Extraction Systems

  Experimental test rig © AVT.FVT  

The increasing use of bio-based raw materials and the implementation of recycling processes as part of circular economy pose new challenges for separation technology. The recycling of residual material streams requires high robustness and selectivity of the separation processes at low production costs. Target molecules from biotechnological syntheses are also often temperature-sensitive, have high boiling points or are present in low concentrations.

One possible unit operation for selective product recovery at mild conditions is liquid-liquid extraction. This low-energy process can potentially reduce production costs and CO2 emissions compared to conventional separation operations such as rectification. Furthermore, liquid-liquid extraction can also be directly coupled to a reaction, as part of an in situ product separation, so that yield and selectivity of the reaction are improved. However, the effects of side products from biotechnological synthesis as well as secondary components in the recycling streams (salts, proteins, particles) on extraction processes have been inadequately investigated so far. Another challenge is the scale-up from laboratory to technical scale.

The goal of the "Extraction Fundamentals" team is to understand the fundamental phenomena and the influencing factors in two-phase disperse liquid-liquid systems, to model them and to transfer the results to complex substance systems. Based on fundamental extraction phenomena, we bring processes to a technical scale in order to understand scale-up effects and to build a bridge to possible applications.

To accomplish this, we characterize mass transfer as well as dispersion, coalescence and phase separation behavior in specially designed test setups. Furthermore, we develop in-house measurement and evaluation methods. We investigate extraction processes specifically relevant for biotechnological processes in the process industry and circular economy. For example, we work on reactive extraction for the processing of biotechnologically produced organic acids or on the recovery of rare earths metals. These extraction systems are investigated with the aid of statistical methods (e.g. DOE - design of experiments) and can be described with simulation models.

Through a deeper understanding of the physical and phenomenological relationships, tailor-made extraction processes can be developed for individual research questions in biotechnology and recycling. At the same time, this also enables the development of new methods for process intensification (e.g. in situ extraction, centrifugal extraction, and microgel-supported extraction) and for the reduction of side streams (e.g. electrochemically induced extraction).

Current research focuses are:

  • Reactive Extraction
  • Dispersion & phase separation behavior
  • Electrochemically induced extraction
  • Microgel-supported extraction
  • Centrifugal extraction
  • Direct product removal by extraction (in situ extraction)

Experimental and simulative student research projects as well as bachelor and master theses are regularly available in the areas mentioned above. Please contact the corresponding person or have a look at the advertised works at the AVT.FVT.