For the situation in Problem 24.2, how would you handle the following temporary process upsets? Be quantitative. Suggest at least three alternatives for each situation.

1. The gas rate must increase by 10%.

2. The feed mole fraction of acetone must increase to 0.025.

3. The outlet mole fraction of acetone in air must be reduced to 0.00075.

Problem 24.2

A five-equilibrium-stage tray absorber is used for the acetone separation described. It is now observed that the outlet mole fraction of acetone in air is 0.002.

1. Suggest at least six individual causes for the faulty absorber performance.

2. For the causes listed in Part (a) that are represented on the Kremser graph, determine the exact value of the parameter (i.e., what flowrate would cause the observed outlet mole fraction?).

3. For each cause listed in Part (b), suggest at least three compensation methods. Be quantitative.

Transcribed Image Text:

24.2.1 Troubleshooting a Packed-Bed Absorber The first troubleshooting problem involves a packed-bed absorber. The absorber has been designed to remove a contaminant from an air purge stream and has been operating for some time as designed. Then it is observed that the outlet air contains more contaminant than it should. A similar problem involving a tray absorber is given at the end of the chapter.