As climate change takes center stage as one of the most pressing global issues in history, the race is on to discover new technologies that will radically reduce CO2 emissions and mitigate the pending damages of rising global temperatures. Some climate change experts believe carbon capture and sequestration (CCS) to be the just the answer.
Renewable energy sources such as biofuels, wind, solar, geothermal, and tidal certainly appear to provide the long-term answer to ending the climate change crisis. Experts concur, however, that it will most likely be at least another half century before these technologies become a global reality. Consequently, the world’s sustained dependency on fossil fuels necessitates an immediate and effective solution.
CCS is the process by which carbon dioxide is captured and securely stored to prevent it from being released into the atmosphere. CCS technologies trap CO2 at its point source—a coal or gas power plant, for example—and transport it to deep underground rock formations, where it remains permanently. Many of these same geological formations have already served for millions of years as natural reservoirs for petroleum and gas.
The specificity of the rock type in these formations is crucial to properly storing captured CO2. Rocks with a high porosity such as sandstone are used as a depository for the gas that has been injected into them. A non-porous, impermeable rock structure, known as cap rock, must also sit on top of the porous rock. The cap rock functions as a natural, airtight lid that prevents the CO2 from making its way back towards the earth’s surface.1
A study released last week in the Proceedings of National Academy of Sciences (PNAS) announced that a massive deposit of volcanic basalt located on the East Coast of the United States may be an ideal spot for injecting carbon dioxide sequestered from possible future CCS technologies. The study suggests that the basalt rock may provide significant advantages over other rock type, including larger potential storage volumes and permanent fixation of carbon by mineralization.2
The primary concern of CCS is that the stored carbon dioxide will escape and make its way back to the surface and be re-released into the atmosphere. CCS technologies are also extremely expensive, and critics cite that any government or corporate funding would be best used in researching and implementing more practical and effective renewable energy technologies.
SOURCES
1 http://www.wri.org/project/carbon-capture-sequestration
3 from Potential on-shore and off-shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts; Proceedings of the National Academy of the Sciences of the United States of America
