Change search
ReferencesLink to record
Permanent link

Direct link
Separation of water out of highly concentrated electrolyte solutions using multistage vacuum membrane distillation
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
2013 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Absorption dehumidification requires regeneration system to regenerate diluted desiccant solutions, which are still highly concentrated. A novel multi-stage vacuum membrane distillation system was applied for separating water out of the highly concentrated solution.

The performance of this novel membrane distillation system with high concentration solution is studied, as well as the effect of solution concentration, heating temperature and feed flow rate on concentration increase, permeate flux and specific energy consumption was studied. Feed solutions are LiCl solution (22-30 wt%) and CH3COOK solution (50-60 wt%).Other experimental parameters studied were: heating temperature, 70-80 °C, feed flow rate, 1.2-2.0 l/min. Response surface method is applied for model building, in order to provide a better understanding of the interactions between different parameters.

Compared with pure water, high concentration solution has lower vapor pressure, which leads to lower permeate flux. The highest concentration the system can reach is 36.5 wt% for LiCl solution and over 70 wt% for CH3COOK solution, when the heating temperature is 80 °C. Lower concentration and higher heating temperature will result in larger increase in concentration, higher permeate flux and also lower specific energy consumption. But due to the configuration of the system, optimal flow rates can be found under different conditions. Within the testing region, the permeate flux ranges between 0.147-1.802 l/(m2h) for LiCl solution and 0.189-1.263 l/(m2h) for CH3COOK solution. With low concentration, high heating temperature and low feed flow rate, low specific energy consumptions, 0.85 kWh/l and 0.94 kWh/l for LiCl and CH3COOK solutions are observed respectively. With external heating recovery system, this value can be further reduced.

Place, publisher, year, edition, pages
2013. , 82 p.
Keyword [en]
membrane distillation, concentration, LiCl, CH3COOK
National Category
Other Mechanical Engineering
URN: urn:nbn:se:kth:diva-129358OAI: diva2:651815
Educational program
Master of Science - Environomical Pathways for Sustainable Energy Systems
2013-09-10, Brinellvägen 68, Stockholm, 11:13 (English)
Available from: 2013-10-24 Created: 2013-09-27 Last updated: 2013-10-24Bibliographically approved

Open Access in DiVA

fulltext(4784 kB)746 downloads
File information
File name FULLTEXT01.pdfFile size 4784 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Heat and Power Technology
Other Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 746 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 133 hits
ReferencesLink to record
Permanent link

Direct link