On‐line monitoring of chord distributions in liquid–liquid dispersions and suspension polymerizations by using the focused beam reflectance measurement technique

Abstract

The on-line monitoring of the droplet/particle size distributions is very important to ensure the quality and applicability of various products in heterogeneous systems. For this reason, the main objective of the present work was to study the usage of the focused beam reflectance measurement (FBRM) technique for monitoring of liquid-liquid dispersions (styrene dispersion in aqueous solutions) and suspension polymerization of styrene. To do better understand the FBRM technique in these systems, the effects of surfactant concentrations, agitation speed and ambient light were evaluated during the in-line monitoring of average chord lengths and chord-length distributions (CLD) at different operation conditions in batch experiments. In addition, a preliminary investigation of the optimal probe position was conducted in the polymerization experiments. It is shown that the FBRM technique is sensitive to variations of particle sizes in the characteristic ranges of particle diameters of typical styrene suspension polymerizations, being useful for monitoring and also control applications that require the on-line characterization of CLD in real time in liquid-liquid dispersions and polymerization systems. POLYM. ENG. SCI., 56:309-318, 2016.

Optimization of cooling strategy and seeding by FBRM analysis of batch crystallization

“…Theoretically, the total counts should not change if there is no nucleation. However, attrition and the change of the crystal shape is possible to increase the FBRM total counts [25][26][27]. Therefore, a criterion should be set to judge whether nucleation took place.…”

New dynamical observer for a batch crystallization process based on solute concentration

“…FBRM ® is commonly employed in pharmaceutical industries to detect online some process deviations. Note however that its use for online estimation of the CSD remains challenging [24,27].…”

Effective sapphire repellency treatment to reduce fouling of a focused beam reflectance measurement (FBRM) probe in bituminous systems

“…F ocused beam reflectance measurement (FBRM) is a measurement technique that allows for in-situ dynamic measurements of particle or drop sizes in a process. The FBRM probe is used extensively in crystallization processes and a number of processes with a solid dispersed phase, [1][2][3][4][5][6][7] as well as in the study of liquid/liquid dispersions [7][8][9][10][11][12] and more recently it has been applied to crude oil systems. [13][14][15][16][17][18] The FBRM probe directs a laser beam through a sapphire window into the fluid and collects backscattered light.…”