Geologic
Before CO2 can be sequestered from power plants or industrial sources, it must be captured as a relatively pure gas. CO2 is routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, hydrogen production, and limestone calcination. However, existing capture technologies are energy intensive and not cost-effective. Research is underway to improve performance, reduce costs and develop novel capture technologies.
The concept of geologic sequestration is based on the fact that carbon and CO2 have been stored in naturally occurring geologic reservoirs throughout the world for thousands of years. For instance, carbon is stored in fossil fuels and there are naturally occurring CO2 deposits that supply CO2 to the oil, chemical and food manufacturing industries. Furthermore, CO2 is routinely injected into deplete oil fields to enhance recovery and there is an extensive pipeline network primarily in the United States. These pipelines were built with internationally recognized standards for design, construction and monitoring and could be utilized to transport CO2 to storage sites. Other methods for large-scale CO2 transport include offshore oil and gas pipelines, barges or tankers.
It is important to note, geologic sequestration is currently being done. Since 1996 in the world's only commercial geologic CO2 storage facility, the Norwegian oil company, Statoil, has been injecting approximately one million tons per year of CO2 into a saline formation located beneath the North Sea floor. In order to meet commercial specifications, the CO2 is stripped from natural gas produced from the Sleipner field and reinjected into the 200-250 meter thick Utsira formation. The amount being sequestered is equivalent to the output of a 150-megawatt coal-fired power plant. However, the formation is enormous – to provide a sense of scale, it takes one hour to fly over the length of the formation, which is about as big as Norway. Utsira, and other geologic formations located throughout the world, have potential to hold significant amounts of CO2.
Frequently Asked Questions (FAQs)
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