Economic Optimizing Control for a U-loop Reactor

To provide a sustainable source of protein for a growing human population, Unibio A/S produces single-cell protein product equivalent to currently used unsustainable protein sources, e.g., fishmeal. 

The fermentation process in which the single-cell protein is produced is difficult to operate at high concentrations, i.e., high productivities. Economic optimizing control for a U-loop reactor is an attempt to stabilise the single-cell protein production, and significantly increase the productivity of the reactors.


Uniprotein, the single-cell protein product produced by Unibio, is produced in a fermentation process using their patented U-loop technology. The process in illustrated in the image below. Fermentation provides a good alternative to unsustainable production of protein. However, the productivity of the fermentation is too low to make Uniprotein a financially viable alternative. Economic optimizing control for a U-loop reactor is an attempt to increase the productivity, and thus also the feasibility of Uniprotein as an alternative protein source for the meat industry.


Using the predictive properties of a mathematical model of the U-loop reactor, nonlinear state estimation and system identification algorithms, and efficient optimization algorithms, we design, implement and test a model-based control solution for the continuous bioprocess. Using this solution, the goal is to increase the productivity of the U-loop reactor from around 3 kg/m^3/hr to more than 6 kg/m^3/hr – increasing the productivity by more than 100%.


The successful completion of the project will mean that Unibio’s product can more effectively compete with the currently used unsustainable protein products, but also that we will have provided a sustainable and feasible protein product for the meat industry. The control system for a continuous bioprocess, which is the end-product of the project, can be much more widely used, and has great potential to increase productivity in a range of industries dependent on fermentation.


Main supervisor:

John Bagterp Jørgensen

Ib Christensen


Co- supervisor:

Jakob Kjøbsted Huusom

Krist V. Gernaey

Jess Dragheim



John Bagterp Jørgensen
DTU Compute
+45 45 25 30 88