Geological Sequestration of Carbon Dioxide: Displaced Waters.

Geological sequestration of carbon dioxide (CO₂) is a potential process for preventing atmospheric emissions of CO₂ where this greenhouse gas can be captured from different industrial sources. Unfortunately, increased geological formation pressures limit the amount of CO₂ that can be injected into the subsurface environment. Therefore it is important to consider extracting water from the formations in order to allow greater storage capacities. The Carbon Management Institute (CMI) within the School of Energy Research (SER) at the University of Wyoming is conducting the Wyoming Carbon Underground Storage Project (WY-CUSP) that is located within the Rock Springs Uplift in southwestern WY. The long-term goal of this project would be to inject up to 750 million tons of CO₂ into two saline aquifers (Weber/Tensleep and Madison/Bighorn) that are 6,000 to 10,000 ft deep over a 50 year period. Displaced saline waters from these aquifers are high in total dissolved solids (TDS) at over 10,000 mg/L that is comprised of predominately sodium – chloride/sulfate constituents. An estimated 800,000 acre-feet of water would be displaced during the lifetime of the project in order to store the long-term goal of 750 million tons of CO₂. Water treatment and beneficial uses of the displaced waters will be the focus of this poster presentation. Utilizing cost-effective treatment technologies was investigated for producing suitable water qualities that will allow the water to be utilized for numerous applications. Beneficial uses that the treated waters could be used for include: increasing irrigated lands, stream habitat improvements, reservoir development, or drinking water supplies for local municipalities. Alternative water uses could involve increasing water discharge into the Colorado River, utilization by the Jim Bridger Power Plant, a water theme park, or replenishing water recharge areas. Opportunities exist in geological CO₂ sequestration, but there is much to be learned before large-scale projects become operational.