A continuous fraction distillation column will be designed to separate a mixture containing 35% benzene and 65% toluene with a flow rate of 30,000 kg/hr to contain 97% benzene in the upper product and 98% toluene in the lower product by weight. The recovery (reflux) rate was determined to be 3 per 1 mole of product. Benzene and toluene form an ideal system with a relative volatility of 2. The molal latent heat values for benzene and toluene are 7360 and 7960 cal/gmol, respectively. The molecular weights for benzene and toluene are 78 and 92 g/mol, respectively. The feed has a boiling point of 95C at 1 atm pressure.

a) Calculate the amount of upper and lower product in mol/h.

b) Specify the ideal number of stages and the stage where the feed is made for the following three different situations.

Please specify.

i) Liquid at feed boiling point

ii) Feed liquid at 20C (specific heat 0.44 cal/gC)

iii) A mixture of two-thirds liquid and one-third steam of the feed

c) If steam with a gauge pressure of 20 lbf/in2 (1.36 atm) is used for heating, how much steam is required per hour for each of the three cases above, ignoring heat losses and assuming the reflux is a saturated liquid?

d) If the cooling water enters the condenser at 28C and leaves at 42C, how many cubic meters of cooling water per hour are needed?