Dow, Dais Analytic and water innovation
The notion that water is a resource available for the taking, anytime anywhere, has fast evaporated in the last couple years as severe droughts plagued many parts of the world
While lack of clean, drinkable water has been a problem in developing countries for millennia, in the U.S. clean water has been taken for granted until recently.
Now water has a price, as farmers, real estate managers, industrial companies, food processors — and residents — in vast parts of the West and midwest have found out.
The good news is that where there’s a market need, innovation follows.
Thus innovations on recycling water, treating used water to pristine levels, and reusing water have been multiplying in the past year or two.
(Listen to "Beyond Purple Pipes" and several other sessions about water innovation at VERGE 2015 in San Jose this week.)
A few have been put into commercial use, but many are on the cusp of that transition to commercialization, waiting chiefly for the economics to make sense. Even in scarcity the true value of water is not being reflected in the market because of how water is delivered in this country.
Nonetheless, the breakthroughs are impressive and finding their way chiefly into agriculture and industrial processes.
The technology of reverse osmosis, though it has been feasible for 30 years, has been the subject of intense R&D lately and the kernel of new commercial processes. With scarcity of water — or cheap water — being felt by municipal water districts, large businesses, commercial real estate managers and farmers, research in the technology went into high gear.
“Thirty five years ago we saw the emergence of membrane technologies, particularly the beginnings of reverse osmosis technology,” said Snehal Desai, global business director for Dow Water & Process Solutions.
But when water shortages were being felt in the middle east and Australia, water businesses turned to boiling ocean water to desalinate it for other uses. The plentiful oil in the middle east made this economical.
Boiling ocean water then became the de facto method of desalination.
Now, that’s shifting, with perfections in reverse osmosis and other technologies.
“For the first time we see the possibility of shifting from thermal to electrical” purification systems for large scale water recycling, Desaid told GreenBiz.
“Reverse Osmosis allows shift from using fuel to using electrical pumps as pressure to en effect push water across a membrane. That membrane is designed to reject the salt and push the water through,” he said.
The advances they’ve invented allow those membranes to reject a whole lot more than salt and so advanced reverse osmosis is being used to purify already used water
Dow Chemical's Water Process Solutions division is the world’s largest manufacturer of reverse osmosis water purification systems.
“There’s been quite a lot of advancement in ten years,” he said, The reverse osmosis has been perfected to have much higher throughput of water and separating out increasingly tiny and even imperceptible elements that are not water. “It is also reduced cost per gallons of water when treated.
For a decade, it has been working in Carlsbad, CA with the San Diego County Water Authority water district to build and perfect a massive ocean water desalination plant to increase the region’s water supply. Now that plant is working and providing drinking water to parched Southern California communities through using an advanced reverse osmosis process to desalinate the water and also purify if of any other substance including bacteria and pathogens.
“Salts are not the only things that membranes can reject. They reject other contaminants from reused water,” he said. “Reverse osmosis has gotten to the level of purity that people are seeking” to make it a source of water.
The Carlsbad plant can produce 50 million gallons per day of desalinated water that exceeds state and federal drinking water standards. It provides water for 112,000 households.
Then, in Northern California, the Santa Clara Valley Water District has completed construction of a new water purification system that is already providing millions of gallons a day to some of its 15 municipalities. It is slowly ramping up the volume of purified water it produces.
The Santa Clara system sends water first through microfiltration process that extracts not only solids but bacteria and such.Then the water is pumped through a very slightly permeable reverse osmosis membrane that blocks any remaining toxins or non-water molecules that remain. Lastly, the water is further treated with ultra-violet light and hydrogen peroxide process.
At the moment, the route purified recycled water from both systems takes is to be pumped into aquifers after treatment. That’s not because it isn’t drinkable — it is, in fact it exceeds federal and state drinking standards. Instead it is largely because of public distrust.
California water regulators directed that recycled purified water be re-injected into the aquifer where it will travel the same routes to households and businesses. Moreover, the earth has for billions of years proven to be the ultimate recycler of water, doing a good job or restoring it to purity levels.
Even in California, reused water, though passing federal and state drinking standards, is being used for non potable uses such as agriculture or industrial cooling. Desai said the earliest adoption has been in industrial settings, where companies are already feeling the higher cost of water, and secondly in municipal or county water districts.
Other applications using reverse osmosis
The science of a membrane allowing only water molecules to pass through has generated other applications.
One of those is the cooling process in large office buildings and many industrial processes.
Often water is used to cool air in a heating-ventilation-and-cooling system. Cool water is circulated through a system to grab the heat from a room or from an industrial process, as a way to cool it down. But typically as cool water meets heat some of it evaporates into the air. Though most of the water is generally recirculated in such systems, a percentage of it evaporates in the process of meeting the hot air.
Dais Analytic, a firm just emerging from development stage into commercial operation, has a technology for preventing that water to be lost in the air - and prevent evaporated water from carrying germs with it into cooled spaces.
Again through the use of membranes — or a proprietary version of a plastic wall that allows water molecules to pass through but not air or gases — Dais has figured out a way to capture for reuse 90 percent of the water in a cooling system and prevent evaporated water from escaping into a room that is being cooled.
Therefore, says CEO Tim Tangredi, its cooling systems need much less water, half to 75 percent less water than traditional HVAC cooling systems where additional water has to be continually added to replace evaporated water.
Its nano filtration process that only allows moisture to penetrate and pass through the barrier also prevents germs from being transmitted into a cooled room, Tangredi said.
“We use a water recycling technology. On one side of the membrane is flowing contaminated water and on the other side is the cold loop of clean water. The water molecules on the dirty side are attracted to the clean side” and flow through the membrane, Tangredi explained. “The membrane, as a solid piece of plastic does not transmit air or gas or anything else through it. Only moisture can go through it.”
Dais is marketing it as a barrier to bacterial transmission and keeping the working fluid isolated in an otherwise closed system for increased safety, reducing the likelihood of passing dangerous germs and viruses.
Dais has two large customers in pilot operations. One is a steel mill with a cooling operation and the other is an petroleum refinery.
Tangredi claims the company's product is "revolutionary" but it is still transitioning from lab to commercialization, however, so it's a wait and see.