Theoretical and experimental investigation of potable water production from atmospheric air with an alternative device design with solar tracking system

This study was conducted to investigate clean water generation from atmospheric air theoretically and experimentally in the climatic conditions of Kirkuk City, Iraq. Blue Silica gel and a composite material were used as desiccant materials, and a single-slope apparatus composed of two identical sections isolated from each other, having dimensions of 56 x 68 x 82.5 cm3 for each, was employed. An acrylic sheet was used as a condensation surface, and an internal reflector was used to increase the desiccant temperature. Also, a solar tracking system was used to track the sunlight throughout the day, and a DC motor was employed to rotate the device with the sun's movement. The procedure involves humidity adsorption during the night and humidity desorption and vapour condensation to produce water droplets during the day. The results of the regeneration process were predicted theoretically using the fourth-order Rung-Kutta method in the MATLAB program, and the cost of water production was calculated using a cost analysis. The experiments were done for five months, and a comparison was made among the results of the months for both desiccants, between the results of Silica gel and the composite material, and between the theoretical and experimental results of Silica gel. The results showed that the theoretical accumulated productivity was notably higher than the collected one, the productivity of Silica gel was higher than the composite material, and the yearly cost of producing water was 2.54 $/L. Also, the highest productivity was found to be 160 g/m2 and 83 g/m2, with a system thermal efficiency of 19 % and 10 % for Silica gel and composite material, respectively.