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, and of organic systems such as latexes, 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.

Clients of Crystallization Consulting include Eastman Kodak, Xerox, Johnson & Johnson, Dow Chemical, Cabot, Southern Clay Products, Sachem, TempTime, Akzo-Nobel, and others.

How You Will Benefit from This Course:

 Understand the principles that control crystal size in precipitations.
 Understand and control the size and size distribuiton of nanoparticles and larger particles.
 Learn advanced principles to solve precipitation problems in batch and continuous processes.
 Quantitatively relate the crystal size to the precipitation variables.
 Learn to minimize the number of experiments  in precipitation R&D and product development.
 Learn to predict process limitations and breakdowns.
 Control competitive heterogeneous and homogeneous nucleation in precipitations.
 Learn a quantitative and self-consistent crystallization model for batch and continuous precipitations.

Who Should Attend:

Chemists, chemical engineers, and other scientists who need to control precipitation processes for size and size distribution will benefit from the material. The information is essential for those who are involved in crystallization R&D, quality control, design, development, production processes, pilot plant operations, and manufacturing.  Basic knowledge of physical chemistry,  chemical engineering, some knowledge of calculus and of process fundamentals is helpful.

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Precision Control of Crystallization Processes

Topics Covered:

Controlled Batch Precipitations 

Review of classical crystallization models 

Principles of crystallization model based on balanced nucleation and growth (BNG)
   General quantitative model
   Nucleation rate, crystal number
   Size distribution
   Nanoparticles
 

Nucleation under diffusion controlled growth conditions 

Quantitative effect of basic reaction parameters during nucleation and experimental examples
   Molar/mass addition rate
   Solubility
   Temperature
   Ostwald ripening agent
   Growth restrainers

Nucleation under kinetically controlled growth conditions 

Heterogeneous nucleation and renucleation in batch processes 

Controlled Precipitations in the Continuous Stirred Tank Reactor (CSTR, MSMPR)

The Randolph – Larsen Model 

The Balanced Nucleation/Growth Model 

Controlled crystal growth in the CSTR crystallizer

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Instructor

Dr. Ingo H. Leubner has over twenty-five years experience in the precision precipitation of crystals for product applications. In the imaging industry he was responsible for the precision precipitation of silver halide particles for commercial products. He consulted on the precipitation of dye particles, which have potential use as pigments. He is founder and senior scientist for Crystallization Consulting, a company specializing in consulting, modeling and teaching of advanced models for controlled high-precision precipitations. He consulted among others with pharmaceutical, imaging, and inorganic, and organic industrial companies. He taught courses at industry, academic institutions, and at conferences. He is continuing to expand the BNG model. Dr. Leubner received a Ph.D. in Physical Chemistry from the Technical University in Munich (TUM) on the relationship between the molecular structure and color of dyes. He continued his studies with a post-doctoral fellowship at TUM. At Texas Christian University, 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 product development. He was team-leader for 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 crystal nucleation. He has given presentations and seminars at national and international conferences, major universities and industries. His publications, presentations, and seminars resulted in national and international recognition. He received numerous awards and honors, including the Lieven-Gevaert Medal for outstanding 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 Professional Consultants Network, Torrey Pines Research, and High-Technology of Rochester.
 

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(C)  2006   Particles Conference