Hydrogen chloride HCl has to be removed from a process off g

Hydrogen chloride, HCl has to be removed from a process off gas in a counter current gas absorption column using HQ free water as liquid stream fed at the top of the column. The exit mole percentage of HCl in the gas stream need to be 2.5% from the Incoming mole percentage of 1394. The inlet flow rate of the gas is 37 kg/s. The column pressure and temperature has been maintained at 1.0 atm and 25C, respectively. The column diameter is 0.6 m. for optimum column operation the actual Ls/Gs ratio should be maintained at 1.62 times of the minimum value. The individual mass transfer coefficient in the gas phase, k_g, is 7.5 times 10^-4 kmol/(m^2.s.kpa) and in the liquid phase, k_L is 0.00135 m/s. (If a numerical integration is needed, use a minimum of 4 points covering the entire relevant range) Find the following: Individual mass transfer coefficients ky and kx Interfacial mole fractions of HCl (x_Ai and y_Ai) at the bottom of the column Overall mass transfer coefficient (Kx) at the bottom of the column relative mass transfer resistance In the gas phase minimum liquid flow rate (in mole/s) that can be theoretically used for this actual mole percentage of \"HCl\" in the liquid stream leaving the column height of the column (consider K_y a = 10 k mole/m^3.s)

Solution

The mass transfer flux in terms of mass transfer film coefficient for each phase can be written as :

N= k_y(y_AG-y_Ai)= k_x(x_Ai-x_AL).

A relation between overall coefficient and individual mass transfer coefficients can be obtained when equilibrium relation is linear as

y_Ai= mx_Ai.

The overall gase phase mass transfer coefficient (K_y) can be determined as

1/K_y= 1/k_y+ m/k_x

The overall liquid phase mass transfer coefficient(K_x) -

1/K_x= 1/mk_y+1/k_x

Put values given in question to get answer