Article
Engineering, Chemical
Yuanhe Yue, Shuai Wang, Yansong Shen
Summary: Two hypotheses were proposed to explain spout deflection mechanisms in spout fluidized beds, and virtual experiments were designed to verify these hypotheses. The study found that asymmetrical particle fountaining and rheological properties of the annulus region play key roles in determining spout deflection.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Zhan Luo, Yuanhe Yue, Shuai Wang, Yansong Shen
Summary: In this study, the spout deflection behavior of cohesive particles in a pseudo-2D spout fluidized bed is investigated using computational fluid dynamics - discrete element method. It is found that cohesive particles, especially those covered with honey, exhibit smaller spout deflection compared to dry particles. Furthermore, the spout deflection angle increases with increasing spouting gas velocity for both dry and cohesive particles.
Article
Engineering, Chemical
Yuanhe Yue, Shuai Wang, Yansong Shen
Summary: This study investigates the instability problem of alternating spout deflection in spout-fluidized beds and proposes three different geometrical designs to mitigate the issue. Design I and Design II show potential in reducing the amplitude of spout deflection, while Design III affects the frequency of the spout deflection. The findings aim to improve the hydrodynamics stability in spout fluidized beds.
Article
Green & Sustainable Science & Technology
Witold Zukowski, Przemyslaw Migas, Marta Zurek, Jan Wrona
Summary: The results of the n-hexane oxidation process in a fluidized bed reactor with a catalytic bed are presented. Baffles were used to modify the flow in the reactor and improve the process efficiency. The best results were achieved with the use of horizontal elements in the form of grids, which significantly improved the conversion of n-hexane to carbon dioxide.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Thermodynamics
Dongxiang Wang, Shuang Fu, Xiang Ling, Hao Peng, Xinjun Yang, Fangyang Yuan, Jiyun Du, Wei Yu
Summary: This study investigated the transition of flow regimes in a spout-fluidized bed reactor (SFBR) using spectral analysis of pressure drop fluctuations and visual observation. The turbulent fluidization transition velocity was analyzed using the standard deviation of pressure gradient, and an empirical model was proposed to predict this velocity. The results showed that the flow regime transition in the SFBR is primarily influenced by the coalescing and breaking up of bubbles formed around the air distributor and spout. The turbulent fluidization in the SFBR does not exhibit obvious jet flow, but rather the formation of clusters, leading to superficial homogeneity in both the spout and annulus zone. The transition from spout-fluidization to slugging fluidization depends on the velocity of the spouted gas.
Article
Engineering, Chemical
Salma Benzarti, Hatem Mhiri, Herve Bournot
Summary: In this study, the effect of ring baffle configuration on fluidization system hydrodynamics was investigated using a multifluid Eulerian CFD model and the Kinetic Theory of Granular Flow. It was found that the incorporation of ring baffles improved system mixing and reduced wall backflow, with limited impact of baffle shape on system hydrodynamics.
Article
Energy & Fuels
Sungkwon Jo, Donghyun Cho
Summary: Efficiency of methane combustion in fluidized beds is low at bed temperatures of 750 degrees C or lower due to increased ignition delay. Using a baffle and H-2 injection as ignition sources enhances methane conversion by a factor of three compared to without H-2 injection.
Article
Engineering, Chemical
Xuelian Xing, Chao Zhang, Bin Jiang, Yongli Sun, Luhong Zhang, Cedric Briens
Summary: In this study, the multi-phase Eulerian-Eulerian two-fluid method coupled with the kinetic theory of granular flow was used to investigate the hydrodynamics of particle flows in a lab-scale bubbling fluidized bed. The study aimed to improve the distribution of an injected liquid by enhancing the flow of bubbles entering the spray jet cavity. Results showed that adding a fluxtube to a baffle can enhance bubble flows, while baffles help smooth out variations in gas distribution.
Article
Energy & Fuels
Kiattikhoon Phuakpunk, Benjapon Chalermsinsuwan, Suttichai Assabumrungrat
Summary: This study used computational fluid dynamics to explore a louver baffles arrangement that could reduce bubble coalescence in a bubbling bed gasifier fueled by biomass. The results showed that 10 mm-gap baffles were effective in reducing bubble size and slowing down bubble coalescence, while also providing better gas-solid contact.
Review
Engineering, Chemical
Yuanhe Yue, Shuai Wang, Yansong Shen
Summary: This article comprehensively reviews the phenomenon of spout deflection in spouted beds, including identification methods, control measures, and potential utilization, which will shed light on the design and optimization of spouted beds.
Article
Engineering, Chemical
Gongpeng Wu, Mingjian Zhang, Yan He
Summary: Research on solid mixing in multistage circulating fluidized beds reveals characteristics such as increased solid mean residence time and dispersion with higher solid flux. Diffusion coefficient in enlarged sections decreases with height, contrary to traditional risers. These findings indicate enhanced overall solid mixing in the multistage riser compared to traditional systems.
Article
Engineering, Chemical
Rong Guo, Jinhao Bai, Feng Wu, Junwu Wang, Xiaoxun Ma, Zhiquan Hui
Summary: The hydrodynamic and heat transfer characteristics of dry and wet particles in quasi-two-dimensional integral multi-jet spout-fluidized bed and conventional spouted bed were studied using computational fluid dynamics and discrete element method. The study found that the appropriate moisture content of particles enhances the heat transfer effect, and the integral multi-jet spout-fluidized bed performs better in handling wet particles.
Article
Thermodynamics
Panxing Kang, Haizhuan Yuan, Luchang Han, Yefeng Zhou
Summary: The hydrodynamics and heat transfer characteristics in a gas-solid spout fluidized bed were investigated using computational fluid dynamics and discrete element methods. Results showed that increasing the spouting gas velocity accelerated both the axial and radial particle mixing rates, with the axial rate being faster. The annulus zone contributed the most to inter-particle conduction, while the particle-fluid-particle conduction played a significant role in convective heat transfer. The findings provide a theoretical reference for optimizing and intensifying gas-solid flow-mixing-heat transfer processes in spout fluidized beds.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Chemical
Shanzhong Zhao, Xuan Xu, Zengqiang Chen, Ruikang Fan, Enhui Zhou, Chenlong Duan
Summary: The introduction of a louver baffle can effectively improve the fluidization quality and coal beneficiation efficiency in gas-solid separation fluidized beds. Experimental and numerical simulation results show that a single guide baffle can effectively break up bubbles, inhibit bubble growth and particle back-mixing, and restore the uniform distribution of the updraft. Under specific conditions, the use of a louver baffle reduces the standard deviation of radial density fluctuation in the bed to 0.028 g/cm3, which is more than 35% lower than that of the conventional GSSFB, and reduces the standard deviation of axial density fluctuation to 0.146 g/cm3. Under these conditions, the separation of 6-13 mm raw coal in a LBSFB resulted in a clean coal yield of 69.97% and a probable error, E, value of 0.082 g/cm3.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Engineering, Chemical
Gongpeng Wu, Yan He
Summary: Gas-solid flow regime in a novel multistage circulating fluidized bed is investigated in this study. The characteristics of gas-solid motion, including the presence of dominant motion peaks in low and high frequencies and intensification of gas-cluster motions, are analyzed. The fuzzy C-means clustering method is introduced to objectively identify flow regime in the multistage circulating fluidized bed. Results show the consistency of flow regime between different sections and indicate a higher transition onset of fast flow regime in the multistage circulating fluidized bed compared to the fast bed.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(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)