7. Batch distillation control

7.1 Specificity of batch distillation

Batch distillation is essentially a dynamic operation: a certain quantity of the product to be distilled (a batch) is introduced into the boiler and distilled to obtain different fractions, some of which may be high-purity products.

Unlike continuous distillation, in which the quantity and quality of the column contents are constant in steady-state operation, in batch distillation the quantity of product contained in the plant varies, as does the composition of the mixtures in the column base, on the trays (or in the packing) and at the condenser. What's more, the concentration profile in the column depends not only on heating and reflux rate, but also on liquid retention on the trays or in the packing and at the condenser....