Desalination Pretreatment Using Fully Insulated Solar Air Heater

The performance of solar desalination systems based on a humidification-dehumidification approach is significantly enhanced by preheating the air coming into the evaporator. To estimate the potential benefits, we present an analysis of integrating a novel solar air heater (SAH) with a humidification-dehumidification system. An analysis of a solar desalination technology based on direct-contact humidification-dehumidification desalination combined with a novel solar air heater (SAH) is presented. The combination of both units leads to intriguing applications, such as incorporating these systems into buildings. A model of the solar thermal system is developed, and their predictions are validated with experimental data. The SAH model is combined with a previously validated model of a humidification-dehumidification. This allows us to estimate the performance of a combined SAH/humidification-dehumidification system under different environmental conditions and to evaluate the annual water treatment capacity at various sites around the world. Simulations suggest that a system with a 3.5 m² solar collector in arid regions (Middle-East, north of Africa, south-west of the USA, East of South America), has the potential to treat 30 tons of water and reduce the CO₂ emission by 150 kg annually.