Development of High-Fidelity Numerical Models for Supercritical CO2 Oxy-Combustion: SBIR Phase I Final Technical Report
- Reaction Engineering International (REI), Midvale, UT (United States)
Reaction Engineering International (REI) has led an effort to develop a CFD-based framework for modeling the combustor in a direct oxy-fired supercritical carbon dioxide (sCO2) system. We achieved this goal by modifying our existing proprietary CFD code, ADAPT, to include real gas thermodynamic and transport properties, and finite rate chemical kinetics for oxy combustion under sCO2 conditions with impacts of impurities. This is the final report describing accomplishments throughout the program. This work was motivated by growing interest in alternative thermodynamic cycles used to generate electric power. The potential benefits of utilizing sCO2 as a working fluid include higher cycle thermal efficiency and smaller facility footprints than steam-based Rankine cycles. Direct-fired oxy-fired sCO2 cycles using fossil fuels are particularly attractive since they inherently produce a pipeline-ready CO2 stream for subsequent utilization and sequestration. REI leveraged the National Institute of Standards and Technology (NIST) Thermodynamic and Transport Properties Software (REFPROP v10.0) to calculate thermodynamic properties, such as enthalpy, heat capacity, and density and transport properties, such as molecular viscosity of a real gas or real gas mixture as function of temperature and pressure in a high pressure environment. The properties of pure fluids along with mixing rules to compute the properties of mixtures were successfully incorporated into the CFD code. Enabling these considerations into the code is supported by REI’s research showing deviations from ideality under the conditions of interest are particularly significant for density and molecular viscosity. REI’s project partners at the University of South Carolina assembled a detailed chemical kinetics mechanism that has been validated over a wide range of conditions. REI used this detailed mechanism to generate a reduced mechanism suitable for inclusion in the CFD code. Chemical kinetic calculations show the reduced mechanism produces results that are in good agreement with experimental data and detailed mechanism predictions for species concentrations and ignition delay in an sCO2 oxy-combustion environment. Validation of the code’s applicability as a design tool was carried out in 3 steps. First, the code was applied to an idealized geometry of a plug flow reactor where simulation results showed good agreement with calculations performed outside of the CFD code for the same conditions. Second, REI explored the model’s range of capabilities by comparing model predictions with experimental data for pressurized oxy-combustion tests with a lignite-derived syngas provided by the Energy and Environmental Research Center (EERC). Lastly, REI performed an evaluation of a conceptual direct-fired sCO2 combustor as described in the literature. This application of the tool targeted conceptual design efforts involving combustor design and shows promise in optimizations of key operational parameters. Additional efforts are planned to continue to improve the chemical mechanisms, turbulence-chemistry interaction and gas property predictions, and to further demonstrate the model’s predictive capability at pilot- and full-scale.
- Research Organization:
- Reaction Engineering International, Midvale, UT (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- SC0019641
- OSTI ID:
- 1602967
- Type / Phase:
- SBIR (Phase I)
- Report Number(s):
- DOE-REI-19641
- Country of Publication:
- United States
- Language:
- English
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