Crystallization

Crystallization is a natural occurring process but also a process abundantly used in the industry. Crystallization can occur from a solution, from the melt or via deposition of material from the gas phase (desublimation). Crystals distinguish themself from liquids, gases and amorphous substances by the long-range order of its building blocks that entail the crystals to be formed of well-defined faces, and give rise to a large number of properties of the solid. Crystallization is used at some stage in nearly all process industries as a method of production, purification or recovery of solid materials. Crystallization is practiced on all scales: from the isolation of the first milligrams of a newly synthesized substance in the research laboratory to isolating products on the mulit-million tonne scale in industry. The book describes the breadth of crystallization operations, from isolation from a reaction broth to purification and finally to tailoring product properties. In the first section of the book, the basic mechanisms - nucleation, growth, attrition and agglomeration are introduced. It ensures an understanding of supersaturation, the driving force of crystallization. Furthermore, the solubility of the substance and its dependences on process conditions and the various techniques of crystallization and their possibilities and limitations are discussed. Last but not least, the first part includes an intensive treatment of polymorphism . The second part builds on the basics, exploring how crystallization processes can be developed, either batch-wise or continuous, from solution or from the melt. A discussion of the purification during crystallization serves as a link between the two sections, where practical aspects and an insight using theoretical concepts are combined. Mixing and its influence on the crystallization as well as the mutual interference of down-stream processes with the crystallization are also treated. Finally, techniques to characterize the crop are discussed. The third part of the book is dedicated to accounts of actual developments and of carried-out crystallizations. Typical pitfalls and strategies to avoid these as well as the design of robust processes are presented.

Crystallization is a natural occurring process but also a process abundantly used in the industry. Crystallization can occur from a solution, from the melt or via deposition of material from the gas phase (desublimation). Crystals distinguish themself from liquids, gases and amorphous substances by the long-range order of its building blocks that entail the crystals to be formed of well-defined faces, and give rise to a large number of properties of the solid.Crystallization is used at some stage in nearly all process industries as a method of production, purification or recovery of solid materials. Crystallization is practiced on all scales: from the isolation of the first milligrams of a newly synthesized substance in the research laboratory to isolating products on the mulit-million tonne scale in industry. The book describes the breadth of crystallization operations, from isolation from a reaction broth to purification and finally to tailoring product properties.In the first section of the book, the basic mechanisms - nucleation, growth, attrition and agglomeration are introduced. It ensures an understanding of supersaturation, the driving force of crystallization. Furthermore, the solubility of the substance and its dependences on process conditions and the various techniques of crystallization and their possibilities and limitations are discussed. Last but not least, the first part includes an intensive treatment of polymorphism . The second part builds on the basics, exploring how crystallization processes can be developed, either batch-wise or continuous, from solution or from the melt. A discussion of the purification during crystallization serves as a link between the two sections, where practical aspects and an insight using theoretical concepts are combined. Mixing and its influence on thecrystallization as well as the mutual interference of down-stream processes with the crystallization are also treated. Finally, techniques to characterize the crop are discussed.The third part of the book is dedicated to accounts of actual developments and of carried-out crystallizations. Typical pitfalls and strategies to avoid these as well as the design of robust processes are presented.

CRYSTALLIZATION: INTRODUCTIONMECHANISMS OF CRYSTALLIZATIONCrystal LatticeNucleation of CrystalsGrowth and Growth Rate of CrystalsSOLUBILITY AND SOLUTION EQUILIBRIA IN CRYSTALLIZATIONPhase Equilibria and Phase Diagrams: General IssuesMelt Phase DiagramsSolution EquilibriaAGGLOMERATION DURING CRYSTALLIZATIONMechanisms and Kinetics of AgglomerationParameters Influencing AgglomerationAgglomeration during CrystallizationMechanical Properties of AgglomeratesPOLYMORPHISM OF CRYSTALLINE SYSTEMSIntroduction and DefinitionsOccurrence and Properties of Polymorphs and SolvatesThermodynamics of Polymorphs of Solid-State FormsThermodynamics of HydratesExperimental Techniques to Elucidate ThermodynamicsFormation of Various Polymorphs and Solid-State Forms-Polymorph ScreensSelection of Optimal Form for DevelopmentTHE INFLUENCE OF ADDITIVES AND IMPURITIES ON CRYSTALLIZATIONInfluence of Additives and Impurities on CrystallizationInfluence of Impurities: ModelingTailor-Made AdditivesModeling the Influence of SolventsPURIFICATION BY CRYSTALLIZATIONIntroductionMechanisms of Impurity Incorporation and PurificationCHARACTERIZATION OF CRYSTALLINE PRODUCTSIntroductionCharacterization of Intrinsic Properties of a SolidCharacterization of Particle Shape and SizePowder Flow PropertiesIn-Process CharacterizationBASICS OF INDUSTRIAL CRYSTALLIZATION FROM SOLUTIONGeneration of Supersaturation in a CrystallizerMass and Population Balance for Growth from SuspensionOperation of a Continuous Crystallizer: BasicsOperation of a Batch Crystallizer: BasicsDEVELOPMENT OF BATCH CRYSTALLIZATIONSSetting GoalsCrystallization of Organic MoietiesGeneration of Supersaturation in Batch CrystallizationsInitiation of Crystallization - Nucleation PhaseSeeded Batch CrystallizationsCrystallization PeriodScale-Up ConsiderationsManipulating Particle ShapeCONTINUOUS CRYSTALLIZATIONConcept and Design of Continuous CrystallizersVarious Continuous CrystallizersPeripherySpecial Features of the ProcessAdjustment of Suspension DensitiesPRECIPITATIONPrecipitation from Solution by Mixing Two StreamsSemi-Batch PrecipitationsModel of Mixing during PrecipitationPrecipitations Using Supercritical FluidsCrystal IssuesParticle Size as a Function of Operating ConditionsMIXING IN CRYSTALLIZATION PROCESSESMixing in Batch and Continuous Crystallization ProcessesBasic Mixing Tasks - Mixing Tasks in CrystallizationImpellers and Agitation SystemsPower Consumption of an Impeller System [2]BlendingSuspendingScale-Up of a Crystallization ProcessDOWNSTREAM PROCESSESTransfer of Suspension and Filter CakeSolid?Liquid SeparationDryingMELT CRYSTALLIZATIONCharacteristics of Melt CrystallizationProcesses of Melt CrystallizationPostcrystallization TreatmentsLaboratory TechniquesEXAMPLES OF REALIZED CONTINUOUS CRYSTALLIZATION PROCESSESChoosing the Drain Point in Process DesignExample Crop Crystallization for Organic CompoundsExample Crystallization of Table SaltResultsDESIGN EXAMPLES OF MELT CRYSTALLIZATIONConcepts of Melt CrystallizationOutlookINDEX