Emerging membrane technology

Forward Osmosis (FO) is an emerging membrane technology for water treatment that typically involves two steps ... 

Membrane contactors (MCs) are another interesting emerging membrane technology for desalination. MCs are devices that bring two phases (gas/liquid, liquid/liquid or liquid/gas/liquid) into contact at the entrance of pores (Fig. 2.1). MCs are today most commonly employed in the production of ultrapure water, wastewater treatments and water purification, as well as being used to control the concentration of several non-volatile solutes in aqueous solutions, such as salt and sugar in fruit juices and blood treatments. 

Forward osmosis (FO) is an emerging membrane technology for water treatment and energy production. In an FO process, a semipermeable membrane is placed in between two solutions of different osmotic pressures. One is a less concentrated feed solution (FS) with lower osmotic pressure, while the other is a more concentrated draw solution (DS) with higher osmotic pressure. The water in the FS permeates through the membrane into the DS due to the osmotic pressure gradient across the membrane, but the solutes in the FS are selectively rejected by the membrane. 

U.S. EPA, Emerging Technology Bulletin Eolatile Organic Compound Removalfrom Air Streams by Membranes Separation, Membrane Technology and Research, Inc., EPA/540/E-94/503, Cincinnati, Ohio, 1994. 

Emerging Membrane Control Technologies The recent improvements in membrane technology have spawned several potentially commercial membrane filtration uses. 

R. G. Bautista, Uquid Membrane Separations of Metals in Aqueous Solutions, Emerging Separation Technologies for Metals and Fuels, V. I. Lakshmanan, R. G. Bautista, and P. Somasundaram, eds., TMS, p. 257, 1993. 

Many chlorine producers are having to tolerate impurities originating from standard plastic materials used in membrane technology. Flot chlorine and hot anolyte emerging from the anodic compartment of the cell place tremendous stresses on these plastic construction materials. 

The emergence of commercial fuel cell cars will depend on developments in membrane technology, which are about one third of the fuel cell cost. Improvements are desired in fuel crossover from one side of a membrane to the other, the chemical and mechanical stability of the membrane, undesirable side reactions, contamination from fuel impurities and overall costs. 

Along these lines, supramolecular, bimolecular, as well as unimolecular approaches successfully mimicked the function of natural ion channels by using completely artificial and very simple molecules. Ion fluxes satisfied several criteria that these molecules form ion channels embedded in the bilayer lipid membrane. Non-peptidic artificial ion channels as well as helical bundles are now in our hands and it is likely that many more will soon emerge. The biological importance of these molecules may attract interest from many diverse branches of science—neurobiology, clinical medicine, biophysics, membrane technology, materials science, and others. 

In conclusion, the use of membrane technology in water and wastewater treatment has begun to emerge as the most significant advancement in water treatment in the past 20 yr, and its presence is expected to become widely spread in the future. 

This chapter reviews existing and emerging applications for membrane technology in stationary power generation. For example, filters are used to clean intake air for combustion and remove particulate emissions from coal-fired power plants [1], while monbrane technologies are used for the purification of NG [2] and the conditioning of boiler feedwater for use in steam turbines [3]. The discussion is divided into three sections ... 

Constructing an experience curve is a simple matter once the data are available. Of course for the Pd-based or ceramic membrane such dates are limited to minimal surface (less than 1 m ), which can, however, be used as starting point of the curve. The other issue associated with drawing an experience curve is that eost and production data must be related to a standard product , which is not the case due to the fact that in the membrane technology no standard is yet emerged and there is a lot of discussion on the membrane composition and preparation method, supporting matrix and other mechanical and construction details. 

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