Downstream variations of air-gap membrane distillation and comparative study with direct contact membrane distillation: A modelling approach

Desalination ◽  
2022 ◽  
Vol 526 ◽  
pp. 115539
Author(s):  
Abolfazl Ansari ◽  
Fariba Malekpour Galogahi ◽  
David V. Thiel ◽  
Fernanda Helfer ◽  
Graeme Millar ◽  
...  
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Air Gap ◽  
Air Gap Membrane Distillation ◽  
Direct Contact Membrane Distillation ◽  
Modelling Approach

Modeling of Air-Gap Membrane Distillation and Comparative Study with Direct Contact Membrane Distillation

2020 ◽  
Vol 59 (50) ◽  
pp. 21930-21947
Author(s):  
Sadaf Noamani ◽  
Shirin Niroomand ◽  
Masoud Rastgar ◽  
Mehdi Azhdarzadeh ◽  
Mohtada Sadrzadeh
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Air Gap ◽  
Air Gap Membrane Distillation ◽  
Direct Contact Membrane Distillation

scholarly journals A Comparison Study of Brine Desalination using Direct Contact and Air Gap Membrane Distillation

2019 ◽  
Vol 25 (11) ◽  
pp. 47-54
Author(s):  
Ahmed Shamil Khalaf ◽  
Asrar Abdullah Hassan
Keyword(s):  
Flow Rate ◽  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Membrane Distillation ◽  
Air Gap ◽  
Feed Flow Rate ◽  
Permeate Flux ◽  
Air Gap Membrane Distillation ◽  
Flat Sheet ◽  
Feed Temperature

Membrane distillation (MD) is a hopeful desalination technique for brine (salty) water. In this research, Direct Contact Membrane Distillation (DCMD) and  Air Gap Membrane Distillation (AGMD) will be used. The sample used is from Shat Al –Arab water (TDS=2430 mg/l). A polyvinylidene fluoride (PVDF) flat sheet membrane was used as a flat sheet form with a plate and frame cell. Several parameters were studied, such as; operation time, feed temperature, permeate temperature, feed flow rate. The results showed that with time, the flux decreases because of the accumulated fouling and scaling on the membrane surface. Feed temperature and feed flow rate had a positive effect on the permeate flux, while permeate temperature had a reverse effect on permeate flux. It is noticeable that the flux in DCMD is greater than AGMD, at the same conditions. The flux in DCMD is 10.95LMH, and that in AGMD is 7.14 LMH.  In AGMD, the air gap layer made a high resistance. Here the temperature transport reduces in the permeate side of AGMD due to the air gap resistance. The heat needed for AGMD is lower than DCMD, this leads to low permeate flux because the temperature difference between the two sides is very small, so the driving force (vapor pressure) is low.                                                                                               

Direct contact and air gap membrane distillation: Differences and similarities between lab and pilot scale

Desalination ◽  
2017 ◽  
Vol 422 ◽  
pp. 91-100 ◽  
Author(s):  
L. Eykens ◽  
I. Hitsov ◽  
K. De Sitter ◽  
C. Dotremont ◽  
L. Pinoy ◽  
...  
Keyword(s):  
Direct Contact ◽  
Pilot Scale ◽  
Membrane Distillation ◽  
Air Gap ◽  
Air Gap Membrane Distillation

Comparison of hollow fiber membranes in direct contact and air gap membrane distillation (MD)

2015 ◽  
Vol 57 (22) ◽  
pp. 10012-10019 ◽  
Author(s):  
Hyeongrak Cho ◽  
Yong-Jun Choi ◽  
Sangho Lee ◽  
Jaewuk Koo ◽  
Taemun Huang
Keyword(s):  
Hollow Fiber ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Air Gap ◽  
Hollow Fiber Membranes ◽  
Air Gap Membrane Distillation ◽  
Fiber Membranes

The Role of Operating Conditions in Osmotic Distillation and Direct Contact Membrane Distillation - A Comparative Study

2006 ◽  
Vol 2 (5) ◽  
Author(s):  
V. A. Bui ◽  
M. H. Nguyen
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Flux Rate ◽  
High Concentration ◽  
Osmotic Distillation ◽  
Direct Contact Membrane Distillation ◽  
Feed Temperature

This paper presents a comparative study on the role of operating conditions in osmotic distillation (OD) and direct contact membrane distillation (DCMD). Comparisons were made for lab scale OD and DCMD experiments on two types of PVDF hollow fibres under similar operating conditions for the concentration of glucose solutions from 30 to 60% (w/w) at temperatures as low as 25 to 45°C. Analysis of the results indicated that temperature was the most influencing factor for process improvement for both OD and DCMD. The flux in DCMD was improved by 3 to 4 times when feed temperature increased by 15 degrees, while this figure was nearly 3 times for OD when feed temperature increased by 20 degrees. The flow rates of the two streams played a more important role in maintaining the driving force, and consequently the flux rate, in DCMD rather than in OD. It was found that feed velocity had significant effect on DCMD performance, but insignificant in OD. Feed concentration, as the determining factor on water activity and viscosity, caused a more serious reduction of the flux rate in the high concentration range of 45-60% rather than in the dilute region of 30-40%. The effect was more significant in DCMD than in OD. The ratio of DCMD flux over that of OD ranged from 0.41 to 0.66 for PV375 when concentrating glucose solutions 30-40% w/w and from 0.35 to 0.69 for PV650 when concentrating high solid content ones. However, DCMD can overcome the disadvantages of OD being poor consumers’ perception, (due to the use of brine solution being a chemical), the potential problem of corrosion by the brine and the cost of its reconcentration.

Sign in / Sign up

Export Citation Format

Share Document