The dilute acetic acid can not
be purified by conventional
distillation methods. Hence,
extractive distillation is
employed to distill dilute
acetic acid.
Dilute acetic acid is fed from
top to the extraction column and
the solvent ethyl acetate is fed
to the column from bottom.
Solvent acid coming from top of
the column is sent to a
distillation column where pure
acetic acid is obtained as a
bottom product. The top product
of the column after condensation
is sent to a decanter. Top over
flow from the decanter is partly
sent to the column as reflux and
partly to the extraction column
through an intermediate tank.
The reffinate i.e. bottom
product of the extraction column
and the bottom over floe of
decanter- I are mixed and sent
to a recovery column to recover
the solvent i.e. ethyl acetate.
The top product of the recovery
column is sent to a decanter -
II after condensation. The top
over flow from the decanter is
partly given as reflux and
partly withdrawn as recovered
solvent which is turn is sent to
extraction column through
intermediate tank. The bottom of
the recovery column is sent to
drain along with the bottom of
the decanter - II.
