Closed Operation of Multivessel Batch Distillation: Experimental Verification

The multi®essel batch distillation column, as well as con®entional batch distillation, ( ) can be operated in a closed total reflux mode where the products are collected in ®essels along the column. A pre®iously proposed and simulated feedback control strategy for the closed operation is to indirectly adjust the ®essel holdups by using the reflux flow out of the ®essel to control the termperature at some location in the column section below. The feasibility of this scheme is demonstrated here experimentally on a laboratory-scale multi®essel column. The experimental column consists of a reboiler, two intermediate ®essels, and an accumulator, where a mixture of methanol ] ethanol ] propanol ] butanol is separated into almost pure components. The first published experimental work on the closed operation of batch distillation is presented, as well as its results on the operation of a multi®essel column.