Gas-Liquid Separations

Gases and liquids may be intentionally contacted as in absorption and distillation, or a mixture of phases may occur unintentionally as in vapor condensation from inadvertent cooling or liquid entrainment from a film. Regardless of the origin, it is usually desirable or necessary ultimately to separate gas-liquid dispersions. While separation will usually occur naturally, the rate is often economically intolerable and separation processes are employed to accelerate the step. 

These operations will be grouped by fhe phases that are to be separated gas-liquid, liquid-liquid, solid-gas. and solid-liquid. The fundamental roechanigns in each group are similar. There are four basic mechanisms that contribute to each group of separations ... 

To evaluate the performance of a two-phase separator (gas-liquid or liquid-liquid) the mass transfer coeflicient or the extraction efficiency need to be known. A number of models have been developed for gas-Uquid systems, which estimate the mass transfer coefficient in the continuous liquid phase. In these models the individual contributions of the caps of the plugs and of the fully developed film separating the plugs from the channel wall are estimated. A study... 

The difference in the adsorption isotherms of isotopic molecules has long been known and it has been used for isotope separation and isotope analysis. For example, deuterium gas exhibits an enrichment factor of 40 ( ) at 20 K on silica gel, but the enrichment factor decreases steeply with increasing temperature (Krumbiegel 1970). Another example is the behavior of CH4/CD4 system in a capillary column with activated glass surface at 153 K the retention time of CH4 is larger than that of CD4, at 130 K they are equal to each other and at lower temperatures CH4 leaves earlier the column than CD4 (Bruner et al. 1966). Similarly to the gas-solid chromatographic separations, gas-liquid separation techniques have also been widely used for isotopic separation and for rapid and convenient analysis of mixtures of... 

MSFIA system for selenium speciation by atomic fluorescence spectrometry. G/L separator gas/liquid separator HC holding coil RC reaction coil V solenoid valve. 

As we did several times in our design of the ammonia process, we investigate the possibility of separating the n-heptane by phase differences. We begin with the most efficient separation, gas/liquid or gas/solid, for which we need to know boiling points. Again we make a table of the relevant thermodynamic data. 

The earliest of the chromatographic methods to be applied to trace analysis was paper chromatography, which in the later 1940s was developed as an advance on the original purely qualitative column chromatographic separations. Gas-liquid chromatography followed in due course, together with many variations of the two-dimensional techniques. 

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