Background

The limitation to reducing greenhouse gases in the atmosphere is the expense of stripping carbon dioxide from other combustion gases. Without a cost-effective means of accomplishing this, hydrocarbon resources cannot be used freely. A few power plants currently remove carbon dioxide from flue gas for sale as an industrial product. Oil companies commonly remove carbon dioxide from natural gas to improve its energy content. In both cases, the most common technology is a temperature-swing absorption (TSA) using a methylated ethyl amine solvent (MEA).

Description

LLNL has developed a new method of separating carbon dioxide from flue gas. LLNL's ion pump method increases the concentration of dissolved carbonate ion solution. This increases the vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, or the Cussler ion pump.

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Advantages

LLNL's novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas and other gas mixtures of inert gas like nitrogen, with acid gases like carbon dioxide of sulfur dioxide. The process may be operated to produce clean water (similar to reverse osmosis water) as an additional product. The simple, robust nature of the process lends itself to small separation plants.

Potential Applications

  • Eliminating carbon dioxide as a greenhouse gas pollutant:
    • coal fired power plants
    • oil or gas fired power plants
    • cement production
    • bio-fuel combustion
  • Separation of carbon dioxide from other combustion gases
  • Separation of carbon dioxide from gas mixtures:
    • natural gas fields
    • methane from landfill decomposition
  • Separation of carbon dioxide from the atmosphere
  • Separation of sulfur dioxide
  • Production of carbon dioxide for use in enhanced oil recovery
  • Production of carbon dioxide as a food additive
Development Status

U.S. Patent 7,828,883

Reference Number
19608
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