Separation and purification apparatus and separation and purification method for unsaturated hydrocarbon

摘要

For example, an extractive distillation column 4 for separating and purifying butadiene, impurity concentration sensors 32 and 34 for detecting the concentration of specific impurities other than butadiene, a target concentration sensor for detecting the concentration of butadiene in the extractive distillation column, and the extractive distillation column 4. A separation and purification apparatus and a separation and purification method having a differential pressure sensor 30 for detecting a differential pressure between the tower top and the tower bottom. Based on the sensor, the concentration of a specific impurity after a predetermined time, the concentration of butadiene at the top of the tower, and the predicted value of the differential pressure between the top and the bottom of the tower are calculated. Based on the predicted value, the concentration prediction control means 60 Control. A raw material flow rate control valve 21a for controlling the amount of the raw material supplied to the extractive distillation column 4, a load detecting means 61 for detecting the load of the extractive distillation tower, and a load detected according to the detection value detected by the load detecting means 61 The raw material flow rate control valve 21a is controlled by the control means 62.