New Discoveries for Carbon Capture and Storage

Climate change is generally attributed to carbon emissions, and efforts to reduce carbon emissions tend to focus on clean energy sources such as wind or solar power. However despite the advances in clean energy sources many believe that humanities greenhouse gas emissions are so vast that these technologies can no longer help solve the problem on their own.

A new MIT study led by Ruben Juanes, the ARCO Associate Professor in Energy Studies in the Department of Civil and Environmental Engineering, has proven that there is enough capacity in deep saline aquifers within the US to store the nation’s carbon emissions produced from coal-power plants for the next 100 years. The approach, known as carbon capture storage (CCS), involves capturing emissions and then storing them as waste in deep geological formations.

Nearly 40 percent of global carbon emissions are produced by coal fuelled power plants so Juanes suggests that climate change “will not be addressed unless we address carbon dioxide emissions from coal plants.” He agrees that clean alternative fuels are important, but that coal is cheap and abundant and therefore is “one thing that’s not going away.”

Deep saline aquifers exist more than half a mile below the surface, and offer a good, safe storage option for CCS. The problem was that no one knew the capacity of these formations within the US and therefore how much carbon they could hold. The reason that no one knew is that deep saline aquifers have no commercial value and therefore exploration has been minimal. Also the dynamics of how liquefied carbon dioxide would seep through the formations is very hard to model, and therefore it is unknown how fast, or to what extent a formations capacity can be filled. Estimates for total capacity of deep saline aquifer formations within the US ranged from a few years up to many thousands of years.

The MIT team managed to design a model that accounted for the total capacity of the formations along with the complex problem of how quickly the carbon could infiltrate the rock over a sustained period of time.

James J. Dooley, a senior staff scientist at the Pacific Northwest National Laboratory who was not involved in the MIT study, said that the study offers “a very sound analysis that demonstrates that given the appropriate regulatory and economic conditions, carbon dioxide capture and storage technologies can be the basis for deep and sustained greenhouse gas reductions in the U.S. and around the world.”

Uncertainties remain, but Juanes believes that “CCS has a role to play. “It’s not an ultimate salvation, it’s a bridge, but it may be essential because it can really address the emissions from coal and natural gas.”

By. James Burgess of Oilprice.com