METTLER TOLEDO is pleased to be presenting and exhibiting at the 1st Asian Crystallization Technology Symposium (ACTS-2012).
Presentation - Changing the Paradigm for Inline Nucleation and Crystal Growth Measurements
The use of Process Analytical Technology (PAT) tools to track real-time crystal size distribution has been established in the chemical and pharmaceutical industries. By measuring dynamic changes to crystals through growth, breakage, dissolution, or agglomeration mechanisms, inline tools such as FBRM® (Focused Beam Reflectance Measurement) and PVM® (Particle Vision and Measurement) provide detailed information that enables improvements in yield, purity, product consistency, and downstream throughput. Yet up to now, interpreting measurement artifacts has been a challenge.
The New Generation of FBRM® technology makes interpreting crystallization mechanisms even easier. By improving Chord Length accuracy, eliminating convoluting surface feature measurements, correcting for crystal fouling, and increasing the dynamic range, the next generation FBRM® provides more intuitive information while tracking critical product parameters with both higher precision and improved accuracy. This paper aims to discuss how new improvements in design, coupled with the use of the latest electronic and software technology, have enabled the next generation FBRM® to surpass its capable predecessors. Specific case studies will demonstrate how new innovations in FBRM® technology offer specific enhancements enabling scientists to understand and optimize crystallization more effectively. These examples include:
- Improved correlation with downstream product quality and process efficiency (filtration)
- Better resolution to crystallization and nucleation and growth kinetics
- Enhanced sensitivity to secondary nucleation and polymorph detection
- Improved accuracy by detecting and correcting for particles which stick to the probe window
Amalgamated Sugar Experiences with Inline Particle Size, Shape and Count Characterization: Real-time Crystal Nucleation and Growth Rates in and Industrial Semi-batch Crystallizer
The process of boiling sugar cane syrup to produce refined sugar crystals was first performed in India around 300 AD. Although sugar manufacturing has evolved dramatically since that time, the basic methods of sugar crystallization in vacuum pans have been unchanged for almost two hundred years. Still, even in one of the oldest industrial processes, there is room for improving process efficiency and maximizing production capacity. As with many batch and semi-batch crystallization processes, the formation of large quantities of fine crystals – through nucleation events – can significantly reduce downstream separation efficiency and overall throughput.
A METTLER TOLEDO FBRM® crystallization monitor (model D600) was installed directly in a White Pan semi-batch crystallizer at The Amalgamated Sugar Company (Twin Falls, ID, USA). Data were collected from 35 consecutive batches to monitor normal batch operation, to characterize batch-to-batch variability and to provide direct real-time analysis of how modifications to the batch recipe would impact the final crystal product.
Inline monitoring of the crystal population with FBRM® permitted the calculation of relative nucleation and growth rates that were used to assess batch to batch variability and were able to pinpoint periods of intense secondary nucleation. The identification of factors and disturbances that promoted nucleation enabled adjustments to the operation of the sugar crystallizer that minimized nucleation events in subsequent batches - as confirmed with the inline particle size measurement.
This White Paper demonstrates the methodology chemists use to optimize critical crystallization parameters such as temperature profile, addition rates and seeding to improve purity, filtration rates and batch repeatability.