Article
Geochemistry & Geophysics
A. Pavlov
Summary: The Maxwell-Stefan diffusion equations for multicomponent neutral gas mixtures with thermodiffusion ratios and diffusion correction factors in the Chapman-Cowling third-order approximation are derived, with explicit functions of masses, number densities, thermal conductivities, and collision integrals. Applications to atmospheric gases and recommendations for studying Earth's atmosphere are provided.
SURVEYS IN GEOPHYSICS
(2021)
Article
Mathematics, Applied
Alexander Van-Brunt, Patrick E. Farrell, Charles W. Monroe
Summary: This study investigates structure-preserving finite element discretizations for the steady-state Stefan-Maxwell diffusion problem, which governs mass transport within a phase consisting of multiple species. Inspired by augmented Lagrangian methods, an approach is developed to construct a symmetric positive definite augmented Onsager transport matrix, leading to an effective numerical algorithm. Inf-sup conditions for the continuous and discrete linearized systems are proven, and error estimates are obtained for a phase consisting of an arbitrary number of species. The discretization preserves the thermodynamically fundamental Gibbs-Duhem equation to machine precision independent of mesh size. Numerical examples, including the diffusion of oxygen, carbon dioxide, water vapor, and nitrogen in the lungs, are provided to illustrate the results.
IMA JOURNAL OF NUMERICAL ANALYSIS
(2022)
Article
Engineering, Chemical
William Q. Rios, Bruno Antunes, Alirio E. Rodrigues, Ines Portugal, Carlos M. Silva
Summary: The study presents accurate analytical equations for effective diffusivities (Di,eff) that consider the nonideal behavior of multicomponent mixtures. A new rigorous approach is proposed and demonstrated to provide accurate calculations for Di,eff, and it is shown that deviations from ideal behavior can lead to substantial errors in these calculations.
Article
Mathematics, Applied
Benjamin Anwasia, Srboljub Simic
Summary: In this study, the maximum entropy principle is applied to derive the properly scaled velocity distribution function of Boltzmann equations for mixtures, leading to a non-isothermal Maxwell-Stefan diffusion model. The entropy balance law is also analyzed, and the kinetic entropy production is derived from the scaled distribution function.
APPLIED MATHEMATICS LETTERS
(2022)
Article
Computer Science, Interdisciplinary Applications
Navid Ahmadi, Katharina Heck, Massimo Rolle, Rainer Helmig, Klaus Mosthaf
Summary: The study compared different diffusion models and coupling concepts for predicting the transport behavior of multicomponent mixtures in porous media and free flow. It highlighted the importance of interaction between different diffusing components and the impact of free flow velocity on gas migration at the interface under diffusion- and advection-dominated conditions. Despite using different modeling concepts and numerical schemes, the two simulators showed excellent agreement and capability to reproduce previous modeling and experimental results.
COMPUTATIONAL GEOSCIENCES
(2021)
Article
Engineering, Multidisciplinary
Dieter Bothe, Pierre-Etienne Druet
Summary: This paper reevaluates the modeling of multicomponent diffusion in relation to the irreversible thermodynamics. The generalized Fick-Onsager multicomponent diffusion fluxes and the generalized Maxwell-Stefan equations, two well-known approaches, are briefly reviewed. A novel and more direct closure that avoids the inversion of the Maxwell-Stefan equations is proposed and discussed. It is shown that all three closures are equivalent when concentrations are required to be positive, revealing the general structure of continuum thermodynamical diffusion fluxes. The paper also addresses the sign of multicomponent thermodynamic or Fickian diffusion coefficients based on the second law.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Engineering, Environmental
John P. Wakefield, Aaron M. Lattanzi, M. Brennan Pecha, Peter N. Ciesielski, Jesse Capecelatro
Summary: This article presents a methodology for modeling multi-step reaction rates in porous catalyst particles. The method accurately captures the cascading reaction systems common in high temperature vapor-phase chemical reactors. The article also provides solutions for various catalyst shapes and discusses the computational challenges caused by diffusion limitations.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Mathematics, Applied
Clement Cances, Virginie Ehrlacher, Laurent Monasse
Summary: The aim of this work is to propose a provably convergent finite volume scheme for the Stefan-Maxwell model, which describes the composition evolution of a multi-component mixture as a cross-diffusion system. The scheme relies on a two-point flux approximation and preserves key theoretical properties of the continuous model, including non-negativity, mass conservation, and volume-filling constraints. Additionally, it satisfies a discrete entropy-entropy dissipation relation similar to the continuous level. This article presents the scheme, its numerical analysis, and provides numerical results to demonstrate its behavior.
IMA JOURNAL OF NUMERICAL ANALYSIS
(2023)
Article
Mathematics, Interdisciplinary Applications
Zuozhuang Yin, Qian Zheng, Huili Wang, Xiuya Guo
Summary: Gas diffusion coefficient is an important parameter in characterizing gas transport in porous media. In this study, the effect of capillary surface roughness on gas diffusion is considered by the Monte Carlo technique based on the fractal characteristics of microscopic capillaries. We proposed a probability model of the effective gas diffusion coefficient of the porous media with rough surfaces, which is expressed as a function of the geometrical parameters of porous media. The simulated results show good agreement with the available experimental data, and the effect of the structural parameters of porous media on gas diffusion is analyzed in detail.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2022)
Article
Physics, Applied
Wenxi Ren, Youjing Duan, Jianchun Guo, Tianyu Wang
Summary: A new multicomponent gas transport model, the adaptive binary friction model (ABFM), has been developed, which rigorously treats viscous slip and diffusion slip. The ABFM shows good agreement with experimental data and can predict the transport of different gas mixtures under various conditions, making it useful in heterogeneous catalysis and membrane transport applications.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Multidisciplinary
Jisheng Kou, Huangxin Chen, ShiGui Du, Shuyu Sun
Summary: In this article, an efficient energy stable numerical method is proposed for the modeling of two-phase flow in porous media. The method preserves important physical properties of the model and shows excellent performance in numerical experiments.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Engineering, Chemical
Artur A. Salamatin, Alyona S. Khaliullina
Summary: The extract obtained from supercritical fluid extraction of plant raw materials is multi-component, and a particle-scale multi-component mass transfer model is developed to consider the non-ideal chemical interactions between solute components. The model utilizes two pseudo-components to represent the oil and considers the chemical potential gradient as the driving force for mass transfer. The model is based on the regular solution and Gibbs energy approaches for thermodynamic modeling and shows a significant improvement compared to the simplified ideal system approach.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Thermodynamics
Patrick Krenn, Patrick Zimmermann, Michael Fischlschweiger, Tim Zeiner
Summary: The solvent absorption of an epoxy o-cresol novolac resin composite in different aqueous electrolyte solutions has been accurately predicted through a complex model, showing qualitative agreement with measured data.
FLUID PHASE EQUILIBRIA
(2021)
Article
Thermodynamics
B. Baradaran Kazemian, Q. Guo, P. Cheng
Summary: In this paper, simultaneous heat and mass transport in porous media is numerically studied using a 2D multicomponent/multiphase phase-change lattice Boltzmann scheme. The evaporation in packed hydrophilic beds is found to play an important role in capillary rise of liquid, and the effects of contact angles and packed bed structures on liquid absorption are investigated. The directional and heterogeneous packed beds are shown to absorb more liquid in a shorter time compared to homogeneous packed beds under the same conditions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Mathematics, Applied
Xiaokai Huo, Hailiang Liu, Athanasios E. Tzavaras, Shuaikun Wang
Summary: The new finite difference scheme for the Maxwell-Stefan diffusion system is conservative, energy-stable, and positivity-preserving, which are proved by reformulating the scheme into an equivalent optimization problem. The solution to the scheme is obtained as the minimizer of the optimization problem, leading to energy stability and positivity-preserving properties.
SIAM JOURNAL ON NUMERICAL ANALYSIS
(2021)
Article
Engineering, Chemical
Eirik H. Hero, Nicolas La Forgia, Jannike Solsvik, Hugo A. Jakobsen
CHEMICAL ENGINEERING & TECHNOLOGY
(2019)
Article
Engineering, Chemical
Lilibeth Nino, Ricardo Gelves, Haider Ali, Jannike Solsvik, Hugo Jakobsen
CHEMICAL ENGINEERING SCIENCE
(2020)
Article
Mechanics
Arturo A. Arosemena, Helge I. Andersson, Jannike Solsvik
Summary: The study shows that shear-dependent fluid rheology mainly affects the flow within the inner layer region, with shear-thinning behavior suppressing near-wall structures and inhibiting turbulence-generating events, resulting in different drag reduction characteristics.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Haider Ali, Jannike Solsvik
Article
Engineering, Chemical
Jannike Solsvik, Eirik Manger
Summary: The study focuses on the kinetic theory of granular mixtures, examining granular temperature, particle velocity distribution, and constitutive equations resulting from collisions. It is found that some existing approximate solutions are inaccurate, while others may provide good approximations. Additionally, a review of balance laws and constitutive relations from mono- and poly-disperse kinetic granular flow model frameworks is conducted.
Article
Engineering, Chemical
S. B. Oyen, H. A. Jakobsen, T. Haug-Warberg, J. Solsvik
Summary: This work combines the concepts of chemical reaction equilibrium and transport phenomena, based on thermodynamic equilibrium rather than reaction kinetics, resulting in fewer model parameters. The model framework, exemplified by steam methane reforming and methanol synthesis processes, shows that orthogonal collocation is more efficient than finite volume, and Gibbs energy is more efficient than Helmholtz energy. The proposed model framework is a novel tool for calculating industrial reactors operating close to equilibrium, useful for process design studies but not accurate simulation.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Mechanics
Haider Ali, Jannike Solsvik
Summary: Mass transfer is essential in designing and scaling up stirred tanks in the chemical and biochemical processes. This study investigates mass transfer in non-Newtonian fluids at a pilot scale. Using a pilot-scale stirred tank, the research explores bubble hydrodynamics and mass transfer, obtaining values of bubble-liquid mass transfer coefficient through measurements and calculations.
Article
Mechanics
Arturo A. Arosemena, Jannike Solsvik
Summary: The study reveals that shear-dependent rheology influences the velocity-vorticity correlations and mean dynamics in turbulent flows, leading to different flow characteristics for different fluid behaviors. Specifically, under shear-thinning conditions, sublayer streaks are more stable, near-wall vortical motions are dampened, and the thickness of certain layers increases.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Mechanics
Arturo A. Arosemena, Ronnie Andersson, Helge I. Andersson, Jannike Solsvik
Summary: The turbulent channel flow simulation of a shear-thinning fluid is compared with a Newtonian base case to study the effects of shear-dependent rheology on near-wall structures. The shear-thinning fluid case shows larger, less intense streamwise vortices that are taller, longer, and with larger volume compared to the Newtonian fluid, but with the same fractal dimension. The number density of vortical structures decreases with shear-thinning behavior.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Chemical
S. B. Oyen, H. A. Jakobsen, T. Haug-Warberg, J. Solsvik
Summary: In this work, a new mass transfer model for interfacial mass transfer was proposed, providing a flexible framework for phase equilibrium description substitution. The comparison between the Soave-Redlich-Kwong equation of state (SRK-EoS) and classical Henry's law approach showed qualitative agreement but quantitative disagreement in solubilities. The new model formulation allows for predicting solvent mass transfer, which cannot be achieved by Henry's law.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Engineering, Chemical
Haider Ali, Sofia Zhu, Jannike Solsvik
Summary: Scaling up stirred tanks presents challenges due to research gaps between laboratory and industrial-scale setups. This study investigates the effects of tank size and aspect ratio on volumetric mass transfer coefficients for shear-thinning fluids, finding that the coefficient decreases with tank size but increases with operating conditions, with impacts from fluid rheology.
INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING
(2022)
Article
Mechanics
A. A. Arosemena, H. Ali, J. Solsvik
Summary: Data obtained from large eddy simulations were used to identify and characterize vortical structures in a baffled stirred tank reactor. Statistical analyses were performed to understand the size, shape, distribution and organization of the vortices, as well as their correlation with turbulence and blade passage. The influence of rotational speed and fluid rheology on the turbulent flow was also explored, along with potential implications for liquid-liquid and gas-liquid dispersed systems.
Article
Mechanics
Ida K. Kure, Hugo A. Jakobsen, Nicolas La Forgia, Jannike Solsvik
Summary: The study emphasizes the necessity of providing new experimental data and thoroughly evaluating statistical uncertainty to reduce the scatter in terminal velocity during the study of single bubbles rising. By conducting single bubble experiments in a stagnant liquid with high-speed cameras and image analysis, the research successfully tracks bubble motion and evaluates bubble properties. The study validates existing correlations for terminal velocity against experimental data and highlights the uncertainty in the data.
Article
Engineering, Chemical
Lilibeth Nino, Ricardo Gelves, Haider Ali, Jannike Solsvik, Hugo Jakobsen
Summary: Gas-liquid mass transfer in non-Newtonian fluids is crucial in the bioprocess industry. This study numerically determines and experimentally compares bubble sizes and kLa in different positions of a stirred bioreactor. The results show that considering the viscous effects improves the predictions of bubble sizes and kLa compared to traditional turbulence models.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
S. B. oyen, H. A. Jakobsen, T. Haug-Warberg, J. Solsvik
Summary: This study theoretically investigates the mass transfer in an industrial-scale Fischer-Tropsch slurry bubble column reactor. Three different driving forces for mass transfer are proposed and the effects of carbon chain length, pressure, and temperature on conversion level are analyzed. The mass transfer models based on Henry's law and phase equilibrium are compared, with the latter being capable of predicting the thermodynamics of additional phase formation.
CHEMICAL ENGINEERING SCIENCE
(2022)
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)