What is Geologic Storage?

Geological storage is a four-step process where:

• first, a pure or nearly pure stream of CO2 is captured from flue gas or other process stream;
• next it is compressed to about 100 atmospheres;
• it is then transported to the injection site;
• and finally, it is injected deep underground into a geological formation such as an oil and gas reservoir where it can be safely stored for thousands of years or longer.

Storage Options

• Depleted oil and gas reservoirs
• Enhanced oil and gas recovery
• Deep saline formations
• Enhanced coal bed methane recovery
• Deep unmineable coal seams

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Over the past several hundred years, atmospheric CO2 concentrations have steadily increased and have now risen to over 370 ppm from the pre-industrial level of 280 ppm. Increases in CO2 concentrations are attributed mainly to burning coal, oil and natural gas for electrical generation, transportation, industrial and domestic uses. Today, globally, over 20 billion tons of CO2 are emitted into the atmosphere. There is growing consensus that increases in CO2 concentrations will disrupt the earth’s climate, cause sea level to rise enough to flood many low-lying coastal regions, and damage sensitive ecosystems. Experts believe that to avoid significant disruption of the climate system and ecosystems, CO2 concentrations must be stabilized within the next several decades. At today’s emission rates, atmospheric CO2 concentrations will continue to grow rapidly and, within 50 years, may exceed the levels needed to protect sensitive ecosystems and avoid flooding in low-lying coastal areas. This situation is even more urgent when we consider that over the next fifty years CO2 emissions are expected to double as the developing world’s economies grow and the standard of living increases. To address this challenge, we need a multi-pronged approach to decreasing CO2 emissions – more efficient production and use of energy, solar power, wind energy, biomass, switching to fuel sources with lower or negligible CO2 emissions and, CO2 Capture and Storage (CCS).

CO₂ Capture and Storage is Part of the Solution

Geologic storage of CO2 in underground formations has quickly advanced from a mere concept to a reality. Significant progress has been made in the critical areas of storage security and integrity, storage optimization, monitoring and verification, and risk assessment and mitigation. More remains to be accomplished before widespread application of this technology takes place, but the results of research conducted in various projects continue to demonstrate that this technology can make large contributions to the climate change problem.