A polluted air stream flowing at 12,000 acfm at 90 °F and 1 atm has a concentration of 500 ppm of ethylbenzene (C8H10). Pilot plant studies of adsorption processes indicate that 11 lb (net) of ethylbenzene will be adsorbed per 100 lb of carbon during normal everyday operations.
a. Calculate the minimum amount of carbon needed in one bed for a two hour run time. Give your answer in pounds.
b. Assuming this carbon has a bulk density of 25 lb/ft3, and if the bed must be at least 1.5 feet deep, calculate the superficial gas velocity in a bed that contains this amount of carbon. Give your answers in ft/min.
c. Comment on this superficial gas velocity. If it is too high or too low, determine what you would do to correct it. Be specific and give dimensions of the re-sized bed. How does the run time change?