Recovering and reusing organic solvents (rather than discharging the solvents in waste streams) is an important part of the operation of most chemical plants. The magnitude of these recovery efforts can be staggering: in recent years the Eastman Chemical Company used 3.6 billion pounds of solvents and recovered 3.5 billion pounds (97%). Eastman’s installation of a $26 million acetone-recovery system reduced acetone emissions by 50% in the division that had been responsible for most of this emissions.⁸ in an acetone-recovery process. a gas stream containing 20.0 mole% acetone and the remainder nitrogen leaves a chemical plant at 90°C and 1 atm. The stream is cooled at constant pressure in a condenser, enabling some of the acetone vapor to be recovered as a liquid. The nitrogen and uncondensed acetone are discharged to the atmosphere.

(a) Give two major benefits of recovering the acetone.

(b) Two cooling fluids are available—cooling-tower water at 20°C and a refrigerant at —35°C. For each fluid, calculate the percentage acetone recovery ((mol acetone condensed mol acetone fed to condenser) x 100%]. Assuming that the condenser temperature equals the coolant temperature

(c) What more would you need to know to decide which coolant to use?

(d) In a real system, the condenser temperature could never be as low as the initial cooling fluid temperature. Why not?