Utilization of solar energy for sea water and brackish water desalination using vacuum pressure and number of trays variations

Universitas Trisakti, Environmental Engineering Department, Faculty of Architecture Landscape and Environmental Technology, Jakarta, Indonesia

^* Corresponding author: author@e-mail.org

Abstract

Surface water pollution caused by industrial, agricultural, and domestic waste limit the availability of clean water sources. One solution is to use sea water as a source of clean water. Seawater desalination using solar energy is now growing. The purpose of this research is to study the effectiveness of desalination equipment with variation of vacuum pressure, number of trays, and type of feed water. First, the environmental conditions were measured, i.e. the intensity of solar radiation, ambient air temperature, and relative humidity. Then the distillator efficiency by variation of vacuum pressure, number of trays, and type of feed water was measured. From the result of observation, it was found that with radiation intensity ranged from 3967.86 - 6459.99 W/m2.day, ambient air temperature 22 - 28°C, and relative humidity 55 - 80%, distilled water produced was 7595 - 11,146 ml/day. The distillator efficiency for pressure of -0.05; -0.1; -0.15, -0.2; -0.25; -0.3 bar respectively were 25.54; 29.45; 29.56; 30.18; 30.90; and 37.77%. Distillator efficiency for evaporator from without tray until five trays were 24.89; 29.01; 27.88; 30.03; 34.05; and 37.77%. It was found that optimum distillator efficiency achieved at vacuum pressure of -0.3 bar and five trays in evaporator. Distillator efficiency for sea water (efficiency of 21.79%) was lower than brackish water (efficiency of 37.77%).