Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
687021 | Chemical Engineering and Processing: Process Intensification | 2014 | 10 Pages |
Abstract
In this study, nine flat-sheet commercially available hydrophobic PTFE membranes were used in desalination by direct contact membrane distillation and their characteristics were investigated under different operating conditions including feed temperature, feed flow rate, cold stream flow rate, and feed concentration. Membrane properties, i.e. pore size, thickness, support layer, and salt rejection were also studied. Moreover, membrane module designs including flow arrangements (co-current, counter-current and tangential) for process liquid and depth both on hot and cold sides were tested experimentally. Finally, the long-term performance of the selected membranes for direct contact membrane distillation as a stand-alone desalination process was investigated. The results indicated that increasing feed temperature, hot feed flow rate, and module depth on the cold side led to increase permeate flux. On the other hand, increasing membrane thickness and module depth on the hot side (at constant flow rate) had negative effects on the flux. The highest permeation flux and salt rejection was achieved when the membranes with a pore size of 0.22 μm were used in the cross-current follow arrangement of hot and cold streams. In addition, the requirements for support layer for a successful DCMD process has been extensively discussed.
Keywords
AGMDPTFEHDPEDCMDVMDSGMDLEPMSPsReverse OsmosisUltrafiltrationDirect contact membrane distillationMembrane distillationVacuum membrane distillationDirect contact membrane distillation (DCMD)Air-gap membrane distillationSweeping Gas Membrane DistillationMembrane characteristicsLiquid entry pressureSupport layerMicrofiltrationdesalinationPETMembrane separation processesHigh density polyethylenepolytetrafluoroethylenePolypropylene
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Mohammad Mahdi A. Shirazi, Ali Kargari, Meisam Tabatabaei,