The distillation is a common operation seen in chemistry, industry and other fields, which is usually regarded as an essential separation process. The following part will specifically explain what distillation is and what equipment can be used.
What is Distillation?
The distillation is a type of thermodynamic separation technology. It can evaporate components with low boiling points by utilizing that the boiling point of each component in the mixed liquid or liquid-solid mixture is different, and then condense the material to separate the whole components. It is the combination of evaporation and condensation unit operations as well as a kind of liquid-liquid separation technology. It can be considered as a physical separation separation process rather than a chemical reaction.
Why do We Use Distillation?
The distillation can be used for liquid mixture and each component with different boiling points that vary greatly. Compared to other separation methods, such as extraction, filtration and crystallization, it has the advantage that no other solvents than system components are required, thus ensuring that no new impurities are introduced.
What is the Basic Principle of Distillation?
The basic principle of distillation is the differences in volatility between individual components. The liquid materials can be turned into gas phase when sufficient heat is applied. Then the liquid product can be condensed from the gas phase.
What Equipment is Used in Distillation?
The equipment used in distillation should satisfy both evaporation and condensation operations. The commonly used equipment is the short path distillation. The pressure difference between the boiling film and condensing surface is the driving force of the steam flow, and the minimum pressure will cause the flowing of steam. Under the 1mbar, the operation requires that there is the shortest distance between the boiling surface and condensing surface. The evaporator manufactured based on the principle is called the short-path distillation.
Evaporation VS. Distillation VS. Rectification
Evaporation is a unit operation process, while both distillation and rectification are the combination of evaporation and condensation unit operations. Rectification differs from distillation in that it requires reflux. When the reflux is involved in the distillation process, distillation turns into a simple rectification. Both distillation and rectification are used for purification. Distillation can be adopted to purify cleaner mixtures with simpler components, while rectification is adopted to purify complex mixtures with muti-components. The rectification equipment is complex and high energy consumption.