It is desired to design a continuous (shelf) rectification column that operates at atmospheric pressure with a capacity of 15000 kg/h and separates a benzene-toluene mixture containing 35% benzene into a head product containing 90% benzene and a base product containing 95% toluene. The % given are percent by weight. For each kg of head product, 2.5 kg of rifax (backflow rate) is used. The mixture to be distilled and rifax enters the column as liquid at boiling temperature. Applying the Ponchon-Savarit method (it will be drawn by hand on millimetric paper), a) Find the required theoretical number of racks and the location of the feeding rack. b) Since the cooling water enters the condenser at 25C and leaves at 50C, find the required amount of cooling water. Cpsu: 1 kcal/(kg C). c) Since the latent heat of saturated water vapor used in the heater is 513.7 kcal/kg, find the required amount of heater water vapor. Condensate leaves the heater as a saturated liquid. Enthalpy-concentration values x, y (the weight fraction) 0 0.3 h (kcal/kg) 48 44 H(kcal/kg) 132 131.1 130.2 129.3 129 0.6 0.9 40 36 34.7 1 balance values at 1 atm 0 0.013 0.075 0.161 0.141 0.281 0.211 0.288 0.37 0.393 0.496 0.591 1 0.459 0.555 0.659 0.773 0.678 0.757 0.831 0.897 y 0.031 1