Energy & Environment

NRG Begins Operation Of Carbon Capture Plant Southwest Of Houston

It’s the nation’s first coal power plant to divert carbon dioxide on a commercial scale.

W.A. Parish, one of NRG’s two coal power plants in Texas, is situated in Fort Bend County, about 30 miles southwest of downtown Houston, amidst ranches, farm fields and cows.

This week, it became the first coal plant in the U.S. that – on a commercial scale – is diverting some of the carbon dioxide it produces and using it to extract oil from the ground.

The plant sits on more than 4,000 acres, which includes a large water reservoir and a site that stores all the coal.

It has four coal power units, each with a tall smokestack with steam coming out, and some cooling towers, water running down underneath. And then there are several mazes of pipes and some very large generators.

All this makes for a noisy affair.

The coal is transported into funnels via a conveyor belt, David Knox, a spokesman with NRG, explains.

The coal is crushed to dust and used to heat water in a boiler. The water then turns into steam, which turns large generators, and electricity is produced.

The burning of the coal produces CO2, which goes into the atmosphere, contributing to pollution and global warming.

None of that is new. What is new is the plant’s Petra Nova system.

It consists of a football-field long metal tower called the absorber. There’s also a cooling tower and a small plant that provides the power for the operation.

David Greeson, vice president of development for NRG, was the driving force behind the carbon capture system.

He points to a duct that leads into one of the smokestacks.

“We installed a breach in that duct to be able to draw out the flue gas that we’re going to treat in the carbon capture system,” he says.

The Petra Nova system is able to divert about 40 percent of the CO2 that’s produced by one of the plant’s four carbon power units.

So overall, only about one-tenth of the plant’s emissions are captured.

But according to NRG, that’s still more than 4,000 tons of CO2 per day. In a year, that’s the equivalent of taking almost 300,000 cars off the road.

The company owns the system together with JX Holdings, a Japanese energy firm. It cost $1 billion to build, supported with a $190 million grant from the Department of Energy.

Greeson says as long as the price of oil remains above $50 a barrel, the system is economically viable. That’s because the captured CO2 is piped 80 miles to Houston-based Hilcorp’s West Ranch oil field in Jackson County.

“The oil field is over a mile deep and is a formation that has held hydrocarbons for millions of years,” Greeson explains. “We inject CO2 into that formation and that’s where it will remain for the next millions of years.”

The CO2 bonds with the oil and helps free it from the rock – while leaving the earth structure intact.

As the oil is pumped to the surface, the CO2 separates and is re-injected into the ground to get more oil. This method is called Enhanced Oil Recovery.

NRG estimates over the next 10 years, its partners will be able to recover 60 million barrels of oil that they wouldn’t have been able to get otherwise.

Since the energy company is a part-owner of the oil field, this will help pay for the carbon capture operation.

Greeson hopes this project is just the beginning.

“We want to see that this project is successful,” he says, “that we’re able to operate it as we think we can, as we plan to, that the oil field responds in a way that we expect it to.”

The goal is to add systems to the other coal combustion units at W.A. Parish and maybe other plants across the country.

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Florian Martin

Business Reporter

Florian Martin is currently the News 88.7 business reporter. Florian’s stories can frequently be heard on other public radio stations throughout Texas and on NPR nationwide. Some of them have earned him awards from Texas AP Broadcasters and the Houston Press Club. Florian is a native of Germany. His studies...

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