THE IMPACT OF ELECTRICITY MARKET CONDITIONS ON THE VALUE OF FLEXIBLE CO2 CAPTURE

Carbon dioxide (CO2) capture with amine scrubbing at coal-fired power plants can remove 90% of the CO2 from flue gas, but operational energy requirements reduce net electrical output by 20-30%. Temporarily reducing the load on energy intensive components of the amine scrubbing process could temporarily increase power output and allow additional electricity sales when prices are high. Doing so could entail additional CO2 emissions, or amine solvent storage can be utilized to allow increased power output without additional CO2 emissions. Priceresponsive flexible capture is studied for $0-200/tCO(2) and $2. 11/MMBTU natural gas using a nominal 500 MW coal-fired facility in the 2010 Electric Reliability Council of Texas (ERCOT) grid. CO2 capture systems use a 7 molal monoethanolamine (MEA) solvent. Venting additional CO2 while increasing electrical output provides significant benefit only at $30-60/tCO(2) and when natural gas prices exceed $4/MMBTU. Solvent storage can improve profitability with CO2 capture at higher CO2 emissions penalties, but primarily at low-to-moderate natural gas prices when power plant capacity factor is less than 90%.