How to Calculate Alcohol Distillation Yield

How to Calculate Alcohol Distillation Yield As temperature and pressure of liquid water and alcohol mixtures increases, their composition in vapor form will eventually reach equilibrium with that in liquid state, meaning their concentration in both phases equalizes. This condition is known as equilibrium; however due to alcohol’s greater volatility its concentration will often far outstrip that in liquid form.

Fractional distillation’s goal is to separate two components so that the final product contains an increased concentration of alcohol, and reduced water. This can be accomplished by passing alcohol-water mixture through several boiling and condensation stages, where product concentrates at each step while waste water (“feints”) condenses down to lower concentration.

Distillation conducted under atmospheric pressure tends to deplete its volatile properties over time due to a large temperature disparity between its source and destination (see Figure 1). To counteract this effect, distillation should be undertaken under vacuum conditions.

Vacuum distillation can also help lower energy requirements in the rectification and stripping sections of a column, making distillation possible at lower temperatures with increased product concentration.