Novel PVDF-HFP flat sheet membranes prepared by triethyl phosphate (TEP) solvent for direct contact membrane distillation

Desalination is a process where fresh water produces from high salinity solutions, many ways used for this purpose and one of the most important processes is membrane distillation (MD). Direct contact membrane distillation (DCMD) can be considered as the most prominent type from MD types according to ease of design and modus operandi. This work studies the efficiency of using DCMD operation for desalination brine with different concentration (1.75, 3.5, 5 wt. % NaCl). Frame and plate cell was used with flat sheet PTFE hydrophobic type membrane. The study proves that MD is an effective process for desalination brines with feed temperature less than 60˚C especially for feed with low TDS. 37˚C, 47˚C, and 57˚C was feed temperature and 17, 22, 27˚C as permeate temperatures used in study, temperature in both sides of membrane are recorded and TDS for permeate collected to assure that there is no penetration of brine to permeate side, the results took every 30 min for time experiment of 180 min. From results, the flux increases with increasing feed temperature and flow rate, and decreasing with increasing feed concentration, experiment time, and permeate temperature.

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Preparation and characterization of PVDF/nonwoven fabric flat-sheet composite membranes for desalination through direct contact membrane distillation

Separation and Purification Technology ◽

10.1016/j.seppur.2012.08.031 ◽

2012 ◽

Vol 101 ◽

pp. 1-10 ◽

Cited By ~ 40

Author(s):

Deyin Hou ◽

Guohua Dai ◽

Jun Wang ◽

Hua Fan ◽

Lin Zhang ◽

...

Keyword(s):

Direct Contact ◽

Composite Membranes ◽

Nonwoven Fabric ◽

Membrane Distillation ◽

Direct Contact Membrane Distillation ◽

Flat Sheet

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

Water Science & Technology ◽

10.2166/wst.2010.740 ◽

2010 ◽

Vol 62 (2) ◽

pp. 347-352 ◽

Cited By ~ 5

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.

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