Mountaineer plant is first to capture and store CO2 onsite

L-667 members help retrofit advanced chilled ammonia technology

LAST SEPTEMBER, AMERICAN Electric Power’s (AEP’s) Mountaineer power plant in New Haven, W.Va., began doing something no other plant in the world has ever done. It began capturing carbon dioxide (CO₂) from a slipstream of exhaust flue gas and pumping it deep underground below the plant for permanent storage in a saline formation. The validation project required retrofitting an advanced chilled ammonia system to the existing coal-fired plant — work performed by members of Local 667 (Charleston, W.Va.) and other building trades.

Initial results of the pilot validation project have been so successful that in December 2009, the Department of Energy awarded a $334 million grant to AEP to bring the project to commercial scale (the total cost to do so is estimated at over $670 million). The carbon capture and storage (CCS) efforts at Mountaineer are widely seen as promising news for clean coal supporters — including Boilermakers who stand to gain hundreds of thousands of man-hours adapting such technologies to new and existing coal-fired plants.

The Mountaineer pilot project captures CO₂ from 20 megawatts of the plant’s 1,300 megawatt capacity. When AEP’s commercial-scale application of the chilled ammonia system is completed in 2015, it should capture at least 90 percent of the CO₂ from 235 megawatts of the plant’s total capacity.

Chilled ammonia process separates CO₂

AEP’S PILOT PROJECT uses Alstom Power’s chilled ammonia process [see article on page xx] for CO₂ capture. This technology was tested in March 2008 in a demonstration project at Wisconsin Energy’s 1.7 megawatt (electric) Pleasant Prairie power plant in Kenosha County, Wis., where members of Local 107 (Milwaukee) erected numerous columns and stainless steel vessels for the project.

The chilled ammonia process absorbs CO₂ using ammonium carbonate. The resulting ammonium bicarbonate slurry is converted back to ammonium carbonate in a regenerator and is reused to repeat the process. The flue gas, cleaned of CO₂, flows back to the stack.

The project at AEP’s Mountaineer plant then injects the captured CO₂ for storage in rock layers approximately 1.5 miles underground. Monitoring wells help verify and evaluate the conditions in the rock layers as the CO₂ is injected. A cap rock keeps the CO₂ from escaping. The project can store approximately 100,000 metric tons of CO₂ per year.

L-667 plays role in successful pilot project

IN OCTOBER 2008, Local 667 members began unloading material from barges for AEP’s Mountaineer project. Through mid-August 2009, they built stainless steel vessels for the chilled ammonia process; set equipment, vessels, and structural steel as duct support (including two towers); and built FRP duct (fiberglass-reinforced plastic piping for exhaust fumes).

According to general foreman Mike Hurlow, all of the work involved at the validation project was traditional Boilermaker work, with the exception of the FRP duct. He said the fiberglass training Local 667 offered his crew prior to the start of this project played a big part in the crew’s successful work with this product.

In September 2009, the project was up and running, and by December of that year, AEP had received a government grant to build the process at a much larger scale.

“This job was unique in that it was the first carbon capture project to sequester the carbon in the ground (actually store it),” reports Tony Templin, craft supervisor for APComPower Inc., the union construction arm of Alstom Power Inc., AEP’s validation project partner at Mountaineer.

“This was a great job for the Boilermakers,” said Local 667 BM-ST George Pinkerman. “APComPower did a good job planning their work, and all crafts worked together to finish this job on schedule. AEP is a great power company to work for. They work all union under the National Maintenance Agreement. We had about 30-35 Boilermakers on site during construction and look forward to doing future maintenance work on this project.”

Intl. Rep Martin Stanton reports that the Mountaineer pilot project brought thousands of man-hours to the IBB, specifically Local Lodge 667. “I want to thank the Local 667 members and leadership for their hard work involved in this project. In addition, it was a benefit to have been part of the plant’s pre-erection planning. We look forward to working with American Electric Power and Alstom Power Inc. on future projects.”

According to Templin, CO₂ capture promises to be the next big provider of Boilermaker man-hours. “This was a smooth job that started from the top down,” Templin said. “It was a true ‘union’ job with all the crafts working in good harmony. The Boilermakers went injury free and were completely on board with a strict APCom and AEP safety program. Drug testing also went very well with some of the best results I’ve seen in years — evidence that the Boilermaker drug program is working.”

AEP was also very happy with the results.

“We are extremely pleased with the cooperation we had from the Building & Construction Trade unions who worked on the Mountaineer carbon capture project,” said Tom Householder, AEP’s director of safety & labor services. “This project was the first of its kind in the world [both capturing and storing CO₂ from a coal-fired power plant]. AEP relied heavily on the Boilermakers from Local 667 to staff this project with safe, skilled craft personnel. The project was completed on time and within budget, the quality was excellent, and, most importantly, there were no recordable injuries.

”This job is a shining example of what a tripartite work effort between the Boilermakers, contractors, and owners can produce,” Householder said. “The skill level, commitment, and cooperation demonstrated on this project were among the best efforts we’ve seen on recent projects, and we thank the Boilermakers International union, Local 667, and the other locals who supported this project.”