Interpellet porosity

Interpellet porosity, 25 294 Interpenetrated wall matrix, in hollow-fiber membranes, 76 15 Interpenetrating polymer networks (IPNs), 79 834... 

The relation between r and Xfinai. given by equation (22-52), can be rearranged to calculate final conversion Xfinai in terms of reactor volume VppR, where the interpellet porosity is an important design parameter ... 

Step 9. Enter the interpellet porosity of the fixed-bed reactor, which is dimensionless ... 

Notice that the final conversion for first-order kinetics in an ideal packed catalytic tubular reactor depends on interpellet porosity of the packed bed in the following manner ... 

Total gas-phase volumetric flow rate = 10 L/min = 10,000 cm /min Diameter of the tubular reactor = 20 cm Interpellet porosity of the packed bed = 0.25... 

Interpellet Damkohler number, A interpeiiet Interpellet porosity, inteipeUet = 0.5... 

Sinter = 0.35 (interpellet porosity, void volume fraction for the entire packed reactor, dimensionless)... 

Sp, interpeiiet, interpellet porosity of the entire packed catalytic tubular reactor. 

Put both curves on the same set of axes. The effectiveness factor, interpellet porosity, and time constants for convective mass transfer and chemical reaction are the same in both cases. 

Intrapellet Damkohler number of reactant A Aa, intrapeUet = 5 Interpellet porosity of the packed bed mteipeUet = 0.50 Time constant for zeroth-order irreversible chemical reaction o) = 1 minute... 

Diameter of each porous catalytic pellet nfpeiiet = 2 cm Radius of the mbular reactor / pfr = 10 cm Length of the mbular reactor Lpfr = 190 cm Interpellet porosity of the packed bed p, mteipeiiet = 0.30 Volumetric flowrate = 15 Liters/min = 250 cm /sec... 

This picture is useful but does not match all adsorbents. Gel-type ion-exchange resins have no permanent pores. Instead they consist of a tangled network of interconnected polymer chains into which the solvent dissolves. In effect, Cp = 0. Macroporous ion-exchange resins have permanent pores and Cp > 0, but often < 1.0 for large molecules. Many activated carbons have both macropores and micropores thus, there are two internal porosities. Molecular sieve zeolite adsorbents are used as pellets that are a omerates of zeolite crystals and a binder such as clay. In this case, there is an interpellet porosity (typically, 0.32), an intercrystal porosity ( pi 0.23) and an intracrystal porosity ( p2 0.19), which has < 1.0... 

Cl. A molecular sieve zeolite adsorbent consists of pellets that are agglomerates of zeolite crystals with density p ystai scattered in a continuous phase of clay binder with a density p gy. In this case, there is an interpellet porosity 8g (between pellets—this is normal Eg) an intercrystal porosity Sp, (which is the porosity in the binder), and an intracrystal porosity p2, (inside the crystals). If the fraction of the particle volume that is crystals (including porosity within the crystals) is f jy, derive formulas for the total porosity, Vavajjabjg, and the particle and bulk densities. 

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