The invention provides a heterogeneous
azeotropic distillation method for separating a 2-
pentanone, 4-
heptanone, water and
carbon dioxide mixture. The method comprises the following steps: feeding a 2-
pentanone, 4-
heptanone, water and
carbon dioxide raw material into a
left half side of a partitioned water
tower from an inlet of a
raw material to be separated, carrying out gas-liquid separation, discharging a
gas phase from a
gas phase outlet, feeding into a condenser, and separating a condensed liquid by using a gas-liquid-liquid separator so as to obtain a
carbon dioxide enriched
gas phase,a
ketone enriched phase and a water enriched phase, backflowing the
ketone enriched phase into the
left half side of the partitioned wall
tower, backflowing the water enriched phase into a right halfside of the partitioned wall
tower, extracting so as to obtain a carbon dioxide enriched gas, carrying out release, feeding the
ketone enriched phase into the tower kettle of a
distillation tower so as to obtain a 4-
heptanone product, condensing a gas phase discharged from the top of the
distillation tower by using a
distillation tower condenser, backflowing a part of the gas phase into the distillation tower, and collecting the other part as a 2-
pentanone product. The method has the advantages of being good in separation effect, and the investment expense and the mounting space can be greatlyreduced and saved.