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Letchumanan K, Abdullah NH, Abdul-Aziz A. A comparative study on the influence of equipment design on the efficiency of dynamic maceration of Azadirachta excelsa leaves. Prep Biochem Biotechnol 2024; 54:749-763. [PMID: 37990367 DOI: 10.1080/10826068.2023.2282529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Dynamic maceration facilitates diffusion in solid-liquid extraction through controlling temperature and providing agitation. However, equipment design for dynamic maceration in previous investigations resulted in inadequate homogeneity of temperature and solid dispersion. A laboratory scale extractor was designed to aid the heat and mass transfer process while preventing solvent vaporization when performing dynamic maceration in a controlled environment. This study aimed to evaluate the efficiency of dynamic maceration using the laboratory scale extractor compared to a shaker incubator to extract triterpenoid saponins from Azadirachta excelsa leaves. The dynamic maceration of A. excelsa leaves was optimized using a Face-centered central composite design (FCCCD) with response surface methodology (RSM). Independent variables analyzed include ethanol-to-chloroform ratio, extraction temperature, extraction time, and sample-to-solvent ratio, while responses include yield of extract and triterpenoid saponins content (TSC). Optimum conditions were ethanol-to-chloroform ratio of 90:10, extraction temperature of 45 °C, extraction time of 60 minutes, and sample-to-solvent ratio of 1:50 g/ml. There was a significant percentage of increase in yield of extract and TSC by 41.1% and 13.3%, respectively, for the laboratory scale extractor compared to the shaker incubator. This study showed the importance of equipment design in enhancing triterpenoid saponins extraction through elevating the efficiency of the dynamic maceration process.
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Affiliation(s)
- Kahviyaah Letchumanan
- Department of Chemical and Environmental Engineering, International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia
| | - Nor Hayati Abdullah
- Natural Product Division, Forest Research Institute Malaysia, Kepong, Malaysia
| | - Azila Abdul-Aziz
- Department of Chemical and Environmental Engineering, International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia
- Institute of Bioproduct Development, Universiti Teknologi Malaysia, Johor, Malaysia
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2
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Yu J, Cheng W, Ni J, Li C, Su X, Yan H, Bao F, Hou L. High-Speed Generation of Microbubbles with Constant Cumulative Production in a Glass Capillary Microfluidic Bubble Generator. MICROMACHINES 2024; 15:752. [PMID: 38930722 PMCID: PMC11205313 DOI: 10.3390/mi15060752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
This work reports a simple bubble generator for the high-speed generation of microbubbles with constant cumulative production. To achieve this, a gas-liquid co-flowing microfluidic device with a tiny capillary orifice as small as 5 μm is fabricated to produce monodisperse microbubbles. The diameter of the microbubbles can be adjusted precisely by tuning the input gas pressure and flow rate of the continuous liquid phase. The co-flowing structure ensures the uniformity of the generated microbubbles, and the surfactant in the liquid phase prevents coalescence of the collected microbubbles. The diameter coefficient of variation (CV) of the generated microbubbles can reach a minimum of 1.3%. Additionally, the relationship between microbubble diameter and the gas channel orifice is studied using the low Capillary number (Ca) and Weber number (We) of the liquid phase. Moreover, by maintaining a consistent gas input pressure, the CV of the cumulative microbubble volume can reach 3.6% regardless of the flow rate of the liquid phase. This method not only facilitates the generation of microbubbles with morphologic stability under variable flow conditions, but also ensures that the cumulative microbubble production over a certain period of time remains constant, which is important for the volume-dominated application of chromatographic analysis and the component analysis of natural gas.
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Affiliation(s)
- Jian Yu
- Key Laboratory of Measuring & Online Assessment of Energy for Jiangsu Province Market Regulation, Suzhou Institute of Metrology, Suzhou 215128, China (C.L.)
- Zhejiang Provincial Key Laboratory of Flow Measurement Technology, China Jiliang University, Hangzhou 310018, China
| | - Wei Cheng
- Key Laboratory of Measuring & Online Assessment of Energy for Jiangsu Province Market Regulation, Suzhou Institute of Metrology, Suzhou 215128, China (C.L.)
| | - Jinchun Ni
- Key Laboratory of Measuring & Online Assessment of Energy for Jiangsu Province Market Regulation, Suzhou Institute of Metrology, Suzhou 215128, China (C.L.)
| | - Changwu Li
- Key Laboratory of Measuring & Online Assessment of Energy for Jiangsu Province Market Regulation, Suzhou Institute of Metrology, Suzhou 215128, China (C.L.)
| | - Xinggen Su
- Dalian Institute of Metrology Inspection and Testing Co., Ltd., Dalian 116000, China
| | - Hui Yan
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Fubing Bao
- Zhejiang Provincial Key Laboratory of Flow Measurement Technology, China Jiliang University, Hangzhou 310018, China
| | - Likai Hou
- Zhejiang Provincial Key Laboratory of Flow Measurement Technology, China Jiliang University, Hangzhou 310018, China
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3
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Rajasekaran SP, Huynh B, Fugolin APP. Tailoring Microemulsification Techniques for the Encapsulation of Diverse Cargo: A Systematic Analysis of Poly (Urea-Formaldehyde) Microcapsules. J Funct Biomater 2024; 15:117. [PMID: 38786629 PMCID: PMC11122521 DOI: 10.3390/jfb15050117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/22/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
Cargo encapsulation through emulsion-based methods has been pondered over the years. Although several microemulsification techniques have been employed for the microcapsule's synthesis, there are still no clear guidelines regarding the suitability of one technique over the others or the impacts on the morphological and physicochemical stability of the final particles. Therefore, in this systematic study, we investigated the influence of synthesis parameters on the fabrication of emulsion-based microcapsules concerning morphological and physicochemical properties. Using poly(urea-formaldehyde) (PUF) microcapsules as a model system, and after determining the optimal core/shell ratio, we tested three different microemulsification techniques (magnetic stirring, ultrasonication, and mechanical stirring) and two different cargo types (100% TEGDMA (Triethylene glycol dimethacrylate) and 80% TEGDMA + 20% DMAM (N,N-Dimethylacrylamide)). The resulting microcapsules were characterized via optical and scanning electron microscopies, followed by size distribution analysis. The encapsulation efficiency was obtained through the extraction method, and the percentage reaction yield was calculated. Physicochemical properties were assessed by incubating the microcapsules under different osmotic pressures for 1 day and 1, 2, or 4 weeks. The data were analyzed statistically with one-way ANOVA and Tukey's tests (α = 0.05). Overall, the mechanical stirring resulted in the most homogeneous and stable microcapsules, with an increased reaction yield from 100% to 50% in comparison with ultrasonication and magnetic methods, respectively. The average microcapsule diameter ranged from 5 to 450 µm, with the smallest ones in the ultrasonication and the largest ones in the magnetic stirring groups. The water affinities of the encapsulated cargo influenced the microcapsule formation and stability, with the incorporation of DMAM leading to more homogeneous and stable microcapsules. Environmental osmotic pressure led to cargo loss or the selective swelling of the shells. In summary, this systematic investigation provides insights and highlights commonly overlooked factors that can influence microcapsule fabrication and guide the choice based on a diligent analysis of therapeutic niche requirements.
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Affiliation(s)
| | | | - Ana Paula P. Fugolin
- Division of Biomaterials & Biomedical Sciences, Department of Oral Rehabilitation and Biosciences, School of Dentistry, Oregon Health & Science University, 2730 S Moody Ave., Portland, OR 97201, USA; (S.P.R.); (B.H.)
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4
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Zeolite NaX Mass and Propeller Agitator Speed Impact on Copper Ions Sorption. Processes (Basel) 2023. [DOI: 10.3390/pr11010264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Sorption is often carried out in stirred batch reactors without any consideration of how much mixing is sufficient to avoid the effect of diffusion without compromising yield and cost due to overmixing. Therefore, the focus of this work was to study how the maximum sorption capacity, removal efficiency, kinetics and power consumption (P) of the studied process are affected by different mixing speeds, i.e., impeller speed/minimum impeller speed for complete suspension (N/NJS) ratio values and zeolite suspension mass concentrations. Experiments were conducted in a baffled reactor with the propeller at a standard off-bottom clearance. In addition to the experimental studies, numerical modelling approaches were carried out to investigate the sorption process using a transient multiphase computational fluid dynamics model and fitting selected kinetic models. The results show that an increase in zeolite mass leads to a slight increase in the NJS and consequently PJS. The impeller speed affects the velocities, power consumption, kinetics, final amount and removal efficiency of copper sorbed. The experimentally determined kinetic data fit Ritchie’s kinetic model well. However, for two experiments, performed at N/NJS ratios of 0.8 and 0.6, Mixed kinetic model fits better, suggesting that the second-order reaction is suppressed by diffusion. Due to the influence of diffusion, the experimentally determined sorption efficiency decreased from 59.377% to 54.486% and 46.372% for N/NJS ratios of 0.8 and 0.6, respectively.
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5
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Mendoza-Escamilla VX, Rivadeneyra-Romero G, Mollinedo H, Yañez-Varela JA, Gonzalez-Neria I, Alonzo-Garcia A, Martínez-Delgadillo SA. Effect of Modified Impellers with Added Leading Edges Flanges on Pumping Efficiency in Agitated Tanks. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c03321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Victor X. Mendoza-Escamilla
- Universidad Autónoma Metropolitana, Av. San Pablo 180, Col. Reynosa Tamaulipas, México CityC.P. 02200, México
| | - Gabriela Rivadeneyra-Romero
- Depto. Ingeniería de Petróleo, Universidad del Istmo, Ciudad Universitaria, S/N, Tehuantepec, OaxacaC.P. 70760, México
| | - Helvio Mollinedo
- Instituto Politécnico Nacional, UPIITA. Av. IPN 2580 Col. La Laguna Ticomán, México CityC.P. 07340, México
| | - Juan Antonio Yañez-Varela
- Unidad de Estudios Superiores de Tultitlan, Universidad Mexiquense del Bicentenario, Edo. MéxC.P. 54910, México
| | - Israel Gonzalez-Neria
- Área Aviónica, Dir. Gestión de la Producción, Universidad Tecnológica de Nezahualcóyotl, Cto. Universidad Tecnológica s/n, Nezahaualcóyotl, Estado de MéxicoC.P. 57000, México
| | - Alejandro Alonzo-Garcia
- CONACyT-Tecnológico Nacional de México/Instituto Tecnológico de Nuevo León-Centro de Investigación e Innovación Tecnológica. Av. de la Alianza No. 507, Nuevo LeónC.P. 66629, México
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6
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Konopacki M, Jabłońska J, Dubrowska K, Augustyniak A, Grygorcewicz B, Gliźniewicz M, Wróblewski E, Kordas M, Dołęgowska B, Rakoczy R. The Influence of Hydrodynamic Conditions in a Laboratory-Scale Bioreactor on Pseudomonas aeruginosa Metabolite Production. Microorganisms 2022; 11:microorganisms11010088. [PMID: 36677380 PMCID: PMC9866481 DOI: 10.3390/microorganisms11010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/23/2022] [Accepted: 12/25/2022] [Indexed: 12/31/2022] Open
Abstract
Hydrodynamic conditions are critical in bioprocessing because they influence oxygen availability for cultured cells. Processes in typical laboratory bioreactors need optimization of these conditions using mixing and aeration control to obtain high production of the desired bioproduct. It could be done by experiments supported by computational fluid dynamics (CFD) modeling. In this work, we characterized parameters such as mixing time, power consumption and mass transfer in a 2 L bioreactor. Based on the obtained results, we chose a set of nine process parameters to test the hydrodynamic impact on a selected bioprocess (mixing in the range of 0-160 rpm and aeration in the range of 0-250 ccm). Therefore, we conducted experiments with P. aeruginosa culture and assessed how various hydrodynamic conditions influenced biomass, pyocyanin and rhamnolipid production. We found that a relatively high mass transfer of oxygen (kLa = 0.0013 s-1) connected with intensive mixing (160 rpm) leads to the highest output of pyocyanin production. In contrast, rhamnolipid production reached maximal efficiency under moderate oxygen mass transfer (kLa = 0.0005 s-1) and less intense mixing (in the range of 0-60 rpm). The results indicate that manipulating hydrodynamics inside the bioreactor allows control of the process and may lead to a change in the metabolites produced by bacterial cells.
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Affiliation(s)
- Maciej Konopacki
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
- Department of Laboratory Medicine, Chair of Microbiology, Immunology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
- Correspondence: (M.K.); (A.A.)
| | - Joanna Jabłońska
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
| | - Kamila Dubrowska
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
| | - Adrian Augustyniak
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
- Chair of Building Materials and Construction Chemistry, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
- Institute of Biology, University of Szczecin, Wąska 13 Str., 71-415 Szczecin, Poland
- Correspondence: (M.K.); (A.A.)
| | - Bartłomiej Grygorcewicz
- Department of Laboratory Medicine, Chair of Microbiology, Immunology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
| | - Marta Gliźniewicz
- Department of Laboratory Medicine, Chair of Microbiology, Immunology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
| | - Emil Wróblewski
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
| | - Marian Kordas
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
| | - Barbara Dołęgowska
- Department of Laboratory Medicine, Chair of Microbiology, Immunology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
| | - Rafał Rakoczy
- Department of Chemical and Process Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Avenue 42, 71-065 Szczecin, Poland
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7
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Solid-liquid suspension in a stirred tank driven by an eccentric-shaft: Electrical resistance tomography measurement. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Mollinedo H, Mendoza-Escamilla VX, Rivadeneyra-Romero G, Gonzalez-Neria I, Yañez-Varela JA, Alonzo-Garcia A, Lugo-Hinojosa J, Martínez-Delgadillo SA. Power Consumption and Energy Dissipation Rate Reduction in Agitated Tanks by Control Rods Attached to a Pitched Blade Impeller. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c01623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Helvio Mollinedo
- Instituto Politécnico Nacional, UPIITA, Depto. Ingeniería, Av. IPN 2580, Col. La Laguna Ticomán, C.P. 07340 Mexico City, Mexico
| | - Victor X. Mendoza-Escamilla
- Universidad Autónoma Metropolitana. Av. San Pablo 180, Col. Reynosa Tamaulipas, C.P. 02200 Mexico City, Mexico
| | - Gabriela Rivadeneyra-Romero
- Petroleum Engineering Department, Universidad del Istmo, University City, S/N, Tehuantepec Oaxaca C.P. 70760, Mexico
| | - Israel Gonzalez-Neria
- Universidad Autónoma Metropolitana. Av. San Pablo 180, Col. Reynosa Tamaulipas, C.P. 02200 Mexico City, Mexico
| | | | - Alejandro Alonzo-Garcia
- CONACyT-Tecnológico Nacional de México/Instituto Tecnológico de Nuevo León-Centro de Investigación e Innovación Tecnológica, Av. de la Alianza No. 507, Apodaca, Nuevo León CP 66629, Mexico
| | - Jesús Lugo-Hinojosa
- Universidad Autónoma Metropolitana. Av. San Pablo 180, Col. Reynosa Tamaulipas, C.P. 02200 Mexico City, Mexico
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9
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Scale-up study of aerated coaxial mixing reactors containing non-newtonian power-law fluids: Analysis of gas holdup, cavity size, and power consumption. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Computational prediction of the just-suspended speed, N, in stirred vessels using the lattice Boltzmann method (LBM) coupled with a novel mathematical approach. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2021.117411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Dai YX, Wang ZH, Fan YW, Cheng ZQ. Analysis of mixing effect and power consumption of cone-bottom dual Rushton turbines stirred tank. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-021-02010-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Ali H, Zhu S, Solsvik J. Effects of geometric parameters on volumetric mass transfer coefficient of non-Newtonian fluids in stirred tanks. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2021. [DOI: 10.1515/ijcre-2021-0210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Scaling up stirred tanks is a significant challenge because of the research gaps between laboratory and industrial-scale setups. It is necessary to understand the effects of scale-up on the mass transfer in stirred tanks, and this requires meticulous experimental analysis. The present study investigates the effects of tank size and aspect ratio (
H
L
T
${H}_{L}}{T}$
) on the volumetric mass transfer coefficients of shear-thinning fluids. The experiments were conducted in three stirred tanks of different sizes (laboratory and pilot scale) and geometries (standard and nonstandard).
H
L
T
${H}_{L}}{T}$
was 1 for the standard tanks and 3.5 for the nonstandard stirred tanks. Three sizes of stirred tanks were used: 11 L with
H
L
T
${H}_{L}}{T}$
of 1, 40 L with
H
L
T
${H}_{L}}{T}$
of 3.5, and 47 L with
H
L
T
${H}_{L}}{T}$
of 1. Impeller stirring speeds and gas flow rates were in the range of 800–900 rev min−1 and 8–10 L min−1, respectively. The volumetric mass transfer coefficient was estimated based on the dissolved oxygen concentration in the fluids, and the effects of rheology and operating conditions on the volumetric mass transfer coefficient were observed. The volumetric mass transfer coefficient decreased as tank size increased and increased with an increase in operating conditions, but these effects were also clearly influenced by fluid rheology. The impacts of scale-up and operating conditions on the volumetric mass transfer coefficient decreased as liquid viscosity increased.
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Affiliation(s)
- Haider Ali
- Department of Chemical Engineering , Norwegian University of Science and Technology , Trondheim , NO-7491 , Norway
| | - Sofia Zhu
- Politecnico di Milano , Piazza Leonardo da Vinci, 32, 20133 Milan , Italy
| | - Jannike Solsvik
- Department of Chemical Engineering , Norwegian University of Science and Technology , Trondheim , NO-7491 , Norway
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Comparative Study on the Power Consumption and Flow Field Characteristics of a Three-Blade Combined Agitator. Processes (Basel) 2021. [DOI: 10.3390/pr9111962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The three-blade combined agitator consists of two propulsion blades of the same type (including planar propeller blades b, δ = 36.87°) and a curved blade (θ = 30°). Using numerical simulation methods, the power characteristics, flow field distribution, turbulence characteristics and dead zone percentage of two kinds of three-blade combined agitators (TBCAs) from laminar flow to turbulent flow in a mixing vessel were studied. Moreover, the torque measurement method was used to perform experimental verification. The results show that the predicted power curve is consistent with the experimental results. The fluid velocity near the propeller blades in the TBC-B type agitator (δ = 36.87°) is significantly high, and the maximum increase of the total velocity can reach 30.3%. The fluid flow velocity near the curved blades is increased, and the radial diffusion ability of the fluid at the bottom of the stirring vessel is enhanced. When mixing low-viscosity fluids, the TBC-B type agitator can increase the fluid velocity near the paddle area, with a maximum increase of 22.1%. The vertical combination of curved blades and planar propeller blades can effectively reduce the tangential velocity and increase the axial and radial velocities. When stirring high-viscosity fluids, the speed of the TBC-B type agitator in the near paddle area and far end of the blade is higher than that of the TBC-A type agitator. Under the same conditions, the TBC-B-type agitator exhibits superior fluid discharge performance and can be used in a wider range of viscosities. When Re = 44,910, the dead zone percentage of the TBC-A type agitator is 0.0216. The percentage of dead zones produced by the TBC-B-type agitator is smaller, and the mixing effect is superior to that of the TBC-A-type agitator.
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Chanquia SN, Vernet G, Kara S. Photobioreactors for cultivation and synthesis: Specifications, challenges, and perspectives. Eng Life Sci 2021; 22:712-724. [PMID: 36514531 PMCID: PMC9731602 DOI: 10.1002/elsc.202100070] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/06/2021] [Accepted: 09/10/2021] [Indexed: 12/16/2022] Open
Abstract
Due to their versatility and the high biomass yield produced, cultivation of phototrophic organisms is an increasingly important field. In general, open ponds are chosen to do it because of economic reasons; however, this strategy has several drawbacks such as poor control of culture conditions and a considerable risk of contamination. On the other hand, photobioreactors are an attractive choice to perform cultivation of phototrophic organisms, many times in a large scale and an efficient way. Furthermore, photobioreactors are being increasingly used in bioprocesses to obtain valuable chemical products. In this review, we briefly describe different photobioreactor set-ups, including some of the recent designs, and their characteristics. Additionally, we discuss the current challenges and advantages that each different type of photobioreactor presents, their applicability in biocatalysis and some modern modeling tools that can be applied to further enhance a certain process.
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Affiliation(s)
- Santiago N. Chanquia
- Biocatalysis and Bioprocessing GroupDepartment of Biological and Chemical EngineeringAarhus UniversityAarhusDenmark
| | - Guillem Vernet
- Biocatalysis and Bioprocessing GroupDepartment of Biological and Chemical EngineeringAarhus UniversityAarhusDenmark
| | - Selin Kara
- Biocatalysis and Bioprocessing GroupDepartment of Biological and Chemical EngineeringAarhus UniversityAarhusDenmark
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15
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Validation of Novel Lattice Boltzmann Large Eddy Simulations (LB LES) for Equipment Characterization in Biopharma. Processes (Basel) 2021. [DOI: 10.3390/pr9060950] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Detailed process and equipment knowledge is crucial for the successful production of biopharmaceuticals. An essential part is the characterization of equipment for which Computational Fluid Dynamics (CFD) is an important tool. While the steady, Reynolds-averaged Navier–Stokes (RANS) k − ε approach has been extensively reviewed in the literature and may be used for fast equipment characterization in terms of power number determination, transient schemes have to be further investigated and validated to gain more detailed insights into flow patterns because they are the method of choice for mixing time simulations. Due to the availability of commercial solvers, such as M-Star CFD, Lattice Boltzmann simulations have recently become popular in the industry, as they are easy to set up and require relatively low computing power. However, extensive validation studies for transient Lattice Boltzmann Large Eddy Simulations (LB LES) are still missing. In this study, transient LB LES were applied to simulate a 3 L bioreactor system. The results were compared to novel 4D particle tracking (4D PTV) experiments, which resolve the motion of thousands of passive tracer particles on their journey through the bioreactor. Steady simulations for the determination of the power number followed a structured workflow, including grid studies and rotating reference frame volume studies, resulting in high prediction accuracy with less than 11% deviation, compared to experimental data. Likewise, deviations for the transient simulations were less than 10% after computational demand was reduced as a result of prior grid studies. The time averaged flow fields from LB LES were in good accordance with the novel 4D PTV data. Moreover, 4D PTV data enabled the validation of transient flow structures by analyzing Lagrangian particle trajectories. This enables a more detailed determination of mixing times and mass transfer as well as local exposure times of local velocity and shear stress peaks. For the purpose of standardization of common industry CFD models, steady RANS simulations for the 3 L vessel were included in this study as well.
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16
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Digital Twinning Process for Stirred Tank Reactors/Separation Unit Operations through Tandem Experimental/Computational Fluid Dynamics (CFD) Simulations. Processes (Basel) 2020. [DOI: 10.3390/pr8111511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Computational fluid dynamics simulations (CFD) were used to evaluate mixing in baffled and unbaffled vessels. The Reynolds-averaged Navier−Stokes k–ε model was implemented in OpenFOAM for obtaining the fluid flow field. The 95% homogenization times were determined by tracer tests. Experimental tests were conducted by injecting sodium chloride into the vessel and measuring the conductivity with two conductivity probes, while the simulations replicated the experimental conditions with the calculation of the transport of species. It was found that the geometry of the system had a great effect on the mixing time, since the irregular flow distribution, which can be obtained with baffles, can lead to local stagnation zones, which will increase the time needed to achieve the homogenization of the solute. It was also found that measuring local, pointwise concentrations can lead to a high underestimation of the global mixing time required for the homogenization of the entire vessel. Dissolution of sucrose was also studied experimentally and by mathematical modeling. The dissolution of sucrose was found to be kinetically limited and a very good agreement was found between the experiments and the modeling approach. The extent of the applicability of CFD simulations was evaluated for enabling rapid process design via simulations.
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Abstract
Turbulent flows featuring additional scalar fields, such as chemical species or temperature, are common in environmental and industrial applications. Their physics is complex because of a broad range of scales involved; hence, efficient computational approaches remain a challenge. In this paper, we present an overview of such flows (with no particular emphasis on combustion, however) and we recall the major types of micro-mixing models developed within the statistical approaches to turbulence (the probability density function approach) as well as in the large-eddy simulation context (the filtered density function). We also report on some trends in algorithm development with respect to the recent progress in computing technology.
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