PHIL WHITE Star-Tribune correspondent | Posted: Thursday, December 4, 2008 12:00 am
LARAMIE - Wyoming and coal were elementary school sweethearts who grew up, got married, succeeded beyond their own imaginations and now are seeing counselors to take advantage of all possible ways to maintain their "chemistry" in the face of new, global challenges.
The state of Wyoming would not look anything like it does today if huge amounts of tropical plant material had not been deposited and converted to coal beneath the surface millions of years ago. The transcontinental railroad would not have been built through southern Wyoming, creating all of the towns from Cheyenne to Evanston, were it not for the discovery of coal near what is now Hanna and Rock Springs. The town of Newcastle and its Burlington railroad would not be what and where they are today were it not for the discovery of coal for steam locomotives in nearby Cambria Canyon in 1887.
During the past 40 years many proposals for using Wyoming coal have come and gone. In the mid-1970s, for example, there was much discussion about building a coal slurry pipeline from the Powder River Basin to Arkansas. In the 1980s the state invested money in a process called "charfuel."
Wyoming's booming economy over the past 20 years would not have been possible without the presence of 100-foot seams of low-sulfur coal near the surface in the Powder River Basin. Wyoming produces about 40 percent of all the coal used in the United States today for electric power generation. Much of that coal is hauled by diesel-burning locomotives on railroads from the Powder River Basin to the Midwest and southeast parts of the country.
But most scientists today are convinced that the burning of coal in conventional power plants, and the release of millions of tons of carbon dioxide into the atmosphere by those plants, is contributing directly to global warming. CO2 and other greenhouse gases allow the high-powered energy from the sun to pass through, but then trap the re-radiation of that heat from the earth back into space.
Governmental restrictions on the unfettered release of CO2 are in the offing, most coal industry observers believe, and therein lies the rub for Wyoming's coal. Because of its low-sulfur content and cheap prices, Wyoming coal for 40 years has been able to compete with Eastern bituminous coals which require more expensive pollution-control equipment to remove sulfur. But when it comes to carbon dioxide, Wyoming coal does not have an advantage.
This problem has led the state, the University of Wyoming and General Electric Energy LLC of Houston to sign an agreement to create the "High Plains Gasification Advanced Technology Center" in Wyoming, a $100 million project to allow GE and UW scientists and engineers to develop ways to economically produce power from Powder River Basin coal while at the same time eliminating most of the CO2 released into the atmosphere.
The technology to be used is the integrated gasification combined cycle, or IGCC, model in which coal is ground up and injected into a high-pressure, high-temperature environment, releasing the energy in the coal and turning it into synthetic gas. After removal of sulfur, carbon dioxide and other pollutants, the gas is used to produce steam that turns a turbine and generates electricity.
According to Keith White, head of GE's gasification products in Houston, "the advantage of IGCC is that the volume of gas being cleaned up is highly concentrated and the cost and efficiency of that cleanup are more favorable" than trying to remove carbon dioxide after combustion in conventional power plants.
"The economics of IGCC with carbon capture and sequestration are positive in almost any study you find when compared to standard pulverized coal plants," he said. "The barrier has always been how to handle the high moisture content of Powder River Basin coal. So the initial focus will be on overcoming that barrier and supplying commercially available technology for the long-term growth of that coal."
One of the ways GE and UW will attack the moisture problem, White said, will be using a technology recently purchased by GE that allows introduction of dry coal into the IGCC instead of the coal and water slurry usually used.
Through the UW-GE advanced technology center, the scientists and engineers want to develop advanced ways to gasify and clean the coal, White said. "But we want to build the facility with the flexibility to expand into ever-increasing areas of interest" later, he said, which would include the issue of the environmental ramifications of injecting large amounts of CO2 into deep underground geologic reservoirs.
He said the ATC "is not so much simply building a specific facility to test its viability. Rather, it is a platform to test and prove out new technologies which we - or even third parties using the center - will then implement commercially into full-scale plants. The university people will be developing new technologies, and they will be able to test them at an appropriate scale to make sure they would work in a commercially viable setting."
White said Powder River Basin coal is not less attractive than Eastern bituminous coals when it comes to carbon capture and sequestration.
"This project is not just to test the viability of IGCC," he said. "The long-term viability of coal itself in a carbon-constrained world is dependent on removing carbon dioxide and storing it underground."
Another major goal of the project is "to bring engineering and research talent to the university long-term," White said, to allow UW to develop human expertise in coal gasification for the country.
"We love the idea of partnering with the university where we can be part of developing not just a facility but a pipeline of future scientists, engineers and operators for plants that will be going in like one at Edwardsport, Ind., today. There will be many more in the future."
GE is working with Duke Energy on a 630-megawatt IGCC facility at that site. "The base plant will be standard IGCC, but they are committed to studying a retrofit for the plant to remove and sequester CO2 underground," White said.
William Gern, UW vice president for research and economic development, said the agreement with GE puts Wyoming at the forefront of the "clean coal" objective, which was a constant theme of the 2008 presidential campaign.
The ATC will enable UW to research ways of making commercially valuable products from coal, he said.
"For the most part up to now, most of the Wyoming coal has been shipped out of state in its raw form," Gern said. "But if we can move coal up in value, where it's processed into something else in the state, we would increase employment in Wyoming. Running plants like this would require a trained work force, both skilled people and those at the baccalaureate level, and so there's a strong economic development piece to this project."
Gern said UW is interested in uses for the syngas from gasification, not only to produce power but also for chemical products.
"The carbon monoxide which emerges from the partial oxidation of the coal is a wonderful chemical feedstock that can be used to make diesel fuel, gasoline, alcohol, even acetate," he said.