Experimental study on a multi-stage air gap membrane distillation (AGMD) unit
Membrane distillation (MD) is a separation process that involves vapour transport through a hydrophobic membrane. The evaporation is caused by the partial pressure difference between a hot fluid and cold fluid/surface. In this study, an air gap MD (AGMD) process is utilized to produce freshwater fro...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
UTM Press
2014
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Subjects: | |
Online Access: | http://irep.iium.edu.my/39101/ http://irep.iium.edu.my/39101/ http://irep.iium.edu.my/39101/ http://irep.iium.edu.my/39101/1/jurnal_teknologi.pdf |
Summary: | Membrane distillation (MD) is a separation process that involves vapour transport through a hydrophobic membrane. The evaporation is caused by the partial pressure difference between a hot fluid and cold fluid/surface. In this study, an air gap MD (AGMD) process is utilized to produce freshwater from saline solution. A multi-stage AGMD unit with 0.45 micro-m pore size Polyvinylidene Fluoride (PVDF) membranes is built and experiments have been carried out with different operating variables including feed temperature, coolant temperature, air gap width and feed inlet concentration. A maximum of 12.9 kg/m2 of distillate flux was obtained per kWh energy input from the multi-stage MD unit while for a previously built single-stage MD unit, the highest water/power ratio obtained was only 2.3 kg /m2 kWh. This variation indicates that multistaging is necessary for efficient energy use in MD system. |
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