Chapter 4, Problem 4.30P

A garment to protect the wearer from toxic agents may be made of a fabric that contains an adsorbent, such as activated carbon. In a test of such a fabric, a gas stream containing 7.76 mg/L of carbon tetrachloride (CC1₄) was passed through a 7.71-g sample of the fabric at a rate of l.OL/min, and the concentration of CCI4 in the gas leaving the fabric was monitored. The run was continued for 15.5 min with no CCI4 being detected, after which the CC1₄ concentration began to rise.

1. How much CC1₄ was fed to the system during the first 15.5 min of the run? How much was adsorbed? Using this information as a guide, sketch the expected concentration of CCI4 in the exit gas as a function of time, showing the curve from f = 0 to r» 15.5 min.
2. Assuming a linear relationship betw een amount of CC1₄ adsorbed and mass of fabric, w hat fabric mass w ould be required if the feed concentration is 5 mg/L, the feed rate 1.4 L/min, and it is desired that no CCI4 leave the fabric earlier than 30 min?