multi-component-multiphase flash calculations for systems containing gas hydrates by direct minimization of gibbs free energy

Multi-Component-Multiphase Flash Calculations for Systems Containing Gas Hydrates by Direct Minimization of Gibbs Free Energy

The Michelsen stability and multiphase flash calculation by direct minimization of Gibbs free energy of the system at constant temperature and pressure, was used for systems containing gas hydrates. The solid hydrate phase was treated as a solid solution. The fugacities of all components of the hydrate phase were calculated as a function of compositions by the rearranged model of van der Wa...

Determination of the Gibbs Free Energy of Gas Replacement in SI Clathrate Hydrates by Molecular Simulation

Eric M. Yezdimer,†,‡ Peter T. Cummings,§,| and Ariel A. Chialvo*,|,⊥ Chemistry Department, UniVersity of Tennessee, KnoxVille, Tennessee 37996-2200, Departments of Chemical Engineering, Chemistry and Computer Science, UniVersity of Tennessee, KnoxVille, Tennessee 37996-2200, Chemical Sciences DiVision, High-Temperature Aqueous Chemistry Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee...

Gibbs energy minimization in gas + liquid + solid systems

An algorithm is described for the calculation of equilibrium compositions of multiple highly nonideal liquid and solid solutions, as well as pure stoichiometric phases, coexisting with a mixture of ideal gas species at fixed temperature and pressure. The total Gibbs free energy of the system is approximated as a quadratic function of the compositions of the gas phase and stable condensed phases...

Driving Force for Nucleation of Multi-Component Gas Hydrate

Based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. Expressions for the supersaturation are obtained in isothermal and isobaric regimes. The results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to ...

Multi-component Multiphase Flow

An axiomatic foundation for models of multi-component multiphase porous flow appearing ubiquitously in the engineering literature is developed. This unifies and extends various disparate and empirical formulations appearing in the literature. Constitutive restrictions are derived from an appropriate statement of the second law of thermodynamics, and the corresponding dissipation inequalities es...

Direct Minimization for Ensemble Electronic Structure Calculations