A gas absorption tower contains two feed streams – F1: a gas containing 33.0 mole% O2, 66% N2, and 1% SO2 at 250L/s at 35°C, and 1.2 atm; and F2: liquid water flowing at a rate of 15.0 mol/s at 35°C, and 1.2 atm. There are two product streams coming out this gas absorption tower – P1: a liquid stream containing most of the entering water and a small amount of dissolved SO2; and P2: a gas stream containing all of the entering O2 and N2, the balance of the entering SO2, and some water vapour. The two product streams are in equilibrium with each other at 35°C and 1.2 atm. The equilibrium distribution of SO2 and H2O between those streams is described by two relations:

where xS02 is the mole fraction of SO2 in the P1 liquid stream, yS02 and yH02 are the mole fractions of SO2 and H2O in the P2 gas stream, respectively. P is the system pressure and pH20 ∗ (T) is the vapour pressure of H2O at temperature T.
a. Draw and completely label a flow chart of this process, including component mole fractions in the labelling of all but the liquid water feed stream (F2 is pure water).
b. Show that the degrees of freedom for this process is zero by naming the unknown variables and the equations you can write to solve this problem. (Note: you do not have to solve the equations)
c. Solve the simultaneous equations in part b to calculate the values of all the unknowns.
d. What is the percentage recovery of SO2?
e. Comment percentage recovery the concentration of SO2 in the gas stream leaving the absorption column (consider that SO2 is an air pollutant and has strict emissions standards). Propose methods for improving the recovery of SO2 and meeting the environmental regulations.

Answer rating: 100% (QA)

X and Y are the notations are used here bDegrees of freedom F as CP2 Noof compon... View the full answer