Question

At what pressure should a mixture of monochlobenzene and dichlorobenzene entry in a distillation column?

Answer 1

Benzene column contain monochlorobenzene and dichlorobenzene. This is fed to the chlorobenzene column, which is again a distillation column. This may contain 12 to 20 trays and is operated at a pressure ranging from 3–7 lb/in.2 abs. The temperature in the chlorobenzene column may be between 100 - 120°C. Monochlorobenzene is the overhead distillate product of a purity of 99%. Dichlorobenzene is the bottom residue product of a purity of 97%. The reactions involved in the process are as follows:

1. C6 H6 + Cl2 D &6H5Cl + HCl

2. C6H5Cl + Cl2 D &6H4Cl2 + HCl