• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.34-35
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• 1995

The unique feature of pervaporation is the mass transfer from a liquid phase to a vapor phase through a non-porous polymeric membrane. When a liquid mixture is brought into contact with a membrane at one side, it is sorbed into the membrane. Due to a driving force applied across the membrane, the sotbed liquid molecules permeate through the membrane and evaporate at the downstream side of the membrane. In pervaporation the permeated species are usually removed from the downstream side under a relatively low vapor pressure, for example by evacuation with a vacuum pump. As far as this condition is fulfilled, the evaporation step can be considered to be much faster than sorption or diffusion. Hence evaporation does not contribute to permselectivity. Therefore the separation by pervaporation results from the differences in the preferential sorption of the individual components of a mixture into the membrane together with the diffusion rates through the membrane. This postulation implies that both sorption and diffusion phenomena have to be accounted for to understand the physico-chemical nature of the pervaporation separation process.

• Membrane Journal
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• v.12 no.4
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• pp.193-206
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• 2002

Pervaporation separation is one of promising membrane technology for the energy saving processes and it has been developed to separate complex mixture systems including azeotropic mixture, close-boiling mixture, aqueous organic mixtures etc. Many researchers focused on dehydration pervaporation separation and they commercialized ethanol dehydration and isopropanol recycling processes. Nowadays, petroleum separation and volatile organic compound removal using pervaporation membranes is one of the emerging application of pervaporation separation. We reviewed the development and application of pervaporation membranes.

• Membrane Journal
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• v.9 no.1
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• pp.51-62
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• 1999

The recovery of trace volatile organic components from water by pervaporation was investigated. Permeation experiments through homogeneous polydimethylsiloxane(PDMS) membrane was carried out and the effect of feed concentrations and membrane thicknesses on the permeation characteristics were investigated. A solution-diffusion model is used to describe the pervaporation transport mechanism. In homogeneous PDMS membrane it appeared that the selectivities of MEK and toluene are constant, and that organic flux has a linear relationship with feed concentration. These results indicate that the coupling effects between organics were negligible. The selectivity of PDMS membranes is invariant with respect to the membrane thickness. The intrinsic membrane permeability of organic components determined by using a solution-diffusion model. Comparing with various composite type membrane, the membrane using PEG treated nonwoven fabric as sublayer showed the best performance in VOC recovery by pervaporation.

• Proceedings of the Membrane Society of Korea Conference
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• 1991.10a
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• pp.1-3
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• 1991

A novel membrane separation process for the separation of liquid mixture is Pervaporation. The term, 'pervaporation', is a combination of permeation and evaporation, and was first introduced by kober[1] in 1917. In this technique, the liquid mixture in feed is in contact with one side of a dense non-porous membrane and after diffusing through the membrane is removed from the downstream side in the vapor phase, but is usually condensed afterwards to obtain a permeate in liquid from.

• Korean Membrane Journal
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• v.6 no.1
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• pp.55-60
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• 2004

In recent years, an increasing interest in membrane technology has been observed in chemical and environmental industry. Membrane technology has advantages of low cost, energy saving and environmental clean technology comparing to conventional separation processes. Pervaporation is one of new advanced membrane technology applied for separation of azeotropic mixtures, aqueous organic mixtures, organic solvent and petrochemical mixtures. Sodium alginate composite membranes were prepared for the enhancement of long-term stability of pervaporation performance of water-ethanol mixture using pervaporation. Sodium alginate membranes were crosslinked with CaCl$_2$ and coated with polyelectrolyte chitosan to protect washing out of calcium ions from the polymer. The surface structures of PAN and hydrolysed PAN membrane were confirmed by ATR Fourier transform infrared (FT-IR). A field emission scanning electron microscopy (FE-SEM; Jeol 6340F) operated at 15 kV. Concentration profiles for Ca in the membrane surface and membrane cross-section were taken by an energy dispersive X-ray (EDX) analyser (Jeol) attached to the field emission scanning electron microscopy (Jeol 6340F). Pervaporation experiments were done with several operation run times to investigate long-term stability of the membranes.

• KSBB Journal
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• v.15 no.4
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• pp.380-387
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• 2000

An extractive fermentation process using pervaporation was studied in a 7 liter fermentor. Pervaporation was performed using a silicone membrane module and a low-acid-producing strain Clostridium acetobutylicu, B18 was used to produce butanol. In batch culture without pervaporation pH 5.5 and initial glucose concentration of 60 g/L resulted in the highest butanol productivity (0.216 g/L$.$h) with butanol yield of 0.261 Butanol flux through the membrane was best at 2.0 L/min-tubing of air flow rate In batch and fed-batch fermentation glucose consumption rate increased by 1.3 times with pervaporation.

• Membrane Journal
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• v.12 no.4
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• pp.226-239
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• 2002

A process simulation model of pervaporation process has been developed as a design tool to analyse and optimize the dehyhration of organic solvents through a commercial scale of pervaporative plate-and-frame modules that contain a stack of membrane sheets. In the simulation model, the mass balance, the heat balance and the concentration balance are integrated in a finite elements-in-succession method to simulate the overall process. In the integration method, a feed channel between membrane sheets in the modules was taken as differential unit element volume to simplify calculation procedure and shorten computing time. Some of permeation parameters used in the simulation model, were quantified directly from the dehydration experiment of ethanol through $AzeoSep^{TM}$-2002 membrane which is a commercial pervaporation membrane. The simulation model was verified by comparing the simulated values with experimental data. Using the model, continuous and batch pervaporation processes were simulated, respectively, to acquire basic data for analysing and optimizing in the dehydration of ethanol through the membrane. Based on the simulation results, a comparison between the continuous and the batch pervaporation processes would be discussed.

• Membrane Journal
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• v.14 no.3
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• pp.258-262
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• 2004

Trifluoroethyl methacrylate (TFEMA) is used in the preparation of water-repellant paints and optical fiber clading materials, and is manufactured by esterification reaction of trifluoroethanol (TFEA) and methacrylic acid (MA). To estimate the applicability of a pervaporation membrane for the esterification TFEMA esterification, the basic pervaporation properties for TFEA/water mixture were determined using a commercial poly(vinyl alcohol) membrane (GFT Membrane $Pervap^{\circledR}1005$). The effect of TFEA concentration in feed solution and operating temperature on the pervaporation properties was determined. The total permeation flux decreased with increasing TFEA concentration from 90 to 99 wt%, but the separation factor of TFEA/water showed maximum values at 95 wt% TFEA concentration. With increasing feed temperatures from 50 to 8$0^{\circ}C$, the permeation flux and separation factor increased. Higher separation factors and permeation fluxes were observed at 8$0^{\circ}C$ of feed temperature. This pervaporation performance confirmed that the commercial pervaporation membrane could be successfully applied to esterification of TFEMA.

• Membrane Journal
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• v.33 no.6
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• pp.377-382
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• 2023

In this study, a PEBAX/PVDF composite membrane was fabricated, and its pervaporation performance was tested in an ethanol/water mixture. In addition, we attempted to improve the pervaporation performance of the composite membrane by forming a ZIF-8 layer on the surface of the PVDF substrate. The thickness of selective layer was optimized by comparing the pervaporation performance depending on the PEBAX thickness. A pervaporation test was performed on the Ethanol/Water mixture. As a result, the composite membrane using PVDF substrate with ZIF-8 layer had a flux of 1.98 kg/m²h and separation factor of 3.88, showing higher values of both permeation flux and selectivity than the composite membrane using bare PVDF substrate.

• Membrane Journal
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• v.17 no.1
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• pp.1-13
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• 2007

Pervaporation process using membrane is newly emerging energy saying and cost effect process instead of distillation process. Especially, in pertrochemical industry, pervaporation process is a strong candidate to substitute the conventional energy consuming processes because that petrochemical industry has much energy consuming separation processes, many azeotrope mixtures to separate and needs to compact space to install new process units. Aromatic/aliphatic separation including benzene/cyclohexane mixture, olefin/paraffin separation, xylene isomer separation, reactive monomer recovery and sulfur compound removal from gasoline have been inversitigated for the application of pervaporation membrane process by many researchers and are under commercializing.