Rotor-stator Spinning Disc Reactor Research Articles

Continuous Production of High-Capacity Iron-Based Prussian Blue Sodium-Ion Cathode Materials Using a Rotor–Stator Spinning Disk Reactor

Iron-based Prussian blue materials have the potential to be used as low-cost, simple-to-synthesize, and high-capacity cathode materials for large-scale energy storage sodium-ion batteries. However, in order to obtain high-capacity sodium storage Prussian blue materials, the currently used high-energy hydrothermal method or interstitial coprecipitation method is difficult to meet large-scale energy storage applications. The electrochemical performance of the product is highly dependent on the crystallization process. In this work, a simple stator–rotor reactor (RSSDR) reactor and precipitation transformation were used to improve the crystallization and precipitation process of iron-based Prussian blue, and continuous production was realized. The effects of particles with different morphologies on the products after aging were investigated, and the specific capacity (162.4 mAh g–1 at 34 mA g–1) and cycle retention rate (capacity retention of 64.97% for 200 cycles at the current density of 170 mA g–1) of iron-based Prussian blue were improved. Overall, this work provides a strategy to continuously produce iron-based Prussian blue sodium-ion cathode materials with improved electrochemical performance through improving the crystallization process.

The Transportation of Maxwell Fluid in the Rotating and Stretching System: Rotor-Stator Spinning Disc Reactor Applications

We have developed a mathematical model and obtained a numerical solution for the motion of a non-Newtonian Maxwell fluid between two disks having rotation and stretching velocity with convective boundary constraints, porous medium and thermal radiation. The present Maxwell fluid flow model with specified boundary constraints is not discussed so far. The proposed model has a lot of applications in electrical power generation, nuclear energy plants, astrophysical flows, space vehicles, geothermal extractions, and spinning disc reactor. The Von Karman similarity approach is used for the solution and validation of the solution is also provided. The solution is obtained numerically with finite difference method (FDM) based ND-solve command in Mathematica software. The effects of magnetic field, porous medium, radiation parameter, Deborah number, Prandtl number, and Reynolds number on skin friction, heat transfer, flow and temperature fields are discussed in detail. Due to the significant void fraction in the medium, porosity parameter shows unique trend compared to other parameters for the radial velocity profile. It has tendency to enhance the radial velocity near both the disc but in the middle part of system, porosity parameter retards radial velocity significantly.

Hydrodynamics of a rotor–stator spinning disk reactor: Investigations by large-eddy simulation

In this work, computational fluid dynamics are used to study the hydrodynamics in a complete rotor–stator spinning disk reactor with throughflow. Large-eddy simulations of OpenFOAM 9 were used to capture the turbulent structures of the flow in combination with the wall-adapting local eddy viscosity sub-grid-scale model. The method was validated based on residence time distributions (RTDs) for a range of rotational Reynolds numbers (Re = ωRD2ν−1 = 3.2–52 × 104) and a dimensionless flow rate (Cw = Q ν−1RD−1) of 150 and G = 0.0303 (G = h RD−1). The experimental RTD was obtained from tracer experiments with UV/VIS flow cells. From the RTD, the plug flow (PFR) volume fraction, the Péclet number, and the radial position (rtrans) where the flow changes from PFR into ideally mixed were determined by using an engineering model based on axial dispersion. For the turbulent cases, good agreement based on the RTD curve, PFR volume, the Péclet number, and rtrans was found. Furthermore, the boundary layer thickness on the rotor and stator and the entrainment coefficient were in good agreement with the literature. Finally, the turbulent intensity was analyzed illustrating a high intensity at the rim of the rotor and was 10% larger in centripetal flow compared to centrifugal flow.

Transesterification of Triglycerides in a Rotor–Stator Spinning Disc Reactor: Scale-Up and Solid Handling

Transesterification of Triglycerides in a Rotor–Stator Spinning Disc Reactor: Scale-Up and Solid Handling

Scale-Up of a Heterogeneous Photocatalytic Degradation Using a Photochemical Rotor-Stator Spinning Disk Reactor.

Many chemical reactions contain heterogeneous reagents, products, byproducts, or catalysts, making their transposition from batch to continuous-flow processing challenging. Herein, we report the use of a photochemical rotor–stator spinning disk reactor (pRS-SDR) that can handle and scale solid-containing photochemical reaction conditions in flow. Its ability to handle slurries was showcased for the TiO2-mediated aerobic photodegradation of aqueous methylene blue. The use of a fast rotating disk imposes high shear forces on the multiphase reaction mixture, ensuring its homogenization, increasing the mass transfer, and improving the irradiation profile of the reaction mixture. The pRS-SDR performance was also compared to other lab-scale reactors in terms of water treated per reactor volume and light power input.

Modeling of extraction chromium (III) using 2-ethylhexyl phosphoric acid mono-2-ethylhexyl in rotor stator spinning disc reactor

To overcome the disadvantages of large mass transfer resistance, long processing time and high investment in the previous extraction equipments, rotor-stator spinning disc reactor (RSSDR) was developed. Because of complex hydrodynamics in the RSSDR, a theoretical model was then established to simulate the extraction performance of chromium (III) using 2-ethylhexyl phosphoric acid mono-2-ethylhexyl as extraction agent. Some important hydrodynamics behaviors were included in the model, such as liquid film thickness, liquid holdup, liquid residence time, mass transfer rate of the surface of the aqueous phase to the organic phase and mass transfer rate of the interior of aqueous phase to the surface. After verified by the experimental results, the effects of rotational speed, liquid flow rate and rotor-stator distance on extraction efficiency were predicted by the model. And then, the contribution ratios of liquid film thickness, liquid holdup, liquid residence time and mass transfer rate on extraction efficiency were detailed analyzed. The extraction process in the RSSDR could be in-depth understanding by the model, and the process of industrialization and other harmful matter removal could be effective guided.

Intensified Sulfite Reduction of Alkyl Hydroperoxides in a Rotor–Stator Spinning-Disc Reactor

The reduction of tert-butyl hydroperoxide and cumene hydroperoxide with sodium metabisulfite was intensified in a rotor–stator spinning-disc reactor (rs-SDR). The reaction kinetics were first obtained in a capillary microreactor. The effects of temperature, aqueous phase ionic strength, mass transfer, and liquid–liquid interfacial area were quantified. A kinetic model was developed, and the kinetic parameters were fitted to the experimental data from the microreactor. tert-Butyl hydroperoxide could be reduced much faster than cumene hydroperoxide because of its higher solubility in the aqueous phase. The reduction rate in the rs-SDR was a factor 15–100 higher than that in the microreactor for rotational disc speeds of 1000–4500 rpm, respectively. This was entirely attributed to the increase in liquid–liquid interfacial area in the rs-SDR, which increased approximately linearly with rotational speed.

Continuous Preparation of Size-Controllable BaTiO3 Nanoparticles in a Rotor–Stator Spinning Disk Reactor

The controlled synthesis of BaTiO3 nanoparticles (BTNPs) with a small particle size and a narrow particle size distribution (PSD) is key for the preparation of multilayer ceramic capacitors with high capacitance and high volumetric efficiency. This paper reports the research to continuously synthesize nanoparticles in a rotor–stator spinning disk reactor (RSSDR) for the first time and obtain BTNPs with a mean particle size (MPS) of 15.71 nm and a yield of 280 g/h. The MPS and PSD of BTNPs are related to the rotor–stator distance, the rotational speed, the volume flow, the molar ratio of Ba to Ti, and the flow rate ratio. The results show that the increasing micromixing efficiency of the RSSDR weakened the influence of mixing restriction on the chemical reaction. However, the enhancement of mass transfer is accompanied by the shortening of residence time, which has a negative impact on the synthesis of BTNPs. Moreover, BTNPs prepared in the RSSDR show superior results compared with other reactors. In addition, a novel dispersion method was proposed to control particle agglomeration in the glycerol matrix and the dispersion effectiveness was verified by comparing transmission electron microscopy results with dynamic light scattering results. The polydispersity index of each result was below 0.200. In conclusion, a large-scale continuous preparation of BTNPs with a controllable particle size can be achieved in the RSSDR.

Experimental and modeling study on meso- and micromixing in the rotor–stator spinning disk reactor

The micromixing efficiency in the rotor–stator spinning disk reactor is studied for increasing injection flow rates of limiting reagent. Using both the Villermaux–Dushman method and second Bourne reaction, an increase in segregation index was found with increasing injection flow rate. Mechanistic models describing micro- and mesomixing were reviewed and implemented to describe the effects of increasing segregation index with increasing injection flow rate. A simplified turbulent-dispersion model was found to describe this trend effectively. A new parameter, based on a logistic function, was proposed to couple mesomixing by turbulent-dispersion and micromixing by engulfment on basis of the ratio of the characteristic times for turbulent-dispersion and engulfment. For injection flow rates where micromixing was calculated to be dominant, the engulfment model was implemented. An experimental relation was fitted to describe the dependency of the local energy dissipation rate on the turbulent diffusion coefficient in the rotor–stator spinning disk reactor. For the Villermaux–Dushman test reaction and the second Bourne reaction, discrepancies were found in the local energy dissipation rates experienced by the reaction zone. These discrepancies were analyzed on basis of the reaction times of both test reactions. The effect of the reaction time was accounted for by introducing a time-dependent local energy dissipation rate, which could be used to study the energy dissipation rate profile in the rotor–stator spinning disk reactor.

Esterification of free fatty acids in a rotor-stator spinning disc reactor

Esterification of free fatty acids in a rotor-stator spinning disc reactor

Micromixing Efficiency in the Presence of an Inert Gas in a Rotor–Stator Spinning Disk Reactor

The effects on micromixing of co-feeding an inert gas with the bulk liquid are studied for a rotor–stator spinning disk reactor by means of the Villermaux–Dushman test reaction. The results of varying rotational speeds and gas–liquid ratios are reported for three configurations: injecting the acid into the dispersed region, into the bottom thin-film region, and into the upper thin-film region. The results show that injecting in the dispersed region is the optimal configuration, as the liquid experiences the shear stress between the rotor and the stator, and with increasing rotational speed, micromixing efficiency subsequently increases. Injecting in the thin-film regions leads to poor micromixing efficiency, since the gas layer reduces the turbulence levels experienced by the liquid. For the bottom thin film, increasing rotational speed improves micromixing efficiency due to inertial rotation of the liquid film. However, in the upper thin film, micromixing is significantly worse, being affected by the dripping of liquid on the stator at the injection point. Gas holdup measurements are compared to previous studies, showing that most of the gas volume is present in the thin-film regions. These results are relevant for the design of modular chemical processes using the spinning disk technology, when fast competitive chemical reactions occur in the presence of gas and liquid.

Droplet size and liquid-liquid mass transfer with reaction in a rotor-stator Spinning Disk Reactor

A liquid–liquid test reaction system involving mass transfer with competitive reactions was used to show the potential for Process Intensification of the rotor–stator Spinning Disk Reactor (rs-SDR) in comparison with batch operation in a Stirred Vessel (SV). Under the investigated conditions, the SV showed a dispersion of droplets of a Sauter diameter d32 between 120 and 75μm, while the rs-SDR achieved values between 35 and 2.5μm due to the high shear forces. In terms of selectivity towards the undesired product, XS, the SV showed a decrease from 0.35 to 0.24 by increasing agitation, while the rs-SDR achieved values from 0.13 to 0.09. By modeling the system, the corresponding values for overall volumetric mass transfer coefficient kLa were one order of magnitude higher in the rs-SDR and as high as 0.24s-1. However, such values are much lower than the expected from the small droplet size. Literature suggests that the system is mass transfer limited, due to the formation of a monolayer of undissociated molecules around the interface. A model of diffusion with reaction is used to further model such effect. The model predicts well the product distribution experimentally obtained in the SV, although underestimates the values from the rs-SDR.

Kinetics and intensification of tertiary amine N-oxidation: Towards a solventless, continuous and sustainable process

• The kinetics of tertiary amine N-oxidation have been studied and modelled. • Reaction times in flow ≈4 mins, under intensified conditions in the RS-SDR. • Significant improvements were observed with better mixing. • Reactor has high productivity and eliminates the use of solvents. The N-oxidation of tertiary amines is an industrially important reaction, with the product having applications as surfactants, biocides, and emulsifiers. Currently, most processes for the production of fatty amine N-oxides are carried out in a batch or semi-batch manner using organic solvents such as n-propanol. Our analysis of the kinetics of both the N-oxidation reaction as well its thermal degradation in an aqueous system illustrated the possibility of intensifying the reaction through the use of a continuous flow reactor. In this paper, we have proposed the use of the rotor–stator spinning disc reactor as a solventless, continuous system, where mass transfer limitations can be overcome using high shear forces. The reactor could be safely operated at high reactant concentrations and temperatures. A specific productivity of 1960 kg h - 1 m R - 3 could be achieved in four minutes of reaction time in flow. In comparison, batch reactions are usually performed in the time scale of hours. The results obtained here illustrate that the rotor–stator spinning disc reactor can be used to produce amine N-oxides in a more sustainable and intensified manner.

The mixing sensitivity of toluene and ethylbenzene sulfonation using fuming sulfuric acid studied in a rotor-stator spinning disc reactor

The mixing sensitivity was studied for the sulfonation of two alkylbenzenes (ArH’s), toluene and ethylbenzene, by using a rotor-stator spinning disc reactor (SDR). Fuming sulfuric acid (FSA), containing 30 wt. % free sulfur trioxide, was used as a sulfonating agent, which resulted in a fast, exothermic, and viscous liquid-liquid reaction system. Experiments were conducted by varying the SDRs’ rotational speed between 50 and 9000 rpm. In addition, different molar flow ratios (ArH:FSA) were investigated, ranging from 0.8 to 3.2, while operating at a maximum residence time of 7.1 s. The selectivity towards mono-sulfonated products was found to increase significantly at a higher rotational speed. This was observed consistently for both alkylbenzenes and all molar flow ratios, confirming the mixing sensitivity of the two alkylbenzene sulfonation reactions. Furthermore, it was proposed that the mixing sensitivity arises from a competition that exists between the desired and highly reactive primary sulfonation and the much less reactive consecutive sulfonation step to disulfonic acids.

Alternative Kinetic Model of the Iodide–Iodate Reaction for Its Use in Micromixing Investigations

The Villermaux–Dushman method, one of the most extensively used test reaction systems for micromixing characterization, has been widely criticized for years due to uncertainties regarding the incomplete dissociation of sulfuric acid and the proposed kinetic study by Guichardon et al. In this work, a renewed study of the kinetics of the iodide–iodate reaction is presented, using perchloric acid to avoid issues concerning incomplete acid dissociation. The experimental results are in good agreement with the fifth-order rate law for the iodide–iodate reaction. The reaction rate coefficient strongly depends on the ionic strength and can be modeled with a Davies-like equation. When implemented in the incorporation model, the kinetic model presented in this study can be used to estimate micromixing times that are in line with the theoretical engulfment time. This is observed in two different reactors with low and high intensities of mixing: an unbaffled stirred vessel and a rotor–stator spinning disk reactor. The results from the latter are also compared with the second Bourne reaction, giving very similar micromixing times. The kinetic model presented in this study in combination with strong monoprotic acids is suggested as an alternative to characterize micromixing behavior.

CFD simulation of liquid flow characteristics in a rotor-stator spinning disc reactor

In this work, the CFD approach is employed to analyse the liquid hydrodynamic behaviour in the rotor-stator spinning disc reactor (RSSDR). The effect of rotational speed (N) and volume flow rate (Q) on the liquid-liquid flow pattern and its transition are investigated. It is found that there are two typical flow pattern (film flow and filament flow) observed in the RSSDR. Increasing N and decreasing Q turn the film flow into the filament flow. The flow pattern criterion for transition of filament flow to film flow is also obtained. The simulation data show a good agreement with our previous published experimental results. In addition, the influence of N and Q on liquid holdup rate (ε) and liquid velocity distribution in the RSSDR are also studied. The results show that ε keeps stable and then decreases with the increase of N, increases and then keeps consistent with increasing Q. While the mean liquid velocity increases as increasing N, Q, and radial radius (r). The mean radial velocity increases with increasing N, Q, and decreasing r. This work leads a deep understanding of the liquid flow characteristics in the RSSDR and its optimization design and scaling up.

Additions to "Micromixing in a Rotor-Stator Spinning Disc Reactor".

ADVERTISEMENT RETURN TO ISSUEPREVCorrespondenceNEXTAdditions to “Micromixing in a Rotor-Stator Spinning Disc Reactor”Arturo N. Manzano MartínezArturo N. Manzano MartínezLaboratory of Chemical Reactor Engineering, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The NetherlandsMore by Arturo N. Manzano Martínezhttp://orcid.org/0000-0001-9608-1527, Kevin M. P. van EetenKevin M. P. van EetenLaboratory of Chemical Reactor Engineering, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The NetherlandsMore by Kevin M. P. van Eeten, Jaap C. SchoutenJaap C. SchoutenLaboratory of Chemical Reactor Engineering, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The NetherlandsMore by Jaap C. Schoutenhttp://orcid.org/0000-0001-5706-7087, and John van der Schaaf*John van der SchaafLaboratory of Chemical Reactor Engineering, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands*E-mail: [email protected]More by John van der Schaafhttp://orcid.org/0000-0002-2856-8592Cite this: Ind. Eng. Chem. Res. 2020, 59, 36, 16095–16097Publication Date (Web):August 27, 2020Publication History Published online27 August 2020Published inissue 9 September 2020https://doi.org/10.1021/acs.iecr.0c03157Copyright © 2020 American Chemical SocietyRIGHTS & PERMISSIONSACS AuthorChoicewith CC-BY-NC-NDlicenseArticle Views876Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (808 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Energy,Ionic strength,Kinetic modeling,Perchlorates,Sulfuric acid Get e-Alerts

Process intensification of a photochemical oxidation reaction using a Rotor-Stator Spinning Disk Reactor: A strategy for scale up

Photochemical transformations have witnessed a remarkable growth of attention in the past decade due to the popularity of photoredox catalysis and the technological progress in energy-efficient light sources. However, the scaling of these photon-induced processes remains a daunting challenge for chemists and engineers in the industry, often discouraging their implementation in the production of fine chemicals and pharmaceuticals. To address this key issue, we report herein the development of a conceptually new photochemical reactor, called photo Rotor-Stator Spinning Disk Reactor. The photocatalyzed gas–liquid oxidation of α-terpinene to the drug ascaridole with Rose Bengal as photocatalyst was achieved with throughputs of over 1 kg·day−1 (270 mmol·h−1) under visible light irradiation. The performance of the reactor is correlated to various process parameters such as rotation speed, liquid flowrate, and catalyst concentration, among others. The conversion and selectivity increase from 37% to 97% and 75% to 90% respectively with an increase of rotation speed from 100 to 2000 RPM. The reactor operates with negligible pressure drop and allows for facile fine-tuning of the mixing efficiency. In this paper, we have also compared the performance of this reactor to other reactors such as the batch, micro, thin-film, and the vortex reactor, among others, and have found the photo-Rotor-Stator Spinning Disk Reactor to have superior productivity as well as higher productivity per volume (2.8 mol ·s−1 ·m−3). The findings of this study can be used to study, design, optimize and scale photochemical processes using the rotor–stator spinning disk reactor.

Extraction of chromium (III) from aqueous waste solution in a novel rotor-stator spinning disc reactor

In this work, the removal of chromium (III) from aqueous waste solution by solvent extraction with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl (P507) as extractant is investigated in a novel rotor-stator spinning disc reactor. The effect of rotational speed, volumetric flow rate and rotor-stator distance on extraction efficiency and volumetric mass transfer coefficient are studied. Experimental results indicates that the maximum values of extraction efficiency and volumetric mass transfer coefficient are 97.2 % and 0.40 1/s, respectively. The mass transfer performance inside the rotor-stator spinning disc reactor exceeds that of conventional reactors. Moreover, it is found that the extraction efficiency increases with the increase of rotational speed but with the decrease of volumetric flow rate and rotor-stator distance. The Volumetric mass transfer coefficient increases as both the rotational speed and volumetric flow rate increase, but decreases with the increase of rotor-stator distance. Furthermore, an analysis on the relationships between volumetric mass transfer coefficient and various parameters is launched by the grey correlation method. The calculation result shows good coincidence with the experimental data.

Experimental investigation on the flow and flow-rotor heat transfer in a rotor-stator spinning disk reactor

In this article, an experimental study has been conducted to provide better understanding of the flow and heat transfer characteristics in the front chamber of a rotor-stator spinning disk reactor. According to the measurements with a one-dimensional hot-wire anemometer probe, the effects of the axial gap width and the temperature on the core swirl ratio are investigated, which are ignored for the past decades. The values of the core swirl ratio are found to decrease by up to 12.2% when G increases from 0.0125 to 0.05 and reduce by up to 6% when the temperature rises from 300 K to 350 K. The measured moment coefficient, which primarily decides the energy dissipation rate, is analyzed according to the flow patterns for the first time. The transient thermochromic liquid crystal technique is used to estimate the heat transfer characteristic. The variations of the moment coefficient, the local Nusselt number and the average Nusselt number appear to be largely determined by the flow patterns. An empirical correlation of the average Nusselt number in the viscous section is determined for the first time, which is aimed to provide better predictions on the average heat transfer capacity. The interaction of the average Nusselt number with the moment coefficient is also introduced. It is speculated that the flow patterns in the chamber plays an important role in the energy dissipation and the heat transfer performance.