Effect of desiccant coating materials on the performance of solar-powered atmospheric water harvesting system based on desiccant wheel
摘要
Water scarcity is one of the most serious issues, as many regions in the world are struggling to meet the basic water needs. Atmospheric water harvesting offers a promising solution as it converts atmospheric water vapor into the fresh drinking water. Many VCRS-based energy-intensive technologies are struggling with high operating costs and low productivity, especially in arid regions. Desiccant-based technology is rapidly gaining the ground, where the desiccant wheel effectively addresses the challenge of limited water productivity. This investigation explores the adsorption and regeneration capability of various solid and composite desiccant materials available commercially, integrated with the desiccant wheel. Initially, a mathematical model of the desiccant wheel has been developed and its results have been validated through in-situ experiments. As the double-ended open-evacuated tube solar air heater able to produce hot air up to 150 °C, this investigation uses regeneration temperature range of 80–150 °C. By increasing regeneration temperature, the performance of desiccant wheel increases in hot & dry and hot & humid climate, while in cool & dry climate, it starts to decline after 140 °C. Among all the desiccant wheel’s molecular sieve-13x/calcium chloride (MS-13x/CC) composite, desiccant wheel achieves a significant DPT of 38.3 °C in hot & humid climate at 150 °C regeneration temperature. Further, using MS-13x/CC composite desiccant wheel, this system obtained average daily water productivity around 21.28 L in cool and dry climate, while it reduced to 5.2 L in hot and dry climate. Moreover, the minimum cost of water obtained through the proposed system is 0.12 $L−1.