Carbon capture and storage
This is also referred to as "carbon capture and sequestration". It is the process of separating and capturing carbon dioxide (or another regulated gas) from an emission source (e.g. a power plant or industrial facility), converting it from a gaseous state to a supercritical fluid, transporting it (typically via pipeline or tanker truck) to an injection site, and injecting it into a deep subsurface rock formation for long-term storage. Key elements of this technology "carbon dioxide capture and deep geologic injection" have been employed in the petroleum industry to promote enhanced oil recovery. However, the long-term stability of injected carbon dioxide is not well understood and the technology has not yet been employed to eliminate emissions from a commercial coal-fired power plant. The term "clean coal" is often used as shorthand for this proposed technology.