Using AntiSolvent For Crystallization

Recrystallization is a technique used to purify solid compounds by dissolving them in a hot solvent and allowing the solution to cool. During this process, the compound forms pure crystals as the solvent cools, while impurities are excluded. The crystals are then collected, washed, and dried, resulting in a purified solid product. Recrystallization is an essential method for achieving high levels of purity in solid compounds.

Opløselighedskurver er almindeligt anvendte for at illustrere forholdet mellem opløselighed, temperatur og type af opløsningsmiddel. Ved at plotte temperatur vs. opløselighed, kan forskerne skabe de nødvendige rammer for at udvikle den ønskede krystalliseringsproces. Når et passende opløsningsmiddel er valgt, bliver opløselighedskurven et vigtigt værktøj til udvikling af en effektiv krystalliseringsproces.

Forskere og ingeniører får kontrol over krystalliseringsprocesser ved omhyggelig justering af niveauet af overmætning under processen. Overmætning er den drivende kraft ved kimdannelse i krystallisering og vækst og vil i sidste ende bestemme den endelige fordeling af krystalstørrelser.

In-process sondebaserede teknologier anvendes til at spore partikelstørrelse og formændringer ved fuld koncentration uden at fortynding eller ekstraktion er nødvendig. Ved at spore hastigheden og graden af ​​ændring i partikler og krystaller i realtid, kan de korrekte procesparametre til ydeevne ved krystallisering optimeres.

Seeding is one of the most critical steps in optimizing crystallization behavior. When designing a seeding strategy, parameters such as seed size, seed loading (mass), and seed addition temperature must be considered. These parameters are generally optimized based on process kinetics and the desired final particle properties, and must remain consistent during scale-up and technology transfer.

Liquid-Liquid phase separation, or oiling out, is an often difficult to detect particle mechanism that can occur during crystallization processes.

In an antisolvent crystallization, the solvent addition rate, addition location and mixing impact local supersaturation in a vessel or pipeline. Scientists and engineers modify crystal size and count by adjusting antisolvent addition protocol and the level of supersaturation.

Crystallization kinetics are characterized in terms of two dominant processes, nucleation kinetics and growth kinetics, occurring during crystallization from solution. Nucleation kinetics describe the rate of formation of a stable nuclei. Growth kinetics define the rate at which a stable nuclei grows to a macroscopic crystal. Advanced techniques offer temperature control to modify supersaturation and crystal size and shape.

Changing the scale or mixing conditions in a crystallizer can directly impact the kinetics of the crystallization process and the final crystal size. Heat and mass transfer effects are important to consider for cooling and antisolvent systems respectively, where temperature or concentration gradients can produce inhomogeneity in the prevailing level of supersaturation.

Crystal polymorphism describes the ability of one chemical compound to crystallize in multiple unit cell configurations, which often show different physical properties.

Protein crystallization is the act and method of creating structured, ordered lattices for often-complex macromolecules.

Lactose crystallization is an industrial practice to separate lactose from whey solutions via controlled crystallization.

A well-designed batch crystallization process is one that can be scaled successfully to production scale - giving the desired crystal size distribution, yield, form and purity. Batch crystallization optimization requires maintaining adequate control of the crystallizer temperature (or solvent composition).

Continuous crystallization is made possible by advances in process modeling and crystallizer design, which leverage the ability to control crystal size distribution in real time by directly monitoring the crystal population.

The MSMPR (Mixed Suspension Mixed Product Removal) crystallizer is a type of crystallizer used in industrial processes to produce high-purity crystals.