Question

A distillation column was designed to separate 424 kg/hr feed (25 oC) contain 40 weight% methanol and remaining water, to produce distillate (38 oC) of 170 kg/hr contains 97 weight% methanol and the residue (85 oC) contains 98 weight% water. Density of liquid = 1005 kg/m3. Cooling water enters at 25 oC and leaves at 35 oC. Column operates at 1 atm and average temperature at 80 oC. Heat capacity of methanol and water are: 2530 J/(kg.K), 4.2 kJ/(kg.K), respectively. Reflux ratio, RD = 5; Boiling point of 97 mol% methanol is 65 oC. Latent heat of methanol and water at 65 oC are: 1085 kJ/kg and 2500 kJ/kg, respectively. Take flooding
constant, Csbflood = 0.12 and σ = 20.

Find (i) actual area of stripping section.

(ii) the amount of heat removed from condenser.

Answer 1

Explanation:

distillation column was designed to separate 424 kg/hr feed (25 oC) contain 40 weight% methanol and remaining water, to produce distillate (38 oC) of 170 kg/hr contains 97 weight% methanol and the residue (85 oC) contains 98 weight% water. Density of liquid = 1005 kg/m3. Cooling water enters at 25 oC and leaves at 35 oC. Column operates at 1 atm and average temperature at 80 oC. Heat capacity of methanol and water are: 2530 J/(kg.K), 4.2 kJ/(kg.K), respectively. Reflux ratio, RD = 5; Boiling point of 97 mol% methanol is 65 oC. Latent heat of methanol and water at 65 oC are: 1085 kJ/kg and 2500 kJ/kg, respectively. Take flooding constant, Csbflood = 0.12 and σ = 20.