Exergoeconomic and enviroeconomic evaluations of conventional solar still using PCM and electric heater powered by solar energy: an experimental study

• Published in: Environmental science and pollution research international Vol. 30; no. 24; pp. 66135 - 66156
• Main Authors: Abdel-Aziz, Eslam Ahmed, Mansour, Tamer M., Dawood, Mohamed M. Khairat, Ismail, Tamer M., Ramzy, Khaled
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2023; Springer Nature B.V
• Subjects: Acids; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon dioxide; Climatic conditions; Cost-Benefit Analysis; Drinking water; Earth and Environmental Science; Ecotoxicology; Egypt; Environment; Environmental Chemistry; Environmental Health; Environmental science; Heat; Humans; Mechanical engineering; Operating temperature; Paraffin; Paraffin wax; Photovoltaic cells; Pollution; Research Article; Saline water; Salvage value; Solar Energy; Solar stills; Spring; Spring (season); Summer; System effectiveness; Temperature; Waste Water Technology; Water; Water Management; Water Pollution Control; Water temperature; Egypt; Solar still; Solar heater; Desalination; Solar energy; Freshwater production; PCM; Performance
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-26761-4

Solar stills are used in distant and arid areas to convert brackish or salty water into potable water fit for human use in a simple, affordable, and effective manner. Even when PCM materials are used, typical solar systems still have minimal production per day. In this study, experimental tests were carried out in order to increase the performance of a single-slope solar still combined with PCM material (paraffin wax) and a solar-powered electric heater. Two identical single-slope solar stills were designed, fabricated, and tested under the same climatic conditions during the summer and spring seasons of 2021 in Al-Arish, Egypt. The first is a conventional solar still (CVSS), and the other is also a conventional still but with PCM and an electric heater (CVSSWPCM). Several parameters were measured during the experiments, including sun intensity, meteorological aspects, cumulative freshwater production, average glass, and water temperatures and PCM temperature. The improved solar still was evaluated at different operating temperatures and was compared to the conventional traditional one. There were four cases studied: one case without a heater (paraffin wax only) and three other cases with a heater operating at 58 °C, 60 °C, and 65 °C, respectively. The experimental results revealed that activating the heater inside the paraffin wax increased daily production (i) in the spring by 2.38, 2.66, and 3.1 times and (ii) and in the summer by 2.2, 2.39, and 2.67 times at the three above-mentioned temperatures respectively (when compared to the traditional still). In addition, the maximum rate of daily freshwater production was achieved at paraffin wax temperature of 65 °C in both spring and summer (Case 5). Finally, the economic evaluation of the modified solar still was carried out according to cost per litre. The modified solar still with a heater operating at 65 °C has a higher exergoeconomic value than the traditional one. The maximum CO
2
mitigation in cases 1 and 5 was approximately 28 tons and 160 tons, respectively.