Page 41 - Separation process engineering

mole fraction solute in gas permeate for gas permeation

y r

mole fraction solute in gas retentate for gas permeation
y r,w

mole fraction solute in gas retentate at membrane wall

y t,A

mole fraction solute A in gas that transfers through the membrane

Greek letters

α

selectivity, dimensionless, Gas Permeation: Eq. (17-4b), RO: Eq. (17-20),
pervaporation: Eq. (17-53a)
Δx

difference in wt frac of solute across the membrane
Δπ

difference in the osmotic pressure across the membrane, Pa, atm, mm Hg, etc.
π

osmotic pressure, Pa, kPa, atm, mm Hg, etc.
θ

cut = , with flows in molar units, dimensionless
θ′

cut = F′ /F′ in flows in mass units, dimensionless
p
in
μ
viscosity, centipoise or g/(cm s)

ν = μ/ρ
2
kinematic viscosity, cm /s
ρ solv

mass solvent density, kg/m 3

solv
molar solvent density, kmol/m 3

λ p

mass latent heat of vaporization of the permeate in pervaporation determined at
the reference temperature, kJ/kg
ω

stirrer speed in radians/s

Chapter 18

a