A Study of Hydrophobic Micro-Porous Membrane for Membrane Distillation

A study of hydrophobic micro-porous membrane for membrane distillation

E. Drioli^{1, 2, 3}, A. Figoli¹,  F. Macedonio^{1, 2}, S. Simone¹,  A. Ali²

¹ National Research Council - Institute on Membrane Technology (ITM–CNR), Via Pietro BUCCI, c/o The University of Calabria, cubo 17C, 87036 Rende CS, Italy

² The University of Calabria - Department of Chemical Engineering and Materials, cubo 44A, Via Pietro BUCCI, 87036 Rende CS, Italy

³ Hanyang University, WCU Energy Engineering Department, Room 917 9th Floor FTC Bldg., 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 S. Korea

                            

Membrane distillation (MD) is one of the non-isothermal membrane separation processes used in various applications such as desalination, nuclear industry, textile industry, chemical industry, pharmaceutical and biomedical industries, food industry, etc. MD industrialization requires improved membranes, with specific morphology and specifically designed for MD applications.

Membranes with different pore sizes, porosities, thicknesses, materials and novel structures are required in order to carry out systematic MD studies for better understanding mass and heat transport phenomena thus improving the MD performance [1].

The ideal characteristics of a MD membrane are as follows: high hydrophobicity, high bulk and surface porosities, optimum pore size and narrow pore size distribution, high pores interconnectivity, high liquid entry pressure, low thermal conductivity, optimum thickness, high thermal stability, less susceptibility to fouling and long term permeance stability [2, 3].

In this work, microporous hydrophobic poly(vinylidene fluoride) (PVDF) hollow fiber membranes were prepared, characterized and tested in a membrane distillation set-up.

PVDF is widely utilized as polymeric material for preparing flat sheet and hollow fiber membranes to be used in membrane contactors and, in particular, in membrane distillation due to its intrinsic characteristics: high hydrophobicity coupled to better solubility in common organic solvents with respect to other hydrophobic polymers, such as poly(tetrafluoro ethylene) (PTFE), polypropylene (PP) and polyethylene (PE).

In this work, the effect of different membrane preparation conditions and other parameters on MD performance has been investigated. It has been confirmed that the trans-membrane flux is a strong function of the membrane morphology which is influenced by the preparation conditions and dope solution composition.

Relevant bibliography

[1] S. Simone, A. Figoli, A. Criscuoli, M.C. Carnevale, A. Rosselli, E. Drioli, "Preparation of hollow fibre membranes from PVDF/PVP blends and their application in VMD", Journal of Membrane Science 364 (2010) 219-232, doi:10.1016/j.memsci.2010.08.013

[2] E. Drioli, A. Criscuoli, E. Curcio, Membrane Contactors: Fundamentals, Applications and Potentialities, Membrane science and technology series, 11, Amsterdam; Boston: Elsevier, 2006.

[3] S. Al Obaidani, E. Curcio, F. Macedonio, G. Di Profio, H. Al Hinai, E. Drioli, Potential of membrane distillation in seawater desalination: Thermal efficiency, sensitivity study and cost estimation, Journal of Membrane Science, 323 (2008) 85-98. doi: 10.1016/j.memsci.2008.06.006.