http://news.nationalgeographic.com/news/energy/2014/03/140319-5-technologies-for-greener-fracking/

t may seem strange to hear the words "fracking" and "environmentally friendly" in the same sentence.

After all, hydraulic fracturing, or fracking, in which high-pressure chemically treated water is used to crack rock formations and release trapped oil and gas, is a dirty term to many environmentalists. Critics decry the practice for consuming vast amounts of fresh water, creating toxic liquid waste, and adding to the atmosphere's greenhouse gas burden, mostly because of increased risk of leaks of the potent heat-trapping gas, methane. (See related quiz, "What You Don't Know About Natural Gas.")

James Hill, chief executive of the Calgary, Alberta-based energy services firm GasFrac, is one of a handful of technology pioneers determined to change that. Hill's company has introduced a new fracking method that uses no water at all. Instead, GasFrac uses a gel made from propane—a hydrocarbon that's already naturally present underground—and a combination of what it says are relatively benign chemicals, such as magnesium oxide and ferric sulfate, a chemical used in water treatment plants. Over the past few years, GasFrac has used the process 2,500 times at 700 wells in Canada and the United States.

"We're actually using hydrocarbons to produce hydrocarbons," Hill said. "It's a cycle that's more sustainable."

GasFrac is one of a growing number of companies, including giant GE and the oil services firm Halliburton, that are pioneering technological improvements to mitigate some of the environmental downsides to the process that has spurred a North American energy boom. (See Interactive, "Breaking Fuel From Rock.") Besides GasFrac's water-free method, other companies are working on ways to use recycled frack water or non-potable brine in fracking. Some are working on replacing harsh chemicals used in the process with more benign mixtures, or to cleanse water that's been used in fracking. Other innovators are looking to replace diesel-powered drilling equipment with engines or motors powered by natural gas or solar energy, and to find ways to find and seal leaks that allow methane, a potent greenhouse gas, to escape.

Such efforts have even won cautious support from some environmental activists, who've decided that it may be more realistic to mitigate the consequences of fracking than to fight its use.