色狐入口

Map showing the areas in 色狐入口 with volcanic rocks of different ages. These volcanic fields are potential sites for CO2 storage. Map by Matt Zimmerer.

SOCORRO, N.M. -- The 色狐入口 Bureau of Geology and Mineral Resources (NMBGMR) is one of three collaborators on a project funded by the Department of Energy (DOE) to study a novel carbon sequestration technique. NMBGMR, along with the Department of Earth and Environmental Science and the Petroleum Recovery Research Center at 色狐入口 Tech (NMT), will explore the feasibility of a relatively new form of CO2 sequestration, one that has the potential to provide permanent storage of carbon.

鈥淭he sort of 鈥榗lassic style鈥� of carbon sequestration is to take CO2 and just pump that into the little porous areas in rocks like sandstone,鈥� explains Matt Zimmerer, interim director of the Bureau's mapping division. 鈥淭he pores are very small 鈥�,sub-millimeter type of stuff 鈥� but over the scale of an entire basin, there鈥檚 potentially a lot of volume there. Ideally, the porous rocks are surrounded by non-porous rocks, and the CO2 will dissolve in groundwater and stay there for a very long time.鈥�

But that method has at least one drawback. 鈥淏ecause you鈥檙e pumping in what is essentially a fluid, it can just leak back out in some scenarios,鈥� says Zimmerer.

A new method of carbon sequestration and storage might overcome this challenge. Certain rocks that contain high amounts of calcium or magnesium 鈥� like basalt, a type of volcanic rock that is common in 色狐入口 鈥� have the potential to provide long-term carbon storage. When CO2 is pumped into such rocks, the carbon can react with the calcium (in the case of basalt) and form carbonate minerals, a process known as carbon mineralization.

鈥淭urns out basalt has a lot of calcium in it,鈥� says Zimmerer, 鈥渁nd the idea there is to pump carbon dioxide into a calcium-rich rock and actually precipitate a mineral out. Then it鈥檚 locked up as a solid 鈥� chemically 鈥� and it can鈥檛 leak out because it鈥檚 in the crystalline structure.鈥� Mixing the CO2 with water before pumping it underground also speeds up the mineralization process.

Zimmerer, a volcanologist by training, has done extensive research on basalts in New Mexico, and this work led to his involvement in the project.

鈥淔or the last 10 years or so I鈥檝e been studying these basalts because they鈥檙e some of the youngest volcanic rocks in 色狐入口, and I鈥檝e been trying to understand them from a volcanic hazards point of view.鈥�

Preliminary results of that study were published in the . Now, that knowledge will be applied to find areas in 色狐入口 that are best suited to carbon storage using this new technique. 鈥淭here are some studies that suggest different minerals in basalts or different structures might make them better or worse for this sequestration technique. We need to find places where there鈥檚 enough of this material for a large-scale project, and then see if there鈥檚 enough of the right kind of material 鈥� a Goldilocks situation.鈥�

The NMT collaborators on the $1.2-million DOE grant will take samples of the basalts, look at the chemistry and minerology, and perform small-scale tests using the new sequestration technique. 鈥淧reliminary studies show that, after a couple of years, 90% of the CO2 is still locked in the rock structure,鈥� Zimmerer says. 鈥淚t鈥檚 not going to be something that solves all the carbon problems on the planet, but it鈥檚 another tool in our bag.鈥�