DUBAI, UAE. Can you imagine a world where water is created from the air in the desert and the sun acts as a catalyst? And next, you see the desert metamorphi
In an exclusive conversation with the Wiyld media, representatives from Czech Republic Pavilion shared in length about sustainability achieved through the Solar Air Water Earth Resources or SAWER system.
The unit with the production capacity of 500 liters of water per day that uses the same technology as the container version is designed as a part of the pavilion technology, and it will irrigate an oasis growing from the sand around the pavilion. Getting water from the air and cultivating the desert into a fertile garden will be the central exhibition topic of the Czech pavilion. The twelve-metre organic structure around the building is a wonder in itself. For the first time such a massive self-supporting structure is built using fiberglass capillaries.
SAWER can turn a dry and hot desert into a green landscape and create water from the air only using solar energy. It is the technological core of the Czech Republic pavilion at EXPO Dubai 2020.
The University Center of Energy Efficient Buildings has developed the SAWER system in cooperation with the Institute of Botany of the Czech Academy of Sciences.
This unique mechanism which acquires water from the air, is used as a two-stage system.
In this stage, a desiccant – a material that binds water to itself through adsorption, is used. The desiccant eliminates the water contained in the outside air and holds it on its surface. The dehumidified air is taken back outside. At the same time, additional desert air with its natural water content is taken from the outside. It is then heated up to the point where the water vapour stuck on the surface desiccant is released into the desert air and humidifies it.
It is the most incredible stage involving desert cultivation. The system uses part of the obtained water for a special photobioreactor, an artificial medium used to cultivate microalgae to produce polysaccharides and retain nutrients in the water. A mixture of water, algae and organically bound nutrients is applied, employing a sealing system located about 20 cm below the soil surface. Plant roots get the nutritious water directly from a grooving pipeline. By pouring algae-containing water into the soil, nutrients are slowly released into the earth and other substances contained within the algae, such as plant hormones, essential for plants’ growth.
Earlier, Tomas Matuska, a civil and environmental engineering professor, a part of the team that developed SAWER in Prague, had stated, “There is a keen interest in our project, from the US to Australia.”
What is the objective of SAWER?
It works around the principle of adsorption and desorption of air humidity. The sorption unit with a desiccant exchanger sits at its core. It facilitates dehumidification of air with low content of water vapor, a typical case in desert conditions. Extracted water molecules collected in desiccant are then released at high temperatures to a smaller amount of air to increase its humidity. High humidity from the air then condenses on the built-in cooler in the unit as liquid water. Thus, unlike ordinary condensing coolers, it can effectively generate water in desert conditions.
Engineering of SAWER
This autonomous unit has production and energy containers. The first one consists of the sorption unit, water reservoir, and a plant to treat the drinking water. Its energy container has a battery repository and storage tanks for heat and cold. Both the containers have a solar roof. Drinking water can be generated and supplied autonomously by connecting the roof with the containers.
Does it need any external intervention to operate?
It doesn’t require any energy from external sources. The SAWER units can function in a completely autonomous way. To operate the solar roof takes energy (electricity, heating
Which areas can be benefited from SAWER?
Its autonomous nature makes it an ideal choice for areas lacking any infrastructure. The technology is optimized for operation in hot and dry climates (deserts). Nevertheless, other regions can also incorporate this process.
Edge over regular condensation-only units
This unit uses the total flow rate of outside air of 2000 m3/h, and its average daily production is 100 liters in the dry and hot desert environment (climatic conditions of Riyadh). In such an environment, compared to standard condensation-only units, SAWER’s water production capacity is about eight times higher. In the case of typical desert conditions (air temperature: 30 °C, relative humidity: 20 %), it produces 8 liters of drinking water every hour, while mere cooling of the air using a cooler with the surface temperature of 5 °C does not produce any water at all.
Can it produce drinkable water?
As the last stage of SAWER technology, EuroClean has developed the WatiMin remineralization unit. Raw water is filtered, disinfected and remineralized in the WatiMin device, making it drinkable for humans and livestock. Using this remineralization device, the required concentration of minerals, such as calcium, magnesium and potassium, can be set.
As an experiment the first version of SAWER was successfully installed and tested in the desert near the city of Sweihan in the United Arab Emirates. Later, it returned to its parent production country.