The effect of the concentration polarization and the membrane layer mass transport on membrane separation

2010 ◽  
Vol 14 (1-3) ◽  
pp. 220-226 ◽  
Author(s):  
Endre Nagy ◽  
Edina Kulcsár
Keyword(s):  
Mass Transport ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Membrane Layer

scholarly journals The Effect of the Concentration Polarization and the Membrane Layer Mass Transport on the Membrane Separation

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Endre Nagy ◽  
Gábor Borbély
Keyword(s):  
Boundary Layer ◽  
Mass Transport ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
Enrichment Factors ◽  
Transport Parameters ◽  
Membrane Layer ◽  
Negative Effect ◽  
Concentration Polarization Layer

The negative effect of the concentration polarization layer on the membrane separation is well known. How the mass transport parameters of the membrane matrix, e.g. the solubility coefficient, membrane Peclet number, can affect the concentration profile of the boundary layer, and consequently, the separation efficiency is not investigated in detail yet. This paper gives the suitable mathematical expressions, in order to predict the well known parameters as polarization modulus, enrichment factors, etc., taking into account the transport parameters for both the concentration boundary and the membrane layers, and analyses the concentration distribution and the polarization modulus. It has been shown that the transport properties of the membrane layer have significant effect on the concentration profiles of the boundary layer and thus, on the polarization modulus, enrichment factors, etc., as well. Thus, the well known equations, e.g. the polarization modulus, enrichment factor given in the literature [see e.g. Equations (2) and (3)], could be considered as approaches.

Fluid mechanics and mass transport in centrifugal membrane separation

2000 ◽  
Vol 176 (2) ◽  
pp. 277-289 ◽  
Author(s):  
J.G Pharoah ◽  
N Djilali ◽  
G.W Vickers
Keyword(s):  
Mass Transport ◽  
Fluid Mechanics ◽  
Membrane Separation

The Effect of Flow Pulsation on Ultrafiltration System Limiting Flux Behavior

2013 ◽  
Author(s):  
Chyouhwu Brian Huang ◽  
Hung-Shyong Chen
Keyword(s):  
Membrane Filtration ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Paper Industry ◽  
Surface Concentration ◽  
Permeate Flux ◽  
Filtration Time ◽  
Protection Systems ◽  
Oil Water

Ultrafiltration (UF) is an important industrial operation and is found in the food industry, separation of oil-water emulsions, treatment effluents from the pulp and paper industry, and environmental protection systems. Despite being widely used in these areas, UF systems exhibit a limiting flux behavior caused by concentration polarization on the membrane surface. Concentration polarization can be severe in macromolecular solutions due to low diffusivity on membrane separation and both mechanical and chemical methods have been used to reduce this phenomenon. This study introduces a new mechanical method that improves the performance of membrane separation and decreases concentration polarization. It involves pulsing the feed flow discontinuously and based on our results, feed flow velocity and solution bypass/membrane filtration time ratio are two vital factors when it comes to improving permeate flux. The proposed method is expected to find wide application, particularly in the processing of macromolecular solution.

Methods to Reduce Concentration Polarization and Fouling in Membrane Filtration

1994 ◽  
Vol 59 (4) ◽  
pp. 737-755 ◽  
Author(s):  
Petr Mikulášek
Keyword(s):  
Membrane Filtration ◽  
Morphological Analysis ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Separation Processes ◽  
Membrane Modules

Various methods and concepts that are currently being used and proposed to control or minimize concentration polarization and fouling in membrane separation processes are reviewed. A morphological analysis of hydrodynamic ways to prevent the detrimental influence on fluxes is given. The potentials of these different approaches are analyzed and some examples of module designs resulting from the various approaches with special attention to rotary membrane modules are given.

scholarly journals 3D-printed electrodes with improved mass transport properties

2019 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Boundary Layer ◽  
Mass Transport ◽  
Transport Properties ◽  
Concentration Polarization ◽  
Voltage Drop ◽  
Electrochemical Reactor ◽  
Limiting Current ◽  
Polarization Effects ◽  
Static Mixers ◽  
Conversion Rates

Today's electrochemical reactor design is a less developed discipline as compared to electrocatalytic synthesis. Although catalysts show increasing conversion rates, they are often operated without measures for the reduction of concentration polarization effects. As a result, a stagnant boundary layer forms at the electrode‐electrolyte interface. This stagnant boundary layer presents an additional voltage drop and reduces the energy efficiency. It is generally accepted that this phenomenon is caused by a combination of fast electrode reactions and slow diffusion of the reacting species. Our earlier work demonstrated the potential of non‐conducting static mixers to reduce concentration polarization effects. However, there are few studies on conductive static mixers applied as electrodes. In this study, we present a new concept of additive manufactured flow through electrode mixers. Our electrode geometry combines a high surface area with mixing properties, diminishing concentration polarization effects of transport‐limited reactions. Mass transport properties of these conductive static mixers are evaluated in an additive manufactured electrochemical reactor under controlled conditions by applying the limiting‐current method.

A Review of Membrane Separation Process Enhanced by Shearing Force

2014 ◽  
Vol 1010-1012 ◽  
pp. 729-732
Author(s):  
Peng Wang ◽  
Yan He Han ◽  
Jia Qing Chen ◽  
Xiao Fei Zhang
Keyword(s):  
Membrane Fouling ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Separation Process ◽  
Membrane Technology ◽  
Shearing Force ◽  
Separation Technology

Due to the concentration polarization and membrane fouling, the application of conventional membrane separation technology is restricted. In order to reduce the concentration polarization and membrane fouling, the shear-enhanced process has become the focus of the current membrane technology. The shear-enhanced processes contain chiefly rotary tubular shear-enhanced process, rotary disc shear-enhanced process and vibratory shear-enhanced process. This article introduced the structures and work principles of the three shear-enhanced processes. Meanwhile, the problems and the prospect of the shear-enhanced process were provided in this article.

The Characteristic Analysis of Interrupted Flow Pulsation on Ultrafiltration System

2013 ◽  
Vol 479-480 ◽  
pp. 373-379
Author(s):  
Chyouhwu Huang ◽  
Hung Shyong Chen
Keyword(s):  
Concentration Polarization ◽  
Fruit Juice ◽  
Membrane Separation ◽  
Industrial Applications ◽  
Membrane Module ◽  
Characteristic Analysis ◽  
Oil Water ◽  
Concentration Polarization Layer ◽  
Interrupted Flow ◽  
Macromolecular Solution

Ultrafiltration (UF) process has been widely used in many industrial applications to separate or concentrate macromolecular solution such as the making of fruit juice, the separation of oil-water emulsions, the treatment effluents from the pulp and paper, and environmental protecting applications. However, this process exhibits a limiting flux behavior caused by concentration polarization and consequently reduces the life of the membrane module. Concentration polarization can be especially severe in macromolecular solutions due to low diffusivity in membrane separation. In this study, we introduce an interrupted pulsatile flow to improve the performance of the membrane and decrease the concentration polarization layer. This method involves pulsing the feed flow discontinuously. Our results show that this method can be applied to membrane module regardless of it geometry and materials. Also, when comparing with un-pulsatile module, this could further leader to the improvement of membrane life. Keywords: ultrafiltation, interrupted - pulsating flow, concentration polarization, limiting flux behavior

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