Q5: Ammonia is being absorbed from its mixture with air using water at 26 C and one atm pressure in an absorption tower. At a particular level in the tower the ammonia concentration in the bulk gas is 0.80 mole fraction, that in the bulk liquid 0.05 mole fraction. The rates of flow are such that the individual mass transfer coefficient are : In the liquid phase K = 2.87 *105 kmol/ m.s (kmol/m) In the gas-phase Kg = 1.47 * 10 Kmol/m.s (mole fraction) (A) Compute the local mass transfer flux for absorption of ammonia. (B) Calculate the overall mass transfer coefficients K, and Kx, assuming m = 2.57 (C) Calculate the resistance to mass transfer in each phase. (D) Calculate the flux based on Ky. Equilibrium data for NH3/ water at 26C NH3 mole fraction in liquid 0 0.05 0.1 0.25 0.3 .( 25 Mark) NH, mole fraction in gas 0 0.0707 0.1347 0.591 0.920

Q5: Ammonia is being absorbed from its mixture with air using water at 26C and one atm pressure in an absorption tower. At a particular level in the tower the ammonia concentration in the bulk gas is 0.80 mole fraction, that in the bulk liquid 0.05 mole fraction. The rates of flow are such that the individual mass transfer coefficient are : In the liquid phase Ki=2.87105kmol/m2s(kmol/m3) In the gas - phase 9=1.47103Kmol/m2s (mole fraction) (A) Compute the local mass transfer flux for absorption of ammonia . (B) Calculate the overall mass transfer coefficients Ky and K assuming m=2.57 (C) Calculate the resistance to mass transfer in each phase. (D) Calculate the flux based on y. Equilibrium data for NH/ water at 26C ( 25 Mark)