to one of the fundamental biological processes I learned in grade school: osmosis. Osmosis explains how solutions of lower concentration flow through semi-permeable membranes into solutions of higher concentration.
The Oasys technology uses a solution containing ammonium salts that is more concentrated than seawater. The solution goes into one side of a chamber, separated by a semi-permeable membrane, with the seawater on the other side. Naturally, the osmotic pressure from the more concentrated solution pulls water through the membrane. The ammonium salts are removed from the water when a heat source converts them into carbon dioxide and ammonia gases, which are then captured and reused. What is left is potable water.
The company’s plan is to house its desalinization systems in power plants where they can use waste heat, Mandell says. In which case the firm’s process would use 90 percent less electricity than the standard desalinization systems. Those systems use hydraulic pressure to push water through a membrane in a process called reverse osmosis. Oasys plans to produce potable water for as little as 35 cents per cubic meter—much cheaper than the 80-cent to $1 cost per cubic meter of water desalinated via standard reverse osmosis, he says.
The next big test for Oasys is to scale up its process to demonstrate its usefulness to potential customers such as municipalities. The Oasys pilot system at Yale can desalinate about 264 gallons, or 1 cubic meter per day. Much of the firm’s $10 million financing will pay for a demonstration facility that can produce about 264,000 gallons, or 1,000 cubic meters of water daily, Mandell says.
Mandell estimates the annual market for water desalinization is between $20 billion and $30 billion. Plans are also to apply the technology to the much larger wastewater treatment market. Giants such as General Electric and Siemens dominate the water treatment business, but Mandell notes that his tiny startup could give them a run for their money due to the lower desalinization costs of its systems.
Desalinization systems are already in use and in demand in southern California, which doesn’t have enough local fresh water to serve its millions of people. Mandell says that California is a potential site for Oasys’ demonstration facility, with other possible sites as close as the firm’s home state of Massachusetts and faraway spots in the Middle East and Spain in the running as well. The firm plans to pick the site within a year.
