Article
Engineering, Chemical
Li-Tao Zhu, Xi-Zhong Chen, Zheng-Hong Luo
Summary: This study investigates the effects of different HDCs on filtered mesoscale model predictions using highly-resolved simulations, showing significant differences between the commonly-practiced Wen-Yu drag closure and DNS-based HDCs in moderate and dense gas-particle flows. At low Reynolds numbers, HDCs from static particle DNS align with dynamic gas-particle flow DNS data, while Wen-Yu drag closure is more suitable for other ranges.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Zheqing Huang, Lingxue Wang, Qiang Zhou
Summary: The study obtains the filtered reaction rate for coarse-grid simulations of reactive gas-solid flows through correcting its microscopic reaction rate, finding that the mean eta(Delta) is almost independent of reaction orders at the same Damkohler number. A closure correlation for the mean eta(Delta) is proposed, while a large standard deviation is observed. A presumed probability density function model is suggested to capture the fluctuating properties of eta(Delta), and the predictability of the closure correlations is evaluated through simulations in circulating fluidized beds of ozone decomposition.
Article
Engineering, Chemical
Christian C. Milioli, Fernando E. Milioli
Summary: A new sub-grid drag model is proposed for fluidized gas-particle flows, which combines filtering over highly resolved simulations and microscopic two-fluid modeling to consider both micro-scale and macro-scale effects. By taking into account particle Froude numbers and ranges of average solid volume fractions and gas flow Reynolds numbers, the proposed model represents an improvement over previous versions.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Yu Li, Yaxiong Yu, Chi Zhang, Zheqing Huang, Qiang Zhou
Summary: An improved filtered interphase heat transfer model is proposed in this study, which takes into account the data with Q values less than 0 and greater than 1, showing better performance compared to existing models when Delta is less than 8.222.
Article
Engineering, Chemical
Bo Ouyang, Li-Tao Zhu, Zheng-Hong Luo
Summary: This study uses an artificial neural network based machine learning method to perform data-driven modeling of mesoscale solids stress closures in gas-particle flows. The optimization of the loss function shows that coupling two loss functions can lead to more accurate predictions of the solids stresses, and an optimal three-marker mesoscale closure is proposed. Comparative analysis suggests that the data-driven model can substantially enhance prediction accuracy compared to conventional models.
Article
Engineering, Chemical
Li-Tao Zhu, He Lei, Bo Ouyang, Zheng-Hong Luo
Summary: This work systematically investigates the applicability of mesoscale drag models in various flow regimes and optimizes the operational and fluidization quality of a fluidized bed reactor through bed internals design and evaluation of bed size effects.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Mechanics
Mahdi Saeedipour, Simon Schneiderbauer
Summary: Developing functional closure models for subgrid scale (SGS) physics in large eddy simulation (LES) of turbulent two-phase flows is challenging due to complicated turbulence-interface interactions. A new approach incorporating surface tension into subgrid eddy viscosity has shown promise for accurate simulation of interfacial turbulence. Implementing this approach in an a-posteriori manner has demonstrated improved performance in predicting local turbulence characteristics and energy spectra, particularly in flows with density contrasts.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Engineering, Chemical
Yu Li, Sen Han, Yaxiong Yu, Xieyu He, Zheqing Huang, Qiang Zhou
Summary: The computational fluid dynamics-discrete element method is employed to simulate gas-solid flows with heat transfer. By adopting the strategy of repetitively resetting the gas phase temperature, the temperature difference between the gas and solid phases is effectively maintained. The study reveals that the traditional heat source method artificially enhances heat transfer in dense regions, hence a filtering approach is used to develop a more accurate model for the interphase heat transfer coefficient.
Article
Engineering, Chemical
Li-Tao Zhu, He Lei, Bo Ouyang, Zhao-Quan Wen, Ya-Nan Yang, Zheng-Hong Luo
Summary: This study introduces the concepts of 'multi-level-nozzle' and 'continuous oscillatory tapered' fluidized beds to enhance contact efficiency and promote mixing between the gas and particle phases in a turbulent fluidized bed. The feasibility of these concepts is assessed through experimental and modeling evaluations. By designing multiple experimental cases, the influence of injection nozzle numbers, heights, angles, and reactor shapes on the hydrodynamic mechanisms is systematically investigated. The implementation of these conceptual designs leads to improved flow quality by enhancing particle intermittency and achieving higher oscillation frequencies.
Article
Thermodynamics
Zhi X. Chen, Salvatore Iavarone, Golnoush Ghiasi, Veeraraghavan Kannan, Giuseppe D'Alessio, Alessandro Parente, Nedunchezhian Swaminathan
Summary: The study focuses on predicting FDFs in MILD combustion using a deep neural network trained with DNS data, which shows superior performance and excellent agreement with DNS data. The comparison between two joint FDF models further highlights the predictive ability of the DNN in this complex combustion problem.
COMBUSTION AND FLAME
(2021)
Article
Engineering, Chemical
Jun-Sen Li, Li-Tao Zhu, Wei-Cheng Yan, Taha Abbas Bin Rashid, Qun-Jie Xu, Zheng-Hong Luo
Summary: The study found that the impact of different turbulence models on predictions of fluidization processes in the mesoscale gas-solid flow system varies. By utilizing a hybrid model and different turbulence closure models in a circulating fluidized bed CFB, more accurate predictions of flow characteristics can be achieved.
Article
Chemistry, Physical
Luis Perez-Mas, Maria del Mar Ramos-Tejada, Alberto Martin-Molina, Jose-Alberto Maroto-Centeno, Manuel Quesada-Perez
Summary: In this study, we use coarse-grained simulations to investigate how electrostatic forces affect the diffusion of solute in flexible gels. The model considers the movement of solute particles and polyelectrolyte chains and uses a Brownian dynamics algorithm. We analyze the impact of three electrostatic parameters on the system. Our findings reveal that changes in the electric charge of the species influence both the diffusion coefficient and the anomalous diffusion exponent. We also observe differences in the diffusion coefficient between flexible and rigid gels, particularly at low ionic strength. Additionally, the flexibility of the chains significantly affects the exponent of anomalous diffusion, even at high ionic strength (100 mM). Our simulations demonstrate that altering the charge of the polyelectrolyte chains does not have the same effect as changing the charge of the solute particles.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Mathematics, Interdisciplinary Applications
Janna Grabowski, Nico Jurtz, Viktor Brandt, Harald Kruggel-Emden, Matthias Kraume
Summary: This paper investigates the coupling of the discrete element method (DEM) with computational fluid dynamics (CFD) to describe fluidized particulate systems, and identifies the limitations of the system-to-grain ratio and system width. To enhance the accuracy of simulations, the study proposes sub-grid drag models, which often lack comprehensive testing of system configurations.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Energy & Fuels
Jin Wang, Xiaoke Ku, Jianzhong Lin, Shuna Yang
Summary: A CFD-DEM model combined with a smoothed voidage algorithm and a multicomponent and multistep pyrolysis scheme was developed to study biomass pyrolysis in different-shaped fluidized-bed reactors. The simulation results showed that reactor shape and gas inlet area have significant effects on the pyrolysis behavior.
Article
Polymer Science
Manuel Quesada-Perez, Jose-Alberto Maroto-Centeno, Maria del Mar Ramos-Tejada, Alberto Martin-Molina
Summary: This work computes the longtime diffusion of a solute in a chemically crosslinked and flexible hydrogel using a coarse-grained model of a polymeric network. The relevance of chain flexibility becomes important when the polymer volume fraction and the solute size increase. The results show that solute particles can moderately diffuse in flexible hydrogels even when their diameter is comparable to the mesh size. The diffusion coefficients obtained here are in good agreement with previously reported experimental data, without the need for any adjustable parameter.
Article
Engineering, Environmental
Jun-Sen Li, Li-Tao Zhu, Zheng-Hong Luo
Summary: This study comprehensively investigates the effect of geometric configurations on flow hydrodynamics, heat transfer, and RTD in a pilot-scale biomass pyrolysis VPU reactor through numerical simulations. The results show that geometric configurations have a significant impact on heat transfer and RTD, while their effect on flow hydrodynamics is less pronounced. Specifically, the carrier gas inlet and particle feed structures play a crucial role in particle distribution and back-mixing behavior in the reactor.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Li-Tao Zhu, He Lei, Bo Ouyang, Zheng-Hong Luo
Summary: This work systematically investigates the applicability of mesoscale drag models in various flow regimes and optimizes the operational and fluidization quality of a fluidized bed reactor through bed internals design and evaluation of bed size effects.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Zhao-Quan Wen, Li-Tao Zhu, Zheng-Hong Luo
Summary: A new quasi-three-phase method was proposed to simulate the mesoscale structures in gas-solid fluidized bed systems. The simulation results showed reasonable predictions of the relationship between gas velocity and flow pattern transition, as well as good agreement with experimental data.
Article
Engineering, Chemical
Jiawei Liao, Litao Zhu, Zhenghong Luo
Summary: Mesoscale drag model is crucial for the reliability and accuracy of gas-solid flow hydrodynamics simulations in fluidized bed reactors. This study investigates the effects of different drag models on hydrodynamic behaviors, nonuniformity analysis, and sensitivity to material properties through extensive simulations.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2022)
Editorial Material
Engineering, Chemical
Hanyu Gao, Li-Tao Zhu, Zheng-Hong Luo, Marco A. Fraga, I-Ming Hsing
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Hui-Long Wei, Bo Ouyang, Li-Tao Zhu, Yuan-Hai Su, Zheng-Hong Luo
Summary: This study investigated the reaction network and kinetic characteristics of the oxidation of cyclohexanone with nitric acid through machine learning model and target factor analysis. The results provide valuable insights into the oxidation process under various operational conditions.
Article
Engineering, Chemical
Bo Ouyang, Litao Zhu, Zhenghong Luo
Summary: The present study applies several novel data-driven analysis approaches to extract human-understandable insights from machine learning-based meso-scale closure in fluid-particle flows. The study aims to quantitatively investigate the influence of flow properties on mesoscale drag correction (Hd), and the results show strong correlations between the features (i.e., slip velocity (u* sy) and particle volume fraction (es)) and the label Hd. The interpretable ML analysis confirms this conclusion and quantifies the contribution of u* sy, es, and gas pressure gradient to the model.
Article
Engineering, Chemical
He Lei, Li -Tao Zhu, Zheng-Hong Luo
Summary: Detailed studies on the effect of cohesiveness on the hydrodynamics, heat transfer, and reaction characteristics in high-temperature polymerization fluidized bed reactors have been rarely reported. This work establishes a CFD-DEM approach coupled with a solid bridge force model and polymerization reaction kinetics model to simulate the reactive gas-solid flows with cohesive particles. The results show that cohesive particle agglomeration significantly affects the concentration, velocity fields, and temperature distribution in the reactor. The model also reveals the influence of cohesion model parameters on the onset temperature and severity of particle agglomeration.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Chemical
Ya-Nan Yang, Hui Liu, Li-Tao Zhu, Jie Jin, Xi-Bao Zhang, Zheng-Hong Luo
Summary: Multizone circulating reactor (MZCR) technology is an advanced olefin polymerization process that enables the production of polyolefins with varying properties. This study proposes a multimodel coupling method to understand the gas-phase propylene polymerization in a MZCR. The developed model considers the molecular and particle properties of polypropylene and examines key operating variables related to product properties. The simulation results show that the MZCR technology allows for a wide range of polymer properties.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Ouyang Bo, Li-Tao Zhu, Zhao-Quan Wen, Xizhong Chen, Zheng-Hong Luo
Summary: In this study, a big data approach is used to analyze approximately 10^8 data points for drag coefficient (F-d) of Geldart Group A particles at atmospheric pressure. It is found that the contribution of particle Reynolds number (Re-s) on F-d is much less than phase fraction (e). Therefore, the drag models are simplified to machine learning and conventional expressions only related to e. The simplified models achieve similar predictive performance as the originals and provide better numerical stability for coarse grid simulations.
Article
Engineering, Chemical
Li-Tao Zhu, Anthony Wachs
Summary: Researchers propose a microstructure-informed probability-driven point-particle (MPP) method to enhance the reliability of Euler-Lagrange simulations in particle-laden flows. However, the MPP model cannot be directly used due to computation limitations. To overcome this, an interpolated MPP (iMPP) method is introduced, which shows promising results in capturing hydrodynamic forces/torques fluctuations in a wide range of cases. This advancement contributes to the development of a more versatile closure model suitable for integration into Euler-Lagrange simulations.
Review
Engineering, Chemical
Sheng-lin Yan, Xu-qing Wang, Li-tao Zhu, Xi-bao Zhang, Zheng-hong Luo
Summary: This review comprehensively analyzes the kinetics of bubble behaviors and the mechanisms of gas-liquid mass transfer. It discusses the correlations between bubble behavior and mass transfer, as well as modeling approaches. The impact of global and local turbulence on bubble behavior and mass transfer is also discussed.
CHEMICAL ENGINEERING SCIENCE
(2023)
Review
Engineering, Chemical
Shi-Jiao Li, Li-Tao Zhu, Xi-Bao Zhang, Zheng-Hong Luo
Summary: Phase change is widely used in various fields such as chemical engineering, energy, electronics, vehicle, and space exploration. Understanding the intricacies of multiphase flow processes with heat and mass transfer due to phase change is crucial. Computational fluid dynamics (CFD) has been increasingly applied as an effective tool to analyze phase change processes, enhance understanding and optimize effects. This review provides a comprehensive overview of CFD methodologies in simulating phase change flows in different applications and discusses the challenges and prospects in facilitating the application of phase change flow.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Li-Tao Zhu, He Lei, Bo Ouyang, Zhao-Quan Wen, Ya-Nan Yang, Zheng-Hong Luo
Summary: This study introduces the concepts of 'multi-level-nozzle' and 'continuous oscillatory tapered' fluidized beds to enhance contact efficiency and promote mixing between the gas and particle phases in a turbulent fluidized bed. The feasibility of these concepts is assessed through experimental and modeling evaluations. By designing multiple experimental cases, the influence of injection nozzle numbers, heights, angles, and reactor shapes on the hydrodynamic mechanisms is systematically investigated. The implementation of these conceptual designs leads to improved flow quality by enhancing particle intermittency and achieving higher oscillation frequencies.
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)