3  Boron

Weller, Andrew S.

doi:10.1039/b109572m

Cited by 12 publications

(13 citation statements)

References 185 publications

(133 reference statements)

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“…Distribution is particularly pronounced when the permeation rate and the channel width are small, but selectivity of the membrane and the fraction of recovery are large. The mathematical analysis developed earlier by Weller and Steiner26 based on complete mixing and plug flow models has been applied to the PV process.…”

Section: Modeling and Simulation Studiesmentioning

confidence: 99%

“…ratio of permeability of water at all values of mole fraction and that of pure water, K 1 , permeate concentration, y

_{italicA}^{italicp}

, stage cut (fraction of feed that has permeated through the membrane), θ, dimensionless area, S , and membrane area, A , for the given values of feed concentration and the desired value of outlet concentration, based on the complete mixing model and plug flow models of Weller and Steiner26 as described before 20. Defining selectivity, α, as: where x A is the mole fraction of water in the feed and y A is the mole fraction of water in the permeate, ideal selectivity is calculated as: where K A is the permeability of water at any value of x A ; K B is the permeability of isopropanol at any value of x B (= 1‐ x A ); and P

_{italicA}^{italico}

and P

_{italicB}^{italico}

are vapor pressures of water and isopropanol, respectively.…”

Section: Modeling and Simulation Studiesmentioning

confidence: 99%

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Pervaporation separation of water‐isopropanol mixtures using polymeric membranes: Modeling and simulation aspects

Aminabhavi

Naidu

Sridhar

et al. 2005

J of Applied Polymer Sci

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ABSTRACT:Pervaporation technique was used to separate water ϩ isopropanol azeotropic mixtures at 30°C using pure sodium alginate, pure poly(vinyl alcohol), and blend membranes of sodium alginate containing 10 and 20 mass % of poly(vinyl alcohol). The membrane performance was studied by calculating flux, selectivity, pervaporation separation index, and enrichment factor. Pure sodium alginate membrane gave the highest pervaporation separation index for all compositions of water. Pervaporation experiments were carried out for 10 mass % containing water ϩ isopropanol mixture at 30, 40, and 50°C. The Arrhenius activation parameters were computed. The PV results have been analyzed by considering complete mixing and plug flow models. Design parameters, like membrane area, permeate concentrations, flux, stage cut, separation selectivity, etc., have been calculated for different feed compositions of water in the mixture. Results are explained in terms of sorptiondiffusion principles.

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Section: Modeling and Simulation Studiesmentioning

confidence: 99%

“…ratio of permeability of water at all values of mole fraction and that of pure water, K 1 , permeate concentration, y

_{italicA}^{italicp}

_{italicA}^{italico}

and P

_{italicB}^{italico}

are vapor pressures of water and isopropanol, respectively.…”

Section: Modeling and Simulation Studiesmentioning

confidence: 99%

Pervaporation separation of water‐isopropanol mixtures using polymeric membranes: Modeling and simulation aspects

Aminabhavi

Naidu

Sridhar

et al. 2005

J of Applied Polymer Sci

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“…Activation parameters have been evaluated and results have been discussed using the solution–diffusion principles 25, 26. Design parameters and membrane area requirements have been computed for the feed rate of 10 L/h at the feed composition of 0.55‐mol fraction of water to achieve the final retentate concentration greater than 0.99‐mol fraction of organics by using the Weller and Steiner theory27 based on complete mixing and plug flow models. Programs were written to determine the minimum stripping concentration, permeate composition, stage cut (fraction of feed permeated through the membrane), and membrane area required for a given value of feed composition and the desired value of retentate (product) composition.…”

Section: Introductionmentioning

confidence: 99%

Computer simulation and comparative study on the pervaporation separation characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) to separate aqueous mixtures of 1,4‐dioxane or tetrahydrofuran

Aminabhavi

Naidu

Sridhar

2004

J of Applied Polymer Sci

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ABSTRACT:A comparative study on the pervaporation separation has been attempted for water ϩ 1,4-dioxane and water ϩ tetrahydrofuran mixtures using sodium alginate and blend membranes of sodium alginate with 5, 10, and 20 mass % of poly(vinyl alcohol). Pure sodium alginate membrane has a selectivity of 111 to water at 0.35-mol fraction of water in the feed mixture containing 1,4-dioxane while for water ϩ tetrahydrofuran mixture, the membrane selectivity to water was 291 at 0.31-mol fraction of water in the feed mixture. Pervaporation results have been discussed using the solution-diffusion principles. Arrhenius activation parameters for diffusion and permeation have been computed from the temperature-dependent pervaporation results. Furthermore, experimental results have been analyzed using the complete mixing and plug flow models to compute membrane area as well as design parameters that are useful in scale-up operations. The plug flow model is more appropriate than the complete mixing model to analyze the pervaporation results.

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“…Automated preparative and semi‐preparative HPLC purification of synthesis products is a popular approach to the high‐speed production of new compounds for pharmaceutical and chemical discovery 1–4. The same automated systems have been applied to the isolation of batch‐lot impurities of interest and the isolation of metabolites from biotransformation of drugs.…”

mentioning

confidence: 99%

“…1). This system has been used to automate purification of parallel synthesis products,2,, 7–9 and its popularity has resulted in the development of several commercial solutions. However, coupling a MS to preparative HPLC is not easy.…”

mentioning

confidence: 99%

A straightforward means of coupling preparative high‐performance liquid chromatography and mass spectrometry

Cai

Kiplinger²,

Goetzinger

et al. 2002

Rapid Comm Mass Spectrometry

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Flow splitting to a mass spectrometer is a common way of coupling a highly specific detector to preparative or semi-preparative high-performance liquid chromatography (HPLC) purification of combinatorial libraries, drug metabolites, and characterizable impurities. The sensitive mass spectrometer consumes only a small fraction of the analyte while providing online structure-specific detection, and its output can thus be used to trigger collection of the desired fraction. Coupling mass spectrometry to preparative HPLC is difficult due to the susceptibility of the detector to fouling under conditions of high analyte concentration or solute amount, or to changes in solvent composition. We report here on a device, the mass rate attenuator (MRA), which automatically produces split ratios over a range of 100:1 to 100 000:1 under programmable user control. The MRA is a flow-control device that periodically gates a small aliquot from one liquid stream into another. The design allows the user to set the frequency of the gating without interruption of the HPLC flow stream. The MRA also allows control of the volume of the aliquot that is transferred between the flow streams. This additional control, compared to passive splitting devices, facilitates optimization of the tubing connecting the separation, detection and collection events. We demonstrate that such optimization can reduce the volume of the collected fraction without compromising recovery, thus reducing the time spent in evaporating solvents to reclaim purified products.

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3 Boron

Cited by 12 publications

References 185 publications

Pervaporation separation of water‐isopropanol mixtures using polymeric membranes: Modeling and simulation aspects

Pervaporation separation of water‐isopropanol mixtures using polymeric membranes: Modeling and simulation aspects

Computer simulation and comparative study on the pervaporation separation characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) to separate aqueous mixtures of 1,4‐dioxane or tetrahydrofuran

A straightforward means of coupling preparative high‐performance liquid chromatography and mass spectrometry

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