Indirect-fired supercritical CO2 (sCO2) power cycles are being explored as an attractive alternative to steam Rankine cycles for a variety of heat sources including fossil, concentrated solar power (CSP), nuclear, waste heat, etc. Due to the near-ambient CO2 critical temperature of 31°C, the effects of ambient temperature on sCO2 power cycles performance are expected to be more significant than for steam Rankine cycles.
This study presents the impact of plant siting on the performance and economics of coal-fired utility scale power plants based on indirect sCO2 power cycles with carbon capture and storage (CCS). Four different plant sites across the United States have been selected for investigation: Chicago, IL; Kemmerer, WY; Houston, TX; Knoxville, TN. For each plant site, local parameters such as design ambient conditions, coal type and prices, captured CO2 transportation and storage (T&S) costs are considered for the techno-economic analyses (TEA). To determine the optimum plant design for each location, two power cycle configurations (recompression cycle, partial cooling cycle with reheat) and two cooling technologies (dry and adiabatic cooling) are examined. The optimization was conducted using automated derivative-free optimization (DFO) algorithms available under NETL’s Framework for Optimization and Quantification of Uncertainty and Sensitivity (FOQUS) platform. The optimization design variables include parameters such as turbine inlet temperatures and pressure, sCO2 cooler outlet temperatures, recuperators approach temperature and pressure drop etc. The study demonstrates the variability in optimal plant design for different ambient and fuel input conditions. The results will be used in future sCO2 technology market analyses.