Carbon dioxide capture and sequestration

A number of means exist to captnre carbon dioxide from gas streams, but they have not yet been optimized for the scale reqnired in coal-bnming power plants. The focus has often been on obtaining pure carbon dioxide for indnstrial pnrposes rather than redncing carbon dioxide levels in power plant emissions. 

Where there is carbon dioxide mixed with methane from natnral gas wells, its separation is well proven. Several processes are nsed, inclnding hot potassium carbonate which is energy-intensive and requires a large plant, an olamine process which yields high-purity carbon dioxide, amine scrubbing, and membrane processes (Mokhatab et al., 2006 Speight, 2007a,b). 

No commercial-scale power plants are operating with this process yet. At the new 1300 MWe Mountaineer power plant in West Virginia, less than 2% of the plant s off-gas is being treated for 

CO2 recovery, using chilled amine technology. Subject to federal grants, there are plans to capture and sequester 20% of the plant s CO2—approximate two million tons of CO2 per year. 

Oxyfuel combustion, where coal is burned in oxygen rather than air, means that the flue gas is mostly CO2 and hence it can more readily be captured by amine scrubbing—at about half the cost of capture from conventional plants. 

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Develop practical and environmentally responsible methods of carbon dioxide capture and sequestration. 

Stewart, C. Hessami, M. A., A study of methods of carbon dioxide capture and sequestration -... 

Options for CO2 sequestration (a) oceanic and (b) geoiogicai. Source After Metz, B., et al. (2005). IPCC Special Report on Carbon Dioxide Capture and Storage. Cambridge University Press. (See companion website for coior version.)... 

Carbon Dioxide Capture and Disposal Carbon Sequestration... 

McKee, B.M. (Secretariat) (2004) Considerations on Legal Issues for Carbon Dioxide Capture and Storage Projects. Report from the Legal, Regulatory and Financial Issues Task Force CSLF-P-2004-14C, Carbon Sequestration Leadership Forum, Washington, DC. 

Nelson, T.O., P.D. Box, D.A. Green, and R.P. Gupta, Carbon Dioxide Recovery from Power Plant Flue Gas using Supported Carbonate Sorbents in a Thermal Swing Process, Sixth Annual Conference on Carbon Capture and Sequestration, Pittsburgh, PA, May 2007. 

Storage of carbon dioxide by carbon capture and sequestration solutions for fossil fuels this is often not seen as a long-term solution and exploratory studies indicate that carbon sequestration may not be acceptable to the public (Whitmarsh et al., 2006) ... 

Capture and sequestration along with carbon dioxide. 

Physical sorbents for carbon dioxide separation and removal were extensively studied by industrial gas companies. Zeolite 13X, activated alumina, and their improved versions are typically used for removing carbon dioxide and moisture from air in either a TSA or a PSA process. The sorption temperatures for these applications are usually close to ambient temperature. There are a few studies on adsorption of carbon dioxide at high temperatures. The carbon dioxide adsorption isotherms on two commercial sorbents hydrotalcite-like compounds, EXM911 and activated alumina made by LaRoche Industries, are displayed in Fig. 8.F23,i24] shown in Fig. 8, LaRoche activated alumina has a higher carbon dioxide capacity than the EXM911 at 300° C. However, the adsorption capacities on both sorbents are too low for any practical applications in carbon dioxide sorption at high temperature. Conventional physical sorbents are basically not effective for carbon dioxide capture at flue gas temperature (> 400°C). There is a need to develop effective sorbents that can adsorb carbon dioxide at flue gas temperature to significantly reduce the gas volume to be treated for carbon sequestration. 

Innovative strategies able to capture and sequestrate carbon dioxide emissions, so-called Carbon Capture and Sequestration (CCS) technologies, are the object of several analysis and heated debate. CCS technologies should be applied for an environmental-friendly diffusion of fossil fuel-based H, production methods, but they are presently in the embryonic stage of development and certainly would involve a great growth of costs. 

Management of atmospheric carbon dioxide levels will require sequestration of carbon dioxide. Research and development into methods to cost effectively capture and geologically sequester carbon dioxide is required in the next 10 to 20 years.5... 

There are key challenges for the chemical sciences if sequestration is adopted as a method to reduce atmospheric carbon dioxide. Carbon dioxide capture after generation is generally estimated to represent three-fourths of the total cost of a carbon capture, storage, transport, and sequestration system.3 To make carbon... 

A key rationale for moving to a hydrogen economy is to minimize carbon emissions. Producing hydrogen from coal actually could result in increased carbon dioxide emissions, unless carbon capture and sequestration is an integral part of these plants. 

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