Vortex Reactor Research Articles

CatchyCFDEM: Open-source microkinetic modeling of heterogeneous catalysis in Eulerian-Lagrangian CFD applied to oxidative coupling of methane

This work introduces catchyCFDEM, an OpenFOAM-based open-source CFD-DEM framework designed for simulating reactive gas–solid fluidized beds with both gas-phase chemistry and heterogeneous catalytic chemistry. A convective gas–solid heat transfer model is implemented and validated using experimental data gathered in a non-reactive pseudo-2D fluidized bed. Catalytic chemistry including different levels of complexity are included: pseudo-homogeneous, heterogeneous without mass transfer, and heterogeneous with diffusive mass transfer. Verification studies are performed by simulating a packed bed reactor using catchyCFDEM and comparing mass fraction profiles to a 1D plug flow simulation in Cantera. To enhance the computational efficiency of the resource-intensive reactive CFD-DEM simulations, speed-up algorithms such as Particle Agglomeration (PA) and in-situ adaptive tabulation (ISAT) are integrated in catchyCFDEM. As a case study, a gas–solid vortex reactor (GSVR) is simulated using the validated framework. The applicability of the GSVR for the oxidative coupling of methane (OCM) is evaluated based on an isothermal analysis evaluating the influence of several operational and geometrical parameters on the process. Finally, a proof-of-concept adiabatic simulation of the GSVR is presented. The catchyCFDEM framework is made publicly available on GitHub.

Bridging the Gap: Scaling up Processes for the Development of Li-Rich Mn-Rich Layered Oxides

As the global demand for more powerful and long-lasting energy storage solutions continues to grow, Li-rich Mn-rich layered oxides (LMR) emerges as a promising class of next-generation cathode materials for lithium-ion batteries. The LMR material stands out due to its impressive electrochemical specific capacity, surpassing 280 mAh g–1, along with a high discharge voltage exceeding 3.5 V. It also boasts a remarkable specific energy density close to 1000 Wh kg–1, all while maintaining a relatively lower cost.Current synthesis methods often rely on batch coprecipitation reactions followed by the calcination of precipitated Mn-rich precursors. However, the inherent challenges of batch reactions, particularly in terms of reproducibility and quality, prompt the exploration of more sophisticated approaches. Moreover, the transition from benchtop experiments to large-scale production introduces a distinct set of challenges. Parameters that work seamlessly on a smaller scale may not translate as effectively when producing the material at the kilogram scale. This scaling-up process involves navigating complexities such as chemical handling risks, and challenges related to reaction heat transfer and mixing efficiency. These factors collectively underscore the difficulties in achieving precise control over critical precursor characteristics, including primary and secondary particle size, morphology, tap density, and stoichiometry.In response to these challenges, this presentation will discuss an innovative approach. High-quality Li-rich Mn-rich materials are synthesized using continuous coprecipitation, facilitated by a pre-pilot scale Taylor Vortex Reactor (TVR) at the Materials Engineering Research Facility (MERF) in Argonne National Lab (ANL). This emerging synthesis technology offers a scalable solution for the production of high-quality cathode materials. This presentation will delve into the intricacies of the synthesis process, providing valuable insights into the relationship between the characteristics of the synthesized LMR precursors and their subsequent impact on cathode performance.

Process Intensification of CO2 Desorption in a Gas–Liquid Vortex Reactor

Process Intensification of CO₂ Desorption in a Gas–Liquid Vortex Reactor

Enhancing CO2 capture efficiency: Computational fluid dynamics investigation of gas-liquid vortex reactor configurations for process intensification

This study employs non-thermal Computational Fluid Dynamics (CFD) simulations to explore the efficacy of a gas–liquid vortex reactor (GLVR) for intensifying CO2 capture. The investigation concentrates on the multiphase flow and mass transfer behavior in diverse GLVR experimental units. Employing a multiphase Euler-Euler CFD model integrated with a Population Balance Model (CFD-PBM), a mass transfer model, and reaction kinetics, allows us to accurately simulate the reactive absorption of CO2 into aqueous Monoethanolamine (MEA). Experiments are conducted using a 30 wt% MEA solution for CO2 absorption, serving the purpose of model validation. This comprehensive approach enables a simulation of complex dynamics within the GLVR, emphasizing bubble breakage, coalescence, and reactive mass transfer processes. Examining bubble size distribution, pressure drop, CO2 absorption efficiency, and energy input systematically across various reactor geometries and operational conditions, our findings demonstrate that an optimized GLVR configuration significantly enhances CO2 absorption compared to the original design. Furthermore, the optimized GLVR outperforms state-of-the-art process intensification equipment in terms of CO2 absorption rate per unit reactor volume and energy efficiency.

Process Intensification of the Continuous Synthesis of Bio-Derived Monomers for Sustainable Coatings Using a Taylor Vortex Flow Reactor.

We describe the optimization and scale-up of two consecutive reaction steps in the synthesis of bio-derived alkoxybutenolide monomers that have been reported as potential replacements for acrylate-based coatings (Sci. Adv.2020, 6, eabe0026). These monomers are synthesized by (i) oxidation of furfural with photogenerated singlet oxygen followed by (ii) thermal condensation of the desired 5-hydroxyfuranone intermediate product with an alcohol, a step which until now has involved a lengthy batch reaction. The two steps have been successfully telescoped into a single kilogram-scale process without any need to isolate the 5-hydroxyfuranone between the steps. Our process development involved FTIR reaction monitoring, FTIR data analysis via 2D visualization, and two different photoreactors: (i) a semicontinuous photoreactor based on a modified rotary evaporator, where FTIR and 2D correlation spectroscopy (2D-COS) revealed the loss of the methyl formate coproduct, and (ii) our fully continuous Taylor Vortex photoreactor, which enhanced the mass transfer and permitted the use of near-stoichiometric equivalents of O2. The use of in-line FTIR monitoring and modeling greatly accelerated process optimization in the Vortex reactor. This led to scale-up of the photo-oxidation in 85% yield with a projected productivity of 1.3 kg day-1 and a space-time yield of 0.06 mol day-1 mL-1. Higher productivities could be achieved while sacrificing yield (e.g., 4 kg day-1 at 40% yield). The use of superheated methanol at 200 °C in a pressurized thermal flow reactor accelerated the second step, the thermal condensation of 5-hydroxyfuranone, from a 20 h batch reflux reaction (0.5 L, 85 g) to a space time of <1 min in a reactor only 3 mL in volume operating with projected productivities of >700 g day-1. Proof of concept for telescoping the two steps was established with an overall two-step yield of 67%, producing a process with a projected productivity of 1.1 kg day-1 for the methoxybutenolide monomer without any purification of the 5-hydroxyfuranone intermediate.

Highly Efficient Water Plasma Vortex Reactor for Obtaining of Extra Thermal Energy and Transmuted Chemical Elements

A highly efficient Water P lasma Vortex R eactor ( PVR-W) w as d esigned, m anufactured a nd t ested f or t he fi rst ti me [1 ]. The groundwork obtained in plasma aerodynamics, plasma-assisted combustion and LENR physics in our Centre was used in the design of this reactor. This work is a continuation of the previous research [2]–[5]. Pulsed repetitive electric discharge was created inside an argon cavity in swirl water flow in the PVR-W. Electrodes made of clean nickel, copper (99,99% and other metals) were used in this reactor. Double-distilled water was used in our experiment. It was revealed that there is an optimal operating regime of this PVR-W reactor with a high value COP ⇠ 2 - 10. Extra heat power in this operating regime was about 2-10 kW. Self-sustained relaxation oscillations of current and voltage were obtained in this stable operation regime. It was revealed that there are many new transmuted chemical elements in the water sediment after plasma experiments. Both light chemical transmuted elements (such as carbon, aluminium, silicon, sulphur and others) and heavy elements (such as copper, zinc, iron and others) were found in the sediment sample. Chemical analysis of these sediment dust particles was carried out by the EDS method and the optical spectroscopy method. In this paper, experimental results on the direct extraction of electrical power from a heterogeneous plasmoid created by a pulsed repetitive electric discharge in the PVR are also discussed.

Spinning Reactors for Process Intensification of Flow Photochemistry.

The design of new and more sustainable synthetic protocols to access new materials or valuable compounds will have a high impact on the broader chemistry community. In this sense, continuous-flow photochemistry has emerged as a powerful technique which has been employed successfully in various areas such as biopharma, organic chemistry, as well as materials science. However, it is important to note that chemical processes must not only advance towards new or improved chemical transformations, but also implement new technologies that enable new process opportunities. For this reason, the design of novel photoreactors is key to advancing photochemical strategies. In this sense, the use of equipment and techniques embracing processes intensification is important in developing more sustainable protocols. Among the most recent applications, spinning continuous flow reactors, such as rotor reactors or vortex reactors, have shown promising performance as new synthetic tools. Nevertheless, there is currently no review in the literature that effectively summarizes and showcases the most recent applications of such type of photoreactors. Herein, we highlight fundamental aspects and applications of two categories of spinning reactors, the Spinning Disc Reactors (SDRs) and Thin Film Vortex reactors, critiquing the scope and limitations of these advanced processing technologies. Further, we take a view on the future of spinning reactors in flow as a synthetic toolbox to explore new photochemical transformations.

Experimental study of the development of centrifugal circulation in a liquid under various boundary conditions

In this work, an experimental study was carried out on the formation of the structure of a limited vortex flow of a liquid swirled by a flow of another liquid or a gas vortex. The results obtained were compared with the structures that arise in closed vortex reactors, where the movement in the working volume is formed by a rotating disk. During the work, patterns of formation of circulating vortex cells in liquid were revealed. A similarity of the flow structure in the working fluid is observed, regardless of the method of creating the swirl (solid disk, liquid vortex, air vortex).

Studying the Quality of Micromixing in a Single-Stage Microreactor with Intensively Swirled Flows

The work considers the results of experimental and numerical study on the hydrodynamic characteristics of a jet vortex reactor mikro-VSA-1, for which one of the application fields is the synthesis of oxide materials (e.g., perovskite-like material for solar panels). The energy-dissipation rate and micromixing quality are studied (by the iodide–iodate method) for various methods of supplying micro-VSA-1 and T-shaped millireactors with solutions. Numerical modeling reveals the volumes with the highest energy-dissipation rate. The quality of micromixing in the micro-VSA-1 is shown to be much higher than in the T-shaped millireactor, due to, among other things, the fact that the zone with the highest energy-dissipation rate is localized near the neck of the micro-VSA-1.

Hydrodynamic study of the operating window of a stator-rotor vortex chamber reactor

The gas-solid vortex reactor is promising for process intensification while the huge gas consumption and relatively low solids loading can be a hurdle for some industrial applications. Therefore, an improved design, the stator-rotor vortex chamber (STARVOC) has been proposed. To construct the operating window, five materials with sizes of 300–1000 μm and densities of 700–2330 kg/m3 are tested at varying rotational speeds from 300 to 600 RPM and superficial gas flow rates from 0 to 2.3 m/s. A quantitative assessment of the bed's axial uniformity is conducted and a minimum rotational speed is determined. A semi-empirical correlation is developed for the terminal velocity of particles, enabling obtaining maximum solids loading and identifying maximum rotational speed. It is found that the operating window can be divided into six zones and the appropriate zone for uniform fluidization is identified. This framework provides operational guidelines for STARVOC implementation in drying and reactive applications.

Topological flow transformations in a universal vortex bioreactor

Research into the flow structure in an aerial vortex bioreactor is relevant for developing the methods to grow cell cultures. It is especially important in the case when, with the culture growth in the bioreactor, such parameters of the medium as density and viscosity can significantly change, accordingly altering the characteristic flow regimes. Since the cultivated culture is not transparent in most cases, it is impossible to visually determine the flow regime. Therefore, a detailed study of the regularities of flow regimes in an aerial vortex reactor is of great fundamental and applied interest. The research was carried out in an 8.5 L universal glass aerial vortex bioreactor, with a washer freely floating on its surface and stabilizing the motion of the working fluid. The regularities of the vortex motion of the culture medium depend on its volume and the rotation intensity of the activator generating vortex motion in the air. The air vortex generated by the impeller (activator) above the liquid surface spins the working fluid and a free-floating washer. The study reveals that despite the complex configuration of the flow stabilizing device (a free-floating washer), the observed vortex structure and its dynamics with increasing flow swirl intensity coincides with the structure of a confined vortex flow in a cylindrical container for both single-fluid and immiscible two-fluid configurations.

A computational-fluid-dynamics model for particle-size evolution in the presence of turbulent mixing

A computational model for the simulation of the particle-size evolution of nanoparticles in mixing-controlled processes is presented. This model accounts for the effect of molecular mixing on particle-size evolution when mixing time scales are smaller than the phase-space time scales. The approach is formulated by deriving evolution equations for the moments of joint mixture fraction-size moments PDF, and closing such moment equations using the conditional quadrature method of moments. A test case consisting of a mixing-dependent aggregation problem in a multi-inlet vortex reactor is considered. The results accounting for the correlation between mixture fraction and size moments are compared against those computed neglecting such correlation to demonstrate its impact on the model predictions. The average particle volumes are different in the order of 104mm3 at the reactor exit under the studied conditions.

THE STRUCTURE OF THE SWIRLING FLOW IN THE COUNTERFLOW VORTEX REACTOR

Two promising designs of counterflow vortex reactor were numerically investigated. Such apparatus utilizes reverse flow to withdraw thermal energy and products from interelectrode area. Complex gasdynamic structure of the water-vapor flow was investigated using turbulent three-dimensional simulation employing Reynolds averaged Navier-Stokes equations along with SST k turbulence model technique tested in earlier papers. Presented velocity profiles and heat flux reports demonstrate viability of both approaches.

Effect of Temperature on a Vortex Reactor for Hydrodynamic Cavitation

The oil and gas sector has recently shown an interest in hydrodynamic cavitation for oil enhancement, as it allows reducing transportation and refinement costs. This work presents a fluid-dynamic study of Colombian oil at different temperatures passing through a vortex reactor. First, an experimental design was elaborated, establishing the temperature and quantity of the injected hydrogen donor as factors and the final viscosity of oil as the response. Then, a numerical model was developed in the Ansys Fluent software using multiphase models, where the required properties of the fluid were obtained via laboratory tests and the Aspen HYSYS software. The results obtained from numerical experimentation were analyzed, and it was observed that the final viscosity was less affected by the temperature than by the hydrogen donor. Moreover, numerical modeling showed an exponential relation between vapor generation and temperature. The experimental and numerical data were compared, and it was found that the temperatures established in the experimental design were not high enough to generate a significant amount of vapor, which is why the decrease in viscosity was lower.

High-Productivity Single-Pass Electrochemical Birch Reduction of Naphthalenes in a Continuous Flow Electrochemical Taylor Vortex Reactor.

We report the development of a single-pass electrochemical Birch reduction carried out in a small footprint electrochemical Taylor vortex reactor with projected productivities of >80 g day–1 (based on 32.2 mmol h–1), using a modified version of our previously reported reactor [Org. Process Res. Dev.2021, 25, 7, 1619–1627], consisting of a static outer electrode and a rapidly rotating cylindrical inner electrode. In this study, we used an aluminum tube as the sacrificial outer electrode and stainless steel as the rotating inner electrode. We have established the viability of using a sacrificial aluminum anode for the electrochemical reduction of naphthalene, and by varying the current, we can switch between high selectivity (>90%) for either the single ring reduction or double ring reduction with >80 g day–1 projected productivity for either product. The concentration of LiBr in solution changes the fluid dynamics of the reaction mixture investigated by computational fluid dynamics, and this affects equilibration time, monitored using Fourier transform infrared spectroscopy. We show that the concentrations of electrolyte (LiBr) and proton source (dimethylurea) can be reduced while maintaining high reaction efficiency. We also report the reduction of 1-aminonaphthalene, which has been used as a precursor to the API Ropinirole. We find that our methodology produces the corresponding dihydronaphthalene with excellent selectivity and 88% isolated yield in an uninterrupted run of >8 h with a projected productivity of >100 g day–1.

Ultrasound Based Noninvasive Estimation of Mixing Time in a Vortex Reactor

Ultrasound Based Noninvasive Estimation of Mixing Time in a Vortex Reactor

Removal of antibiotics from milk via ozonation in a vortex reactor

Antibiotics (ABX) residues occur frequently in milk, causing considerable wastage of medicated milk and serious economic losses, and making the issue a burden for the dairy industry. Improper disposal of medicated milk harms dairy production, animal welfare, and the environment. This work studies the use of ozonation in a vortex reactor for removing ceftiofur hydrochloride (CEF), sulfamonomethoxine sodium (SMM), marbofloxacin (MAR) and oxytetracycline (OTC) from milk. In terms of residual concentration, O3 efficiency and the degradation kinetics of the various O3-involving processes in the vortex reactor, ABX removal via ozonation is better using stronger vortexing, which induces hydrodynamic cavitation. CEF undergoes the fastest degradation, followed by SMM, MAR, and OTC. High ABX hydrophobicity favors ABX degradation via ozonation, O3/H2O2, and O3/Na2S2O8. ABX oxidation by •OH at the O3 gas-bubble/milk interface is the principle degradation pathway, except for MAR. ABX degradation follows pseudo-first-order kinetics and is affected by initial ABX concentration, O3 concentration/flow rate, reaction temperature, and milk components to varying degrees. Under optimal ozonation conditions, ABX residues meet the maximum limits as set by the European Commission and no antimicrobial activity was observed. The decontaminated milk was therefore suggested to be reused as calf food, animal feed, organic fertilizer, etc.

Gas-solid hydrodynamics in a stator-rotor vortex chamber reactor

The gas–solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid’s kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics. A constructed fluidization flow regime map for a fixed solids loading of 100 g shows that the bed can only be fluidized for a rotation speed between 200 and 400 RPM. Below 200 RPM, particles settle down on the bottom plate and cannot form a stable bed due to inertia and friction. Above 400 RPM, the bed cannot be fluidized with superficial velocities up to 1.8 m/s (air flow rate of 90 Nm3/h). The bed thickness shows some non-uniformities, being smaller at the top of the bed than at the bottom counterpart. However by increasing the air flow rate or rotation speed the axial nonuniformity can be resolved. The bed pressure drop first increases with increasing gas flow rate and then levels off, showing similar characteristics as conventional fluidized beds. Theoretical pressure drops calculated from mathematical models such as Kao et al. model agree well with experimental measurements. Particle velocity discrepancies between the top and bottom particles reveal that the impact of gravity cannot be completely neglected. Design guidelines and possible applications for further development of STARVOC concept are proposed based on fundamental data provided in this work.

Development of an Active and Mechanically Stable Catalyst for the Oxidative Coupling of Methane in a Gas–Solid Vortex Reactor

Development of an Active and Mechanically Stable Catalyst for the Oxidative Coupling of Methane in a Gas–Solid Vortex Reactor

Effect of gas-induced inlet design on flow pattern and energy loss for small-scale countercurrent vortex reactor: Numerical simulation and experimental investigation

Small-scale vortex reactors have gained attention in the fields of gas-particle multiphase reactions because of the great potential of process intensification. Their performances highly depend upon the vortex flow-induced structure. However, its role has not yet been completely understood. To address the effect of the vortex flow-induced design of a small-scale countercurrent vortex reactor, the gas-induced inlet design with varying aspect ratio (the ratio of inlet height to inlet width of 0.56, 2.25, and 5.06) was designed to numerically and experimentally investigate the flow distribution, energy loss, and process intensification. It was found that for a given flow rate (inlet velocity), and with increasing aspect ratio the maximum tangential velocity is increased whereas the decay of the vortex flow is decreased. The semi-empirical equations were further developed to characterize the spatial distribution of the gas tangential velocity. There is no significant differentiation in axial velocity, but the static pressure near the wall increases significantly. Moreover, the pressure drop of the reactor increases as the inlet aspect ratio increases. Finally, an aspect ratio of 2.25 was found to be optimum for potential multiphase mixing and mass transfer. The results may provide a positive reference for the vortex-flow-based process intensification.