Seminar Series

The Chemical and Biochemical Engineering Department Graduate Student Seminar series is a bi-weekly seminar taking place during the Fall and Winter terms. Each seminar features a different student presenters.

Fall 2025 - Winter 2026: Seminars will be held from 12:30 pm - 1:30 pm every second Thursday. The location will be announced. *Please bring Student Card for attendance*

Speakers to Present in Fall 2025

November 6, 2025

Location: ACEB 1420

Presentation #1: Fluidization Characteristics and Transition Behaviours of Geldart Group C+ Powders

Presenter: Yue Song

Supervisor: Dr. Jesse Zhu

Committee members: Dr. Hui Zhang 

Abstract:

Fluidized beds are widely used as chemical reactors and processing devices, where performance largely depends on effective gas-solid contact. Fine particles offer large interfacial areas and are commonly employed as catalysts, but when particle size becomes very small, strong interparticle forces make cohesive powders (Geldart Group C) difficult to fluidize. A nanoparticle modulation technique is adopted to reduce these interparticle forces and thereby improve the flow and fluidization quality of Group C powders, referred to as Group C+. This study investigates the hydrodynamic behaviour of nano-modulated Group C powders in a two-dimensional fluidized bed, focusing on pressure fluctuations, solids holdup, and regime transitions from bubbling to turbulent fluidization. Results show that nano-modulation promotes a more uniform suspension and leads to an earlier onset of the turbulent regime compared with Group A powders. These observations provide a new insight into the transition behaviour of cohesive particle systems and lay the groundwork for further control of fine particle fluidization.

Presentation #2: Examination of metabolic oscillation in Clostridium pasteurianum during continuous fermentation for Butanol production

Presenter: Annika Tyszak

Supervisors: Prof. Lars Rehmann

Committee members: Prof. Amarjeet Bassi, Prof. Arghya Paul

Abstract:

Butanol, a potential biofuel, can be generated fermentative using Clostridium pasteurianum and glycerol as the sole substrate. Glycerol is a low-cost resource produced in large amounts by the biodiesel industry. To industrially utilize butanol fermentation with glycerol feedstock using C. pasteurianum further optimization is needed. An undesirable metabolic oscillation phenomenon observed during continuous fermentations of C. pasteurianum in the production of CO2 and H2 as well as the redox potential is one obstacle in the optimization of butanol production with this organism. The mechanism causing the oscillation remains unknown, while a better understanding is required to potentially mitigate it.

 During previous work in the research group a culture of C. pasteurianum that did not display oscillating behaviour was created using an oxidizing agent. It appeared to open an opportunity to investigate the mechanism behind the observed oscillation. Single colony isolates were created from this “mixed culture” and two isolates were picked for further investigation based on their butanol production. Further continuous fermentations were performed to validate the non-oscillating nature of the “mixed culture” and the isolates, and contrary to expectations all of the examined strains showed oscillations with varying amplitudes and frequencies.