►Distillation separates chemicals by the difference in how easily they vaporize. The two major types of classical distillation include continuous distillation and batch distillation. Continuous distillation, as the name says, continuously takes a feed and separates it into two or more products. Batch distillation takes on lot (or batch) at a time of feed and splits it into products by selectively removing the more volatile fractions over time.

►Other ways to categorize distillation are by the equipment type (trays, packing), process configuration (distillation, absorption, stripping, azeotropic, extractive, complex), or process type (refining, petrochemical, chemical, gas treating).

►Many industries use distillation for critical separations in making useful products. These industries include petroleum refining, beverages, chemical processing, petrochemicals, and natural gas processing.