Performance modeling of Allam cycle integrated with a cryogenic air separation process

The performance of an integrated Allam cycle and a cryogenic air separation process is numerically simulated. In contrast to previous research which has primarily focused on the design of the cycle alone, this work accounts for the operational co-dependence of the cycle and a co-located air separation unit (ASU). Heat integration between the cycle and ASU includes adiabatic heat of the main air compressor (MAC), and booster compressor of the ASU overlooked in past studies. The discharge pressure of the recycled CO₂ compressor is determined based on its saturation pressure at cycle minimum temperature. The cycle efficiency exhibits a maximum at a MAC discharge pressure of 4.2 bar whereas it consistently decreases with discharge pressure of the booster. A genetic algorithm optimization is applied to estimate an optimum operational point. A maximum efficiency of 59.7% is obtained at turbine inlet temperature, inlet pressure, and outlet pressure of 1500 K, 305.5 bar, and 28.1 bar, respectively.