Highlights • Use of microprocesses for rapid process development. • Improved microprocess design via use of computational tools. • New microprocess control via advanced on-line microsensors. • New ...microbioprocesses offer continuous, intensified, and integrated processing.
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► Ionic liquid-based aqueous two-phase protein extraction: theory and experiments. ► The first report on an extraction within a microfluidic device using selected IL-ATPS. ► ...Experimental verification of a 3D model describing microextractor behavior. ► IL-ATPS was more efficient extraction media as compared to PEG/phosphate ATPS. ► Further process optimization using 3D model is feasible.
Ionic liquid-based aqueous two-phase systems (IL-ATPSs) are great candidates for the replacement of volatile organic solvents in liquid–liquid extractions. Besides, microfluidic separation techniques are a promising alternative to conventional systems since they provide continuous operation, better performance and easier capacity increase by a numbering-up approach. Herein, the advantages of IL-ATPSs and microfluidic continuous separation were combined within a microfluidic device with parallel flow allowing for the separation of the two phases at the exit of the microchannel. An aqueous solution of C4mim BF4 and d-fructose was used as an IL-ATPS and compared with a conventional ATPS consisted of polyethylene glycol/salt solution. Based on the evaluated partitioning coefficient of a model substance, namely bovine serum albumin, the ionic liquid concentration and pH value of the IL-ATPS have been selected for the use within a pressure-driven microchannel system with y-shaped inlet and outlet. Furthermore, a three-dimensional model considering convection in the flow direction and diffusion in all spatial directions at steady-state conditions was developed, validated by experimental results and used to assess the feasibility of micro-scale parallel flow extraction in a wide range of flow rates. The chosen IL-ATPS was shown to be much more efficient media for continuous microfluidic extraction as compared to conventional ATPS, primarily due to much lower dynamic viscosity of IL-rich phase related to PEG-rich phase.
Experimental and theoretical modeling on low-temperature dry methane reforming over Ni-containing CeO2 rods was studied. The catalyst was characterized by means of N2 physisorption, in-situ XRD, TPR ...and H2 chemisorption techniques. The characterization studies revealed the distortion of CeO2 flourite structure due to the Ni incorporation. Lattice expansion (due to reduction) and contraction (due to oxidation) suggest the reversible redox nature of CeO2. Ni–O–Ce solid solution formation was evidenced by both XRD and TPR studies. H2 chemisorption study revealed that the catalyst reduction temperature plays a significant role in Ni dispersion. The catalyst showed similar activity trends in two model geometries: a between-two-plates microchannel fixed-bed reactor and a conventional fixed-bed reactor. The activity tests were conducted in the kinetic regime, where conversions of CH4 were not influenced with the gas flow rate. A lattice Boltzmann model for mixed gas flow was developed along with a boundary condition for catalytic sites. The lattice Boltzmann model was used in a multiscale simulation of the studied reaction systems and produced data that qualitatively matched the experiments.
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•Ni was incorporated into CeO2 fluorite lattice to form Ni–O–Ce solid solution.•Reversible redox nature of rod-shaped CeO2 was observed in in-situ XRD examination.•A lattice Boltzmann (LB) model for gas mixtures is coupled with a macroscopic model.•Dry reforming of methane is simulated through a modified LB bounce-back boundary.•The multiscale model qualitatively reproduces the experimental results.
► A packed-bed microbioreactor for biocatalytic reactions was developed. ► The integrated system included a continuous miniaturized separator. ► Several ionic liquids were tested for their ...suitability as the reaction medium. ► Ionic liquid bmpyTf2N was an excellent medium for butyl butyrate synthesis. ► The pure product was isolated with a 91% yield.
An integrated system consisting of a packed bed microbioreactor and a miniaturized separator was developed for performing biocatalytic reactions in an ionic liquid medium in continuous mode. Immobilized lipase B from Candida antarctica was used as a catalyst for butyl butyrate synthesis in bmpyTf2N, which was initially selected among various commercial ionic liquids and was proven to provide good enzyme activity and stability. The microbioreactor enabled 100% conversion of 0.5M equimolar concentration of both substrates in the chosen ionic liquid within 5min at 25°C. A mathematical model considering Ping Pong Bi Bi enzyme kinetics with inhibition by both substrates was developed to describe the microbioreactor performance. Consecutive separation of butyl butyrate with 90% efficiency was achieved in the developed miniaturized separator based on the high difference in the boiling point of products regarding the ionic liquid medium. The process set-up successfully exploits the benefits of process intensification along with the integration of processes enabling ionic liquid recycling and is, regarding its easy handling, perfectly suited for enzyme process development at the microscale.
•A chemical vapor deposition of ferrocene in air is studied in a small scale reactor.•A 3D CFD model was coupled with transport and kinetics of species.•The kinetics parameters were determined at ...temperature range between 733 and 873K.•Good agreement between model predictions and experimental data is observed.•We report the most efficient iron oxide nanoparticles deposition at 793K.
A 3D mathematical model for chemical vapor deposition of ferrocene on silica substrates in a horizontal small scale reactor was developed and validated by experiments. The model includes a computational fluid dynamics combined with transport equations for ferrocene and iron oxide nanoparticles. The temperature dependence of the mass flux of iron oxide on the catalytic support was predicted and measured in the range between 733K and 873K. Bulk and surface reactions of ferrocene decomposition in air were considered, and kinetic parameters were defined based on experimental data. It has been shown that the deposition of iron oxide on the substrate surface is limited by the transport of ferrocene vapors to the silica substrates and the surface reaction rate. The most efficient iron oxide deposition on the substrate surface was achieved at 793K. At higher temperatures, the surface deposition process is less efficient due to more intensive bulk reaction and formation of nanoparticles.
This work explores the innovative use of copper-alginate (Cu-alginate) hydrogels within microfluidic systems to catalyze dipolar cycloaddition reactions, emphasizing green chemistry principles and ...process intensification. Utilizing naturally occurring biopolymers, such as alginates, provides an environmentally friendly alternative to conventional catalyst supports due to their biocompatibility, biodegradability, and effective metal ion immobilization capabilities. The integration of these biopolymer-based catalysts into microfluidic devices allows for precise control over reaction conditions, leading to enhanced reaction kinetics and mass transfer efficiencies. Our results demonstrate that Cu-alginate hydrogels effectively catalyze the formation of 1,4-disubstituted 1,2,3-triazoles through 3 + 2 dipolar cycloaddition reactions with high regioselectivity and conversion. The microfluidic setup ensures rapid and efficient synthesis, surpassing traditional batch reaction methods in both reaction rate and environmental impact by reducing solvent usage and waste generation. Furthermore, the use of microfluidics contributes to the reproducibility and scalability of the synthesis process, important for industrial applications. The model-based design and its simulations have been employed to further understand and optimize the reaction system. Diffusion through the gel layer and catalytic reaction kinetics estimated from experimental data were included in the model, providing a theoretical foundation for a comprehensive process evaluation. This study not only advances the field of sustainable catalysis by demonstrating the practical utility of biopolymer-supported catalysts in microfluidic systems, but also sets the stage for further research into biopolymer applications in complex chemical syntheses.
Droplet-based liquid-liquid extraction in a microchannel was studied, both theoretically and experimentally. A full 3D mathematical model, incorporating convection and diffusion in all spatial ...directions along with the velocity profile, was developed to depict the governing transport characteristics of droplet-based microfluidics. The finite elements method, as the most common macroscale simulation technique, was used to solve the set of differential equations regarding conservation of moment, mass and solute concentration in a two-domain system coupled by interfacial surface of droplet-based flow pattern. The model was numerically verified and validated online by following the concentrations of a solute in two phases within the microchannel. The relative azobenzene concentration profiles in a methanol/
n
-octane two-phase system at different positions along the channel length were retrieved by means of a thermal lens microscopic (TLM) technique coupled to a microfluidic system, which gave results of high spatial and temporal resolution. Very good agreement between model calculations and online experimental data was achieved without applying any fitting procedure to the model parameters.
A thermal lens microscopic technique was performed for following droplet-based extraction inside a microreactor with detailed modeling of transport phenomena.
In this work, the lattice Boltzmann (LB) method was applied to simulate incompressible steady and unsteady low Reynolds number (Re) flows around a confined cylinder. In the LB method, different ...collision models (Bhatnagar–Gross–Krook model, two-relaxation-time model, multi-relaxation-time model, and entropic lattice Boltzmann model) and a regularization model were used, and the results were compared. Numerical results pertaining to a two-dimensional flow around a cylinder are reported and compared with numerical and experimental data available in the literature. The results agree with the predictions made from the literature. A correlation for Strouhal number (St) for 55
≤
Re
≤
300 is suggested.
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