Modeling And Experimental Study Of Air Gap Membrane Distillation Unit: Application For Seawater Desalination

The single stage air gap membrane distillation (AGMD) has been successfully realized to desalt simulated and natural seawater. The effect of different operating parameters including feed temperature, width of air gap, feed salt concentration and feed and permeate flow rates on the performance of AGMD process has been investigated. Two different commercial polyvinylidene fluoride (PVDF) membranes, with different pore size (0.45 and 0.22 mu m) were tested and compared for different operating parameters. Experimental results displayed that the larger pore size membrane showed a better mass transfer performance but led to a slight decrease of water production quality. However, AGMD process can produce water with high salt rejection, more than 99% and a maximum permeate flux of 9.06 kg m(-2) h(-1) was obtained at a feed temperature of 77 degrees C. The comparison between predicted model and experimental AGMD permeate fluxes shown a good agreement, their average deviation was around 6.9%.