1. A mass-transfer tower is to be designed for reducing a VOC concentration from 0.0394 to 0.0131 mg mol/L. Five thousand gallons per hour of wastewater will be fed to the 0.6 m diameter tower, countercurrent to a stripping air stream that will enter the tower free of any VOC. If a volumetric flow rate QL(m3 /h) to a gas flow rate G(mol/h) of 1.5 is used, the overall mass-transfer capacity coefficient, KLa, will equal 0:01/s. The equilibrium data at the pressure and temperature of the tower are
Determine
a. the minimum gas flow rate that might be used;
b. the height of the tower.
2. The absorption of water in sulfuric acid is an exothermic process. Describe the effect this would have on the required height of a mass-transfer column as compared to the height that is evaluated if isothermal conditions are assumed.