Dense composite membranes

Fig. 11.5. Formaldehyde yields in various reactors under similar experimental conditions. V, conventional plug-flow reactor , a PBMR using a Pd/AljCb dense composite membrane A, a PBMR using a mesoporous AI2O3 membrane , a CMR using a mesoporous AI2O3 membrane catalytically impregnated by a sol-gel technique. Reproduced from Deng and Wu [61] with permission.

Dense, composite membranes that are 35 p,m in thickness were successfully fabricated. A cross section of a supported, thin membrane structure is shown in Fig. 4.6. 

Hydrogen Separation Using Dense Composite Membranes Part 1 Fundamentals... 

Mundschau MV. Hydrogen separation using dense composite membranes. Part 1. Fundamentals. In Bose A. editors. This Volume. Springer 2007. 

The pervaporation dehydration study of isopropanol-water and ethanol-water mixtures was carried out by Moon et al. [90]. The two-ply dense composite membranes were prepared using successive castings of sodium alginate and CS solutions. The membranes showed improved mechanical strength, flux, and separation factor. The three factors like polymer type contacting the feed stream, NaOH treatment, and type of cross-linking agent decide the flux and separation factor of the two-ply membrane system. 

Porous membranes (low H2 selectivity) are used as substrate onto which a very thin but continuous film of a selective metal, generally Pd-based, is deposited. Dense composite membranes are also fabricated by sintering together powders of highly H2 permeable metals (Pd, Pt, Nb,Ta,1i, V, Zr and their alloys) with powders of a second metal or alloy which is non-permeable to H2 (Mundschau, 2005), having the function of providing the mechanical support. Some fundamental science related to the H2 separation using dense composite membranes is reported by Mundschau (2008). 

Mundschau M. (2008), Hydrogen Separation Using Dense Composite Membranes, Part 1 Fundamentals,in 7norga tc Membranes for Energy andEuel Applications, (A. Bose Ed., Springer, Berlin). 

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