Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA
Surface area and pore size distribution are attributes used by adsorbent and catalyst manufacturers and users to ensure quality control and to determine when products are at the end of their useful lives. The surface area of a porous solid is directly related to its adsorption capacity or catalytic activity. The pore size distribution of an adsorbent or catalyst is controlled such that pores are large enough to easily admit molecules of interest, but small enough to provide a high surface area per mass.
Surface area and pore size distribution can be measured by the technique of isothermal nitrogen adsorption/desorption. In this experiment, a nitrogen porosimeter will be used to measure the surface area and pore size distribution of a silica/alumina powder.
1. Starting the porosimeter
In the capillary condensation region, the isotherm generally shows hysteresis so that the apparent equilibrium pressures observed in adsorption and desorption experiments are different (Figure 2). The desorption branch is always at lower fugacity and pressure. The hysteresis begins at P/P0 = ~0.6, where capillary condensation begins to dominate the adsorption process, although the pore size distribution algorithm uses the entire isotherm. The calcu
The method of measurement and calculation presented here is the gold standard in porosimetry. The mercury porosimetry technique is an alternative, but its high pressures and possibility of exposure to mercury are disadvantages. Better pressure transducers, vacuum pumps, and software have greatly extended the utility of N2 porosimetry, and the method gives all 3 key adsorbent or catalyst morphological measurements (A, pore volume, pore size distribution) in one experiment. It also provides info
Atla...
Bu koleksiyondaki videolar:
Now Playing
Chemical Engineering
9.5K Görüntüleme Sayısı
Chemical Engineering
17.7K Görüntüleme Sayısı
Chemical Engineering
43.6K Görüntüleme Sayısı
Chemical Engineering
31.9K Görüntüleme Sayısı
Chemical Engineering
9.9K Görüntüleme Sayısı
Chemical Engineering
36.3K Görüntüleme Sayısı
Chemical Engineering
85.9K Görüntüleme Sayısı
Chemical Engineering
76.7K Görüntüleme Sayısı
Chemical Engineering
47.9K Görüntüleme Sayısı
Chemical Engineering
9.6K Görüntüleme Sayısı
Chemical Engineering
23.9K Görüntüleme Sayısı
Chemical Engineering
18.7K Görüntüleme Sayısı
Chemical Engineering
15.9K Görüntüleme Sayısı
Chemical Engineering
29.7K Görüntüleme Sayısı
Chemical Engineering
7.2K Görüntüleme Sayısı
JoVE Hakkında
Telif Hakkı © 2020 MyJove Corporation. Tüm hakları saklıdır