Question

A wide 2000 m3 laboratory has a ventilation system. This may be designed to eliminate toxicants from the laboratory to the outside so the ventilation system maintains safe , comfortable and respiratory conditions for all laboratory users and decreases the risk of dangerous pollutants. At a volumetric fluctuation rate of 900 m3 / min at 20 °C and 1 atm, the ventilated air is discharged, which is often to be known as a lab temperature and pressure. The lab was contaminated by 1.5 mol of carbon monoxide ( CO) by a gas leak from the reactor in the laboratory. The risk for health is determined if in laboratories the mol fraction of CO reaches 0.7 ppm (7 x 10-7). CO assume as the ideal gas.

a) Consider that air is completely homogenized at the laboratory, write the differential CO balance, which allows N to be the total air moles and x the CO fraction of the mol in the laboratory. Provide the initial state.

b) Solve the balance to get an expression for x(t).

c) Draw the structure of an x versus t plot.

d) Convert the expression for x(t) to the expression for the concentration of CO in the laboratory, CCO (mol CO / L) with respect to time.

e) Determine the concentration concentration of CO in the laboratory after one minute of leakage and the time needed for the concentration of CO to be at the health level from answer at d.

Answer 1

co Malance. ACC. Lons. in-out t gen. 1.5 mtoles of co- moles at t=0 ý a air and room mol fr. Conti in outlet B co let 2000 N, PV Balance d (1.5- N) - at Epax 900 Total moles of Air = hvidla 1x1.012810*x20 ht RT 8.314 x 293 300 X 1013 Xios 83169.06 mol 8.314 * 293

- Nda 37426.084 de > da - 0 - 4 - (a) 80 -0.45 x du at -OUS fat t at du 1.80x105 1.5 N 83169.06 -0.45 t en x leyxios 0:45+ (6) 1.7 X10 c Cod) Conc. of co NA 2000X10" R 1.8810 mall o.ust Cco ୧ t 1.5 41584.53 2x10-6 -ou5t tܓܦܝܘܢ am Co= 3 1188.3915e عهد 24475 ppm Ecolearmin 't=1 min 19886.6 ppm time for Cco = 0.7 ppm = 23.78 mins -I lo 0.1 0.45 31188.39