Back to search

FRINATEK-Fri prosj.st. mat.,naturv.,tek

Fundamental investigation of non-Newtonian fluid flow in bioprocessing

Alternative title: Fundamental studie av ikke-newtonsk væskestrømning i bioprosessering

Awarded: NOK 9.7 mill.

This project seeks knowledge about how the suspended living organisms can be optimally brought from small-scale biotechnological laboratories to large-scale liquid systems found in industrial production. This includes, among other things, that we seek an understanding of how liquids with complex and special properties behave in liquid systems. Furthermore, it is also important to understand how gas bubbles behave in such liquids, as the supply of components such as oxygen is crucial for the suspended living microorganisms in aerobic processes. The doctoral student in the project has completed a 6-month stay at Chalmers University of Technology. The doctoral student has studied turbulent properties in canonical and complex flows with shear-thinning behaviour through direct numerical simulations and large eddy simulations. The scholarship holder has two articles approved in a very prestigious journal in fluid dynamics (Journal of Fluid Mechanics), another article marked as "editor's choice", and a fourth article in a good journal. The defence of the doctoral thesis received very positive reviews from the opponents. At the end of the project, a revised journal article is being considered for publication, and another manuscript is due for evaluation in a journal. In this project, the scholarship will contributed to in total 6 journal articles as first author and 1 journal article as co-author. The postdoctoral fellow in the project has completed a one-year stay at Imperial College London. The postdoctoral fellow has carried out experimental studies of mass transfer and bubble dynamics in stirred tanks with shear-thinning fluids. Experimental studies of the flow field of single-phase flows in tubular tanks with shear-thinning fluid were also carried out. Both the multi-phase and single-phase experiments have been simulated by CFD. The single-phase simulations were carried out by the postdoctoral candidate, while the multi-phase simulations were carried out in collaboration with researchers in Colombia. The CFD simulations of the single-phase simulations are compared with experiments from collaboration established in the project. The post doctoral fellow has published 3 journal articles as first author and co-authored three journal articles. Yet another journal article as first author and another as co-author are pending. The project's PI has produced two journal articles as first author and will be evaluated for publication in a journal. The collaboration with researchers in Colombia in this project has resulted in two journal articles, a third article has been sent for consideration for publication in a journal, while a fourth article is nearly completed and will be sent for consideration for publication in a journal. The project received a personal invitation to give a lecture at an international conference on industrial biotechnology. The results so far indicate that the method and hypotheses in the project will provide a valuable and new understanding of flow in bioprocessing.

Både doktorand og post doktor har oppnådd et godt resultat i prosjektet med hensyn til antall publikasjoner i tidsskrifter, noe som er viktig i en akademisk merittliste. Videre har begge stipendiatene, samt PI, utført lengre utenlandsopphold som har gitt verdifulle erfaringer og bidratt til nettverksbygging. PhD stipendiat har kvalifisert seg til en videre karriere innen akademia som post doktor. I tillegg til utenlandsopphold har prosjektet etablert samarbeid med andre forskere ved NTNU samt internasjonalt. Prosjektet har bidratt til etablering av en forskningsgruppe ved NTNU som - basert på kunnskap og resultater i prosjektet - har blitt tildelt nye finansieringer til nye prosjekter. Kunnskapen og resultatene etablert i prosjektet er viktig i NTNU's posisjonering og bidrag til, blant annet, industrialisering av bioprosesser.

In this project, the young project manager will establish a new research activity at NTNU with the aim of enhancing the national knowledge on optimal design, operation and scale-up of bioreactors. Research effort that will enable realization of economical viable bioprocessing plants is necessary to ensure that Norway becomes a leading country in the green shift with significant bio-based industry. In particular, this project addresses challenges related to fluid flow in bioreactors. Non-Newtonian fluids will be considered because such rheology is common in bioreactors and these types of fluids induce different and more complex flow behavior compared to Newtonian fluids. Most bioreactors contain multiphase flow systems which induce challenges with optimal operation related to bubbles such as interfacial mass transfer and gas holdup. This project will provide fundamental understanding of bubble size distribution (BSD) and its influence on gas holdup - a key step for the industry towards more optimal and safe operation of digesters. In contrast to previous studies of aerated bioreactors, interfacial mass transfer fluxes will be investigated with detailed information on the interfacial area through BSD data. Unlike the traditional approaches for turbulence characterization, this project will develop a new fundamental method to investigate details of turbulent vortices such as their three-dimensional structure, size, tilting, stretching and how they dissipate. A significant achievement is obtained in this project if the turbulent characterization of non-Newtonian fluid flows can explain trends in BSD and mass transfer data during scale-up, because such knowledge of turbulence will help to enable the necessary improvements in bioreactor performance. The project will establish a strong and multidisciplinary research group that has the best possibilities to produce new knowledge necessary to bring the society a step closer to the realization of significant bio-industry.

Funding scheme:

FRINATEK-Fri prosj.st. mat.,naturv.,tek