Jiangsu Shuoyun Petrochemical Equipment Co., Ltd.

Products

Melt crystallization technology and equipment

Principle of Melt Crystallization:
The driving force of melt crystallization is the supersaturation or supercooling degree of a certain component in the melt. The whole process consists of three stages: crystallization, sweating and melting.

Crystallization: As the temperature of the melt gradually decreases, a component reaches a supersaturated state in the melt and starts nucleation, then gradually grows into crystals.
During crystal growth, mother liquor impurities are inevitably trapped inside crude crystals. Therefore, crude crystals need to be purified via the sweating process.
The purified crystals are fully melted by heating.

Advantages of Melt Crystallization Technology:


High Product Purity Purity can exceed 99.99% (chromatographic grade)	Low Operation Requirement Generally operated under atmospheric pressure and low temperature; simple and safe operation	Solvent-free No additional solvent required in crystallization, avoiding impurity increase and environmental pollution


Lower Capital Investment No stringent requirements for equipment, reducing cost and equipment investment	Energy-saving & Eco-friendly Energy consumption of melt crystallization is generally only 10%-30% of that of distillation	Suitable for Special Systems Capable of separating isomers, chiral substances and other components extremely difficult to separate by distillation

Static Melt Crystallization Process:

Melt crystallization is preferred when meeting some of the following conditions:


● Substances prone to thermal decomposition ● Severe operational issues caused by substance polymerization ● Very close boiling points leading to high distillation energy consumption ● High theoretical plate number required for distillation	● Substituted benzenes, carboxylic acids, polycyclic aromatic compounds ● Phenylalkanes, phenyl ketones, diamines ● Dinitriles, diisocyanates


● Over 70% of substances have freezing points between 20–200℃ with low utility consumption	● Product purity requirement >99% ● Crystals meet food grade, polymer grade and electronic grade requirements

Typical Applications of Melt Crystallization:


Petrochemical Industry Durene, Maleic anhydride, p-Xylene, m-Xylene	Polymer Monomers Bisphenol A, Acrylic acid, Caprolactam, Dimethyl terephthalate, Hexamethylenediamine


Electronic Chemicals Ethylene carbonate, Dimethyl carbonate, Vinylene carbonate, Hydrogen peroxide, Phosphoric acid	Biosynthetic Materials Dimethyl succinate, Lactide, Pentanediamine, Long-chain dicarboxylic acids