What is carbon sequestration?

Carbon Sequestration is capturing and securely storing carbon dioxide emitted from the global energy system.

Types of Sequestration:

There are number of technologies under investigation for sequestering carbon from the atmosphere. These can be discussed under three main categories:

• • Ocean Sequestration: Carbon stored in oceans through direct injection or fertilization.

     

  • Geologic Sequestration: Natural pore spaces in geologic formations serve as reservoirs for long-term carbon dioxide storage.

• Terrestrial Sequestration: A large amount of carbon is stored in soils and vegetation, which are our natural carbon sinks. Increasing carbon fixation through photosynthesis, slowing down or reducing decomposition of organic matter, and changing land use practices can enhance carbon uptake in these natural sinks.

Geologic Sequestration is thought to have the largest potential for near-term application. The MIDCARB Consortium and this web site are dedicated to providing information on the potential for geologic sequestration in the heartland of America.

Geologic Sequestration Trapping Mechanisms

• Hydrodynamic Trapping: Carbon dioxide can be trapped as a gas under low-permeability cap rock (much like natural gas is stored in gas reservoirs).

• Solubility Trapping: Carbon dioxide can be dissolved into a liquid, such as water or oil.

• Mineral Carbonation: Carbon dioxide can react with the minerals, fluids, and organic matter in a geologic formation to form stable compounds/minerals; largely calcium, iron, and magnesium carbonates.

While research continues on mineral carbonation, early results indicate reaction times to be too slow for this technology to have near-term widespread applicability. Carbon dioxide can be effectively stored in the earth's subsurface by hydrodynamic trapping and solubility trapping - usually a combination of the two is most effective.