Session: 30-09 Oxy-Fuel Combustion

Paper Number: 153655

Impact of Different Equations of State on Allam Cycle Efficiency 

Cycle efficiency is one of the main drivers in the decarbonization field for power generation. A promising solution in this direction is the Allam cycle based on oxy-combustion in a supercritical CO₂ environment with an intrinsic highly efficient CO₂ capture. The working cycle operating conditions require a suitable equation of state for thermodynamic modeling and performance evaluation significantly influenced by the fluid properties.

Considering that a validated model for the prediction of the evolving fluid mixture properties is not available yet, the present paper investigates the impact of using several types of equations of state for cycle performance. The analysis includes  both simple thermodynamic models such as cubic type and more complex models such as multiparameters and multicomponents ones. The selected equations of state are compared for their predictive capability with respect to phase behavior, enthalpy, entropy, heat capacity and density over the cycle operating conditions. These differences have direct impact on the main cycle components such as turbomachinery and recuperator whose performance are evaluated. Finally, the cycle efficiency is predicted and compared showing variation in results due to the selected thermodynamic model. This paper highlights the importance of using an appropriate thermodynamic model to have a good prediction of the cycle’s overall efficiency.

Presenting Author: Emanuela Alfarano Baker Hughes

Presenting Author Biography: Competent gas turbines performance engineer with 10+ years of experience in Oil and Gas Industry with a background in chemical engineering. Solid knowledge in models’ development for cycle simulation and multidisciplinary optimization, gas turbine performance evaluation both for feasibility studies and New Product Development initiatives.
Since 2023, Emanuela is also doing a PhD at University of Perugia, "Energy and Sustainable Development" about Allam Cycle, focusing on supercritical CO2 equation of state development and its application for turboexpander performance and operability.
She had her Bachelor Degree in Chemical Engineering at University of L'Aquila and her Master Degree in Chemical Engineering at Polytechnic of Milan.

Authors:

Emanuela Alfarano Baker Hughes
Ever Avriel Fadlun Baker Hughes
Francesco Fantozzi Università di Perugia