Retrofitting saves millions in TransAlta's carbon plan
Keephills addition would be world's first
By Dave Cooper, Edmonton JournalJune 27, 2009
Behind TransAlta's Keephills generating station is land that could soon make history, housing the world's first chilled-ammonia carbon-dioxide-capture system to be "bolted on" to an existing coal-fired electrical plant.
The new system, from a Europeanbased global power generation firm, Alstom, is only now operating as a small test model. But TransAlta has chosen to take the plunge and use it as the heart of its proposed system to remove one million tonnes of CO 2 a year from its emissions.
"Alstom is very anxious for this project to go forward, and so are we. It will be groundbreaking for the industry," TransAlta spokesman Michael Lawrence said.
Called Pioneer Project, it is one of the finalists for assistance under Alberta's $2-billion carbon capture and storage (CCS) fund. At least three projects are to be selected later this summer.
TransAlta's project could be operating as early as 2012, taking part of the flue gas from a portion of one of the two Keephills turbine units, and capturing one million tonnes of CO 2 each year.
The compressed gas would be sent to partner TransCanada, piped away and injected deep underground to enhance oil recovery or to be stored in saline aquifers.
While power-generating neighbour Epcor Utilities is proposing an amine system for CO 2 capture that comes complete with a new power plant--a project which could cost $2 billion--TransAlta believes the future is more simple and inexpensive: retrofitting existing plants at a cost of hundreds of millions.
"Pioneer will be post-combustion, a system that can be retrofitted to existing power plants all over the world," said Ralph Leriger, Trans-Alta's Wabamun-area stakeholder relations manager.
He said the first phase is to take the flue gas, in this case a "slipstream," a portion of gas representing 100 megawatts of the 380-megawatt turbine output, and clean it to remove sulphur, nitrous oxides and particulates.
What is left is chilled, from 80 C to perhaps 5 C. The CO 2 can be stripped out of the chilled ammonia.
The CO 2 recovery rate is expected to be in the 90-per-cent range.
Steve Snyder, TransAlta's president, recently said Pioneer's system "will be one of the most advanced and has the highest potential, so a lot of people who are interested might want to be part of early projects to gain knowledge."
The Alstom technology is to be shared around the world, and partnerships allow it to advance more quickly, Snyder said.
He has said that with half of North America's electricity generated by burning coal, "kneecapping the economy for the sake of pursuing a pure environmental agenda is unthinkable, undesirable and undoable."
Synder said utilities must innovate and deliver energy while minimizing their impact on the environment.
"If we do things right, we see the potential to make coal-fired generation near carbon-neutral within the next 10 to 20 years."
Alberta officials said recently that the $2-billion CCS fund won't be spend immediately; in fact, over the next three years, just $800 million will be given out, $100 million of that in 2009. The full $2 billion is supposed to be distributed over 12 years.
dcooper@thejournal.canwest.com
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