Is Clean Coal the Solution?
It seems like the ideal solution to the climate change problem keep burning coal, but do it without sending millions of tons of carbon dioxide into the atmosphere.
That's the "Clean Coal" solution. But it's a controversial idea.
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At Ohio State University researchers are trying to figure out if there is such as clean burning coal. It's run by chemical engineering professor Liang-Shih Fan. A student in the lab, Shwetha Ramkumar, is testing a method to capture carbon dioxide with calcium.
"This is a pilot scale demonstration of the calcium-based process," says Ramkumar.
Ramkumar says the method involves directing the exhaust of a standard power plant into a mixing device. The machine injects calcium powder into the stream of gas. The calcium reacts with the CO2, and captures the greenhouse gas by converting it into something else: Calcium Carbonate.
"And actually Calcium Carbonate is just limestone," says Ramkumar.
But emitting tons of limestone powder into the air instead of CO2 is not much better. So, Ramkumar says her group uses a particle separator to extract the limestone from the exhaust.
"This will separate the calcium from the gas and the gas will now be free of CO2 emissions, so then this is a clean technology," says Ramkumar. A special machine - called a calciner - then breaks the limestone back into calcium and pure CO2. The calcium is recycled for another capture process, while the CO2 is isolated for storage.
Most people agree on this part of the clean coal process. But... then what?
"It's one thing to capture the carbon dioxide it's a second thing what do you do with it?" says McConnell.
Charles McConnell oversees the clean coal research activities at Battelle. He explains the different options on the table.
"Actually injecting it deep underground into the large saline aquifers and other geological formations far down below the earth's surface in areas where it can be safely and effectively stored for 100s of years going forward," says McConnell.
But it's unclear whether it's possible to lock up a greenhouse gas - safely - for 100s if not 1000s of years.
Another challenge is cost. Clean coal technology is expensive because it requires a lot of energy. For every four new power plants that would be built with clean coal technology, one of them would have to be entirely devoted to powering the clean coal process. McConnell questions what impact clean coal will have on the cost of electricity.
"Nobody really knows what the impact economically will be," says McConnell.
Developers have yet to build a clean coal power plant in the US. And out of some 200 power plants planned for construction, virtually none of them incorporates blueprints for clean coal technology.
Joe Lucas is a vice president for The American Coalition for Clean Coal Electricity. The coalition spent 10s of millions of dollars in TV ads aimed at rallying public opinion around clean coal.
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Lucas says the technology is too new for companies to heavy investments in planning or construction.
"What we're doing is that right now we're in the demonstration phase. This is a process where you have to walk before you run," says Lucas.
Walking' in clean-coal research means testing the technology on small boilers instead of full-scale power plants.
Kate Rooth is with Greenpeace and maintains its website - Coal-Is-Dirty.Com. She says her organization opposes any process of electricity generation with coal - even clean coal.
"It covers a wide range of issues - not just carbon capture and storage. But other problems we have with mining," says Rooth.
Rooth says Greenpeace advocates for the use of renewable energy resources.
"We need to rather focus on alternatives to get us off completely off global warming," says Rooth.
Whether coal can be clean or not, there is a good chance the coal industry will have to do something about its CO2 emissions. The cap-and-trade bill - which passed the House - asks for an 80% reduction in greenhouse gas emissions by 2050.
Battelle's Charles McConnell says these guidelines are asking a lot from clean coal technologies.
"Are these technologies available today at those scales, demonstrated, and cost effective? And the answer is, no, they're not," says McConnell.
Regardless of what happens to the Cap-And-Trade bill as it goes through the Senate, McConnell suggests leaving emotions aside.
"Everyone has their own opinion. The answer will lie in the truths that science brings. And taking the emotion out of the issue what will the technology do?," says McConnell.