1st Edition

Melt Crystallization Technology

By Tine Arkenbout-de Vroome Copyright 1995

    From the Author's Preface

    There is a growing demand for ultrapure organic compounds such as fine chemicals, pharmaceuticals, and basic materials for use in the polymer industry. . . . In quite a number of cases, it is difficult or impossible to manufacture ultrapure organics efficiently using conventional separation techniques such as distillation. Moreover, conventional techniques usually require large amounts of energy.
    To improve the purification efficiency of organics, special techniques based on crystallization from the melt have been developed. Melt crystallization meets industry's need for a highly selective separation process for organic compounds which operates at low enough temperatures to prevent thermal degradation. Melt crystallization processes have the added advantage that they are energy-efficient and ecologically sound.
    Melt crystallization techniques appear to be particularly promising for upgrading organic materials and are one of the few routes that appear to be feasible for purifying starter materials for high-tech polymers. The aim of this book is to provide basic information on melt crystallization technology. . . . This monograph consists of three parts: 1. basic principles, 2. process options, and 3. technical equipment and applicability.
    This new book is the first unified guide and reference to an important chemical process technology. It is comprehensive and organized for easy reference. More than 150 diagrammatic representations, flow charts and photographs illustrate equipment and processes. More than 40 tables provide useful reference data.

    The Author

    Dr. Arkenbout studied chemistry at the University of Utrecht, and joined TNO, the Netherlands Organization for Applied Scientific Research. He has specialized in research on new separation processes and has had thirty of his articles on this subject published. He recently retired from the position of manager of physical separation research, but has remained active in this field through affiliations with the Laboratory of Solid State Chemistry at the University of Nijmegen, the Laboratory for Process Equipment, Delft University of Technology, and TNO.

    Preface, Notation
    I. Basic Principles
    1. Prospects of Melt Crystallization
    General Introduction The Method of Melt Crystallization Energy Efficiency, Environmental Impact Process Options Some Alternative Techniques
    2. Basic Principles in Crystallization
    Introduction Crystal Structure, Morphology Crystal Growth, Mechanisms
    3. Thermodynamic Limits
    Solid-Liquid Equilibria Product Purity Recovery Prediction of Eutectic Compositions Prediction of Miscibility in the Solid Phase Methods to Improve Recovery Conclusions
    4. Kinetic Limits
    Incorporation of Impurities into Crystals Effective and Integral Distribution Coefficient Purification Efficiency in Dependence on Process Conditions Purity Attainable by One Single Crystallization Operation
    5. Further Purification
    Scope of Techniques Washing Sweating Recrystallization
    II. Process Options
    6. Layer Growth
    Normal Freezing Operation Principle Multistage Operation Continuous Layer Growth
    7. Suspension Growth
    Growth, Kinetics Proper Crystal Size Agglomeration, Breakage Approach to Technical Crystallizer Crystallizer Configuration Crystallizer Cascades
    8. Crystal-Melt Separation
    The Washing Operation Countercurrent Separation Columns Based on Gravity Transport The Kureha Continuous Crystal Purifier Wash-Columns Based on Forced Transport Two-Stage Crystal-Melt Separation Comparison between the Two Types of Wash-Columns
    9. On the Choice of the Process Option
    Crystal Layer Processes Suspension Growth Processes Flow Diagrams for Suspension Growth Comparison between Layer and Suspension Growth
    10. Melt Crystallization Feasibility
    Applicability Collection of Physical Data Orientating Tests Laboratory-Scale Experiments Pilot Plant Tests Technological Study

    III. Technical Equipment, Applicability


    11. Technical Equipment for Crystal Layer Growth
    Survey of Commercially Available Equipment Commercial Static Layer Growth Processes Commercial Dynamic Layer Growth Processes
    12. Technical Equipment for Suspension Growth
    Survey of Commercially Available Equipment Installations with Gravity Transport Columns Installations with Forced Transport Columns
    13. Technical Applicability
    Scope of Technique Para-Xylene Acetic Acid Acrylic Acid Cyclohexane para-Dichlorobenzene Maleic Anhydride Phenol Caprolactam Naphthalene para-Chloronitrobenzene 4,4-Diphenylmethanediisocyanate (MDI) Survey of Technical Applications
    14. Technical Implementation of Melt Crystallization
    Introduction Increase of Product Purity Increase of Recovery Replacement of Solution Crystallization by Melt Crystallization Recovery of Solvents
    15. Related Fields of Application
    Introduction Freeze Concentration Dry Fractionation of Fats and Fatty Acids Dewaxing of Oils Use of Wash-Columns Outside Melt Crystallization
    16. Status of Development, Future Outlook

    Biography

    Tine Arkenbout-de Vroome. Dr. Arkenbout studied chemistry at the University of Utrecht, and joined TNO, the Netherlands Organization for Applied Scientific Research. He has specialized in research on new separation processes and has had thirty of his articles on this subject published.