The Illinois State Geological Survey is evaluating the potential feasibility of reusing three types of non-traditional water sources for cooling or process water for existing and planned coal-based power plants in the Illinois Basin.  The three type of non-traditional water sources are: (1) produced water from carbon dioxide enhanced oil recovery; (2) coal-bed methane (CBM) recovery; and (3) active and abandoned underground coal mines.  In Illinois, the thermoelectric power sector accounts for approximately 84 percent of the estimated 14 billion gallons per day of freshwater withdrawals and one-third of the state's 1 billion gallons per day of freshwater consumption.  Illinois electric power generation capacity is projected to expand 30 percent by 2030, increasing water consumption by 55 to 160 percent.  Increasing public resistance to the withdrawal or consumption of freshwater for industrial purposes suggests that the use of non-traditional water sources in power plants may alleviate the expected increase in water demand.

Reuse of Produced Water from CO2-EOR, Coalbed Methane, and Mine Pools in the Illinois Basin

EOR involves the injection of water and CO₂ into depleted oil fields to extract up to 10 percent of the oil remaining after normal operations have ceased.  EOR using CO₂ that has been captured from coal-fired power plants is viewed as an economically attractive option for maintaining and expanding Illinois’ power production capacity in an environmentally acceptable manner.  However, about 10 barrels of water are produced for each barrel of crude oil recovered via EOR; this water is treated and re-used for further EOR, but it is eventually released to the environment.  Power plant usage of water produced by CO₂-EOR may be an environmentally-sustainable alternative for “closing the CO₂-water loop,” but the technical and economic viability of this scenario has not been fully explored.