How is crystallization different from evaporation
Answers
Answer:
Crystallization is a process by which a liquid transitions to the solid phase. The molecules of the liquid, when subjected to appropriate physical conditions (temperature, pressure, residence time, agitation, etc.), arrange themselves in highly organized, tightly bonded structures. These are called crystals, and the pattern of arrangement, or the crystal lattice, depends on the characteristics of the material involved.
Aside from reactive crystallization, which involves chemical processes, crystallization of a given substance can be achieved through evaporation or cooling. In both cases, the process involves separating out the compound involved from a solution. In evaporation, the solvent is removed by heating the solution until the solvent is evaporated; in cooling crystallization, the solution is cooled until the solubility of the compound involved is reduced, causing it to separate from the solvent through crystallization. The choice of one process over another depends on the specific behavior of the compound involved and product characteristics required.
Evaporative Crystallization
In evaporative crystallization, the solution containing the solvent and the soluble component to be crystallized is heated until the solvent evaporates. The evaporation of the solvent causes the molecules of the soluble compound to separate out as crystals due to the higher concentration exceeding the chemical compound’s solubility. This is the most popular method of crystallization, especially when working with common compounds such as inorganic salts and sucrose. Steam is typically employed as the heat source, and forced circulation is usually integrated into such crystallization units. Since evaporation is the key process involved, the transition takes place at practically isothermal conditions.
Thermal Kinetics provides evaporative crystallizers for both small and large-scale applications. Our Draft Tube Crystallizer uses continuous vacuum evaporation, in which a draft of the mixture is pushed up through a supersaturation zone at the liquid surface as vapor is released to cause crystallization. Mild heating of the walls prevents any crystal formation on the tubes, and moderate control over crystal size can be achieved with this model.
Ex.: Water is converted into the vapour form easily.
Crystallization: Is the process in which the heat is provided to liquid solid mixture and liquid is evaporate then solid is converted into the crystal form(the liquid should be in low amount.)
Evaporation: Generally occurs on the surface area of the liquid.
Crystallization: It is occurs through out the mixture.
The evaporation occurs only on liquid (generally).
The crystallization occurs on the mixture of solid and liquid.
Evaporation is used to distillation and separation of mixed liquid/solid.
Crystallization is used to formation of crystal.