Can This Green Method Of Disposing Leftover Drilling Water Beat A Hole In The Ground?

May 30, 2017

Every day, about 200 barrels of something called produced water bubbles out of each of the roughly 9,600 shale gas wells in Pennsylvania. The water is laced with chemicals and minerals, and since energy companies have been fracking gas wells, they have tried to figure out the best way to deal with it.

Several companies ship the water to sites in Ohio where it is injected thousands of feet into the ground. It’s a cheap solution – one that Shyam Dighe, president and CEO of AquaSource is trying to beat.

“What the competition is, is the hole in the ground in Ohio, not GE or Halliburton,” Dighe said. “The drillers will take it to the cheapest disposal site. So with that in mind, three of us started this company with a very laser focus that we have to beat the hole in the ground.”

According to Dighe, the deep injection wells in Ohio charge $3 to $5 a barrel to take fracking water. Depending on how for that water is shipped, it can add an additional $18 per barrel. The practice has also likely responsible for earthquakes in areas not known for seismic activity.

His company is attempting to remove the toxins and leave behind clean water. AquaSource has built a 70 barrel-a-day demonstration facility in Mt. Pleasant that takes produced water in at one end and out the other comes distilled water and salt.

“The salt could be of road salt grade or it could be of edible quality because it’s sodium chloride,” Dighe said.

AquaSource expects to have a 6,000 barrel-per-day production unit up and running in six to eight months. That would be followed by 20-30 units of that size or larger spread across the Marcellus shale formation.

It operates on a simple concept: when water boils, it creates steam, which is pure water in gaseous form. Any impurities are left behind. In this case, it’s salt.

Sodium chloride (table salt) removed from water produce at Marcellus Shale gas wells sits on a table at the AquaSource demonstration facility in Mt. Pleasant, PA. The bottles hold heavy brine which can also be produced at the facility.
Credit Mark Nootbaar / 90.5 FM WESA

So, why is AquaSource the first to use middle school-level science to boil produced water and collect the salt? Because heating water through normal means, such as with natural gas or coal, uses and wastes so much energy that it can’t compete with the inexpensive and option of dumping it in a hole in the ground.

AquaSource instead heats the water using a plasma torch, which is created by arcing a spark between two electrodes — much like a spark plug — and then using that spark to heat a stream of gas.

“So just imagine this device is putting 10,000 spark plug energy into that gas. So the gas that comes out is at about 10,000 degrees centigrade,” Dighe said. “That gas is no different than the surface temperature of the sun.”

The leftover fracking water is then sprayed into the path of the torch and vaporized.

The secret is getting the right mix of water and heat. Not enough water and the salt will turn into a glass-like substance. But too much water will make brine.

To make the process even more efficient, AquaSource uses the energy released as the water cools, to preheat the water about to be blown into the torch.

“That’s where we got our patents,” Dighe said. “Because otherwise it’s a very simple concept. So we will use only one-fifth the energy that is required, theoretically, to boil water.”

The patented process also includes removing the chemicals originally added to the water to frack the well. It also removes the radioactive material that sometimes comes out of the ground with the water.

With the combination of energy efficiency, the ability to sell the salt and the lower cost of transporting water from the well site, Dighe said he thinks AquaSource can offer a cheaper solution than a hole in the ground, as well as a more environmentally friendly method of disposal.

Dinge said once this is perfected, he hopes to use the same technology to efficiently turn seawater into drinking water and in a decade or so, maybe even shrink the process to a unit no bigger than a refrigerator that could purify water for poor villages around the world. 

In this week’s Tech Headlines:

  • A team of researchers from the University of Pittsburgh and the University of Oklahoma said they found a better way to create ethanol than from corn. Recent studies question the efficiency of corn when the full life cycle of energy needed to produce the fuel is calculated. In an article published in The Royal Society of Chemistry journal, the group said grasses and trees could provide a sustainable fuel resource. In 2007, the United Nations called for a five-year moratorium on food-based biofuels because of concerns that they would consume farmland and lead to worldwide food shortage.
  • A French designer unveiled his humanoid DIY robot to the public last week at a technology fair in Romania. The life-size robot created by Gael Langevin responded to English-language commands and swiveling its head to follow people. The robot was made with a 3-D printer and micro-cameras. The designer imagines the robot working with children in schools and hospitals.

The Associated Press contributed to this report.