Pgmd has 20% higher gor energy efficiency than an air gap membrane distillation agmd system. Superhydrophobic condenser surfaces for air gap membrane. Membrane desalination technologies in water treatment. Air gap membrane distillation agmd air gap membrane distillation is the most energyefficient of our process configurations.
Membrane distillation md is a broad reference that covers. Air gap membrane distillation agmd experiments were performed with varied temperature and varied module inclination angles to characterize the effect of module angle on permeate production and. Experimental and mathematical study of air gap membrane. The membrane was evaluated using the minimum membrane area that is a lower bound to the actual membrane area and thus to the investment cost. In all these md configuration, membrane coefficient permeability limit the performance of md system. Membrane distillation md is a thermally driven separation process in which separation is driven by phase change. Seawater desalination through the air gap membrane distillation agmd process shows merit for its ambient operational conditions and low energy consumption. Enhanced vapor transport in membrane distillation via. Cost estimating manual for water treatment facilities.
This model is based on mathematical equations that describe the heat and mass transfer mechanisms of a singlestage agmd process. Membrane distillation producing high quality water from. The membrane and air gap allow vapor molecules to pass across and condense on the cooling surface lee et al. Directcontact and airgap membrane distillation dcmd and agmd, respectively processes have been modeled as a twodimensional conjugate problem in which a simultaneous numerical solution of the. It is characterised by the presence of a stagnant air gap between the membrane and the condensation surface to reduce. Energy efficiency of permeate gap and novel conductive gap. Membrane distillation has been developed to stage that commercial applications will become feasible in the near future, aiming at fresh water extraction from seawater. The membrane distillation process constitutes one of the possibilities for a new method for water desalination. Air gap membrane distillation for enrichment of h218o isotopomers in natural water. The standard agmd cell has a membrane active area of 45. Abstract numerical and experimental analyses were performed for a modified air gap distillation membrane that combines the low.
An experimental study is used to examine the effect of high concentration of several salts, i. Air gap membrane distillation agmd has been implemented to treat produced water. Design of hybrid distillationvapor membrane separation. In this case, the vapor molecules penetrate through the membrane pores and the air gap region and they finally condense in the cold surface inside the membrane module. Effect of air gap membrane distillation parameters on the removal of. Experimental evaluation of a modified airgap membrane distillation. Air gap membrane distillation cell, acrylic 1160071. The water vapour transport across the membrane is described by the dusty. Desalination using membrane distillation experimental and. Basic principles of the md process membrane distillation is an emerging nonisothermal membrane process which uses thermal energy in order to provide a vapor. C airgap and permeategap membrane distillation systems that utilize a. Membrane distillation with solar heat as a main power source is a good solution for this problem. Flux enhancement of air gap membrane distillation for.
Air gap membrane distillation on the different types of. Theoretical and experimental investigation of membrane distillation. Membrane distillation md is a nonisothermal process known for more than forty years first patent was filed by bodell on 3rd june 1963, first md paper was published 4 years later by findley in the. Regression models have been developed to predict the. Membrane distillation md desalination is an emerging technology for fresh water production. Journal of membrane science 255 2005 239253 transport analysis of airgap membrane distillation a. A predictive model for air gap membrane distillation in a counter current flow configuration using fibre membranes is presented. Membrane distillation md is a thermally driven membrane separation technique that is used for water desalination by separating water vapor from feed saltybrackish water using microporous hydrophobic membrane. In this work, an air gap membrane distillation agmd process was applied for. Tests of direct contact membrane distillation dcmd and air gap membrane distillation agmd were carried out on 40 cm2 labscale modules equipped with a commercial flat polypropylene membrane of. Theoretical and experimental investigation of membrane. Pvdf hollow fiber and nano fiber membranes for fresh water. Experimental investigation on fresh water production using air gap.
The janus nanofibrous membranes were composed with various thickness configurations and tested in an air gap membrane distillation system. Water free fulltext advances in membrane distillation for water. Membrane distillation is a process that utilizes differences in vapor pressure to. Air gap membrane distillation agmd, in which an air gap is interposed. The air gap configuration is the most general and can be used for any application. Comparative study of directcontact and airgap membrane. An air gap membrane distillation agmd module with a surface area of 9 m2 was tested for seawater desalination using a solar multistage md system with a potential capacity of 0.
A one dimensional 1d air gap membrane distillation agmd model for flat sheet type modules has been developed. Flux prediction in direct contact membrane distillation. The permeate fluxes, rejection factor and energy consumption for three different membranes, tf200, tf450 and. Sterlitech membrane distillation test cells are benchscale crosstangential flow membrane test cells used in temperature driven membrane separation processes. Four kinds of polypropylene membranes with different diameters of capillaries. The removal of oil from produced water is one of the main. Energyefficient desalination and water treatment technologies play a critical role in. Pgmd has 20% higher gor energy efficiency than an air gap membrane distillation agmd system of the same size, whereas cgmd can have two times higher gor than even pgmd.
Membrane distillation md is a nonisothermal membrane separation process applied. The separation using agmd is based not only on vaporliquid equilibrium but also on the diffusion rates of the feed components through the gas trapped in the membrane pores and the air gap between the. Air gap membrane distillation on the different types of membrane ke he, ho jung hwang, and il shik moon department of chemical engineering, sunchon national university, 315 maegok dong. Produced water treatment by using nanofibrous polyvinylidene.
Department of mechanical engineering and applied mechanics, university of pennsylvania, philadelphia, pa 191046315, usa. In agmd, a thin air gap is created between the membrane and the cooling surface. Nair, 2000 desalination by solarpowered reverse osmosis in a remote area of the. Enhancing air gap membrane distillation melissa deutsch in conjunction with the goddard institute for space studies at the new jersey institute of technology dr. A novel visualization technique was implemented to see through pvdf membranes and confirm air gap behavior. Membrane permeability is a function of applied temperature. This makes it ideal for solargreen energy applications without limiting the. Response surface methodology has been applied for modeling and optimization of air gap membrane distillation process used in desalination. Pdf membrane distillation is a process that utilizes differences in vapor. To ascertain membrane distillation md as an emerging desalination technology to meet the global water challenge, development of membranes with ideal material properties is crucial.
Cgmd has a conductive spacer in the gap between the membrane and. Air gap membrane distillation agmd, applications of. Air gap membrane distillation agmd is one of the four common md configurations. While agmd is one of the most thermally efficient membrane distillation desalination configurations, large transport resistances in the air gap limit distillate production rates. The performance of an air gap membrane distillation agmd system for water desalination was optimized and compared using taguchi orthogonal design arrays and the response surface. Air gap membrane distillation agmd, in which an air gap is. In the present study, the feasibility of air gap membrane distillation agmd process is investigated for breaking an azeotropic mixture. Air gap membrane distillation is a thermally driven separation technique in which vapors travel through a hydrophobic membrane. Pdf janus nanofibrous membranes for desalination by air. Pdf advances in membrane distillation for water desalination. Membrane distillation md is a thermallydriven separation process, in which only vapour molecules transfer through a microporous hydrophobic membrane. Exergy analysis of airgap membrane distillation systems.
Modelling of a modified air gap distillation membrane for. Modern membrane engineering is critical to the development of processintensification strategies and to the stimulation of industrial growth. Because the md module houses a range of evaporation. Membrane distillation md is an emerging technology for seawater or ground water desalination process. A hydrophobic membrane presents a barrier for the liquid phase, allowing the vapour. Design study of the coupling of an air gap membrane. Since the airgap membrane distillation agmd is a simple and lowcost approach, researchers are highly focusing on this method 31. Membrane distillation water vapour is transported through the membrane due to a pressure difference caused by the difference in temperature. Invented in 1960s, membrane distillation is an emerging technology for water treatment attracting more attention since 1980s. This shareable pdf can be hosted on any platform or network and is fully compliant with publisher. Pdf experimental and theoretical investigation on water. In the agmd process, the feed solution enters the module and.
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