A total condenser for a distillation column is designed to condense all the tetrahydrofuran (THF) vapour exiting from the top column. The distillation column is used to separate a binary feed which consists of 50 wt.% THF and the rest 1-butanol. The feed enters the distillation column at 2000 kg/h. The effective condensation temperature for benzene is 66 C while the enthalpy of condensation is 29.6 kJ/mol. The condenser is expected to operate 12 hours daily. The heat capacity of the cooling water is 4.2 kJ/(kg.K). The overall heat-transfer coefficient may be taken as 0.534 kJ/(ms K). Molecular weight for THF can be taken as 72.11 g/mol. The cost of the cooling water at 20C is RM 1.50 per 50 m of volume and its density is 1.0 g/ml. The cost for the installed total condenser is RM 370 per m of heat-transfer area, and annual fixed charges including maintenance are 12.5% of the initial investment. (a) Determine the cost of cooling water in RM/kg. (2 marks) (b) Determine the heat in kJ/s that must be removed from the condenser. (4 marks) (c) Estimate the optimum temperature of cooling water leaving the condenser. (8 marks) (d) Determine the cooling water flow rate in kg/h and the heat transfer area in m for the optimum economic conditions determined in Q4(c). (6 marks) (e) Calculate the total annual variable cost in RM/year. (3 marks) (f) Give ONE (1) assumption made in the calculation for Q4. (2 marks)