Evaporative pertraction

Ace p.

Order the writing of a tailor-made Physics Term papers

Free quote online

Thesis Format .doc

Evaporative pertraction

Download

Read an extract

Reader
Abstract
Contents
Extract

Abstract

Evaporative Pertraction is membrane processes that has fascinating advantages over conventional process for the separation of volatile solutes from aqueous solutions. This novel athermal Membrane separation process retains flavors and fragrances better than thermal techniques. It promises to play an important role in the processing of foods, pharmaceuticals and other products. As the result of this characteristic Evaporative Pertraction recently has favorable attention in particular for the Dealcoholization of ferments for the production of Wine and Beer. This process does not require a substantial system pressure or temperature gradient across the membrane. Therefore, this process advantageously can be carried out at ambient pressure. Such low temperature and pressure condition decreasing the solute concentration in an initially liquid phase of a temperature and pressure sensitive compounds.

Introduction
What is evaporative pertraction process?
1. Pertraction: an economically attractive process
Literature review
1. Process
2. Features of pertraction
3. Economical features
Methods for the pertraction process
Applications of membrane separation methods
New components in the method
Hallow fiber membrane pertraction for purification of water
Applications of pertraction
1. In water streams of Industries
2. Advantages
Conclusion
References

Get this table of contents for free after login.

Extract

[...] In pertraction of silver through a layered BLM with increasing concentration of the carrier the flux remained constant despite the fact that the value of the distribution coefficient increased proportionally, as it was reported in paper. This behavior can be connected with higher stability of the complex Ag-Cyanex 471X comparing with the complex Ag-MF18. The kinetics of the stripping reaction rate of decomposition of the complex is faster for MF18 complexes. The first results on silver transport through a layered BLM show increasing flux of Ag through the extraction interface with increasing concentration of the carrier MF18. [...]

[...] An advantage of pertraction over conventional extraction is the use of a low amount of organic extractant resulting in lower chemical costs. Pertraction: an economically attractive process Cost comparisons with the existing techniques show the pertraction process to be highly attractive in economic terms. For trichloroethenes, for example, pertraction is cheaper than the alternatives (air stripping or activated carbon filtration) in all the cases calculated. Other substances which can be treated by pertraction include chlorinated solvents (eg. Carbon tetrachloride, chloroform, tetrachloroethene, trichloroethene), pesticides and other polycyclic hydrocarbons. [...]

[...] Therefore, the MHS composed of the AFN-7 membranes and either hexane or decane was used in order to test the pertraction of PA and AA from the propionic fermentation broth. The purpose of this tentative experiment was to test the long-time operation of the MHS in contact with the fermentation mixture, and to measure fluxes and separation coefficients as dependent on pH of the feed and the mode of preparation. A significant result deals with a long-time operation of the MHS in contact with the native fermentation broth. [...]

[...] The application of MHS for pertraction and separation of carboxylic acids: Generally, liquid-liquid extraction remains a basic method for carboxylic acids separation from aqueous media involving the fermentation broths. This method has been recognized to be very effective but somewhat exhibiting many disadvantages because of toxicity of solvents and other operating reagents in respect to bacteria, yeast, or fungi cultures. The problem can be partly solved by various membrane methods such as: ultra filtration, reverse osmosis, reverse osmosis and nano-filtration, membrane electro dialysis, dialysis through charged ionic membranes, membrane extraction, and liquid membrane pertraction. [...]

[...] Hollow-fiber-shaped membranes enable construction of parallel-flow or crossflow multiphase contactors for pertraction processes. It has already been shown in our previous work that membrane extraction technique enables the successful utilization of solvents, even with a very low distribution coefficient, such as LMACH (linear monoalkyl cyclohexane), for the removal of phenol from water without any of the operational problems characteristic for conventional dispersion-based processes. It has also been shown that the diffusion of phenol through the organic boundary layer is rate-determining. [...]

doc