PROCESS AND APPARATUS FOR SEPARATION AND PURIFICATION OF CONJUGATED DIENE

A method of separating and purifying conjugated diene, including the steps of: obtaining a first bottom product by distilling a hydrocarbon mixture including 80% or more conjugated diene under an environment in the presence of a polymerization inhibitor in a lower boiling distillation column 14; obtaining a second bottom product and distillation portion by distilling said first bottom product under an environment in the presence of a polymerization inhibitor in a higher boiling distillation column 16; measuring concentration of a polymerization inhibitor included in said first bottom product and second bottom product respectively; controlling the concentration of the polymerization inhibitor included in said first bottom product and/or second bottom product by changing a supply amount of the polymerization inhibitor to said lower boiling distillation column 14 and/or higher boiling distillation column 16 in accordance with said measured concentration of the polymerization inhibitor included in said first bottom product and second bottom product respectively; measuring concentration of a polymerization inhibitor included in said distillation portion; and controlling the concentration of the polymerization inhibitor included in said distillation portion by changing a supplying stage of the polymerization inhibitor to said higher boiling distillation column 16 in accordance with said measured concentration of the polymerization inhibitor included in distillation portion. The method allows the suppression of generation of a popcorn polymer in the apparatus with good efficiency and stability.