Absorption Columns: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

Example Problem 1

A lab operation results in releasing air containing chloroform into the environment. To remedy this, an absorber is being proposed to scrub the gas using pure water to decrease the chloroform concentration to a permissible 10 ppm. If the air stream enters the column at 1,000 kmol/hr with 200 ppm chloroform and the water enters the column at 187,300 kmol/hr, how many stages should be designed into the absorption column? The air is at 25ÂșC and 1.5 atm.

The following screencasts present two approaches to solve this problem.

Example Problem 2

We wish to remove 65% of the CO2 from a gas stream by contact with room temperature water at atmospheric pressure. The inlet gas stream consists of 8 mol% CO2 in nitrogen. How many equilibrium stages would be required for a 100 mol/h gas stream, if we operate at 1.5x S/G[min]?