RICHARDTON, N.D. – The North Dakota Industrial Commission approved Red Trail Energy’s (RTE’s) storage facility permit at its October 19 meeting. The approved permit moves RTE’s carbon capture and storage (CCS) project one giant leap closer to becoming the first commercial-scale CCS project in North Dakota, capturing and permanently storing nearly 200,000 tons of CO2 annually.
North Dakota is the first of only two states to take on the regulatory responsibility of awarding permits for and regulating permanent CO2 storage that is not associated with enhanced oil recovery. State legislators and regulators had worked for more than a decade to establish the framework for safe, permanent storage when, in April 2018, the U.S. Environmental Protection Agency granted the state’s Department of Mineral Resources primary regulatory authority (aka primacy) over the special class of wells (Class VI) established to govern safe, permanent CO2 storage (sometimes called sequestration) in a dedicated storage facility. The RTE CCS project permit is the first Class VI well approved under state primacy in the United States.
One common question about CCS has to do with the storage facility. The term evokes images of a shed, barn, or underground storage tank, none of which seem like plausible places to store CO2. In actuality, the term storage facility refers to a specific naturally occurring geologic formation: a layer of porous and permeable rock such as sandstone with rock layers both above and below that block the flow of CO2, such as shale. Focused geologic studies of the rock layers more than a mile below the surface confirm that this configuration exists below the RTE facility.
At Richardton, a more-than-200-foot-thick layer of sandstone (called the Broom Creek Formation) lies nearly 6400 feet below the surface. Immediately above that sandstone is a layer of shale more than 1000 feet thick. Shale is neither porous nor permeable, meaning that nothing can filter through it. There is also a layer of shale below the Broom Creek Formation. These two shale layers with sandstone between make up the CO2 storage facility. CO2 will flow through the tiny gaps (pore space) between the grains of sand that make up the sandstone, and the shale will keep it in the sandstone.
RTE and research partner the University of North Dakota Energy & Environmental Research Center will host a virtual open house over Zoom on Wednesday, November 10, at 6:00 p.m. MST (7:00 p.m. CST) to share an update on the project and the science behind it. All are welcome to join by registering at RedTrailEnergyVirtualOpenHouse.eventbrite.com.