Assessment of desalination technologies for treatment of a highly saline brine from a potential CO2 storage site

Abstract

Brine extraction is a promising strategy for the management of increased reservoir pressure, resulting from carbon dioxide (CO2) injection in deep saline reservoirs. The extracted brines usually have high concentrations of total dissolved solids (TDS) and various contaminants, and require proper disposal or treatment. In this article, first by conducting a critical review, we evaluate the applicability, limits, and advantages or challenges of various commercially available and emerging desalination technologies that can potentially be employed to treat the highly saline brine (with TDS values >70.000ppm) and those that are applicable to a ~200,000ppm TDS brine extracted from the Mt. Simon Sandstone, a potential CO2 storage site in Illinois, USA. Based on the side-by-side comparison of technologies, evaporators are selected as the most suitable existing technology for treating Mt. Simon brine. Process simulations are then conducted for a conceptual design for desalination of 454m3/h (2000gpm) pretreated brine for near-zero liquid discharge by multi-effect evaporators. The thermal energy demand is estimated at 246kWh per m3 of recovered water, of which 212kWh/m3 is required for multiple-effect evaporation and the remainder for salt drying. The process also requires additional electrical power of ~2kWh/m3.