Stacked planar membrane

Figure S.9 Exploded view of a stacked planar membrane array of the type used in the modules shown in Fig. 5.1 and 5.2.

In contrast, tube-and-shell type membrane modules do not have these engineering challenges with deflection and compromise of seal integrity. For this reason, tubular membrane modules will generally be lighter in construction relative to stacked planar membrane modules of comparable membrane area. However, a drawback to the tubular membrane module is that the packing density of the membrane is often substantially less than that which can be achieved with the stacked planar designs. 

The stacked planar module design is readily used with any foil-based membrane because foils are available as flat sheet stock. This design is not so readily adapted... 

Regardless of the membrane module design, effective performance is dependent on rapid mass transfer at the feed side of the membrane. There are several comprehensive references on mass transfer [10], so it will not be addressed in detail here. However, one should consider mass transfer because it affects two design issues the manifolding of the feed stream to each membrane, and the feed channel design and dimensions. The detailed analysis of these issues differs somewhat when one considers stacked planar modules and tubular modules, but the fundamental objectives are quite similar. 

Figure 8.13 Cross-section of a conceptual syngas reactor for planar membranes showing the stacks of planar membranes (top), air feed manifolding to the stacks (middle) and the nonpermeate exit manifolding (bottom).

Figure 8.14 Figure 5 from U.S. Patent Application 20050031531 A1 [27] showing a longitudinal cross-section ofa reactor for planar membranes, and showingthe stacks of membranes (501, 503, etc), the reactant feed (517),the syngas product (557), the fresh air feed (553), the nonpermeate (555) exhaust (555). 

The electrolysis in aqueous sulfuric acid with methanol as a cosolvent was perfomed in a filterpress membrane cell stack developed at Reilly and Tar Chemicals. Because of the low current density of the process, a cathode based on a bed of lead shot was used. A planar PbOa anode was used. The organic yield was 93% with approximately 1% of a dimer. The costs of the electrochemical conversion were estimated as one-half of the catalytic hydrogenation on a similar scale. 

Fig. 1.6 Illustration of a planar-stack, solid-oxide fuel cell (SOFC), where an membrane-electrode assembly (MEA) is sandwiched between an interconnect structure that forms fuel and air channels. There is homogeneous chemical reaction within the flow channels, as well as heterogeneous cehmistry at the channel walls. There are also electrochemical reactions at the electrode interfaces of the channels. A counter-flow situation is illustrated here, but co-flow and cross-flow configurations are also common. Channel cross section dimensions are typically on the order of a millimeter.

Photoinduced electron transfer across planar bilayer membranes doped with discrete cofacially stacked porphyrin trimers and tetramers has been demonstrated... 

The gross structure of collagen in many tissues, for example tendons, involves wave-like curved fibrils, which provide elasticity. This sort of curvature occurs also when fibrils in two directions are linked into a planar net. A highly ordered collagen structure is fovmd in the so-called "decemats membrane", which is the basement membrane of corneal endothelial cells. Stacks of hexagonal lattices have been observed which are parallel to the basement membrane [17]. 

Figure 8.4 A membrane module consisting of a stack of planar microchanneled membranes (left) and the air flow path In each membrane (right).

A home-built solid state NMR probe for membrane protein studies has been described by Kim et al. Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. The stack of glass slide with planar lipid bilayers is not well fit for commercial solid state NMR probe with round coil. Therefore, homebuilt solid state NMR probe was built by Kim et al. The overall filling factor of the coil was much better and the large surface area increased the extent to orientation by providing uniform environments for the... 

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