February 15, 2008

Alstom’s chilled ammonia CO2-capture process advances toward commercialization

Dr. Robert Peltier, PE

Other steps to follow

Meanwhile, Alstom and AEP have signed an agreement to bring Alstom’s chilled ammonia process for CO₂ capture to full commercial scale by 2011. The project will be implemented in two phases. In phase one, Alstom and AEP will jointly develop a 30-MW (equivalent) product validation plant that will capture more than100,000 tons of CO₂ per year from the flue gas of AEP’s 1,300-MW Mountaineer Plant in New Haven, W.Va. Notably, the captured CO₂ will be sequestered in deep saline aquifers at the site. This pilot project is scheduled to start up at the end of 2009 and operate for at least 12 to 18 months.

In phase two, Alstom will design, build, and add the first commercial-scale (up to 200-MW) CO₂ capture system to one of the 450-MW coal-fired units at AEP’s Northeastern Station in Oologah, Okla., by late 2011. If the system captures about 1.5 million tons of CO₂ a year, Alstom will consider the accomplishment a successful validation of the chilled ammonia separation technology. The CO₂ captured at Northeastern Station will be used for enhanced oil recovery.

Alstom’s 5-MW (equivalent) CO₂ capturing demo plant being built at E.ON’s Karlshamn Power Plant in southern Sweden is expected to begin operation later this year. The two companies plan to introduce the technology at other Swedish power plants if it passes muster.

For the longer term, Alstom has signed a joint development contract with Norway’s state-owned oil gas and company, Statoil-Hydro, to test the chilled ammonia technology’s ability to remove the CO₂ from flue gases particular to natural gas–fired combined-cycle power plants. The first milestone of the agreement calls for designing and building a 40-MW (equivalent) test and product validation facility at Statoil’s Mongstad refinery in Norway by 2009–2010. The facility will then be operated for up to a year and a half to see whether it can capture at least 80,000 tons per year of CO₂, either from flue gases from the refinery’s cracker unit or from a new combined heat and power plant now under construction on-site. A commercial-scale unit now in the early planning stages for Mongstad would capture over 2 million tons of CO₂ per year.

Policymakers try to keep pace

Once CO₂ has been removed from a power plant’s flue gas, what can and should be done with it? Given that a 1,000-MW coal plant produces about 3 million pounds of CO₂ per hour, storing it on-site is not an option.

A bill called the Carbon Dioxide Pipeline Study Act of 2007 recently introduced by Sen. Norm Coleman (R-Minn.) would require the DOE to identify and resolve key obstacles to commercializing CO₂ sequestration, transportation, and storage technologies. S. 2144 also would ensure that a robust national CO₂ infrastructure would be created as part of any federal climate change legislation.

Last year also saw the introduction of the National Carbon Dioxide Storage Capacity Assessment Act of 2007 (S. 731) by Sen. Ken Salazar (D-Colo.) and The Department of Energy Carbon Capture and Storage Research, Development and Demonstration Act of 2007 (S. 962) by Sen. Jeff Bingaman (D-N.M.). The three bills are meant to work together to bring all relevant federal departments and regulators (Energy, Interior, Transportation, the Federal Energy Regulatory Commission, and the Environmental Protection Agency) together to address the broad range of policy questions surrounding CO₂ sequestration, transportation, and storage.