A Bengaluru-based company has been manufacturing drinking water from air. They currently make 3,000 litres of water a day.
Called Uravu, it was initially a college project that Swapnil Shrivastav, one of the founders, worked on when he was at National Institute of Technology, Kozhikode.
In 2016, when there was a water crisis in college, Shrivastav and his team began making prototypes of equipment that could absorb moisture from air and turn it into water. But it was only in 2018, after they won $ 50,000 (Rs 42 lakhs approximately) prize for their technology that they decided to dedicate all their time to Uravu. However, it has been only 10 months since they started selling their products.
There are over 100 companies across the world that make water from air. But the technique used by Shrivastav’s team is followed by only three or four companies world wide, he claims.
“Most companies use the condensation method. But we employ a method that uses a desiccant (material that absorbs moisture) to absorb moisture and applies heat to release it,” he explains. The machine developed by Uravu has two chambers — one is an absorber and the other is a desorber. The desiccant they use is a solution of calcium chloride. In the first chamber, a fan draws in air, which reacts with the salt solution to absorb moisture.
“There are many gases in the air, like nitrogen and carbon dioxide. But through the selected desiccant material only H2O is absorbed,” Shrivastav explains. The liquid is then transferred to the second chamber where heat is applied and the absorbed moisture turns steam-like. Finally this is condensed at ambient conditions and collected as pure water. As the air lacks minerals, they add food grade minerals to the water before bottling.
Shrivastav states that Bengaluru currently requires 1.4 billion litres of water a day. “At any given point, air has 2 billion litres of water. Also, the moisture in air gets replenished every 8-10 days. On the other hand, ground water takes 1,400 years to get replenished,” he points out.
They currently sell their bottled water, at Rs 10-15 for 500 ml, to hotels and restaurants. Supermarkets are out of the question at the moment as they want to steer clear of plastic. “If we sell them in glass bottles, the prices will shoot up. And we want to avoid that,” Shrivastav shares.