The 3M company removes benzene from synthetic resin-based sandpaper by passing the sandpaper product through a dryer in which the benzene is evaporated into a stream of hot air. The air exiting the dryer leaves saturated with benzene at 40°C and one atmosphere. A process to recover this benzene cools the exit gas to 10°C and compresses it to 25 psig.
a) What fraction of the benzene is recovered in the cooler/compressor?
b) The air leaving the compressor/cooler is recycled back to the dryer for reuse. Determine how much heat per mol must be transferred to the recycled stream if it enters the heater at 10°C and 1.5 atm and leaves at 50°C and 1.4 atm.?