The primary objective of this project was to investigate the cycle efficiency through a newly developed process model which accounts for the co-dependence of the cycle integrated with a cryogenic air separation unit. A net cycle efficiency of 58.2% is achievable for the cycle with the operating parameters of the cycle developers subject to integration of the adiabatic heat produced by all ASU compressors, maintaining a minimum cycle temperature of 290 K and a CO2 compressor discharge pressure of 53.5 bar. An optimum discharge pressure of 4.2 bar and 80 bar is found for the MAC and booster compressor, respectively.

 

Aside from differences in the modeling methods, one main reason for discrepancy in the optimum design point reported in past studies is the difference in the assumed operating parameters and the design constraints. The cycle efficiency and optimum design are notably dependent on the design constraints. A genetic algorithm optimization is applied to maximize the efficiency of the integrated system with respect to turbine parameters. An optimum efficiency of 59.7% is found at turbine inlet temperature, inlet pressure, and outlet pressure of 1500 K, 305.5 bar, and 28.1 bar, respectively. Although the computed inlet temperature is 70 K higher than that of the cycle developers, the turbine inlet/outlet pressures and the net efficiency are very well comparable to those enunciated by the cycle designers.