Modularized Melt Crystallizer Process System

BACKGROUND

Pasadena, TX

The client needed to separate two isomers of diphenylethane–compounds that have the same molecular formula and very close boiling points but with slightly different structures.

CHALLENGE

Separating isomers with close boiling points presents a significant challenge as traditional distillation relies on boiling point differences to achieve separation. When these differences are minimal, distillation becomes inefficient or impractical.

SOLUTION

We evaluated the physical properties of the isomers and discovered a significant difference in their melting points. By cooling the mixture, one isomer would freeze and form crystals while the other remained a liquid and passed through. This separation method, known as melt crystallization, leverages the difference in freezing points (or melting points) to isolate the compounds. Distillation was not a practical solution, so melt crystallization was used instead.

RESULTS

Few companies manufacture melt crystallizers. While Koch Modular does not produce melt crystallizers, we partnered with a French company that does. Koch Modular provided the necessary supporting equipment for the project and delivered the complete solution to the client as a modular system, which has been operating successfully for over 20 years.