Fluidisation and dispersion behaviour of small high density pellicular expanded bed adsorbents

Area of Science:

• Biochemical Engineering
• Separation Science

Background:

• Expanded bed chromatography (EBC) is crucial for direct protein purification from unclarified feedstocks.
• Agarose-based matrices are common in EBC, but their fluidisation properties require optimization.
• The Richardson-Zaki correlation is widely used to predict fluidisation behaviour.

Purpose of the Study:

• To evaluate the fluidisation and dispersion properties of novel agarose-based expanded bed matrices.
• To compare the performance of stainless steel cored prototypes against commercial supports.
• To assess the suitability of the Richardson-Zaki correlation for these systems.

Main Methods:

• Studied fluidisation in 1-cm diameter expanded bed contactors with locally stirred fluid entry.
• Utilized the Richardson-Zaki correlation to predict fluidisation behaviour.
• Conducted residence time distribution studies with acetone tracers.

Main Results:

• Fluidisation behaviour was poorly predicted by the Richardson-Zaki correlation, with higher experimental expansion indices.
• Small pellicular prototype matrices exhibited significantly better hydrodynamic properties than commercial supports.
• The validity of the Richardson-Zaki correlation for characterizing EBC systems was questioned.

Conclusions:

• Novel agarose-based matrices, particularly small pellicular prototypes, demonstrate superior hydrodynamic performance in EBC.
• These findings suggest improved efficiency for future expanded bed chromatographic separations.
• Further investigation into predictive models for EBC fluidisation is warranted.