DTU Studieprojekt - Liquid-Liquid mixing characterization and scale up down

Liquid-Liquid mixing characterization and scale up down

Udbyder
Vejleder
Sted
København og omegn
A common goal in the kitchen, the lab or in industry, is the creation of a dispersion of two immiscible liquids. This might be in mayonnaise production, a solvent extraction, or in the creation of emulsions, foams, nano particles, micro capsules etc. In stirred tanks, one often hears terms like “NJD” and NFD” (N/rpm agitation speed, Just Dispersed and Fully Dispersed, Zwietering, 1958*), although these are predominantly applied to the suspension of solids, they may also be applicable to 2 phase liquid-liquid mixing. Further to this, and somewhat more challenging, is the desire to achieve some specified drop size distribution, which is clearly critical for the successful production of a mayonnaise, or avoiding the production of something mayonnaise like, for hitting the right sizes for nano particle or micro particles etc (Leng & Calabrese, 2004*). Classical semi empirical approaches to developing product and equipment specific correlations involve relationships that consider P/V (power per unit volume or mass, emax W/kg) and the interfacial tension (s) (Davies, 1987*).

While some of these are well established principles, tailoring to specific systems has historically been tricky, as practical measurement of particle or drop sizes in systems that are not always in a steady state, and may coalesce, has historically been very time consuming or close to impossible. For similar practical reasons, experimentally verifying how these things change as a function of scale has also been difficult. In modern times, PAT technology using high speed cameras, microscopes, endoscopes, or FBRM technology can potentially help us immensely.

LEO Pharma’s MSAT crew is keen to learn more about practical approaches to the characterization of such processes, and how they can be successfully scaled up and down. As such, we propose a MSc project where the student is expected to initially update us regarding the present state of the art, verify that one of our seemingly simple stirred systems obeys the rules, but where the dispersed phase has an unusually low volume fraction. The student together with the supervisors will then need to demonstrate some creativity to discover good scale up rules for just dispersed and fully dispersed conditions, and finally a drop size distribution.

LEO has well equipped laboratories as well as production scale equipment and is a short bus ride from DTU. DTU has some of its own facilities but also has considerable expertise in modelling and simulation, including CFD. The student will have considerable autonomy in managing the required time spent at the different sites, the design of any experiments (DoE), and the final approach taken (completely empirical? or guided by CFD? Which PAT technology?).

This might seem like a simple project, but as with many things in Chemical Engineering, the devil is very much in the detail. It is not expected to be a walk in the park, but if you make good progress you will find that LEO is very interested in the work, and you will have an excellent thesis and experience for your CV.

• Davies, J. T. (1987). A physical interpretation of drop sizes in homogenizers and agitated tanks, including the dispersion of viscous oils. Chemical Engineering Science, 42(7), 1671–1676. https://doi.org/10.1016/0009-2509(87)80172-0
• Leng, D. E., & Calabrese, R. V. (2004). Immiscible liquid-liquid systems. In E. L. Paul, A. A. Atiemo-Obeng, & S. M. Kresta (Eds.), Handbook of Industrial Mixing, Science and Prcatice (pp. 639–746). New Jersey: Wiley-Interscience.
• Zwietering, T. N. (1958). Suspending of solid particles in liquid by agitators. Chemical Engineering Science, 8, 244.

* All of these articles are in the top 20 most influential publications on the subject of mixing (NAMF, North Americas Mixing Forum). It is highly recommended that you take a look.

I samarbejde med
Leo Pharma A/S

Forudsætninger
Experience in CFD

Emneord

• Bioteknologi og biokemi
• Fysik
• Informationsteknologi
• Kemi
• Matematik
• Transport og logistik
• Teknisk kemi
• Sundhed og sygdomme

• CFD
• emulsions
• mixing
• Scaledown
• scaleup

Navn
Ulrich Krühne

Stilling
Lektor

Mail
ulkr@kt.dtu.dk

Vejleder-info
Kandidatuddannelsen i Kemisk og Biokemisk Teknologi
Vejleder
Ulrich Krühne

ECTS-point
30 - 35

Type
Kandidatspeciale

Skal have taget
28831 Desired