Distillation column is the main equipment for distillation operation. The column is cylindrical, A tray or packing for gas-liquid mass transfer is provided in the column. In a simple distillation column, only one raw material is introduced into the column, and product is extracted from the top and bottom of the column.
In actual production, several materials with different compositions should be separated. If the materials are mixed and separated, the energy consumption is much higher. Therefore, a plurality of feeding ports can be arranged at the proper position of the column body, and each material is added into the column. We call it composite column with Multi feeding and multiple discharging
In the distillation column, the temperature of gas-liquid increases gradually from top to bottom, and the column top with lowest temperature; the column bottom with highest temperature. If the temperature difference between the column bottom and the column top is large, and the middle reboiler can be set up in the distillation section to reduce the operating cost.