Most processes are scale dependent. Most experimental work to seek for optimal process conditions is performed at lab-scale, or at best at pilot scale. However, taking a process from laboratory scale or pilot scale to full-scale is usually a challenging endeavor, because simply transferring the set of conditions leading to optimal production at small scale to larger scale does not necessarily lead to an optimal process at the larger scale. Therefore as well, the scaling-up of a process is in many cases not based on detailed process understanding, but on empirical rules, and can in the worst case fail completely due to the lack of detailed understanding of the mixing and the mass transfer in large reactor vessels. One important characteristic of large reactor vessels is that they are not well-mixed, and the resulting gradients in such a large vessel are one of the main causes of the scaling-up challenges, i.e. the biomass at the bottom of the reactor can experience conditions which are very different from the conditions close to the top of the tank.
This workshop focusses on highlighting the potential use of computational fluid dynamics (CFD) to address some of the challenges involved in transferring processes from lab-scale to pilot scale to production scale, where CFD can help to identify the occurrence of gradients in large tanks.
The workshop will start with a summary of the experiences with CFD at DTU Chemical Engineering in the fermentation area, where considerable work has been done on the use of CFD for modelling pilot scale reactors. It will be highlighted how such CFD models lead to improved process understanding. Furthermore, focus will also be on how to use CFD models for full-scale reactors, discussing advantages and disadvantages of such an approach.
In the discussion following the presentation, the focus will be on how to seek for useful applications for CFD in the wastewater treatment area, and how to transfer knowledge from the fermentation area to the wastewater treatment area.
The workshop will be held by Krist V. Gernaey, Christian Bach and Ulrich Krühne from CAPEC-PROCESS Research Center, Department of Chemical and Biochemical Engineering.