A look at the technological advances in extracting tar sands oil that could help mitigate environmental impact
While hundreds of people (including actress Daryl Hannah and climate scientist James Hansen) have been arrested outside the White House, the Obama administration has been edging toward approval of the tar sands oil pipeline they’re protesting.
The State Department has offered its blessing to the project, and earlier this week Energy Secretary Steven Chu said that the technological advances in extracting tar sands oil were already mitigating its environmental impact. “The companies that are extracting these tar sands are making great strides in improving the environmental impact of the extraction of this oil and will continue to do so,” he said in an interview with energyNOW! We asked the Department of Energy which technologies, exactly, the secretary was referring to, but we haven’t heard back.
The tar sands oil industry points to a couple of innovations, though, as evidence of its efforts to green what’s always going to be, on some level, a dirty business. Tar sands oil is denser than conventional oil and comes mixed with clay, sand, and water. Extracting the oil from this mess takes more energy and creates more greenhouse gas emissions than extracting conventional oil. Tar sands extraction also requires huge amounts of water: Companies use hot water to separate the oil from the clay and sand. Some operations use steam to coax thick oil to the surface when it's too deep to be dug out from the ground.
Suncor, the first company to mine tar sands in Canada, still leads the industry. The company has developed two techniques to address water issues. The first is called “Zero Liquid Discharge,” and it involves capturing and recycling the water pumped into the ground to extract oil and the excess water from the tar sands that comes up with the oil. The company says that by treating and reusing it as injection steam, it can recycle more than 90 percent of the water it uses.
Another huge problem for the industry is the "tailing ponds," which hold the water, sand, and clay that’s been separated from the oil. Dumped into ponds, the water will eventually separate from the sand and clay on its own, but that process takes decades. Suncor has developed a technique for “tailings management,” which involves taking a slush of fairly concentrated water and clay and spreading it on a beach, where it dries more quickly. The company then scoops it up and uses it in construction materials or to fill back in the ponds.
The techniques “have been helpful in raising the bar,” said Jennifer Grant of the Pembina Institute, an environmental think tank in Canada. The government only set standards for tailings management in 2009, and although Suncor has made some strides, the industry as a whole is having a hard time meeting the standards.
Paul Painter, a Penn State scientist, has developed a process that could help. He says this new way of separating tar sands from clay and water takes much less energy and water than the techniques the industry has relied on. The technique uses an ionic liquid (basically, water with certain types of salt in it) to separate tar sands’ components. Unlike water, the ionic liquid doesn’t have to be heated up to function.
Painter says that when he first developed the process, oil sands companies weren’t that interested in it, because of its potential costs. In the past few months, though, he’s been working with “one or two investors” on putting the idea into practice. But he’s found it slow-going. “Making a large industry change its habits is very difficult. They've got a huge investment in what they do now,” he says.
What worries tar sands skeptics, though, is not only how companies are extracting the oil, but how quickly they’re expanding. Although the per-barrel emissions of tar sands oil dropped in the past two decades, the total emissions from the sector grew. And Canada’s federal environmental agency has predicted that by 2020, despite efforts to draw down carbon, Canada’s total emissions will have increased, because the jump in emissions from the tar sands sector will have wiped out all other gains.
“Despite project specific improvement, things are going to get worse,” said Grant. “We’re just talking about small steps towards improvement, and cumulatively it's not helpful.”
Photo via Penn State