A distillation column separates 10,000 kg/hr of a mixture containing equal mass of Benzene B and Toluene T. The product D recovered from the condenser at the top of the column contains 95% Benzene, and the heavy product H from the column contains 96% Toluene. The vapor V entering the condenser from the top of the column is 8000 kg/hr. A portion of the product from the condenser is returned to the column as reflux R, and the rest is withdrawn as the final product D. V, R, and D are identical in composition. Find: (a) The flowrates R, D, and H. [3 marks] (b) The optimum reflux flowrate R if the profit P was found to follow the function: P($) = 200 x R + 15 x R x D. [3 marks] (c) The surface area A available for heat exchange in the condenser. [2 marks] (d) The fail mode of the three control valves shown in the diagram. [2 marks] COOLANT Vapor V=8000 kg/hr 0.95 kg B/kg 0.05 kg T/kg CONDENSER Q= 1 MW h= 70 W/m-C ATLM= 40C V=8000 kg/hr 0.95 kg B/kg 0.05 kg T/kg REFLUX DRUM REFLUX Reflux R 0.95 kg B/kg 0.05 kg T/kg Distillate D 0.95 kg B/kg 0.05 kg T/kg Feed F = 10,000 kg/hr 0.5 kg B/kg 0.5 kg T/kg DISTILLATION COLUMN REBOILER Heavy Product H 0.04 kg B/kg 0.96 kg T/kg