Q1. A distillation column is used to separate 400 kg h of a mixture containing 61 wts benzene (CaHi) in toluene (CHo), to give top product of 85 % mole benzene and 69% mole toluene waste (at bottom). 1. Calculate the mole flow rate, mole fraction and mole percentage of each stream in the (F, D & W) around the column? All results should be tabulated in the Table below. 2. Calculate the heat removed by condenser? Given the following data; The enthalpy of feed stream is- - 897.00 kJkgmol The enthalpy of distillate is The enthalpy of waste is The heat added by boiler is - s00.00 kkgmol - 3000.00 kkg mol 4500.00 Jh Given: The molar mass of Carbon is 12 The molar mass of Hydrogen is 1
Given data:
Mass flow rate of feed = 400 kg/h
Composition of feed is,
Benzene = 61 wt %
Toluene = 39 wt %
Composition of benzene in distillate = 85 mol %
Composition of toluene in waste stream = 69 mol %
The enthalpy of feed, distillate, waste, and reboiler is also given.
The composition of feed is given in weight percent.
Convert the wt % in to mol % as follows:
The total mass flow rate of feed = 400 kh/h
Composition of benzene inn feed = 0.61
Therefore, the mass flow rate of benzene becomes 244 kg/h (400×0.61).
The molar mass of benzene = 78 kg/kmol
Therefore, the molar flow rate of benzene becomes,
The composition of toluene in feed = 0.39
Therefore, the mass flow rate of benzene becomes 156 kg/h (400×0.39).
The molar mass of toluene = 92 kg/kmol
Therefore, the molar flow rate of toluene becomes,
Therefore, the total molar flow rate of feed becomes,
The mole fraction of each component in feed can be calculated by dividing its molar flow rate by total molar flow rate of feed.
Thus, the mole fraction of benzene and toluene in the feed becomes,
Apply overall balance
............ (1)
Where,
F represents the flow rate of feed.
D represents the molar flow rate of distillate stream.
W represents the molar flow rate of waste stream.
F = 4.823 kmol/h
Therefore, equation (1) becomes,
........... (2)
Step by step
Solved in 5 steps
