Precision Control of Crystallization Processes



Synopsis:

This course offers new concepts and quantitative models which are vital to those who need precision control of crystal size in products.  The crystal size is a function of both crystal nucleation and growth.  Control of nucleation is the most challenging factor.  Classical nucleation theories  do not give precise guidance to control crystal nucleation.  Solutions to specific problems are generally obtained by trial and error. 

We have developed new models and equations that relate the  crystal number and size distribution (nucleation) to experimentally controlled reaction variables.  In the models, the crystal number is quantitatively related to reactant addition rate, crystal solubility, temperature, and solvent and  crystal properties. It also models the effect of other factors like crystal ripening agents and crystal growth restrainers.  For the first time, equations for both controlled batch and continuous precipitations were developed using the same model.  Unexpected predictions were experimentally confirmed. 

These new concepts can be applied to the precipitation of inorganic materials such as silver halides in the photographic industry, carbonates in paper manufacturing, and of organic systems such as dyes and pigments.  Other applications are in pharmaceuticals, catalysis, imaging systems,  separations, and surface modifications.  Because this work is at the cutting edge of crystallization science and technology, this information is not yet available from textbooks and academic institutions.  Thus, the course provides a unique opportunity to learn up to date principles for precision controlled precipitations.

How You Will Benefit from This Course:

 Control of crystal size in precipitations
 Control of size and size distribution from nanoparticles to larger particles
 Batch and continuous precipitations, based on one quantitative and self-consistent crystallization model
 Solve precipitation problems in batch and continuous processes
 Learn the five controllable precipitation variables to control crystal size
 Minimize experiments in R&D and product development, shorten transition to production
 Control process limitations and breakdowns
 Control competitive heterogeneous and homogeneous nucleation in precipitations

Particle-based products and devices rely on the availability of precision-sized particles and on reliable sources of such particles. There is a need for better crystals for better products. Academic research and industrial processes profit from more efficient understanding of the crystallization processFor Nano to Macro sized crystals, this course offers vital practical and quantitative concepts for the precision preparation of such particles. This knowledge is essential to in-house preparations, as well as to knowledgeable interaction with suppliers. The course focuses on the control of crystal nucleation, the most important and challenging factor for controlled crystallizations. Crystal growth is a natural part of the course.

Five experimental control variables control the particle and crystal size. The course teaches the necessary information and methods for controlling crystal size through these variables.

This information applies to inorganic materials such as silver halides in the photographic industry and of clays, and to organic crystal systems like polyacetylenes and organophosphates. It is crucial for the control of nanoparticle precipitations.

The model concepts are applicable to systems such as pharmaceuticals, latexes, dyes, imaging pigments, toners, and of catalysts.

The presenter and coworkers have developed new and practical models and equations that relate the crystal number and size distribution (nucleation) to experimentally controllable reaction variables. This sets these models apart from all other models. The crystal number is quantitatively elated to reactant addition rate, crystal solubility, temperature, and solvent and crystal properties. Crystal ripening agents (macro-sizing) and crystal growth restrainers (nano-sizing) are other important reaction factors which are quantitatively modeled.  For continuous precipitations the reactor residence time is an additional modeled critical factor.

For the first time, equations for both controlled batch and continuous precipitations are available using the same fundamental model.  Unanticipated predictions of the models were experimentally confirmed, confirming the power of these for your crystallization needs.

The course provides a unique opportunity to learn up to date principles for precision controlled precipitations for precision size control, providing better crystals for better products.

Who Should Attend:

Anyone in crystal production: R&D, pilot plant operation, and manufacturing - Teachers and students of crystallization processes - Consumers of crystalline materials to knowledgably work with providers - Chemists, chemical engineers, other scientists, practitioners, and managers who need to control precipitation processes for precision crystal size and size distribution

Those who have profited from this course include:

Scientists, engineers, and managers fro Eastman Kodak, Xerox, Johnson & Johnson, Dow Chemical, Cabot, Southern Clay Products, Sachem, Supresta, TempTime, Akzo-Nobel, and Niacet Corporations, Consultants to the US and Belgium Governments, and Academics from the Canadian Research Council, Clarkson U, Illinois U. at Urbana, New Hampshire SU, Pennsylvania SU, Rochester Inst. Technol., U of Rochester, and Washington U.

Basic knowledge of chemical engineering and of process fundamentals is helpful.

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Precision Control of Crystallization Processes

Topics Covered:

Principles of Crystallization Based on the Balanced Nucleation and Growth (BNG) Model 

BNG Model of Nucleation Phase 

Nucleation Rate  

Size Distribution 

Crystal Number 

Nanoparticles 

Nucleation Under Diffusion and Kinetically Controlled Growth Conditions 

Quantitative Effect of Fundamental Reaction Variables
   Molar/mass addition rate

   Solubility

   Temperature

   Ostwald Ripening Agents (Macro Sizing)

   Growth Restrainers (Nano Sizing)

Nucleation under kinetically controlled growth conditions 

Heterogeneous nucleation and renucleation in batch processes 

The Continuous Stirred Tank Reactor (CSTR, MSMPR)

The Randolph – Larsen Model (Review) 

The Balanced Nucleation/Growth Model 

   Crystal Size Dependence on Residence Time

   Crystal Size Dependence on Crystal Solubility

   Controlled Crystal Growth in the CSTR Crystallizer

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Instructor

Dr. Ingo H. Leubner has many years of industrial hands-on experience in the precision precipitation of crystals for product applications. In the photographic imaging industry he was responsible for the precision precipitation of silver halide particles for commercial products. In this context he performed and supervised over fifteen hundred precipitations. He applied his information to the preipitation of dye particles, which have potential use as pigments. Dr. Leubner is founder and senior scientist for Crystallization Consulting, a company specializing in consulting, and modeling and teaching of advanced models for controlled high-precision precipitations. He is continuing to expand the balanced nucleation and growth (BNG) model, the fundamental model for controlled crystallization. He consulted with Akzo-Nobel, Dow Chemical Company, Cabot Corp, TempTime Corp, Transform Pharma, Xerox Corp, and other pharmaceutical, imaging, inorganic, and organic industrial companies. He taught courses at industry, academic institutions, and at national and international conferences. He was consultant to the Belgium and US Governments. Dr. Leubner received a Ph.D. in Physical Chemistry from the Technical University in Munich on the relationship between the molecular structure and color of dyes. He continued his studies with a post-doctoral fellowship at TU Munich. At Texas Christian University (TCU), Fort Worth, Texas, he held the position of R. Welch Fellow studying photochemistry of benzene and benzene derivatives. From there, he accepted a position as research scientist at Eastman Kodak Company, working in photographic and precipitation science, and in product development. As a team-leader he led the development of commercially successful products. He is an experienced author, lecturer, scientist, and technical project manager. His work on the precipitation of silver halides for the development of photographic films and papers led to new insights, theories, and models for the precision control of crystallization. His publications, presentations, and seminars resulted in national and international recognition. He received numerous awards and honors, including the Lieven-Gevaert Medal, the highest award for contributions to photographic science, and the Fellowship and Service Awards from the Society for Imaging Science and Technology. He is listed in American Men and Women in Science and in Who’s Who in Science and Engineering. He is a Fellow of Sigma Xi, and a member of the American Chemical Society, the Society for Imaging Science and Technology, the American Association for the Advancement of Science, the American Geographical Union, the Rochester Academy of Science, and the Rochester Professional Consultants Network.
 

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(C)  2007   Particles Conference