Characterization of crystallization processes with video imaging
Abstract
Crystallization processes are extensively utilized for the purification and separation of a
variety of final and intermediate products. Despite its widespread use, in the fine
chemicals, pharmaceutical and food industries, crystallization still has many unknowns
which can affect the purity, quality and quantity of the crystals produced. As a result,
monitoring crystallization processes in order to better understand the underlying science
is of utmost importance. To this end, various tools have been developed. They are,
however, not without their flaws. The work in this PhD project aims to develop and
demonstrate the viability of process video imaging as a reliable methodology for the
monitoring, recording and analysis of crystallization processes which either minimizes
or removes these flaws altogether.
Experimental investigations to test the robustness of the process video imaging
focused on three commonly found crystallization processes: melt crystallization in the
form of clathrate hydrates, anti-solvent crystallization and cooling crystallization. The
results from these investigations were compared to previously reported findings of
similar systems in order to examine the degree of accuracy of the process video imaging
tool. The significant findings from this work are that the process video imaging can be
successfully implemented into melt, anti-solvent and cooling crystallization systems
with relative ease. This allowed key crystallization parameters to be determined;
including but not limited to: solubility, metastable zone width, crystallization rate and
growth kinetics.