Listen Now(Part one of a two-part series. Listen to part two here.)Welcome to the guts of the world’s largest coal-fired power plant. The gigantic boiler inside American Electric Power’s Mountaineer plant in West Virginia incinerates up to 12 thousand tons of coal every day. It generates enough power to juice up 200 New Havens—the plant’s hometown on the Ohio River. It also sends more than 9 and a half million tons of carbon dioxide into the atmosphere every year. But that’s about to change.
Project manager Brian Sherrick leads a group past the boiler and up onto the roof, to point out some new equipment on a smokestack.“You look down the stack, you see duct work, going into the side of the stack. On the far side of the absorber outlet hood, you see two white pieces of duct work," says SherrickSherrick is describing the plant’s brand new system of pipes and tanks designed to cull the global warming gas before it goes up the stack."That’s the inlet and outlet duct work for the CO2 capture process.”"So this is where the CO2 as a fluid will get transported over to the booster pump for injection into the two injection wells. So all this capture process on the back end comes down to this four-inch CO2 pipe," Sherrick says.That process is the chilled ammonia method, developed by French company Allstom. AEP keeps the details secret, but basically they’ve fine-tuned a way to say a chemical “come hither” to the CO2 before it hits the stacks, coax it into this new structure, compress it, and shoot it into a deep underground reservoir of salt water and sponge-y rock for good. What makes it different is the amount of energy it takes to do. Plant managers call it “parasitic load.” Other methods can take nearly 30 percent of a plant’s power. But Sherrick says this takes less.
"The goal of Allstom’s chilled ammonia process is to get somewhere down to 10 to 15 percent. Also, as you scale up the technology, you’ll have some efficiencies that you gain because you’ll be able to use the same size pump or motor as you did here.”AEP is betting more than 70 million dollars on the process, along with partner investors. Other industry leaders, like E.on vice president John Voyles, aren’t convinced the technologies are ready to deploy yet.
“It will take 25 to 30 percent of the output from any particular unit just to run that equipment. And obviously all of the electric generators that are installed and running today are there to serve customers’ needs. So, there will be a cost to install that equipment that certainly will impact customer bills and rates," says Voyles.And a cost to replace the electric generation that goes into capturing the carbon dioxide. Which could mean using more coal. It’s a conundrum. Voyles says E.on has invested in carbon capture and sequestration research. And he believes legislation requiring carbon reductions is inevitable. But it may be sooner than we think. For the first time in many years, both lawmakers and regulation writers are tackling plans to deal with greenhouse gas emissions. The Environmental Protection Agency just finalized a rule that will require power plants to report theirs. And two versions of a climate bill requiring serious reductions are wending their way through the halls of congress. If something passes, more power plant operators may have to come to terms with a technology that’s still young and expensive.Next in the series, Kristin looks into the future–with all its technical and economic uncertainties—of carbon capture and storage.
