نتایج جستجو برای: pervaporation
تعداد نتایج: 620 فیلتر نتایج به سال:
Mass transfer phenomenon that occurs in the pervaporation process when applied to the microemulsion breakdown, was confirmed by the results of inverse gas chromatography. The stationary phase for this study was polydimethylsiloxane (PDMS), a hydrophobic polymer employed as a membrane in the pervaporation technique. The retention times of the different molecule probes (toluene, cyclohexane, and ...
A review concerning pervaporation and vapor permeation membrane separation techniques used to separate liquid mixtures, is presented. Examples of polymers for membrane preparation as well as performance parameters of pervaporation and vapor permeation membranes are described. The second part of the paper presents applications of pervaporation and vapor permeation in environmental protection. At...
In this study, the behaviour of a continuous membrane bioreactor with in situ removal of product ethanol by pervaporation and cell recycle has been investigated. The kinetic model used is an unstructured growth model taking into account product as well as substrate inhibition and the product formation rate is represented by the Leudeking-Piret model. The effect of pervaporation on the performan...
As part of a Department of Defense project, the US Environmental Protection Agency was responsible for designing, building and field operating a pilot-scale pervaporation unit. The field site was an active dry cleaning facility on the grounds of Marine Corps Base Camp Lejeune in Jacksonville, NC. The overall goal of the project was to remove tetrachloroethylene (PCE) from the soil beneath the d...
Ethanol-water concentration profiles in cellulose acetate membranes were measured under steady-state pervaporation conditions. Knowledge of these profiles leads to a better understanding of the diffusion process during pervaporation. The concentration profiles were determined by a film-stack method, using three to six layers. It is shown that permeation of ethanol-water mixtures proceeds in a c...
The U.S. Federal Register of April 17, 1987, contains a list of priority pollutants found at Superfund Sites. About half of these are volatile organic compounds (VOC’s), which are known to be toxic and/or carcinogenic in nature. Pervaporation is a membrane technology utilizing a dense non-porous polymeric film to separate the contaminated water from a vacuum source. A membrane is used that pref...
Article history: Received 14 December 2016 Received in revised form 12 May 2017 Accepted 14 May 2017 Available online 1 July 2017 Alcohol-permselectivity pervaporation has been arousing increasingly more attention in bioalcohol production due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. With the intrinsic feature of larger ...
The development of a reactive distillation process for the production of n-butyl acetate by transesterification of methyl acetate with n-butanol is presented. Thermodynamic aspects of the quaternary system n-butyl acetate – n-butanol – methyl acetate – methanol are discussed and UNIQUAC interaction parameters derived using the Dortmund Data Bank (DDB) are given. The reaction kinetics of the het...
In this paper, polydimethylsiloxane (PDMS) composite membranes that were supported using polyvinylidene fluoride (PVDF) microfiltration membrane were developed for the pervaporation (PV) of dimethyl carbonate (DMC) from a methanol solution. Experimental studies on the solubility and the diffusivity of pure DMC and methanol in the membrane were first measured. Higher DMC uptake indicates that th...
Copolyamides with anthrazoline units in the backbone (coPA) were synthesized and dense nonporous films were prepared by solvent evaporation. Glass transition temperature, density, and fractional free volume were determined for the dense nonporous films composed of polyamide and two of its copolymers containing 20 and 30 mol % anthrazoline units in the backbone. Transport properties of the polym...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید