A widespread program to manage carbon emissions from industrial sources will require adoption of technologies to separate and capture carbon from point sources. While technology exists today to remove carbon from stationary emission sources, the high cost and energy penalty associated with capture, coupled with limited economic drivers, have prevented any significant use. Worldwide research and development funding from both public and private sources is attempting to reduce the penalty associated with carbon capture; for example, the US Department of Energy has stated a goal of developing capture technologies that result in less than a 10% increase in the cost of energy services by 2012. With today's carbon capture technologies increasing the cost of energy services, the gap between desired and actual technology remains significant.
The separation and capture technologies are traditionally split into "pre-combustion" and "post-combustion" categories. Pre-combustion usually applies to gasification processes for power generation, but the terminology is sometimes used to describe concepts for decarbonation of natural gas. Post-combustion applies to pulverized coal boilers, gas turbines and other technologies where fuel is combusted with air. "Combustion modification" or oxygen combustion (oxy-combustion) is another expression and developing technology for CO2 capture, especially in Canada and Europe and more recently the US.
Nexant has engaged in recent studies examining the design, cost, and potential of conventional and advanced carbon capture technologies in a number of industries. Major projects include:
- Chilled Ammonia Process for post combustion CO2 capture: A Chilled Ammonia Process (CAP) for CO2 capture is under development based on the chemistry of the NH3-CO2-H2O system and the ability of ammoniated solution to absorb CO2 at low temperature and to release the CO2 at elevated pressure. This will decrease the size and power requirements of the compressor, lowering system cost and raising efficiency. The use of ammoniated salts at low temperature practically eliminates ammonia emission to the atmosphere.
Nexant is a subcontractor to Alstom in building a 5 MW demonstration plant in Wisconsin, a skid mounted unit for Statoil in Norway, and also a 30 MW demonstration plant for American Electric Power (AEP) to capture CO2 from an existing coal fired power plant.
- Amine CO2 Separation Cost Reduction - CO2 Capture Project: Nexant recently completed a $0.5 million cost reduction study of CO2 capture from natural gas fired combined cycle flue gas for the CO2 Capture Project (CCP). The work was sponsored by US DOE and eight major energy companies: BP, ChevronTexaco, EnCana, Eni, Norsk Hydro, Shell, Statoil and Suncor. In the study, Nexant shows that efficiency penalty, additional capital expenditure, and avoided cost related to the use of an amine process to capture CO2 from the flue gas can be reduced more than 50% by incorporating several system design improvements. The project is now moving into a second phase, in which Mitsubishi will test Nexant's process improvements based on their advanced amine process.
Amine CO2 Capture Project Summary
- Survey of Carbon Capture Options, Japanese Client: In March 2007, Nexant completed a "Survey of Carbon Dioxide and Associated Gas Treatment Technologies" for a Japanese client. The technology survey broadly examines natural gas treatment to remove CO2 and acid gases, along with the technologies, capabilities, and issues of CO2 sequestration in geological formations. Commercial technologies are reviewed to define today's benchmarks for design and cost. New technologies and research activities are reported for gas treatment both at the pre-commercial and laboratory stages of development. CO2 storage and transport operations are covered including areas of types of potential storage, monitoring of sequestered CO2, transport, injection, and storage costs, and global storage potential. Three case studies of major CO2 capture and sequestration operations are documented in the survey.
- Hydrate (Clathrate) Formation for CO2 Removal: In partnership with Los Alamos National Laboratory, Nexant performed engineering analysis and economic evaluation on data generated for the SIMTECHE process in the NETL program to compare a conceptual design of the process to a conventional alternative and evaluate the economics of the capture processes. Nexant worked with the US Department of Energy, SIMTECHE, and Los Alamos to develop an engineering test module of the SIMTECHE Hydrates process to test various designs and process conditions.
DOE Fact Sheet on Hydrates Project
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Tan-Ping Chen
Senior Vice President, Energy Technology
Tel: +1 415 369 1077
Email: tpchen@nexant.com
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