Evaluation of MD process performance: Effect of backing structures and membrane properties under different operating conditions

Abstract The paper presents investigations on the process performance of different membranes with and without backing structure in direct contact membrane distillation. Influences of backing structures and their orientation are identified. An integrated membrane and backing model was developed. Laminates with different backing designs were examined over a wide range of operating conditions and compared to results for the same membranes without backing. Experimental results and model predictions for flux and thermal efficiency are compared. The model predictions agree well with the experimental results. An influence on the effective area for diffusion, an increase in effective diffusion path length in the membrane and the formation of a complex network of thermal resistances are considered to be the main effects, leading to a significant reduction in process performance due to backing structures. The backing was identified to be one of the key components for further improvement in MD applications. An integrated assessment of membrane properties in combination with backing structures was carried out by analysing membranes with different thicknesses and different pore sizes. The experimental observations show good agreement with theoretical considerations. A combined analysis of specific flux and thermal efficiency leads to comprehensive understanding of the process and its potential for optimisation.

[1]  Enrico Drioli.  Workshop on membrane distillation , 1986 .

[2]  W. Kast,et al.  Mass transfer within the gas-phase of porous media , 2000 .

[3]  Baltasar Peñate,et al.  Operational experience of a solar membrane distillation demonstration plant in Pozo Izquierdo-Gran Canaria Island (Spain) , 2012 .

[4]  Antoni W. Morawski,et al.  Membrane distillation with laminar flow , 1997 .

[5]  L. Martinez-diez,et al.  Study of membrane dis-tillation using channel spacers , 1998 .

[6]  Jun-de Li,et al.  Identification of material and physical features of membrane distillation membranes for high performance desalination , 2010 .

[7]  Pedro Prádanos,et al.  Characterisation of three hydrophobic porous membranes used in membrane distillation , 2002 .

[8]  L. Martinez-diez,et al.  Temperature and concentration polarization in membrane distillation of aqueous salt solutions , 1999 .

[9]  M. C. García-Payo,et al.  Air gap membrane distillation of sucrose aqueous solutions , 1999 .

[10]  Fawzi Banat,et al.  Performance evaluation of the “large SMADES” autonomous desalination solar-driven membrane distillation plant in Aqaba, Jordan , 2007 .

[11]  Enrico Drioli.  Membrane Development for Seawater Desalination , 1987 .

[12]  Anthony G. Fane,et al.  Factors affecting flux in membrane distillation , 1990 .

[13]  Siegfried Ripperger,et al.  Membranes and modules for transmembrane distillation , 1988 .

[14]  Lucio Rizzuti,et al.  CFD simulation of a membrane distillation module channel , 2009 .

[15]  Peng Wang,et al.  Morphological architecture of dual-layer hollow fiber for membrane distillation with higher desalination performance. , 2011, Water research.

[16]  Enrico Drioli,et al.  Membrane distillation : An experimental study , 1985 .

[17]  Edward L Cussler,et al.  Diffusion: Mass Transfer in Fluid Systems , 1984 .

[18]  Anthony G. Fane,et al.  Gas and vapour transport through microporous membranes. I. Knudsen-Poiseuille transition , 1990 .

[19]  Mohamed Khayet,et al.  Monte Carlo simulation and experimental heat and mass transfer in direct contact membrane distillation , 2010 .

[20]  Enrico Drioli,et al.  Membrane distillataion in the treatment of aqueous solutions , 1987 .

[21]  Anthony G. Fane,et al.  The efficient use of energy in membrane distillation , 1987 .

[22]  Sharmiza Adnan,et al.  Commercial PTFE membranes for membrane distillation application: Effect of microstructure and support material , 2012 .

[23]  J. Koschikowski,et al.  Desalination using membrane distillation: Experimental studies on full scale spiral wound modules , 2011 .

[24]  Tzahi Y. Cath,et al.  Experimental study of desalination using direct contact membrane distillation: a new approach to flux enhancement , 2004 .

[25]  M. Khayet.  Membranes and theoretical modeling of membrane distillation: a review. , 2011, Advances in colloid and interface science.

[26]  Mohamed Khayet,et al.  Study of Asymmetric Polarization in Direct Contact Membrane Distillation , 2005 .

[27]  Anthony G. Fane,et al.  Heat transport and membrane distillation coefficients in direct contact membrane distillation , 2003 .

[28]  K. Lucas,et al.  Berechnungsmethoden für Stoffeigenschaften , 2002 .

[29]  Anthony G. Fane,et al.  Effects of net-type spacers on heat and mass transfer in direct contact membrane distillation and comparison with ultrafiltration studies , 2003 .

[30]  Anthony G. Fane,et al.  Heat and mass transfer in membrane distillation , 1987 .

[31]  Anthony G. Fane,et al.  Gas and vapour transport through microporous membranes. II. Membrane distillation , 1990 .