Problem 1. (60 points) . Carbon dioxide is absorbed in water from a mixture of 2

Question

Problem 1. (60 points).  Carbon dioxide is absorbed in water from a mixture of 20 mol% CO2, 40 mol% N2 and 40 mol% H2 at atmospheric pressure and 300 K. The resistance to mass transfer can be regarded as lying entirely in a gas film 2 mm thick, where both nitrogen and hydrogen remain stationary, with CO2 undergoing instantaneous absorption on the water surface. The diffusivity of CO2 is 0.16 cm2/s in N2 and 0.35 cm2/s in H2 at 300 K.

a.    20 points.    Calculate the total molar flux (absorption rate) of CO2 in the film.

b.      8 points.    Calculate the total molar average bulk flow velocity in the film.

a.     10 points.     Calculate the absorption rate of CO2 if all nitrogen in the mixture was

                            replaced by hydrogen (assuming negligible change in the film thickness).

b.       4 points.     What is the physical explanation of this result (i.e., why does the absorption

                            rate change when all nitrogen is replaced by hydrogen?)

c.     18 points.     Calculate the CO2 concentration and velocity 1 mm from the water surface                              (i.e., at the central plane of the diffusion film).

Explanation / Answer

nCO2 = 3.00 g CO2/ (44.01 g CO2 / mol CO2)

= 0.0682 mol CO2

2

A)

0.0682 mol

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.