Global warming concerns have prompted the Utah Geological Survey to join a consortium of western state researchers to investigate reservoirs that could be used to permanently store the greenhouse gas emissions from fossil fuels.
Coal is known for the ability to hold significant amounts of carbon dioxide, a greenhouse gas, within the fossil fuel's molecular structure.
Coal beds at depths greater than 2,000 feet are logistically and economically difficult to mine due to high pressures and stresses.
The less likely to be mined coal deposits are present in east-central Utah in the Book Cliffs, Emery, Sego and Wasatch Plateau fields.
Deposits located within about 20 miles of Utah's coal-fired power plants are logical targets to store greenhouse gas emissions because the electricity generating facilities are close enough to the source to make a project potentially economic, pointed out the geological survey office.
Target coal deposits at depths ranging from 2,000 to 6,000 feet are present in the Blackhawk and Neslen formations of the Mesaverde group as well as the underlying Ferron and Emery sandstone members of the mancos shale.
The Utah Energy Office has inventoried the amount of carbon dioxide emitted annually by the state's coal-fired electric power plants and found that the amount varies up to 12.5 million tons depending on the size of the plant.
No deep coal deposits occur within 20 miles of the Intermountain Power plant in western Utah, indicated the state geological survey agency. But several electricity generating facilities operating near the Book Cliffs and the Wasatch Plateau are situated to take advantage of deep coal beds for sequestering greenhouse gas emissions.
The deep coal deposits in the Emery coalfield near Price are currently being tapped for stored methane gas reserves, continued the state agency.
A network of pipelines and wells is currently in place that could also be used for carbon dioxide sequestration efforts, explained the state's geological survey office.
As methane reserves in that area decline, pumping greenhouse gases into the coal reservoirs might have the added benefit of enhancing methane production by flushing out additional recoverable coal bed methane.
Based on the inventory, it appears that deep coal resources near existing coal-fired power plants in central Utah could theoretically provide adequate reservoirs to store carbon dioxide emissions for at least 35 years, or the expected life of at least several of the power plants, noted the state's geological survey office.
Whether it is technically and economically feasible to sequester greenhouse gas emissions of coal-fired power plants in deep coal beds remains the subject of future research.