Closed operation of multivessel batch distillation: Experimental verification

The multivessel batch distillation column, as well as conventional batch di stillation, can be operated in a closed (total reflux) mode where the produ cts are collected in vessels along the column. A previously proposed and si mulated feedback control strategy for the closed operation is to indirectly adjust the vessel holdups by using the reflux flow out of the vessel to co ntrol the temperature at some location in the column section below. The fea sibility of this scheme is demonstrated here experimentally on a laboratory -scale multivessel column. The experimental column consists of a reboiler, two intermediate vessels, and an accumulator, where a mixture of methanol-e thanol-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 multivessel colu mn.