Solve problem 10.10 using UNIFAC to model the liquid phase.

Data from problem 10.10

Solvent vessels must be purged before maintenance personnel enter in order to ensure that: (1) sufficient oxygen is available for breathing; (2) vapor concentrations are below the flash point; (3) vapor concentrations are below the Occupational Safety and Health Administration (OSHA) limits if breathing apparatus is not to be used. Assuming that a 8 m³ fixed-roof solvent tank has just been drained of all liquid and that the vapor phase is initially saturated at 22°C, estimate the length of purge necessary with 2 m³/min of gas at 0.1 MPa and 22°C to reach the OSHA 8-hr exposure limit.

(a) Hexane 500 ppm

(b) 1-butanol 100 ppm

(c) Chloroform 50 ppm

(d) Ethanol 1000 ppm

(e) Toluene 200 ppm