scholarly journals Advances in Membrane Distillation Module Configurations

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
Lijo Francis ◽  
Farah Ejaz Ahmed ◽  
Nidal Hilal
Keyword(s):  
Standardized Testing ◽  
Hollow Fiber Membrane ◽  
Feed Solution ◽  
Pilot Scale ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Module Design ◽  
Temperature Polarization ◽  
Membrane Design ◽  
System Configurations

Membrane Distillation (MD) is a membrane-based, temperature-driven water reclamation process. While research emphasis has been largely on membrane design, upscaling of MD has prompted advancements in energy-efficient module design and configurations. Apart from the four conventional configurations, researchers have come up with novel MD membrane module designs and configurations to improve thermal efficiency. While membrane design has been the focus of many studies, development of appropriate system configurations for optimal energy efficiency for each application has received considerable attention, and is a critical aspect in advancing MD configurations. This review assesses advancements in modified and novel MD configurations design with emphasis on the effects of upscaling and pilot scale studies. Improved MD configurations discussed in this review are the material gap MD, conductive gap MD, permeate gap MD, vacuum-enhanced AGMD/DCMD, submerged MD, flashed-feed MD, dead-end MD, and vacuum-enhanced multi-effect MD. All of these modified MD configurations are designed either to reduce the heat loss by mitigating the temperature polarization or to improve the mass transfer and permeate flux. Vacuum-enhanced MD processes and MD process with non-contact feed solution show promise at the lab-scale and must be further investigated. Hollow fiber membrane-based pilot scale modules have not yet been sufficiently explored. In addition, comparison of various configurations is prevented by a lack of standardized testing conditions. We also reflect on recent pilot scale studies, ongoing hurdles in commercialization, and niche applications of the MD process.

scholarly journals Organic Fouling Impact in a Direct Contact Membrane Distillation System Treating Wastewater: Experimental Observations and Modeling Approach

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 493
Author(s):  
Amine Charfi ◽  
Fida Tibi ◽  
Jeonghwan Kim ◽  
Jin Hur ◽  
Jinwoo Cho
Keyword(s):  
Particle Size ◽  
Membrane Fouling ◽  
Direct Contact ◽  
Feed Solution ◽  
Membrane Distillation ◽  
Mixed Solution ◽  
Permeate Flux ◽  
Direct Contact Membrane Distillation ◽  
Organic Fouling ◽  
Specific Cake Resistance

This study aims to investigate the effect of operational conditions on organic fouling occurring in a direct contact membrane distillation (DCMD) system used to treat wastewater. A mixed solution of sodium alginate (SA) and bovine serum albumin (BSA) was used as a feed solution to simulate polysaccharides and proteins, respectively, assumed as the main organic foulants. The permeate flux was observed at two feed temperatures 35 and 50 °C, as well as three feed solution pH 4, 6, and 8. Higher permeate flux was observed for higher feed temperature, which allows higher vapor pressure. At higher pH, a smaller particle size was detected with lower permeate flux. A mathematical model based on mass balance was developed to simulate permeate flux with time by assuming (i) the cake formation controlled by attachment and detachment of foulant materials and (ii) the increase in specific cake resistance, the function of the cake porosity, as the main mechanisms controlling membrane fouling to investigate the fouling mechanism responsible of permeate flux decline. The model fitted well with the experimental data with R2 superior to 0.9. High specific cake resistance fostered by small particle size would be responsible for the low permeate flux observed at pH 8.

scholarly journals Fabrication and Performance Evaluation of Integrated Solar-Driven Membrane Distillation System with Serpentine-shape of Flat Plate Solar Collector for Seawater Desalination

2019 ◽  
Vol 23 (3) ◽  
Author(s):  
M. A. H. M. Hanoin ◽  
N. S. Mohammed ◽  
M. A. I. Z. Arris ◽  
A. I. A. Bakar ◽  
N. M. Mokhtar ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Flat Plate ◽  
Solar Collector ◽  
Pure Water ◽  
Feed Solution ◽  
Membrane Distillation ◽  
The Self ◽  
Permeate Flux ◽  
Salt Rejection ◽  
Flat Plate Solar Collector

Solar-powered membrane distillation (SPMD) system has gained its popularity in desalination application for past decade credit to the system efficiency in producing pure water and the utilization of renewable energy. However, most of the past SPMD works used commercial solar thermal collector (STC) as the thermal energy supply to the feed solution and the study only focused on the performance of the system in terms of flux and salt rejection. In this work, a self-made flat plate solar collector (FPSC) with the serpentine-shape pipe was designed and fabricated to study the effect of the STC towards the membrane performance. Before testing, a simulation work of the fluid flow inside the serpentine-shape pipe of the FPSC was analyzed using NX 10.0 computer-aided design simulation. After that, the efficiency of the self-made FPSC system was tested directly to sunlight in order to identify the maximum irradiance and the temperature of the feed solution. Due to the fluctuation of solar irradiance, the experimental setup of the SPMD system was tested using a solar simulator, and the performance was compared with the membrane distillation (MD) system without integration with FPSC system. Based on the simulation data, it can be concluded that the heat losses across the pipe are due to the slower fluid velocity and sudden pressure drop, which attributed to centripetal force and pressure differences. Meanwhile, the outdoor evaluation data showed that the temperatures of collector and water inside the feed tank could reach up to 84°C and 64°C, respectively when the maximum irradiance of 938 W/m2 was applied. For the performance evaluation between with and without the self-made FPSC system, it can be seen that only marginal difference can be observed for the permeate flux and salt rejection with an average difference of 6.06% and 1.29%, respectively.

Experimental Study and Numerical Simulation of the Air Gap Membrane Distillation (AGMD) Process

2016 ◽  
Vol 11 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Ehsan Karbasi ◽  
Javad Karimi-Sabet ◽  
J. Mohammadi Roshandeh ◽  
M. A. Moosavian ◽  
H. Ahadi
Keyword(s):  
Numerical Simulation ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Air Gap ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Air Gap Membrane Distillation ◽  
Temperature Polarization ◽  
Output Ratio ◽  
Cfd Method

Abstract Some challenges, including inappropriate distribution of currents on the membrane surface, poor hydrodynamics and existing severe temperature polarization (TP) phenomenon in MD modules, impede industrialization of MD process. Computational fluid dynamics (CFD) method was used for numerical simulation of hydrodynamics in air gap membrane distillation modules. One of two simulated modules in this work is a novel developed one in which heat and mass transfer data was compared with available literature data. Moreover, the effect of using baffles in module was investigated. Comparison between the novel module and conventional module indicates higher trans-membrane mass flux and gained output ratio (GOR) coefficient by 7% and 15%, respectively. Moreover, the effects of different operating conditions including feed temperatures and feed flow rates on permeate flux were investigated.

scholarly journals Modification of porous polyetherimide hollow fiber membrane by dip-coating of Zonyl® BA for membrane distillation of dyeing wastewater

2021 ◽  
Author(s):  
S. A. Mousavi ◽  
Z. Arab Aboosadi ◽  
A. Mansourizadeh ◽  
B. Honarvar
Keyword(s):  
Pore Size ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Pure Water ◽  
Dip Coating ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Fiber Membrane ◽  
Air Gap Membrane Distillation

Abstract Wetting and fouling have significantly affected the application of membrane distillation (MD). In this work, a dip-coating method was used for improving surface hydrophobicity of the polyetherimide (PEI) hollow fiber membrane. An air gap membrane distillation (AGMD) process was applied for treatment of the methylene blue (MB) solution. The porous PEI membrane was fabricated by a dry-wet spinning process and the hydrophobic 2-(Perfluoroalkyl) ethanol (Zonyl® BA) was used as the coating material. From FESEM, the modified PEI-Zonyl membrane showed an open structure with large finger-like cavities. The modified membrane displayed a narrow pore size distribution with mean pore size of 0.028 μm. The outer surface contact angle of the PEI-Zonly membrane increased from 81.3° to 100.4° due to the formation of an ultra-thin coated layer. The pure water flux of the PEI-Zonyl membrane was slightly reduced compared to the pristine PEI membrane. The permeate flux of 6.5 kg/m2 h and MB rejection of 98% was found for the PEI-Zonyl membrane during 76 h of the AGMD operation. Adsorption of MB on the membrane surface was confirmed based on the Langmuir isotherm evaluation, AFM and FESM analysis. The modified PEI-Zonyl membrane can be a favorable alternative for AGMD of dyeing wastewaters.

Channel Length Influence on the Performance of the Vacuum Membrane Distillation

2020 ◽  
Author(s):  
Abdulaziz M. Alasiri ◽  
Umar Alqsair ◽  
Sertac Cosman ◽  
Robert Krysko ◽  
Alparslan Oztekin
Keyword(s):  
Membrane Surface ◽  
Membrane Distillation ◽  
Channel Length ◽  
Water Vapor Transport ◽  
Membrane Thickness ◽  
Local Concentration ◽  
Permeate Flux ◽  
Hydrophobic Membrane ◽  
Vapor Flux ◽  
Temperature Polarization

Abstract The demand for freshwater has been increased globally. Membrane distillation (MD) technique can be an attractive option for desalination applications. MD is defined as a thermal-driven separation process that implements a hydrophobic membrane for allowing only water vapor transport through the membrane. VMD system is investigated in this study to examine its sensitivity toward the channel design. PTFE membrane is employed and treated as a functional surface where its main properties, such as porosity, tortuosity, pore diameter, and membrane thickness are defined. Different flow rates and inlet temperatures of the feed solution are involved to intensely study the effect of the channel length on VMD performance. The local concentration and temperature polarization coefficient and mass flux along the membrane surface are presented and discussed. With the increasing length of the module, concentration and temperature polarization levels are increased, and the vapor flux is decreased. It is shown that the permeate flux decreases linearly with the channel length. The slope of the permeate flux with length can be used to estimate the flux performance of modules with varying length.

scholarly journals A Numerical Simulation of Membrane Distillation Treatment of Mine Drainage by Computational Fluid Dynamics

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3403
Author(s):  
Ji Qi ◽  
Jiafeng Lv ◽  
Zhen Li ◽  
Wei Bian ◽  
Jingfeng Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Mine Water ◽  
Membrane Distillation ◽  
Transfer Efficiency ◽  
Permeate Flux ◽  
Heat Transfer Efficiency ◽  
Temperature Polarization ◽  
Feed Temperature

Membrane distillation (MD) is a promising technology to treat mine water. This work aims to investigate the change in mass and heat transfer in reverse osmosis mine water treatment by vacuum membrane distillation (VMD). A 3D computational fluid dynamics (CFD) model was carried out using COMSOL Multiphysics and verified by the experimental results. Then, response Surface Methodology (RSM) was used to explore the effects of various parameters on the permeate flux and heat transfer efficiency. In terms of the influence degree on the permeation flux, the vacuum pressure > feed temperature > membrane length > feed temperature membrane length, and the membrane length has a negative correlation with the membrane flux. Increasing the feed temperature can also increase the convective heat transfer at the feed side, which will affect the heat transfer efficiency. Furthermore, the feed temperature also has a critical effect on the temperature polarization phenomenon. The temperature polarization becomes more notable at high temperatures.

scholarly journals Evaluation of Permeate Quality in Pilot Scale Membrane Distillation Systems

Membranes ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 69 ◽  
Author(s):  
Alba Ruiz-Aguirre ◽  
Juan A. Andrés-Mañas ◽  
Guillermo Zaragoza
Keyword(s):  
Surface Membrane ◽  
Pilot Scale ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Distilled Water ◽  
Permeate Flux ◽  
Membrane Area ◽  
Intermittent Operation ◽  
In The Beginning ◽  
Membrane Level

In this work, the salinity of permeate obtained with membrane distillation (MD) in pilot scale systems was analyzed. Experiments were performed with three different spiral-wound commercial modules, one from Solar Spring with 10 m2 surface membrane area and two from Aquastill with 7.2 and 24 m2. Intermittent operation meant that high permeate conductivity was measured in the beginning of each experiment, which was gradually decreasing until reaching a constant value (3–143 µS·cm−1 for seawater feed). The final quality reached did not depend on operating conditions, only the time it took to reach it. This can be because the permeate flux dilutes the minimal feed leak taking place through pinholes in the membranes. Larger feed leak through the membrane was observed when operating in vacuum-enhanced air-gap MD configuration (V-AGMD), which is compatible with this explanation. However, for the increase of feed leak with salinity (up to 1.8 M), a conclusive explanation cannot be given. Pore wetting due to crystallization is discarded because the high permeate quality was recovered after washing with distilled water. More studies at higher salinities and also at membrane level are required to investigate this.

Performance evaluation of ePTFE and PVDF flat-sheet module direct contact membrane distillation

2010 ◽  
Vol 62 (2) ◽  
pp. 347-352 ◽  
Author(s):  
Ching-Jung Chuang ◽  
Kuo-Lun Tung ◽  
Yang-Hsiang Fan ◽  
Chii-Dong Ho ◽  
James Huang
Keyword(s):  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Membrane Distillation ◽  
Membrane Properties ◽  
Energy Integration ◽  
Permeate Flux ◽  
Increase Energy Efficiency ◽  
Module Design ◽  
Direct Contact Membrane Distillation ◽  
Flat Sheet

This paper reports experiments using a flat-sheet module with 0.18 ∼ 0.45 μm ePTFE (expanded polytetrafluoroethylene) and PVDF (polyvinylidene fluoride) membranes to show the effects of membrane properties, salt concentration and fluid hydrodynamics on the permeate flux and salt rejection of DCMD (direct contact membrane distillation). A theoretical prediction of the permeate flux was carried out, and was in close agreement with the experimental results. In addition, the energy integration of the process was also analyzed in order to evaluate module design to increase energy efficiency. According to the simulated results of the energy integration design, a combination of simultaneous cooling of the permeate stream and an additional heat exchanger to lower the temperature of the permeate stream not only enhances the MD flux, but also reduces energy consumption.

scholarly journals Bispacer Multi-Stage Direct Contact Membrane Distillation System: Analytical and Experimental Study

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1297
Author(s):  
Morteza Aliabadi ◽  
Hassan Ghorashi ◽  
Shamim Shokri Motlagh ◽  
Seyedeh Fatemeh Nabavi ◽  
Seyed Arash Pakzad ◽  
...  
Keyword(s):  
Direct Contact ◽  
Mechanical Stability ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Direct Contact Membrane Distillation ◽  
Multi Stage ◽  
Temperature Polarization ◽  
Output Ratio ◽  
Polarization Coefficient

A multi-staged direct contact membrane distillation (MDCMD) system is designed considering a novel bispacer configuration in the present study. The proposed bispacer DCMD, which has not been addressed in the literature to best of our knowledge, is considered with two purposes, including increasing mechanical stability and turbulence. As increasing turbulence leads to increasing Nusselt number, the bispacer MDCMD provides higher permeate flux. An analytical approach is considered using energy and mass balance correlation. The effect of bispacer and feed operating conditions, including feed temperature, feed flow rate, feed salinity, and the number of stages on permeate flux and salt rejection of the developed MDCMD, are examined both analytically and experimentally. The performance and sustainability of the developed system were investigated by analyzing the parameters, including thermal efficiency (η), gained output ratio (GOR), and temperature polarization coefficient (TPC).

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