Simulation-Based Learning of Distillation Principles in Historical Context: From Da Vinci's Alembics to Modern Applications

摘要

One of the most difficult concepts in physical chemistry for grasp - and, because of its wide range of practical applications, one of the most important concepts - is that of relative volatility. Although grade-school students are familiar with the related concept of boiling, most require formal instruction to be able to distinguish it from evaporation. The concept of vapor pressure is taught in college-level general and physical chemistry, and thermodynamics, but is not well retained. Chemical engineering professors quickly realize the necessity of emphasizing, repeatedly, that when multi-component solutions begin to evaporate, the emerging vapors consist not only of the most volatile component, but in fact contain all of them, albeit in different proportions than those in which they prevailed in the liquid. This concept is crucial to understanding the physicochemical mechanisms exploited in air conditioning (as well as cooling via sweating and evaporation), refrigeration, power plant steam cycles, distillation of alcoholic beverages and petroleum fractions, and numerous other important processes.