Simultaneous Multiphase Flash and Stability Analysis Calculations Including Solid CO₂ for CO₂–CH₄, CO₂–CH₄–N₂, and CO₂–CH₄–N₂–O₂ Mixtures

This work deals with solid–vapor equilibria and solid–liquid–vapor of carbon dioxide in mixtures interest for natural gas purification biogas upgrading. Experimental data available the literature are reviewed an algorithm solving isobaric–isothermal flash coupled to a phase stability analysis is presented, which does not require a-priori knowledge number type phases existing at equilibrium. The good agreement between calculation results, also performed tool that makes use Gibbs free energy minimization, experimental suggests proposed approach can be used determining suitable operating conditions processes aimed separating CO2 out by freezing it. points more studies should on presence solid multicomponent containing species other than methane (e.g., nitrogen oxygen), representative gaseous streams from needs removed, such as gas, biogas, flue power plants. Such important proper calibration thermodynamic models must selected reliable process simulations.