|TransAlta and Alstom Canada are developing and implementing a proprietary chilled ammonia process that will help store CO2 underground. Click to enlarge.|
When complete, Project Pioneer will be one of the largest CCS facilities in the world and the first to have an integrated underground storage system. The project will pilot Alstom Canada’s proprietary chilled ammonia process—with an estimated CO2 capture rate of 90%—and will be designed to capture one megatonne (Mt) of carbon dioxide (CO2) from an existing coal plant in the Wabamun area west of Edmonton. The CO2 will be used for enhanced oil recovery (EOR) as well as injected into a permanent geological storage site.
In the chilled ammonia capture system, flue gas is cooled to 0-10°C, condensing water and removing residual contaminants. This also reduces flue gas volume, increasing the concentration of CO2. This cooled gas then flows to the absorber, which operates at 0-10°C for high CO2 capture and low ammonia emission.
There, the ammonia reacts with CO2 and water to form ammonia carbonate or bicarbonate. Raising the temperature to 120°C or more and pressure to above 20 bar reverses the reaction, generating a high pressure CO2 stream with low moisture and ammonia concentration. The CO2 can then be processed for sequestration.
TransCanada brings expertise in the design and construction of pipeline infrastructure to Project Pioneer. In addition to TransCanada, TransAlta is seeking industry partners from the oil, natural gas and oilsands sectors who can provide expertise and knowledge across the full spectrum of process plant operations and reservoir knowledge for underground storage and EOR.
TransAlta is submitting detailed funding proposals to both the Alberta government’s CCS initiative and the Federal government’s eco-Energy Technology Initiative. It hopes to receive funding commitments during 2009. That would allow construction of Project Pioneer to begin in early 2010 and operations to commence in 2012. In the interim, preliminary front-end engineering and design (FEED) work is underway.
Project Pioneer is expected to deliver at least 20% of the Government of Alberta’s 2015 target of five Mt in annual CO2 reductions. This CCS technology can be applied to other coal-fired power plants in Alberta and globally. It also has the potential for broader application to capture CO2 emissions generated in other industrial sectors.