Missouri S&T Studies Sequestration for Utilities
Researchers at Missouri University of Science and Technology are studying how City Utilities of Springfield, Mo., can sequester carbon dioxide in shallow formations.
The Department of Energy is funding the Missouri S&T portion of the two-year study through City Utilities of Springfield at a cost of $644,174. Utility companies around the country are conducting similar studies in anticipation of regulations that limit emissions of carbon dioxide.
The idea is to capture and separate carbon dioxide emissions and then return the gas permanently to the earth. In many areas of the country, the carbon dioxide can be disposed of in extremely deep formations, where it is sequestered under pressure in a liquid state. That is not possible in most of Missouri due to predominantly shallow geological features.
The Missouri S&T researchers are studying the feasibility of depositing the carbon dioxide gas into sandstone formations that are approximately 2,000 feet deep.
"Shallow sequestration of carbon dioxide gas has not been studied extensively," says Shari Dunn-Norman, Ph.D., professor of petroleum engineering at Missouri S&T. "We are trying to understand as much as possible about the process."
The researchers plan to drill an exploratory well at a test site. Core samples will be collected to understand critical rock properties that can affect the sequestration process. Laboratory studies are also planned to gain a better understanding of the geochemical processes occurring when carbon dioxide is injected into the sandstone formations.
If initial results are favorable and the project advances, carbon dioxide gas will be injected into the subsurface. The researchers will then monitor subsurface conditions to see how the carbon dioxide moves through the sandstone.
"We are going to be looking very closely at the geological features to determine things like porosity and permeability," Dunn-Norman says. "We need to know how much carbon dioxide the formation can hold and the economics of storing it."
Although 2,000 feet is considered shallow for carbon sequestration, Dunn-Norman says the gas would be deposited well beneath any regional aquifers. "Over time," she says, "a portion of the carbon dioxide would naturally mineralize and become trapped in the formation."
Other Missouri S&T researchers involved in the study are David Wronkiewicz, Ph.D., professor of geological sciences and engineering, and Baojun Bai, Ph.D., assistant professor of geological sciences and engineering.