Vacuum swing adsorption

Calculators c4-8 through c4-10 are for an air-feed ozone system. For a more rigorous calculation (or for calculations for pressure swing adsorption, vacuum swing adsorption, and vacuum-pressure swing adsorption systems), refer to Ozone in Drinking Water Treatment (Rakness 2005). 

Air separation by PSA on a large scale is today dominated by machines in which the pressure swing may be from near atmospheric to substantially sub-atmospheric pressure. The industry typically calls these machines vacuum swing adsorption (VSA) separators. A second sub-class in air separation is the machines that use a pressure swing the ranges from somewhat super-atmospheric to sub-atmospheric and these may be called trans-atmospheric PSA. The distinctions made here have implications as to equipment specifications and performance limitations in both bed size factor and O2 recovery. 

In lab-scale applications 02 is normally supplied in cylinders. In industrial applications it is either delivered in tanks as liquid oxygen or produced on-site from ambient air, usually with pressure swing or vacuum swing adsorption (Horn et al., 1994). 

Pressure Swing and Vacuum Swing Adsorption Systems, Air Products and Chemicals, Inc., 1996-2002. (www.airproducts.com/membranes). 

Alternatives to the cryogenic separation process include the membrane separation process and adsorption processes. The adsorption processes include pressure swing adsorption (PSA)10 and vacuum swing adsorption (VSA). These methods are noncryogenic and produce a vapor product only. This reduces the cost of production considerably when the local use of gas-phase product is the primary objective. 

Vacuum swing adsorption (VSA) system for on-site supply, and... 

Vacuum swing adsorption (VSA) air separation in, 2, 32, 34 carbon monoxide recovery in, 107, 108 vacuum pressure swing adsorption (VPSA), 2, 32-34 Valeric acid, 263... 

These differences become more pronounced with increasing deviations of the adsorption isotherm from a hnear relationship. As a rule the decision on the separation process as temperature swing adsorption (TSA), pressure swing adsorption (PSA), or vacuum swing adsorption (VSA) is a compromise between the steps of adsorption and desorption. Applying the PSA technique on approximately linear adsorption isotherms is advantageous. 

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