Improving the saline water evaporation rates using highly conductive carbonaceous materials under infrared light for improved freshwater production

Abstract

Because of the growing population and scarcity of limited freshwater resources, one out of three people in the world do not have access to safe drinking water today; thus, there is an urgent need to address this global concern. Desalinating sea water using renewable energy concepts can be one of the most efficient freshwater solutions for water scarcity issues. We hypothesized that the freshwater scarcity problem could be addressed using effective desalination processes associated with renewable energy and highly porous materials. The primary objective of this study is to investigate the capability of enhancing the saline water evaporation rates using thermally and electrically conductive carbonaceous materials. This study used commercially available carbon felt, woven carbon fiber fabrics, and carbon fiber reinforced composites (60% carbon fiber) to evaporate the saline water with different percentages of salt concentrations. Tap water (or 0 wt% water), 1.5 wt% saline water, and 3.0 wt% saline water sources were prepared and used in the saline water desalination process under simulated solar infrared (IR) light with a power of 250 W. The test results exhibited that the carbon felt water evaporation rate was about 5.37 kg m−2 h−1 with a water temperature of 97.9 °C for 3.0 wt% saline water, which is 32% greater than the base cases and considerably higher than other selected carbonaceous materials. Here, 3.0 wt% saline water represents the average salt concentration of the earth's ocean water, and the high surface area carbon felt seems an effective solar-driven water evaporator for this water. This research provides the potential to deliberate highly durable carbon materials for future freshwater production.