ALL ABOUT CARBON DIOXIDE
CO2 is made of one carbon and two oxygen atoms. It occurs naturally as part of the earth’s system in both the atmosphere and underground. CO2 can be found in many products that consumers use every day. For example, CO2 is what makes soft drinks fizzy and is used in pain relievers, such as Alka-Seltzer. CO2 can be found in fire extinguishers or in solid form, more commonly known as dry ice. The chemical properties of CO2 are inherently stable, so it is not considered to be a detriment to humans or the environment in regulated quantities. Geological sequestration can act as a shortcut in the carbon cycle by bypassing the atmosphere and injecting it directly into the ground.
WHERE CAN CO2 BE SEQUESTERED?
CO2 PLUME MIGRATION AND TRAPPING MECHANISMSOnce CO2 is injected into a deep underground formation, it is confined in tiny pore spaces within the rock layer. Subsurface temperature and pressure keep sequestered CO2 in a supercritical state. Impermeable rock units, or cap rocks, serve as barriers against migration of the CO2 toward the surface. Over time, the CO2 becomes even more securely trapped as it dissolves into the salty water of a saline formation or undergoes natural reactions to form a solid mineral. Ongoing geologic research has demonstrated that the risk of CO2 finding its way back to the surface is extremely low.