measured with an isotherm experiment under different DCD to binder ratios. Based on their isotherms, composite desiccants are chosen for characteristic study under different humid conditions and validated with available literature data. Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses are carried out to understand the physical properties of DCD, DCD+PVP (3:1) and DCD+Clay (3:1). Total heat load reduction, exergy efficiency and power required for these dehumidification systems are calculated for different inlet conditions. Desorption characteristics are tested at 328 K and 6% RH. Results show the maximum moisture uptake capacity of DCD and DCD+PVP as 14.42 and 14.72 g/100 g, respectively. The maximum exergy efficiency of the DCD+PVP dehumidification system is found to be 55%. Desorption time for DCD+PVP desiccant is 17 min, which is 4 and 2 min higher compared to DCD, and DCD+Clay, respectively. With this experimental study, it is concluded that the DCD+PVP has the potential to become an alternative to chemical desiccants based on their exergy efficiency and moisture uptake capacity. © 2022 Elsevier LtdItem Experimental study on sorption–desorption characteristics of natural composite desiccant with metal embedment(Elsevier Ltd, 2023) Dasar, S.R.; Anish, S.; Kadoli, R.; Yadav, A.K.The present study investigates the effect on total moisture sorption, moisture sorption rate, moisture desorption rate, and reduction in the temperature of dehumidified air of metal-embedded natural composite desiccants (MENCDs), which can be used in dehumidification systems. A natural composite desiccant, in which the unutilized portion of the spherical desiccant material is replaced with a metallic ball, is proposed. Stainless steel balls with a diameter of 4.75 and 6.35 mm are used to make different thickness ratios (TR = 1, 0.525, and 0.365) of MENCDs. The natural composite desiccant is prepared from dried cow dung and polyvinyl pyrrolidone with a ratio of 3:1. Experiments are conducted to find the optimum thickness ratio of MENCDs. The total moisture sorption, moisture sorption rate, total heat load reduction, and exergy efficiency of these dehumidification systems are investigated under different relative humidities (RH = 65% to 85%), and at a constant temperature and velocity. Desorption characteristics are tested under 328 K and 5% RH. The total moisture sorption of MENCDs with a TR of 0.365 is found to be 11.84 g/100 g, which is 17% higher compared to natural composite desiccants (i.e., TR = 1) at 85% RH, whereas, the total moisture sorption rate is 0.4 g/100 g⋅min, which is 20.57% higher for TR of 0.365 compared to TR = 1. Moisture desorption rate for TR = 0.365 is 16.66% higher compared to TR = 1. The average exergy efficiency of these systems is 60%. The average exergy efficiency of these composite desiccants with a TR = 0.365 is 9.6% higher compared to TR = 1. The average total heat load reduction for composite desiccants with a TR = 0.365 is 24% higher compared to TR = 1. The experimental study shows that the MENCDs will help to increase total heat load reduction, sorption and desorption rate, and total moisture sorption of dehumidified air with optimum thickness ratio for enhanced utilization of a composite desiccant for dehumidification systems. © 2023 Elsevier Ltd