Page 224 - Academic Press Encyclopedia of Physical Science and Technology 3rd Chemical Engineering

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548 Distillation

FIGURE 1 Large distillation column for the production of styrene. [Courtesy of Shell Chemical Canada, Ltd.]

with alcoholic beverage production and the concentration I. DISTILLATION EQUIPMENT
of essential oils from natural products. Over the centuries
the technique spread widely, and the first book on the sub- A. General Description
ject, Das kleine Distillierbuch, by Brunswig, appeared in
1500. Originally, distillation was carried out in its sim- Distillation is the dominant separation process in the
plest form by heating a liquid mixture in a still pot and petroleum and chemical industries. It is carried out con-
condensing the vapor that boiled off. Condensation was tinuously more often than batchwise, in large, verti-
simply carried out by air cooling and later in water-cooled cal, hollow cylindrical columns (or towers). Figure 1
condensers. The origin of the word distillation is the Latin shows a large distillation column with its associated pip-
destillare, which means “dripping down,” and it is re- ing, heat exchangers, vessels, ladders, platforms, and
lated to the dripping of condensed vapor product from the support structures. Figure 2 shows a simple schematic
condenser. representation.