Intermediate concentrations in the outlet concentration profile for trace PSA systems can be estimated using Eqs. (20-28a) to (20-28c). For Example 20-4,

Example 20-4

a. Show that point 10 in Figure 20-13B can be determined by starting with \(\mathrm{t}=1 \mathrm{~s}\) (end of blowdown) at \(z_{\text {after }}=0.40 \mathrm{~m}(0.10 \mathrm{~m}\) from feed end) by using Eq. (20-28c) to find \(p_{\text {before }}\) and Eq. (20-28a) to find \(\mathrm{y}_{\mathrm{M} \text {,after. }}\). Since solute of this mole fraction moves as a wave at the known velocity \(\mathrm{u}_{\mathrm{M}}\) during the feed step, the time it exits the top of the column can be determined.

b. Starting at the point \(\mathrm{t}=1 \mathrm{~s}, \mathrm{z}_{\text {after }}=0.48 \mathrm{~m}\), calculate point 11 in Figure 20-13B.

YA,after YA,before H Pafter Pbefore. (strong-1) (20-28a) Zafter Pafter Zbefore Pbefore strong (20-28b)