An interphase convective mass-transfer process involves the transfer of the industrial contaminant, methylene chloride (species A), between air and water at 20°C and 2.20 atm total system pressure. Air is the inert carrier gas, and water is the inert solvent. The equilibrium mole fraction of methylene chloride dissolved in water vs. the mole fraction of methylene chloride in air at 20°C and 2.2 atm total pressure is shown below.
At the present operating conditions, the bulk phase mole fraction of methylene chloride is 0.10 in the gas phase and 0.0040 in the liquid phase. The fluid flow rate associated with each case predicts a gas film mass transfer coefficient, ky, to be 0:010 g mol/m2 s and a liquid film convective mass transfer coefficient, kx, to be 0:125 g mol/m2 s. At 20°C, the density of liquid water is 992:3 kg/m3.
a. Is the process (1) a liquid stripping process or (2) a gas absorption process?
b. Determine the Henry's law constant for methylene chloride dissolved in water, according to the definition pA = H cA.
c. Determine the overall coefficient KL.
d. What is the flux of species A across the gas and liquid phases?
e. Determine the interface mole fractions xA; i and yA; i.