Energy policy — oil shale: Water requirements for production of kerogen less than estimated

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From The Grand Junction Daily Sentinel (Gary Harmon):

Much of the water savings could stem from using natural gas to heat shale in place instead of using coal-fired electrical plants the size of those near Craig, the study suggests. Much also depends on the quality and quantity of what is known as “produced water,” or water drawn out of the earth as a byproduct of heating oil shale.

The study offers no assurance that an oil shale industry eventually or ever will take shape, said Greg Trainor, of the Colorado River Basin Roundtable, one of two that joined forces to commission the study by Boulder-based AMEC, a consulting, engineering and project-management company. It does, however, suggest an oil shale industry could operate with 120,000 acre-feet of water per year, down from previous estimates of 400,000 acre-feet per year.

The assumptions of the report, which forecasts the potential water demand of the industry by 2050, might also turn out to be too rosy, according to Western Resource Advocates, which monitors oil shale developments.

Much of the foundation of the study “represents industry’s hopes,” said David Abelson of Western Resource Advocates, “but with the technologies used in this report being in their infancy, whether these projections come true will not be known for a generation or two.” Previous studies of the potential water demand of oil shale have been based on the need for a dozen coal-fired power plants to generate electricity to heat shale, but it appears natural gas, an abundant energy source in the Piceance Basin, could run gas-turbine generators to produce the needed electricity, but without the water demand of a coal-fired plant. That’s one part of the reduced demand for water.

Much of the demand for water could be met through produced water, which could be used for domestic purposes, revegetation and other purposes, Trainor said.

A third factor that might reduce water consumption in western Colorado would be refining elsewhere the kerogen that results from in-situ heating of shale. Refinery capacity is available in Salt Lake City, meaning refineries wouldn’t have to be built in more remote, arid western Colorado.

Meanwhile, the economics of producing and refining kerogen for fuel still aren’t convincing. Here’s a report from the Summit County Citizen’s Voice. From the article:

A new study commissioned by an environmental group suggests that it takes nearly as much energy to produce fuel from oil shale as the process ultimately yields — and that the emissions of greenhouse gasses associated with oil shale development are disproportionately high compared to other energy sources…

The report was compiled by Dr. Cutler Cleveland, a Professor of geography and environment at Boston University. Cleveland assessed oil shale’s potential for energy return on investment, finding that, with existing technologies, fuel derived from shale has one of the lowest returns of any fuel source, falling between 1:1 and 2:1 when internal energy is counted as a cost. Cleveland said previous studies of oil shale’s energy return have left out the energy used elsewhere in the economy to produce the goods and services needed to extract fuel from oil shale. “Cleveland’s analysis is proof that the impacts to the West would far outweigh any perceived benefits,” said Sheldon. “Westerners must understand the trade-offs they will make if public lands and resources are signed over to private companies in the hopes of making oil shale a transportation fuel source,” she added.

More oil shale coverage here and here.

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