CRI-Criterion

Tubular porous metal supports with 1 and 2 inch outside diameters (OD) were selected because they can be easily assembled with normal welding techniques, are not fragile like ceramic materials, and do not require special fittings to achieve leak-tight seals. CRI-Criterion currently produces membranes of ODs up to 2 inches and lengths up to 24 inches. Current focus is to extend the viable individual unit length to approximately 1 meter. 

Recycle procedures for spent membranes have been developed to improve membrane economics by recycled membranes to function in the same manner as the originals. The permeances of the membranes vary in a range of 30-70 N m m h bar ° and are affected by the support and process parameters. The CRI membranes operate in a pressure range of 30 5 bar dP and at temperatures of up to 550 °C. Typical examples of the performance of CRI-Criterion Pd/Stainless Steel H2 separation membrane are given in Table 11.7. 

The membranes tested show long-term robustness and demonstrate stability during and after experiencing a number of uncontrolled shutdowns. The membranes consistently delivered hydrogen purity in a range of 98.16 to 100%. 

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A high temperature Pd/Stainless Steel H2 separation membrane manufactured by CRI-Criterion by deposition of Pd on sintered porous metal support with permeable dimensions of 1 inch OD and 6 inches length is shown in Figure 11.7. An SEM cross section of the top layers of the membranes showing the porous stainless support, the inter-metal diffusion barrier, and the selective Pd layer. Note that the picture lack pinholes in Figure 11.8. 

Table 11.7 Typical examples of the performance of CRI-Criterion Pd/stainless steel H2 separation membrane...

High temperature Pd/stainless steel H2 separation membrane manufactured by CRI-Criterion by deposition of Pd on sintered porous metal support with permeable dimensions of 1 inch OD and 6 inch length. 

Figure 11.9 Long-term performance of a Pd/stainless steel H2 separation membrane as manufactured by CRI-Criterion during 7000 h of operation.

Figure 11.10 Effect of CO partial pressure on the hydrogen flux obtained with a CRI-Criterion Pd membrane. During this period, the total gas flow (wet basis) was held constant at 794 SLPH. The CO/CO2 ratio was changed. This was done while holding all other flows, temperature (430 °C), pressure constant (30 barg).

The section, "Conformance how each safe shutdown cri criterion with references These subsections are not provide objective evidence are met. As appropriate, as it relates to the parti... 

That is, ttcr is directly proportional to K c/cry) since oh is a fraction of Oy. Thus, the larger the value of acr, the more attractive is the material, since cracks can be easily detected without the use of sophisticated equipment. The Ashby plot of fracture toughness versus density (Figure 8.10) indicates that of the three classes of materials selected with Criterion 1, only the engineering composites and engineering alloys provide suitable possibilities for Criterion 2. Again, of the alloys, titanium, steel, nickel, and copper alloys are the best here. 

It may be commented that the loop identification methodology and tearing criterion does not include control loops. With control loops present, one ordering deduced from a minimum loop tear may be vastly more efficient than an equivalent solution ordering. Just how to incorporate control loops in the tearing cri-terions does not appear to be addressed in the literature. 

To what degree do you still use the criterion [insert placement cri-... 

If we use the Tresca yield criterion, yielding occurs exactly at cri = Rp. With the von Mises yield criterion, the result is /i/2 [(tri — ctc) + cr f + a ] = Rp. Depending on the value of the circumferential stress, the axial stress at which yielding starts may be up to 15.5% larger than with the Tresca criterion (see... 

At present, the most frequently used CP criterion in the case of steel structures is the potential value of -0.85 V versus the CSE at a flowing protective current. The basic disadvantages of potential criteria are no possibility of recalculation of the potential of steel to the corrosion rate, the occurrence during potential measurement of the IR ohmic voltage drop, and a large differentiation of protective potential values according to the environmental conditions. This information questions the generally adopted cri-... 

The first criterion is probably the best known and widely used in industry due to its ease of apphcation. Using the Nemst equation and a ferrous ion concentration of 10 M (a criterion commonly used to define negligible corrosion in thermodynamics), a potential for steel of -930 mV w.r.t. Cu/CuS04 can be derived, which is somewhat more negative than this criterion. The satisfactory performance imder the less stringent potential requirement may be related to the formation of protective ferrous hydroxide on the surface. Strictly speaking, potential protection cri-... 

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