CAN’T CLEAN COAL

Politicians and pundits talk about clean coal technology like its ready to go but there’s no such thing right now, there’s only the hope for it in the future.

Experts debate the best way to make coal cleaner; Doubts exist on main technologies for capturing carbon
Matthew Wald, February 21, 2007 (International Herald Tribune)
- Within the next few years, U.S. power companies are planning to build about 150 coal plants…none of the plants will be able to capture the thousands of tons of carbon dioxide each will spew into the atmosphere.

- Environmentalists are worried, but they put their faith in a technology that gasifies the coal before burning because such plants are designed, they say, to be more adaptable to separating the carbon and storing it underground.
- Most utility officials counter that the gasification approach is more expensive and less reliable, but they say not to worry because their tried-and- true method, known as pulverized coal, can also be equipped later with hardware to capture the global warming gas.
- But now, influential technical experts are casting doubts on both approaches…

- A major new study by faculty members at the Massachusetts Institute of Technology, scheduled for release soon, concludes in a draft version that it is not clear which technology — the so-called integrated gasification combined cycle or pulverized coal — would allow for the easiest carbon capture, because so much engineering work remains to be done…
- Retrofitting either a gasification or pulverized coal power plant is not just a matter of adding new equipment and might be impractical, the experts say. Temperatures and pressures would be designed to be in one range for a plant that captured its carbon, and another if it merely produced electricity with minimum use of fuel. Less fuel means less carbon dioxide production.
- Adding carbon capture later also has implications for power supply.
- Early estimates are that carbon capture will require so much energy that it could reduce plant output by 10 percent to 30 percent.

- Some experts say that the best choice may vary according to the type of coal used…
- The technical assessment is certainly at odds with the hopes expressed by environmentalists…

- Others point out that carbon capture from gas made from coal has proven workable, at least at a relatively small nonpower plant that manufactures methane, but that it is still unproven at a large power plant. They say the only way to prove its feasibility is to go ahead now, rather than simply build plants to be modified later…
- Some environmentalists dispute the need for new coal plants, but unless there is very rapid progress soon in adopting energy efficiencies or developing the ability to extract and store huge amounts of wind and solar power at reasonable cost, more coal plants seem certain.
- Compared with cleaner fossil fuels, like natural gas and oil, coal is cheaper and more widely available. So finding a way to capture the greenhouse gases from these plants is critical…it is easier to remove…conventional pollutants from plants that use gasification. But they are more expensive to build, and the industry has little experience with their reliability…
- "It will work," Randy Zwirn, the chief executive of Siemens Power Generation, said of the ability to separate carbon from a gasified coal plant. "The question is, can it be done economically?"