Article
Engineering, Chemical
Ege Ertekin, John M. Kavanagh, David F. Fletcher, Dale D. McClure
Summary: This paper presents a model that accurately simulates the hydrodynamics of bubble columns and shows good agreement with experimental data. The study also takes into account the presence of surface-active compounds in industrial processes, providing computational predictions in line with experimental measurements. Furthermore, a dataset has been provided to facilitate validation work by others and identify areas for further research.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Mechanics
Y. Mezui, M. Obligado, A. Cartellier
Summary: This study revisits the hydrodynamics of bubble columns in the heterogeneous regime. By conducting experiments and analyzing data, the self-organization phenomenon in the heterogeneous regime and the applicability of velocity scaling under different conditions are confirmed. Furthermore, the importance of velocity scaling for coalescing media is discussed.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Cheng-Hsien Lee
Summary: This study developed a multiphase model with a novel evolution equation to address the issues of shear-induced volume change and pore-pressure feedback in submarine granular flows simulated using an Eulerian-Eulerian two-phase model. The evolution equation effectively describes the relaxation process of static solid pressure and shear-induced volume change, allowing the model to capture phenomena such as time delays in initiating flows and different collapse processes for differently packed columns.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Marine
Han Cheng, Yong Liu, Fu-Ren Ming, Peng-Nan Sun
Summary: This paper studies the bouncing and coalescing behavior of two bubbles rising side by side in a fluid, using a multi-phase smoothed particle hydrodynamics (SPH) model. The numerical simulation is validated through various testing cases and the effects of viscous forces and surface tensions on bubble interaction are considered.
Article
Engineering, Environmental
Quan Liu, Jingchang Zhang, Xiaoping Guan, Ning Yang
Summary: A simplified correlative model was developed to consider the surfactant effect on the average drag coefficient in CFD simulation of two-phase flow. This model can improve gas holdup prediction in the homogeneous regime and reasonably estimate gas holdup in the heterogeneous regime by considering both surfactant effect and swarm effect. The model reproduces the peak of gas holdup at a certain surfactant concentration.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Linmin Li, Weisen Xu, Xiaojun Li, Xun Sun, Guojun Yang, Zuchao Zhu
Summary: A two-way discrete-continuum transition algorithm is used in a multiscale model to simulate bubble injection, coalescence, and its interaction with the bath and slag layer in gas-stirring vessels. The interfaces are captured using the volume of fluid (VOF) and adaptive mesh refinement (AMR) methods. For unresolved microbubbles, a discrete phase model (DPM) is used, and the transition between DPM and VOF-AMR is achieved through introduced criteria and source terms. The predicted results agree well with experimental measurements, and the modeling framework accurately represents the behavior of bubbling flow and slag layer.
Article
Computer Science, Interdisciplinary Applications
P. -N. Sun, D. Le Touze, G. Oger, A. -M. Zhang
Summary: In this research, the Δ-SPH model is extended to simulate multiphase and strongly compressible flows, considering energy equations and adjusting particle smoothing lengths over time. A new volume adaptive scheme is proposed to control particle volumes and maintain a homogeneous volume distribution in the flow field.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
Shimpei Saito, Alessandro De Rosis, Linlin Fei, Kai Hong Luo, Ken-ichi Ebihara, Akiko Kaneko, Yutaka Abe
Summary: The research findings suggest that the CM-based LBM can successfully reproduce various boiling mechanisms without the need for artificial input, including nucleate boiling, transition boiling, and film boiling. Experimental observations and simulation results are consistent, showing intermittent solid-liquid contact during the film-boiling stage.
Article
Engineering, Geological
Mohamad Chaaban, Yousef Heider, Bernd Markert
Summary: In this paper, a reliable micro-to-macroscale framework is presented to model multiphase fluid flow through fractured porous media. The lattice Boltzmann method (LBM) is utilized within the phase-field modeling (PFM) of fractures to achieve this. New phase-field-dependent relationships for various parameters are proposed and a multiscale concept for coupling is achieved. Numerical simulations on real microgeometries of fractured porous media validate the reliability of the model.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Engineering, Chemical
Chen Li, Yongli Ma, Mingyan Liu, Kaiyue Wang
Summary: In this study, PIV was used to investigate the flow fields in gas-liquid mini-bubble columns. It was found that the increase of superficial liquid velocity could change the trajectory and size of bubbles, and the terminal velocity of bubbles was influenced by bubble buoyancy and flow resistance, slightly increasing with bubble coalescence.
Article
Mechanics
Stephane Perrard, Alienor Riviere, Wouter Mostert, Luc Deike
Summary: In this study, the deformation modes and lifetime of a bubble in a turbulent flow are investigated through numerical simulations and theoretical analysis. Two temporal regimes are observed during the bubble deformation process, with the first regime driven by inertial forces and the second regime resulting from a balance between inertial forces and surface tension.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Daniel J. Ruth, Marlone Vernet, Stephane Perrard, Luc Deike
Summary: The study shows that the average rising speed of bubbles in liquid decreases with increasing turbulence intensity, following a specific proportional relationship. This is mainly due to the effects of nonlinear drag and the nearly isotropic behavior of the slip velocity on the mean rise speed.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Kazuki Maeda, Masanobu Date, Kazuyasu Sugiyama, Shu Takagi, Yoichiro Matsumoto
Summary: A series of experiments and modelling were conducted to study the interaction of a pair of spherical bubbles rising in a vertical channel. The results showed that bubbles take two preferential configurations depending on their mutual distance, which helps to elucidate the clustering mechanisms.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Alienor Riviere, Wouter Mostert, Stephane Perrard, Luc Deike
Summary: This study investigates the dynamics and statistics of bubble break-up in homogeneous and isotropic turbulence through direct numerical simulations, focusing on the influence of the Weber number on bubble break-up dynamics. The findings reveal that during the transition to stable conditions, bubble break-up occurs through both local and non-local production processes, resulting in a range of bubble sizes.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
D. Raciti, P. Brocca, A. Raudino, M. Corti
Summary: We present a new interferometric method to study the interactions between two gas bubbles in a liquid undergoing small-amplitude oscillations. The technique allows for accurate measurement of the amplitude, frequency, and phase of oscillation, as well as probing the interactions between the bubbles. This method is of great importance for understanding bubble interactions.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Chemical
Rahul Subburaj, Yali Tang, Niels G. Deen
Summary: The objective of this work is to establish a lift model that considers the variation in the bubble spreading mechanism with different column aspect ratios. A strategic approach has been developed to explore the dependency of the lift variation with local flow variables. Numerical simulations using Computational Fluid Dynamics - Discrete Particle Method (CFD-DPM) coupled with Volume of Fluid (VOF) method in the open-source framework OpenFOAM are performed. It is found that the local gas fraction and the vorticity are strongly correlated with the lift coefficient. However, using one of these two variables alone cannot describe the lift variation within the bubble columns. A unified lift model is established that depends on both local gas fraction and vorticity. Euler-Lagrange simulations using this lift model demonstrate excellent agreement on the bubbly dynamics with experiments of homogeneous bubbly flows and bubble swarms.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Evan Milacic, Dylan R. Rantong, J. A. M. Kuipers, Maike W. Baltussen
Summary: This study experimentally investigates the effect of liquid injection on the particle temperature distribution in a fluidized bed of porous particles. The specific surface area of the porous particles is identified as the main property influencing the distribution, while the porosity greatly affects the defluidization of the fluidized bed.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Engineering, Chemical
X. Liu, X. Zhang, J. Li, Q. Zhu, N. G. Deen, Y. Tang
Summary: Direct reduction of combusted iron powders using renewable energy is crucial for a carbon-neutral iron fuel cycle. Lab-scale reduction experiments show that a temperature of 500 degrees C achieves a reduction degree higher than 90%, while higher temperatures result in particle sintering and lower reduction degree due to quick defluidization. The study highlights the significance of temperature on sintering and reduction behavior, with negligible impact from gas velocity. The findings offer insights for the design of hydrogen-based iron fuel regeneration processes.
Article
Engineering, Chemical
X. Liu, X. Zhang, J. Li, Q. Zhu, N. G. Deen, Y. Tang
Summary: Hydrogen-based direct reduction of iron oxide powder in gas-fluidized beds is a developing technology, but the agglomeration of fine powder at high temperatures is a key issue. This study experimentally investigates the (de-)fluidization behavior of micron-sized combusted iron particles to understand the high-temperature agglomeration mechanism. The effects of various operating and material variables on the fluidization and agglomeration behavior are examined, and a theoretical model is developed to predict the boundaries of fluidization regimes. The obtained knowledge is then applied for experimental design of the hydrogen-based iron direct reduction process.
Article
Energy & Fuels
M. W. Baltussen
Summary: We are at risk of losing our current living standards due to the depletion of natural resources. It is vital to reduce waste production. In reactor engineering, waste production is caused by the formation of byproducts. To improve reactor selectivity, fluid dynamics should enhance intrinsic reaction kinetics by ensuring each molecule has the same experience. However, the concentration profile during mass transfer from a bubble is non-uniform, with structures confined by the hydrodynamic wake of the bubble. This leads to large concentration gradients that impact selectivity, especially in consecutive reactors. Therefore, studying local mixing profiles in bubbly flows, including multi-phase flows, is crucial for future research.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2023)
Article
Engineering, Chemical
A. Fathiganjehlou, A. Eghbalmanesh, M. W. Baltussen, E. A. J. F. Peters, K. A. Buist, J. A. M. Kuipers
Summary: This research investigates the hydrodynamics of packed beds containing random packings of spherical particles using particle-resolved computational fluid dynamics (PR-CFD) and pore network model (PNM) approaches. The results show that the PNM captures local variations in the bed well. The low computational cost and ability to provide locally resolved data make the PNM a promising approach for the pore-scale modelling of packed bed reactors.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Faeze Khalighi, Niels G. Deen, Yali Tang, Albertus W. Vreman
Summary: Enhancing the efficiency of industrial water electrolysis for hydrogen production is crucial for the energy transition. This study investigates the growth of a single hydrogen bubble on a vertical cathode in a 30 wt% KOH solution, and examines the effects of flow rate and operation pressure on bubble growth behavior, species concentrations, potential, and current density. The results show that increasing flow velocity slightly improves efficiency, while increasing operation pressure slows down bubble growth and slightly decreases efficiency.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Energy & Fuels
C. J. M. Hessels, D. W. J. Lelivelt, N. C. Stevens, Y. Tang, N. G. Deen, G. Finotello
Summary: In this study, the fluidization and reduction behavior of micron-sized iron oxide powder produced by iron combustion were investigated in a lab-scale cylindrical fluidized bed. The minimum fluidization velocity (umf) was found to stabilize above a normalized static bed height of 0.5 H/D. Experimental results deviated from the Ergun correlation at temperatures above 560 K, prompting the proposal of a new correlation that takes cohesive inter-particle solid bridge force into account. Reduction experiments revealed gradual defluidization at temperatures exceeding 800 K, with a maximum reduction degree of 61% achieved at 807 K and 100 vol% H2.
Article
Engineering, Chemical
Juan Ramirez, Martijn de Munck, Zhitao Liu, David Raphael Rieder, Maike Baltussen, Kay Buist, Johannes A. M. Hans Kuipers
Summary: In this study, different drag force correlations were used to predict the clustering phenomenon in riser reactors. The predictions for global variables and cluster variables were accurate for most simulations, but significant deviations were observed in the pneumatic transport regime.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Chih-Chia Huang, Jeroen A. van Oijen, Niels G. Deen, Yali Tang
Summary: In Euler-Lagrange models, the information exchange in particulate systems is often smoothed from particles' location to nearby computational cells. However, the current constant diffusivity approach fails to consider the variation in particle sizes in polydisperse systems. This paper proposes a particle-size dependent smoothing scheme called non-constant diffusivity approach.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Electrochemistry
Akmal Irfan Majid, Niels van Graefschepe, Giulia Finotello, John van der Schaaf, Niels G. Deen, Yali Tang
Summary: Sustainable iron production requires reducing energy consumption and emissions. The electroreduction of iron oxide at low temperatures offers a promising solution as it utilizes electrical energy with competitive energy consumption. Experimental studies show that electrochemical reduction in alkaline electrolytes achieves higher current efficiency, lower energy consumption, and higher purity of the iron product.
ELECTROCHIMICA ACTA
(2023)
Article
Energy & Fuels
X. Liu, C. J. M. Hessels, N. G. Deen, Y. Tang
Summary: In this study, the (de-)fluidization behavior of micron-sized iron oxide particles in a 3-D fluidized bed was investigated using Computational Fluid Dynamics coupled with a coarse-grained Discrete Element Method. The effects of temperature on various parameters such as bed pressure drop, void fraction distribution, particle velocity distribution, and agglomerate size were studied. The developed model demonstrated the ability to predict particle agglomeration behavior, providing insight for the design of the DRI process in high-temperature fluidized beds.
Article
Electrochemistry
A. M. Meulenbroek, B. W. J. Bernts, N. G. Deen, A. W. Vreman
Summary: This work develops and validates a numerical model for Marangoni flow around a growing hydrogen bubble on a microelectrode. The model accurately predicts the evolution of the bubble radius, the temperature profile around the bubble, and the profile of the Marangoni velocity. Different models are recommended for different stages of the bubble evolution.
ELECTROCHIMICA ACTA
(2023)
Article
Engineering, Chemical
P. M. Durubal, A. Tavanaei, K. A. Buist, J. A. M. Kuipers, M. W. Baltussen
Summary: A detailed understanding of the collision dynamics of liquid droplets is important for both natural phenomena and industrial applications. This study investigates the effect of temperature on viscosity during the collision of two equal-sized droplets. The results show that higher temperature leads to lower viscosity and increased interface oscillations, causing separation at lower Weber numbers. Local cooling of droplets creates viscosity profiles and forms ridges when the droplets combine. Furthermore, collision outcomes cannot always be explained solely based on effective viscosity, suggesting limitations of existing collision regime maps.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Rahul Subburaj, Yali Tang, Niels G. Deen
Summary: This study investigates the effect of wire mesh on bubbles in a microstructured bubble column reactor and develops a closure model to predict bubble behavior. The validated model accurately predicts reactor performance and aids in the design of wire meshes to increase bubble interfacial area.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Qing Han, Mengqing Shi, Linkai Han, Di Liu, Mingwei Tong, Yuxin Xie, Zhonghua Xiang
Summary: Developing highly efficient bifunctional oxygen electrocatalysts is crucial for zinc-air flow batteries. Metal-organic frameworks (MOFs) and covalent organic polymers (COPs) have emerged as promising alternatives due to their designable and controllable atomic-level structures. However, their catalytic performances are limited by conductivity and catalytic activity. In this study, nanosheet FeNi-MOF and iron phthalocyanine rich COP hybrid materials are assembled through the pi-pi stacking effect to create highly efficient bifunctional electrocatalysts. The resulting catalyst exhibits superior catalytic performance and stability, making it a promising candidate for zinc-air flow batteries.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Daria Grigorash, Dmytro Mihrin, Rene Wugt Larsen, Erling H. Stenby, Wei Yan
Summary: The article introduces a new approach to describe the cross-association between molecules, allowing for the simulation of weakly bound molecular complexes with different conformations in mixtures. By incorporating this approach into the equation of state, accurate predictions of vapor-liquid equilibrium and liquid-liquid equilibrium can be made. The new method is validated through experiments on alcohol and acid mixtures, with the results compared to experimental data, demonstrating its accuracy and reliability.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Mohammed Al-Sharabi, Daniel Markl, Vincenzino Vivacqua, Prince Bawuah, Natalie Maclean, Andrew P. E. York, Axel Zeitler
Summary: This study used terahertz pulsed imaging to investigate the transport process of different solvents into ceramic catalytic materials. The results showed that the heating rate of the samples influenced the water transport rate, while the viscosity of 1-octanol slowed down its transport.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chukwunonso Anyaoku, Sati Bhattacharya, Rajarathinam Parthasarathy
Summary: This study aimed to enhance understanding of settling dynamics in viscoelastic fluids by developing a semi-empirical correlation and a dimensionless ratio, which accurately described the characteristics of settling suspensions.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Antti I. Koponen, Janika Viitala, Atsushi Tanaka, Baranivignesh Prakash, Olli-Ville Laukkanen, Ari Jasberg
Summary: This study focuses on the development of foam application chemicals for the paper and board industry. The research explores the rheology of the polyvinyl alcohol foam used in the process. Measurements were conducted to determine the foam viscosity and slip flow. The results suggest that slip flow contributes significantly to the total flow rate, and the obtained viscosity and slip models provide a solid foundation for industrial processes.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Dalei Sun, Jinghui Cai, Yating Yang, Zhiwu Liang
Summary: In this study, Fe-doped alpha-Bi2O3 catalysts with different Fe/Bi molar ratios were synthesized and utilized in the carbonylation of isobutyl amine with CO2. The results showed that Fe doping significantly enhanced the catalytic abilities of alpha-Bi2O3.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Yuan Tian, Xinxin Wang, Yanrong Liu, Wenping Hu
Summary: This paper predicts the solubility of nitrogen gas in ionic liquids (ILs) using two quantitative structure-property relationship (QSPR) models. By combining machine learning methods and ionic fragments contribution method, the accuracy and reliability of the prediction models are improved.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Liwang Wang, Wei Liu, Pan Yang, Yulong Chang, Xiaoxu Duan, Lingyu Xiao, Yaoming Hu, Jiwei Wu, Liang Ma, Hualin Wang
Summary: This study investigates the effective phase interfacial area (ae) of hydro-jet cyclones at different injection angles. The results show that a 45 degrees upward incidence angle yields the most favorable flow field characteristics for efficient mass transfer. The significant enhancement in ae of the hydro-jet cyclones offers the advantage of reducing equipment volume and cost savings.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chuanjun Wu, Jiangzhi Chen, Jiyue Sun, I-Ming Chou, Shenghua Mei, Juezhi Lin, Lei Jiang
Summary: In this study, the solubility of H2S hydrate in water was measured using Raman spectroscopy. The results showed that the solubility increases with temperature under certain equilibrium conditions, and the solubility also depends on pressure and temperature under different equilibrium conditions. A thermodynamic model based on the van der Waals-Platteeuw theory was developed to predict the solubility, demonstrating its accuracy.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Lorenzo Brivio, Serena Meini, Mattia Sponchioni, Davide Moscatelli
Summary: This study investigates the influence of three main parameters and proposes a kinetic model to predict the optimal operating conditions for high yield of dimethyl terephthalate (DMT) in the chemical recycling process of polyethylene terephthalate (PET).
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Hongju Lin, Fanhui Liao, Yanchang Chu, Mingyu Xie, Lun Pan, Yuanyuan Wang, Lijian Leng, Donghai Xu, Le Yang, Gangfeng Ouyang
Summary: A honeycomb NiCo/C-Na catalyst with a micro-meso-macroporous structure has been fabricated and shown to have significantly higher catalytic activity for the decarboxylation of fatty acids. It also proves to be efficient in upgrading sludge HTL bio-crude, resulting in a biofuel with decreased viscosity and increased density.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Xiaoxian Li, Rui Li, Min Lin, Mingde Yang, Yulong Wu
Summary: A series of coated non-noble metal porous carbon catalysts were synthesized and applied to the aqueous-phase deoxygenation of algal bio-oil. One of the catalysts showed excellent deoxygenation selectivity and catalytic activity at 250 degrees C. The catalyst exhibited good hydrothermal stability and the reaction mechanism was proposed based on product analysis and active site analysis.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
M. V. Chudakova, M. V. Popov, P. A. Korovchenko, E. O. Pentsak, A. R. Latypova, P. B. Kurmashov, A. A. Pimenov, E. A. Tsilimbaeva, I. S. Levin, A. G. Bannov, A. V. Kleymenov
Summary: A series of catalysts with different potassium contents were prepared using solution combustion synthesis and characterized using various techniques. The results showed that the potassium content affected the phase composition and texture of the catalysts. The addition of a small amount of potassium resulted in a change in particle size distribution, leading to higher hydrogen yield. The Ni-1%K2O/Al2O3 catalyst exhibited the highest hydrogen yield at temperatures of 675 and 750 degrees Celsius.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Aliakbar Roosta, Nima Rezaei
Summary: In this study, we modified the electrolyte cubic plus association equation of state (e-CPA EoS) and integrated it with two electrical conductivity models to estimate the electrical conductivity of 11 monovalent electrolyte solutions in water. The modified e-CPA model demonstrated better performance and the hybridization with electrical conductivity models resulted in two predictive models for estimating the electrical conduction of dilute and concentrated electrolyte solutions. These predictive models showed relative average percentage deviations (AARD) of 11.15% and 13.87% over wide ranges of temperature and electrolyte concentration.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Haoren Niu, Jianzheng Wang, Qingzhu Jia, Qiang Wang, Jin Zhao, Fangyou Yan
Summary: A study developed two quantitative structure-property relationship models for the complexation performance of alpha- and beta-cyclodextrins and validated their stability and predictive ability through internal and external validation. The models showed robustness and satisfactory performance, as demonstrated by the experimental results and model validations. These models can effectively predict the binding constants between cyclodextrins and various types of molecules, providing valuable tools for cyclodextrin design.
CHEMICAL ENGINEERING SCIENCE
(2024)