A regional coalition that includes Arizona, is injecting [right, SWRP] 75,000 tons of carbon dioxide into a coal seam to test geologic sequestration, while simultaneously producing natural gas (coalbed methane - CBM) from the horizon, in a first of its kind test. U.S. Dept. of Energy is supporting the Southwest Regional Partnership (AZGS is a member) started the 6-month demonstration project a week ago in the San Juan basin near Navajo City, in northwest NM.
The DOE announcement said, "Many coal beds in the United States are saturated with natural gas (methane), but the gas is difficult to produce because methane typically binds to coal. However, CO2 shares the same tendency … Injecting [it] into the coal bed essentially displaces the methane and makes the gas easier to produce."
My understanding is that CO2 binds to the coal better than does methane and can effectively displace the methane molecules (increasing production) while being locked into the coal.
The San Juan basin is one of the largest CBM sources in the world. DOE and SWRP chose it for this test because of "favorable geology, high methane content, available CO2 from nearby power plants, low capital and operating costs, and well-developed natural gas and CO2 pipelines."
The demonstration project is also desalinating some of the abundant produced water from the CBM to irrigate nearby riparian areas, which will result in vegetation taking up additional CO2.
"The Southwest Regional Partnership is one of seven managed by the DOE Fossil Energy Office's National Energy Technology to determine the best carbon capture and storage approaches. It is led by the New Mexico Institute of Mining and Technology, and includes the states of Colorado, Oklahoma, New Mexico, Utah, and parts of Arizona, Kansas, and Wyoming. The partnership is conducting five field tests (three geologic and two terrestrial) at various stages of planning and execution," DOE said.