Alcohol Distillation and the Concept of Purity

Alcohol distillation and the concept of purity

Alcohol distillation has long been used as a key method of producing potable alcoholic beverages and industrial fuels.

Distillation works by boiling away less volatile components from a mixture, collecting them at the top of a column. Alcohol has the advantage of having a much lower boiling point than water for easier distillation.

As complete separation requires that each component have zero partial pressure, this cannot be accomplished using distillation alone and further chemical separation will likely be required for ultra-pure products.

Distilling ethanol involves many steps, with one of the key ones being eliminating acetaldehyde (CH3CHO). This toxic byproduct of fermentation has a boiling point of 20.8@C and often causes hangovers resembling metallic green apples.

Master distillers possess the unique talent of knowing when and how to “cut” their still’s outflow of heads and hearts, so as to separate out those hearts which contain more ethanol from those which contain low boiling point compounds (known as faints ). This cuts energy costs while simultaneously maintaining high concentrations of ethanol.

Any distillation apparatus is susceptible to rapidly fluctuating internal pressure that could rupture its connections. To combat this risk, it is common practice to leave some route open for airflow so as to allow atmospheric pressure equalize with internal pressure in the apparatus. In addition, installing sight gauges for water level, pressure and temperature will enable operators to quickly identify problems within their system.