Permeation, hydrogen defined

In relation to the hydrogen membrane processes, the direction of mass transfer would be defined from the retentate (hydrogen rich feed stream) to the permeate (hydrogen poor stream). Assuming a steady state permeation process and integrating Eq. 10.2 yields the governing, steady state form of Pick s law for membrane processes, Eq. 10.3,... 

X-ray crystallographic studies (59) have defined the conformations and hydrogen bonding of the tetracyclines under nonpolar and polar conditions. These are shown ia Figure 3. It is beheved that the equiUbrium between the 2witterionic and nonioni2ed forms is of importance for the broad-spectmm antibacterial activity, membrane permeation, and pharmacokinetic properties. 

The steady-state hydrogen permeation rate, V, (mol/m s), can be defined according to equation 2... 

In MR technology, the quantification of H2 recovered with respect to that totally extractable in the feed is an important issue. The extraction index (eqn (12.5)) defined as the ratio between H2 permeated through the membrane with respect to that totally fed to the reactor, gives an indication about the limitations of an MR in the achievement of a complete conversion. If the hydrogen is the permeating species, as in the case study considered, El takes into account... 

Defining Concentration Polarization Coefificient According to Hydrogen Permeation Driving Force... 

All of the considerations made in the previous section lead to the necessity of defining a concentration polarization coefficient that could be directly connected to specific permeation quantities.Here, this approach will be direct to hydrogen permeation through Pd-based membranes. 

The permeation yield is an important parameter defining the tubular membrane s capacity to separate pure hydrogen. It is defined as the ratio of the hydrogen permeated through the tube cathode to the overall hydrogen... 

Ihe hydrogen recovery factor (HRF) is defined as the mole ratio of permeated Hj to Hj contained in the input strearrr. fit the case of tttetrtbrane reactors, the H2 producible inside of the module also has to be accounted far. Iherefore, for a water gas shift membrane reactor, HRF is defined as the mole ratio of permeated H2 to H2 + CO in the errtering syngas. 

The effect of the substrate on the hydrogen permeation through the composite membrane can be evaluated by the substrate influence factor, defined by the ratio of the pressure drop across the substrate to the total pressure difference across the composite membrane ... 

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