structures Dr. Ing. Daniel Jussen B. Sc. David Lthy Dr. Ing. Peter - PowerPoint PPT Presentation

Mixing in microfluidic structures Dr. Ing. Daniel Jussen B. Sc. David Lüthy Dr. Ing. Peter Riedlberger

Microprocess engineering and particulate systems Advantages: Challenges: • Rapid mixing • Macro to micro interface • Defined temperature • Backpressure control • Fouling • Continuous processing • Overhead • Ease of serial reactions • Favorable for hazardous processes • Ease of Scale up • Flexible processes

Microfluidic mixing concepts Multilamelar mixer (Simm V2) High collision mixer Kashid, M. N., Renken, A., & Kiwi-Minsker, L. (2015). Microstructured Devices for Cemical Processinf . Campos Domínguez, C., & Gamse, T. (2016). Process intensification by the use of micro devices for liquid fractionation with supercritical carbon dioxide. Chemical Engineering Research and Design , 108 , 1 – 7. http://doi.org/10.1016/j.cherd.2016.01.011

Mixing efficiency – Test reaction Competitive parallel reaction 𝑌 𝑡 = 𝑍 𝑍 𝑇𝑈 𝑌 𝑡 = Segregation index 𝑍 = Y is the ratio of acid mole number consumed by reaction (2) to the total acid mole number 𝑍 𝑇𝑈 = Y in the total segregation case when the micromixing process is infinitely slow 4

Villermaux-Dushman Method - detectable 353 nm  I 3

Villermaux-Dushman Method SIMM-V2 (multilamellar mixer) R300 (SAR/caterpillar mixer) R600 (SAR/caterpillar mixer) Segregation index (X S ) depence on the mixer type and flow rate (Q)

Precipitation of Bariumsulfate 2-  BaSO 4 Model reaction: Ba 2+ SO 4 Intensity /% flow rate Q /mL min -1 Particle Size d/ nm M4 (high collision mixer) SIMM-V2 (multilamellar mixer) R600 (SAR/caterpillar mixer) Batch process R300 (SAR/caterpillar mixer) left: particle size distribution for diferent mixers and batch reaction, right: dependence of the mean particle diameter for different mixers 7

Summary and Outlook • Mixing has significant influence on reactions • Choice of mixer influences reaction and performance • Utilization of microfluidic mixing setups for a model process – P/TiO2 process for exemplary process intensification – Fouling remidation studies for exemplary process

Villermaux-Dushman Method 𝑌 𝑡 = 𝑍 𝑍 𝑇𝑈 𝑌 𝑡 = Segregation index 𝑍 = Y is the ratio of acid mole number consumed by reaction (2) to the total acid mole number 𝑍 = Y in the total segregation case when 𝑇𝑈 the micromixing process is infinitely slow