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 waals ...

A numerical framework has been proposed to model the interacting effects of mixture non-ideality and mass transfer on hydrodynamics of a multiphase system using CFD methods.Mass transfer during condensation and vaporization is modeled by chemical potential at the liquid-vapor interface. Species mass transfers are related to the diffusion at the interface which in turn is related to the conc...

use of zinc and iron oxide are common in the desulfurization process from natural gas. in thisresearch, after determinations of the size and specifications through tem and xrd for each of the metaloxides, two different size ratios were used, 0.66 for zinc oxide and 0.142 for iron oxide. further, absorption of sulfur compounds in gas (hydrogen sulfide (h2s), carbonyl sulfide (cos), methyl mercap...

A class of non-equilibrium models for compressible multi-component fluids in multi-dimensions is investigated taking into account viscosity and heat conduction. These models are subject to the choice of interfacial pressures and interfacial velocity as well as relaxation terms for velocity, pressure, temperature and chemical potentials. Sufficient conditions are derived for these quantities tha...

the chemical composition of the essential oil obtained from the aerial parts of laurus nobilis l. has been examined by gas chromatography (gc) and gc- mass spectrometery (ms). the main components of the oil were identified. 1,8-cineole was the major component in the oil together with b-terpinyl acetate, terpinene-4-ol, a-pinene, b-pinene, p-cymene, linalool and terpinene-4-ylacetate. the essent...

a method based on the genetic algorithm (ga) was developed to study the phase behavior of multicomponent and multiphase systems. upon application of the ga to the thermodynamic models which are commonly used to study the vle, vlle and lle phase equilibria, the physically meaningful values for the binary interaction parameters (bip) of the models were obtained. using the method proposed in this ...

a very efficient one-pot three-component synthesis of pyran derivatives has been improved by condensation of aldehydes and malononitrile with dimedone under 80 °c using sucrose as natural and biodegradable catalyst in water. this method offers some advantages including inexpensive, high to quantitative yields, short reaction time, and easy work-up. therefore, this methodology is entirely green ...