Process Control Using Advanced Particle Analyzing Systems: Applications from Crystallization to Fermentation Processes

Abstract

An advanced particle analyzing system (APAS) was applied to track information on size, shape, and number of particles in suspension. The measurement principle is based on laser reflection. In comparison to conventional laser reflection methods like focused beam reflectance measurement which determines chord/arc lengths, APAS sensors allow to measure exposed particle surface areas (EPSA). Furthermore, APAS is capable to collect information on the particle shape by evaluation of the reflection raw signals. The technique was tested for two different application fields to monitor crystallization and fermentation processes in case studies with L-glutamic acid as well as with cancer cells and Escherichia coli bacteria. It could be demonstrated that improvements in design and technology, coupled with the use of new software, permit to track changes of particle shape, size, and density as well as to analyze features such as cell vitality by the obscuration factor, cell proliferation, and growth effects by the distance of particles. The case studies proved that the innovations of the APAS, i.e., EPSA and particle shape, offer specific enhancement, enabling users to understand, monitor, and optimize products and processes more effectively.

Advanced methods for in situ chemical and bio processes analysis based on the Laser back-reflectance measurement technology

“…Hình 6 minh họa mức độ phản xạ quang học của tế bào sống và chết. Kết quả nghiên cứu các tế bào sống cho thấy tín hiệu phản xạ của chúng có cường độ cao hơn so với các tế bào chết tương ứng [10,16]. Tỷ lệ sống và chết của các tế bào có thể được đánh giá bằng cách phân tích các giá trị OBF (obscuration factor, hàm tích hợp trong thuật toán Sequip) mà giá trị trung bình phản ánh hành vi phản xạ Laser trên bề mặt của các tế bào.…”

Novel semibatch supersaturation control approach for the cooling crystallization of heat‐sensitive materials

“…It is well known that concentration feedback control (CFC) is a simple yet very effective control strategy for the design and control of crystallization processes . The main principle behind CFC is the simple idea that in the metastable zone of the concentration‐temperature phase diagram predominantly crystal growth happens, with negligible nucleation rate.…”

Computing Crystal Size Distribution by Focused‐Beam Reflectance Measurement when Aspect Ratio Varies

“…Therefore, it is essential for CSD to be obtained online in manufacturing processes. Process analytical technologies (PATs) such as optical reflectance measurement [11][12][13], online image processing [14][15][16][17], focused-beam reflectance measurement (FBRM) [18][19][20][21], etc. are increasingly used for in-line measurement of CSD.…”