From Al Gore's "An Inconvenient Truth" to heated Congressional debates about federal tax incentives for new alternative fuels, the issue of coal's place in supplying America's energy and fuel needs has taken on added importance in recent months.
A research institute at the University of Kentucky, though, has been exploring ways to increase the efficiency of converting coal to liquid fuel well in advance of national discussions of the process.
At the UK Center for Applied Energy Research (CAER), Burt Davis is refining the process to identify ways to reduce or capture carbon dioxide generated by the Fischer-Tropsch method of converting coal to diesel and other products, such as paraffin and chemicals for making plastics.
"We've been doing Fischer-Tropsch research for 15 years. In the last five years, interest in general has picked up," particularly by private companies," says Davis, the center's associate director and its chief researcher on clean fuels.
"We've done testing for 25 companies, both large petroleum companies and small startup companies," he says.
"North America is one of the world's largest coal-reserve regions. Its petroleum is declining, but coal is still the largest resource. If the United States is to become independent from foreign sources of petroleum, it has to make it from oil shale, coal or both.
We have about equal amounts of reserves of oil shale and coal, at the current rate of usage, to be able to generate petroleum substitutes for the United States for the next 200 years," Davis says.
"The dominant reason petroleum is what we use today is, it's the most efficient (fuel)," Davis notes. "It's a matter of time, as I see it, until the two (petroleum efficiency and coal-to-liquid fuel efficiency) become equal."
That efficiency equality will result from the continuing decline of available petroleum and the increased efficiency of coal-to-liquid fuel that results from researchers' efforts, he says.
Rodney Andrews, the center's acting director, says CAER's focus places the university among the leaders of researchers seeking fuels to provide energy independence.
"We're looking at new catalyst systems and new process systems to make the process be more efficient (and) be more effective, and to better control what products are made," Andrews says.
Since it opened in 1977, CAER has performed research seeking cost-effective, energy-efficient and environmentally friendly ways to use coal and carbon.
However, the low cost of oil and gasoline discouraged energy companies from seeking alternative fuels. As the cost of oil and gasoline has risen to record levels in the last few years, interest in alternative fuels has emerged, generating renewed interest in ongoing research in processes such as coal-to-liquid.
UK is one of several universities - most situated in states with large coal reserves - engaged in research to discover the best ways to convert coal to liquid.
"One of the concerns coming out right now is CO2 emissions. When you convert carbon-rich coal into a more hydrogen-rich diesel fuel, you produce carbon dioxide. You don't want to produce any more than you have to," Andrews says.
Andrews says UK researchers are considering ways to capture carbon dioxide for injection into oil wells to increase pressure and reduce the costs of pumping petroleum from existing American reserves. Such methods of carbon dioxide sequestration also trim the impact of greenhouse gases on the environment.
Andrews notes the process - which was based on formulas developed by two German chemists in the 1920s - is already proven to be successful, both scientifically and commercially.
"It's been used in South Africa for several decades," Andrews says.