Regional evaluation of brine management for geologic carbon sequestration

Large scale deployment of carbon dioxide (CO₂) capture and sequestration (CCS) has the potential to significantly reduce global CO₂ emissions, but this technology faces social, economic, and environmental challenges that must be managed early on. Carbon capture technology is water-, energy-, and capital-intensive and proposed geologic carbon sequestration (GCS) storage options, if conducted in pressure-constrained formations, may generate large volumes of extracted brine that require costly disposal. In this study, we evaluate brine management in three locations of the United States (US) and assess whether recovered heat, water, and minerals can turn the brine into a resource. Climate and aquifer parameters varied between the three regions and strongly affected technical feasibility. We discovered that the levelized net present value (NPV) of extracted brine can range from −$50 (a cost) to +$10 (a revenue) per ton of CO₂ injected (mt-CO₂) for a CO₂ point source equivalent to emissions from a 1000 MW coal-fired power plant (CFPP), compared to CCS NPV ranging from −$40 to −$70 per mt-CO₂. Upper bound scenarios reflect assumed advancements in current treatment technologies and a favorable market and regulation landscape for brine products and disposal. A regionally appropriate management strategy may be able to treat the extracted brine as a source of revenue, energy, and water.