July 29, 2008
Oil shale extraction has environmental cost
Method would create greenhouse gases
At a glance
Brandt's research found that over the full "life cycle" of the fuel – from its production to its combustion to power a car – fuels from oil shale produced greenhouse gas emissions that were 21 percent to 47 percent higher than those from conventionally produced petroleum fuels if the oil shale is heated underground, and about 50 percent to 60 percent higher if it's mined and heated aboveground.
July 29, 2008
WASHINGTON – Oil shale in the American West might contain three times the oil of Saudi Arabia, but getting it out of the ground would require much more energy than drilling for conventional oil does, and the result would be more greenhouse-gas emissions.
Department of Interior Secretary Dirk Kempthorne announced proposed regulations last week to start a commercial oil-shale program on public lands in Colorado, Utah and Wyoming. He said that with gasoline around $4 a gallon, "we need to be doing more to develop our own energy here at home, through resources such as oil shale."
President Bush started speaking about the prospects for oil shale in June, when he said that Congress shouldn't block regulations that would allow exploration to proceed. Congress last year blocked final regulations through September.
Bush "wasn't speaking to emissions. He was just talking about expanding more American energy," White House spokesman Scott Stanzel said. The amount of emissions would depend on what kinds of energy are used to obtain fuel from the shale, he said.
The Department of the Interior estimates that it'll be several years before the technology is ready for commercial oil-shale development. The government has given oil companies leases for five demonstration projects in Colorado and one in Utah.
Adam Brandt, a graduate student at the University of California at Berkeley's Energy and Resources Group, has analyzed the greenhouse gas emissions from converting oil shale to liquid fuels.
Brandt said that most companies had abandoned the idea of aboveground processing, which requires open pit mining and cooking the crushed rock in huge drums. Instead, they're looking at what's known as "in situ" – in place – processing, in which electricity is used to heat the underground rock slowly, while a "freeze wall" is built around the area to keep water out. Then wells are drilled to pump the oil.
Either way, the greenhouse gas emissions would be higher than conventionally produced petroleum-based fuels. They'd probably be roughly the same if nuclear power were used to convert the oil shale, Brandt said.
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