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Fuel-Cell Technology Could Help Cut CO2 Pollution

A new technology might be able to strip the CO2 from power plant emissions, and generate more electricity at the same time
fossil-fueled power plant
fossil-fueled power plant



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Armed with new Department of Energy money, a Connecticut company announced this week it is moving forward with a carbon capture project that it thinks could revolutionize the technology.

FuelCell Energy is one of a handful of companies investigating how to address one of the biggest barriers in trying to capture carbon dioxide from coal plants for later storage underground, an unproved concept. The problem is called parasitic load. It refers to the phenomenon that a typical carbon capture system requires a great deal of electricity and thus saps power from a power plant and can cause electricity costs to spike by 70 percent or more.

The Danbury company's potential solution for this problem is fuel cells. The company says that fuel cells have the potential to essentially reverse parasitic load and cause a carbon capture system to generate as much as 40 percent more electricity for a power plant, rather than take away power.

"This award enables us to further advance and refine our research as we pursue this opportunity that has the potential to favorably impact public health while providing FuelCell Energy with the possibility of a new and potentially large market share," said Chip Bottone, the company's CEO.

DOE awarded $3 million for the carbon capture project with $800,000 authorized this week. The capture test will be run in a lab next year.

Carbon capture is an obvious extended use for fuel cells, said Tony Leo, vice president of application engineering and advanced technology development at FuelCell Energy.

Company fuel cells have a naturally high concentration of CO2 in their fuel stream -- about 75 percent concentration of CO2, compared to 10 percent or so from a typical coal plant emissions stream. That makes them prime candidates to be "CO2 concentration membranes," Leo said.

In its test in its Danbury lab, the company plans to mix carbon dioxide, air and nitrogen to simulate coal plant emissions and then shoot those gases into a fuel cell stack.

Because the CO2 becomes concentrated in the fuel's cell stream, the greenhouse gas is easy to strip away.

Simultaneously, natural gas is sent to the cell stack to generate electrical power that could in theory be sent back to a power plant and cancel out the parasitic load. Any extra carbon dioxide released from using natural gas this way also would be captured, Leo said.

Additionally, the greenhouse gas nitrous oxide is destroyed through a process that "is not fully understood," said Leo. That is significant, because it wouldn't occur with other types of capture systems, he said. The system also uses much less water than other types of carbon capture proposals, the company said.

Small step in the direction of commercial use
The test will be small, the equivalent of 20 kilowatts, he said. To receive the new $800,000 in DOE money this week, however, the company had to document that the technology likely would remove 90 percent of carbon dioxide from an emissions stream and keep electricity prices to a 35 percent increase if attempted at scale.

If the small test is successful, the next step is to find financing for a commercial-scale project at the megawatt level, Leo said. There also will be additional tests at Pacific Northwest National Laboratory to test impurities that can exist in actual coal-plant emissions as opposed to simulated gas streams in a lab.

FuelCell Energy's project is one of 16 awarded funds from a $41 million DOE pot established last year to test advanced capture technologies. Other companies and universities are trying out different solvents and sorbents that in theory could scrub CO2 from coal plant emissions more efficiently than the amines and chilled ammonia mixes that exist today.

Carbon capture and sequestration has never been proved at commercial scale in coal-fired power plants, and many critics think the DOE money is a waste of funds. The cost of one project can run at the $1 billion level or higher, causing critics to say that full use of CCS on most of the world's coal plants would bankrupt the energy industry and possibly spur earthquakes (ClimateWire, June 19).

At the same time, supporters say there are few alternatives, considering that coal is expected to be a dominant player globally for years to come. According to a report from the Energy Information Administration, coal is expected to generate 39 percent of the nation's electricity in 2035, despite a decline from its current level of 45 percent.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

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