1000 kg/hr of a mixture containing 42 mole percent heptane and 58 mole percent ethyl benzene is to be fractionated to a distillate containing 97 mole percent heptane and a residue containing 99 mole percent ethyl benzene using a total condenser and feed at its saturated liquid condition. The enthalpy-concentration data for the heptane-ethyl benzene at 1 atm pressure are as follows:
xheptane 0 0.08 0.18 0.25 0.49 0.65 0.79 0.91 1.0
yheptane 0 0.28 0.43 0.51 0.73 0.83 0.90 0.96 1.0
Hl (kJ/kmol) x 10-3 24.3 24.1 23.2 22.8 22.05 21.75 21.7 21.6 21.4
Hv (kJ/kmol) x 10-3 61.2 59.6 58.5 58.1 56.5 55.2 54.4 53.8 53.3
Calculate the following:
a. Minimum reflux ratio
b. Minimum number of stages at total reflux
c. Number of stages at reflux ratio of 2.5
d. Condenser duty
e. Reboiler duty