UNITED STATES: Coal Gasification and CO2

There is a growing consensus that increased demand for electricity will cement coal's place in the energy portfolio for years to come. In fact, more than half of the electricity produced in the United States comes from coal. With demand for electricity expected to double by 2050 and renewable resources still years away from offsetting increased demand, it is clear -- coal is here to stay.

But can 'dirty' coal be used cleanly?" The answer may be a resounding yes if gasification becomes common place, researchers said today at the 2008 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston.

"Coal gasification offers one of the most versatile and clean ways to convert coal into electricity, hydrogen and other valuable energy products," said George Muntean, staff scientist at the Deparent of Energy's Pacific Northwest National Laboratory, during his presentation at the AAAS symposium entitled "Coal Gasification, Myths, Challenges and Opportunities."

PNNL scientists organized the symposium to provide an overview of how coal gasification can help meet the growing demand for clean energy.

"Gasification provides significant economic and environmental benefits to conventional coal power plants," Muntean said. Rather than burning coal directly, gasification breaks down coal into its basic chemical constituents using high temperature and pressure. Because of this, carbon dioxide can be captured from a gas stream far more easily than from the smokestacks of a conventional coal plant.

"If we plan to use our domestic supply of coal to produce energy, and do so in a way that does not intensify aospheric CO2 concentrations, gasification is critical," Muntean said. "It has the potential to enable carbon capture and sequestration technologies and play an important role in securing domestic sources of transportation fuels."

Many experts predict that coal gasification will be at the heart of clean coal technology if current lifespan and economic challenges are addressed. One significant challenge is the historically short lifespan of refractories, which are used to line and protect the inside of a gasifier. Currently, refractories have a lifespan of 12 to 16 months. The relining of a gasifier costs approximately $1 million and requires three to six weeks of downtime.

"Gasification happens in an extreme environment so the lifespan of refractories is historically low," said S.K. Sundaram, PNNL staff scientist. "Refractory lifespan must be increased before we can realize the promise of clean coal."

During the symposium, S.K Sundaram highlighted two advanced gasifier models developed at PNNL that provide a scientific understanding on when and why refractories fail at such high rates. The data collected from these models could enable advanced or alternative gasification technologies to be produced. Use of these models could extend refractory lifespans by 3 years.

"Advances in modeling will help us better understand some of the key challenges associated with coal gasification - refractory durability and lifespan," Sundaram said. "This will help reduce the capital costs of operating a coal gasifier."

During the symposium, researchers at PNNL also highlighted advances in millimeter wave technology that could be used for real-time measurement of critical parameters (temperature, slag viscosity, refractory corrosion) inside a gasifier. The millimeter wave technology, developed at PNNL, has been used for a number of different applications, from airport security to custom fit clothing.

Although in the early stages of development for this application, the technology shows promise to increase the efficiency and safety of coal gasifiers.

"Advances in gasification will help us meet demand for clean energy worldwide," Sundaram said. "Science and technology are paving the way for cleaner coal for future generations."

Source: SPX

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UNITED STATES: After US pulls plug, future unclear for 'clean coal'

The US government's decision to end funding for a "zero emissions" coal-fired power plant project has cast doubt over the future of "clean coal" to meet growing global energy needs.

The US Department of Energy in late January decided to pull the plug on funding for the FutureGen project launched in 2003 to demonstrate how coal can be burned cleanly, with carbon emissions stored underground in a process known as sequestration.

Government officials say they remain committed to the idea of clean coal, but a public spat with a public-private alliance raises doubts about any viable project.

FutureGen, a partnership with utilities and coal companies in the US, China, Europe and Australia, announced Thursday it would continue to pursue the project despite the loss of an estimated 1.1 billion dollars in US government funding, or some three-fourths of the project.

The project, which last year selected a site at Mattoon, Illinois, "is in the best position to move ahead with the urgency that the energy and climate challenges demand," FutureGen chief executive Michael Mudd said.

"The board wants to move forward with the project," said FutureGen spokeswoman Carly Baker.

"They believe it is in the best interest of the public."

But FutureGen officials said they would continue to work with the US Congress and administration officials in an effort to secure funding.

US Energy Secretary Samuel Bodman argued that FutureGen no longer needs taxpayer support.

"Innovations in technology and changes in the marketplace have created other viable options," Bodman wrote in a letter to the St. Louis Post-Dispatch. "That diminished the need for a demonstration project."

But FutureGen officials disagree. Baker said the project is developing methods "to get the technology that could be used in future plants around the world."

"There's no other plant," she said, which uses both coal gasification and carbon capture and sequestration to virtually eliminate pollution and greenhouse gas emissions, she said.

Coal has been blamed by environmentalists as a major culprit in global warming because of its high level of carbon dioxide emissions.

But it supplies about half the electric power needs in the United States and two-thirds of energy needs in China, since it costs less than most alternatives and both countries have ample domestic supplies.

President George W. Bush has long been a backer of clean coal technology, and some studies suggest coal could be competitive with other energy sources even with new technology to remove carbon and other pollutants.

Senator Dick Durbin, an Illinois Democrat, said the administration's decision to turn its back on FutureGen after years of planning was a "cruel deception."

Julie Ruggiero, a spokeswoman for the Department of Energy, said the administration remains committed to clean coal efforts but wanted to change course in face of a project with "escalating costs," much of which were to be assumed by the government.

"Coal is our nation's most abundant energy resource, and we want to burn coal more cleanly," Ruggiero told AFP. "This administration has invested over 2.5 billion dollars since 2001 on clear coal research."

Ruggiero said the administration is seeking to restructure FutureGen to establish "multiple commercial sites" and "a better balance of taxpayer and private share" of costs.

Deputy Energy Secretary Clay Sell said the government began reassessing its role after "I learned early last year that the cost estimates for this project had nearly doubled."

Sell said FutureGen would place the government at risk by surrendering the plant to mortgage holders if any of the private companies defaulted.

"Ultimately, we could not come to an agreement with the FutureGen Alliance as to how to restructure the existing project and, ultimately, we believed that the public interest mandated that we restructure our overall approach to accomplish the objectives of the FutureGen effort," Sell told a conference call of journalists.

The deputy secretary said there are over 33 plants that are being proposed using the new technology to store carbon underground.

"This fact, this changing underlying market dynamic, underpins why we believe our new approach is fundamentally better to advance the state of carbon capture and sequestration," he said.

Source: Agence France Pressee

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