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Pervaporation vapor permeation

Under ideal conditions, a thermodynamic equilibrium will be reached when the chemical potential of the solute i is equal at the membrane surface and the feed phase adjacent to it. The sorption of these solutes at the membrane surface creates a solute concentration gradient across the membrane, resulting in a diffusive net flux of solute across the membrane polymer (Fig. 3.6-lOB). In vapor permea-tion/pervaporation, any solute that has diffused toward the membrane downstream surface is ideally instantaneously desorbed and subsequently removed from the downstream side of the membrane (Fig. 3.6-lOC). This can be achieved either by applying a vacuum (vacuum vapor permeation/pervaporation), or by passing an inert gas over the membrane downstream surface (sweeping-gas vapor permea-... [Pg.272]

Fig. 3.6-10 Sorption (a), diffusion (b) and desorption (c) of permeating solutes during vapor permeation/pervaporation. Fig. 3.6-10 Sorption (a), diffusion (b) and desorption (c) of permeating solutes during vapor permeation/pervaporation.
Table 3.6-3 Solvents routinely dehydrated in vapor permeation/pervaporation units... Table 3.6-3 Solvents routinely dehydrated in vapor permeation/pervaporation units...
Reverse osmosis Thermoosmosis Vapor permeation Pervaporation Gas permeation Dialysis Electrodialysis Liquid membranes Nanofiltration... [Pg.538]

Pervaporation. Vapor arbitrated pervaporation is used to remove ethanol from whiskey by selective passage of the alcohol through a membrane. Whiskey flows on one side of a membrane. A water-vapor stream flows on the other side and sweeps away the ethanol that permeates the membrane. Thus alcohol reduction and selective retention of flavor and aroma components can be achieved usiag membranes with a particular porosity. The ethanol can be recovered by condensing or scmbbiag the vapor stream. Pervaporation systems operate at or slightly above atmospheric pressure (Fig. [Pg.87]

FIG. 25-19 Pervaporation of gas from liquid feed across membrane to vaporous permeate. (SOURCE Redrawn from Ref. 24.)... [Pg.2194]

The most common membrane systems are driven by pressure. The essence of a pressure-driven membrane process is to selectively permeate one or more species through the membrane. The stream retained at the high pressure side is called the retentate while that transported to the low pressure side is denoted by the permeate (Fig. 11.1). Pressure-driven membrane systems include microfiltration, ultrafiltration, reverse osmosis, pervaporation and gas/vapor permeation. Table ll.l summarizes the main features and applications of these systems. [Pg.262]

On-line pervaporation, 18 518 On-line probes, for fermentation, 11 39 On-line vapor permeation, 18 518 On/off feedback controllers, 20 691 Onstream analyzers, 20 682 On-tank leak detection systems, 24 311 Onyx thermal printing process, 19 321 Oocytes, retroviral infection of, 12 457 Oolitic limestone, 15 28 Opacification, colorants for ceramics, 7 344-345... [Pg.648]

K., Kondo, M., and NaA, Z. (2001) membrane preparation, single-gas permeation, and pervaporation and vapor permeation of water/organic liquid mixtures. Ind. Eng. Chem. Res., 40, 163-175. [Pg.326]

B. Will, R.N. Lichtenthaler, Comparison of the separation of mixtures by vapor permeation and pervaporation using PVA composite membranes. Part I. Binary alcohol—water systems, J. Membr. Sci. 68 (1992) 119-125. [Pg.57]

T. Kataoka, T. Tsuro, S.-I. Nakao and S. Kimura, Membrane Transport Properties of Pervaporation and Vapor Permeation in an Ethanol-Water System Using Polyacrylonitrile and Cellulose Acetate Membranes, J. Chem. Eng. Jpn 24, 326 (1991). [Pg.84]

Both Mitsui [26] and Sulzer [27] have commercialized these membranes for dehydration of alcohols by pervaporation or vapor/vapor permeation. The membranes are made in tubular form. Extraordinarily high selectivities have been reported for these membranes, and their ceramic nature allows operation at high temperatures, so fluxes are high. These advantages are, however, offset by the costs of the membrane modules, currently in excess of US 3000/m2 of membrane. [Pg.314]

Figure 9.3 illustrates the concept of permeation from a saturated vapor phase in equilibrium with the feed liquid as a tool to obtain Equation (9.5). A number of workers have experimentally compared vapor permeation and pervaporation separations and have sometimes shown that permeation from the... [Pg.359]

Figure 9.12 Isothermal vapor permeation and multistage pervaporation with intermediate heating. GFT poly (vinyl alcohol) membranes [45]... Figure 9.12 Isothermal vapor permeation and multistage pervaporation with intermediate heating. GFT poly (vinyl alcohol) membranes [45]...
U.H.F. Sander, Development of Vapor Permeation for Industrial Applications, in Pervaporation Membrane Separation Processes, R.Y.M. Huang (ed.), Elsevier, Amsterdam, pp. 509-534 (1991). [Pg.391]

Figure 8.18 Flow schemes ofthe separation train of a 50-million gallon/y bioethanol plant. Current technology is illustrated in (a). Pervaporation membranes can be used to replace the molecular-sieve drier of the plant (b) or vapor-permeation membranes can be used to replace the rectifier column and molecular-sieve units (c). Figure 8.18 Flow schemes ofthe separation train of a 50-million gallon/y bioethanol plant. Current technology is illustrated in (a). Pervaporation membranes can be used to replace the molecular-sieve drier of the plant (b) or vapor-permeation membranes can be used to replace the rectifier column and molecular-sieve units (c).
A process referred to as vapor-arbitrated pervaporation addresses these issues by manipulating the transmembrane activity gradients of water and ethanol in a pervaporation system. Using a permeate side sweep stream that contains water vapor at a partial pressure corresponding to the activity of water on the feed side, permeation of water is halted while ethanol continues to diffuse through the membrane into the sweep stream and is removed. In this way, the native permselectivity of the membrane system can be altered in a controlled fashion to extract one or more volatile components from a solution. [Pg.378]

Vapor Permeation Vapor permeation is similar to vapor pervaporation except that the feed stream for permeation is a gas. The future commercial viability of this process is based upon energy and capital costs savings derived from the feed already being in the vapor-phase, as in fractional distillation, so no additional heat input would be required. Its foreseen application areas would be the organics recovery from solvent-laden vapors and pollution treatment. One commercial unit was installed in Germany in 1989 (Ref. 26). [Pg.53]

Separation of liqui(J mixture Application of PV and VP General review, examples of polymers for membrane preparation, as well as performance parameters of pervaporation and vapor permeation membranes, are described [159]... [Pg.131]

Kujawski W. Application of pervaporation and vapor permeation in environmental protection. J. Env. Stud. 2000 9(1) 13-26. [Pg.138]

Indeed, in many cases the membrane system cannot be used directly and often pretreatment is necessary to facilitate the membrane process. Pretreatment is important and necessary in micro-, ultra-, and nanofiltration, while it is not that important for pervaporation (PV), vapor permeation (VP), or gas separation for which feed streams are usually much cleaner and do not contain many impurities. The cost of pretreatments can contribute appreciably to the overall costs. However, due to the intrinsic... [Pg.156]

Pervaporation and vapor permeation are typical membrane processes with high application potential in chemical industry due to their high efficiency in the separation or the dehydration of organic solvents. Developed initially with organo-polymeric... [Pg.167]

FIGURE 6.27 General working principle of a pervaporation or vapor permeation module equipped with tubular ceramic membrane elements. [Pg.168]

These separations are usually carried out by pervaporation (see Section 10.5) or vapor permeation but they have also been performed using gas-phase feeds on organophihc [75] or hydrophilic membranes [76]. On organophdic membranes the permeation of the organic or less polar compound is favored, while the opposite trend is expected for hydrophilic membranes. [Pg.283]


See other pages where Pervaporation vapor permeation is mentioned: [Pg.527]    [Pg.273]    [Pg.280]    [Pg.284]    [Pg.49]    [Pg.91]    [Pg.527]    [Pg.273]    [Pg.280]    [Pg.284]    [Pg.49]    [Pg.91]    [Pg.360]    [Pg.375]    [Pg.384]    [Pg.57]    [Pg.144]    [Pg.376]    [Pg.666]    [Pg.139]    [Pg.167]    [Pg.168]    [Pg.168]    [Pg.169]   
See also in sourсe #XX -- [ Pg.284 , Pg.287 ]




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Vapor Permeation and Pervaporation

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