Benzene freed from coal gas in a scrubber is recovered by passing the benzene-wash oil solution through a tower in contact with steam.
The entering liquid stream contains 7 mol % benzene and the steam is benzene free. It is desired to recover 85% of the benzene by using a steam rate 1.4 times the minimum steam rate. A wash-oil (liquid solvent-benzene free) flow rate of 6.94 mol/s will be used.
Determine the required moles of steam if
a. a countercurrent tower is used;
b. a cocurrent tower is used.
Equilibrium data for the benzene-wash oil-steam system are as follows:-
