Comparative study of solar-powered water production from atmospheric air using different desiccant materials

Abstract

In this paper, experiments have been performed in order to determine the quantity of water produced from the atmospheric air using different desiccant materials named Silica gel, Activated alumina and Molecular sieve 13 X. On the bases of experimental results, a correlation is derived among the different temperatures and water production using Central Composite Design (CCD) of Response Surface Methodology. A newly designed solar glass desiccant box type system (SGDBS), three in number, has been used. Design parameters for the production of water has been taken as depth of material from the glass is 0.22 m, inclination in angle as 30°, effective thickness of glass as 3 mm and number of glazing as single. It has been found experimentally that the maximum quantity of water produced by Silica gel, Activated alumina and Molecular sieve 13 X is 160, 20 and 35 ml/kg/day, respectively. Whereas theoretically, value of water produced by the Silica gel, Activated alumina and Molecular sieve 13 X is 600, 28 and 60 ml/kg/day, respectively.

An overview of solid and liquid materials for adsorption-based atmospheric water harvesting

“…Comparison of the water production rate of silica gel with RH <60%. Blue Silica gel, 80–82 hygroscopic silica gel, 79 silica gel, 77 silica gel + C black, 85 and orange silica gel. 83,84 …”

“…Activated alumina contains a sequence of nonequilibrium forms of partially hydroxylated alumina oxide. Kumar and Yadav 82 investigated theoretically and experimentally solar powered glass box having desiccant for the atmospheric water harvesting. The theoretical results showed about 28 mL/kg activated alumina /day, while the experimental results showed 20 mL/g activated alumina /day of water.…”

“…The theoretical results showed about 28 mL/kg activated alumina /day, while the experimental results showed 20 mL/g activated alumina /day of water. 82 Similar study 80 investigated the atmospheric water harvesting using Scheffler reflector using with 1 kg activated alumina. According to the results, water collection was about 38 mL/day of water.…”

Low temperature desiccants in atmospheric water generation.

“…Typically, in these systems, atmospheric air is sent through a solid desiccant packed bed [34][35][36][37] as illustrated in Figure 3, or a liquid desiccant [38].…”

“…Traditional desiccant systems such as silicates (like silica gel) have very slow kinetics and require relatively high temperatures (Table 1) to desorb the water [41,42]. Despite this limitation these have been installed in solar cooling systems [43] for a number of years, and recently investigated as a means to produce water from humid atmospheric air [34]. Newer materials such as halide salts and metal organic frameworks (MoF) have pushed the capacities to more than 100% of the weight of the desiccant; however, the costs and scalability of these are questionable [35,44].…”