Article
Engineering, Chemical
Guoqing Lian, Wenqi Zhong
Summary: The CFD-DEM coupled with heat transfer and chemical reaction sub-models was used to simulate oxy-char combustion in a fluidized bed. The study investigated the thermal conversion characteristics of char, including reaction rate, combustion temperature, and heat transfer. Results showed that convection heat and radiation heat were the main contributors, while conduction heat played an insignificant role.
Article
Energy & Fuels
Guoqing Lian, Wenqi Zhong
Summary: A CFD-DEM model with multiple chemical reactions was developed and validated in the open-source MFIX. It was used to study oxy-fuel combustion in a pressurized fluidized bed, showing that volatile combustion positively impacts fuel combustion. Increasing pressure and O2 concentration enhances the combustion rate and temperature of fuel particles. Heat transfer during stable combustion is dominated by reaction heat, followed by convection, radiation, and particle-wall conduction, while inter-particle conduction can be safely ignored.
Article
Engineering, Chemical
Jun Xie, Hao Zhang
Summary: The CFD-DEM approach coupled with thermochemical submodels is used to study the heat transfer characteristics during solid fuel combustion in a bubbling fluidized bed. The model considers particle flow behavior, gas turbulence, heat transfer between and within phases, and chemical reactions. The study verifies the model using experimental data and quantifies the contributions of different heat transfer modes at a particle scale. It also explores the formation and development of hot spots and analyzes the influence of different particle properties on heat transfer modes.
Article
Engineering, Environmental
Dali Kong, Kun Luo, Shuai Wang, Jiahui Yu, Jianren Fan
Summary: The study uses a particle-scale computational fluid dynamics-discrete element method to investigate biomass gasification in a bubbling fluidized bed reactor, exploring the effects of operating temperature and steam to biomass ratio on particle mixing and heat transfer modes. Increasing operating temperature and S/B ratio can enhance biomass mixing index and promote chemical reactions and heat transfer.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Tianning Zhang, Youjun Lu
Summary: This paper investigates the heat transfer characteristics between the wall and bed in SCWFB, comparing the accuracy of different methods in predicting heat transfer coefficients, and studying the influence of factors such as temperature, pressure, and velocity on heat transfer characteristics.
Article
Engineering, Chemical
Jun Xie, Wenqi Zhong, Yingjuan Shao
Summary: This study simulated char combustion in a three-dimensional bubbling fluidized bed using the CFD-DEM method coupled with a thermochemical submodel. The influence of particle properties on temperature, reaction rates, and the relationship between particle mixing, heat transfer, and reaction were investigated. Results showed that particle size affects the char combustion rate, while density has a slight effect. The distribution of particle temperature, CO, and CO2 concentrations is consistent with the fuel particle profile in most cases.
Article
Engineering, Environmental
Yaxiong Yu, Feng Lu, Haolong Bai, Fei Wei, Chenxi Zhang
Summary: This study investigates the influence of adding fines on heat transfer performance in fluidized beds through experiments, simulations, and theoretical analysis. The results show that adding fines enhances the heat transfer performance, with the bed-wall heat transfer coefficient presenting a volcano-shaped curve. Simulations and theoretical analysis reveal that improved particle dispersion due to fines addition is responsible for this phenomenon. The theoretical analysis further uncovers that fines addition creates more free-space for particle movement, thereby improving particle dispersion and enhancing heat transfer in fluidized beds.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Suyang Pan, Jiliang Ma, Xiaoping Chen, Daoyin Liu, Cai Liang
Summary: This paper investigates the diffusion combustion of NH3 in a single bubble of fluidized bed through experimental approach and CFD-DEM simulation. The results show that NH3 combustion occurs intermittently in the bubble injection period and slow oxidation happens in the bubble rising period. The chemical reaction in the bubble is highly correlated to mass transfer between the emulsion phase and bubble phase.
Article
Engineering, Chemical
M. J. A. de Munck, E. A. J. F. Peters, J. A. M. Kuipers
Summary: Computational Fluid Dynamics - Discrete Element Method (CFD-DEM) is widely used for heat transfer modeling in gas-solid fluidized beds. This study introduces a technique of coarse-grained CFD-DEM to overcome computational limitations and simulate larger fluidized beds. A scaling law commonly used for coarse-graining hydrodynamics is generalized to gas-solid heat transfer. The approach is successfully tested for different gas velocities, providing accurate predictions of particle temperatures and Nusselt numbers.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Riccardo Uglietti, Daniele Micale, Damiano La Zara, Aristeidis Goulas, Luca Nardi, Mauro Bracconi, J. Ruud van Ommen, Matteo Maestri
Summary: This study demonstrates the potential of combining numerical and experimental approaches in understanding catalytic reactors, particularly fluidized beds. Through experiments and data analysis, the effectiveness of the in-house first-principles multiscale Computational Fluid Dynamic-Discrete Element Method (CFD-DEM) model is validated, and the fundamental insights that can be achieved through detailed numerical methods are reported. The integration of experimental information and numerical simulations allows for optimal design and scale-up procedures for reactor configurations with promising prospects in the energy transition.
REACTION CHEMISTRY & ENGINEERING
(2023)
Article
Engineering, Environmental
Shuai Wang, Kai Zhang, Yurong He
Summary: In this study, the mass transfer behavior of a clouded bubble is investigated using a coupled computational fluid dynamics-discrete element method (CFD-DEM). The results show that diffusion-induced mass transfer is more significant for clouded bubbles compared to cloudless bubbles. Additionally, the effect of non-isothermal conditions on mass transfer is also explored.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Energy & Fuels
Mais Baqain, Can Rustu Yoruk, Dmitri Nesumajev, Oliver Jarvik, Alar Konist
Summary: The CO2-intensive oil shale power industry in Estonia produces a significant amount of ash, which is mainly disposed of in landfills. Switching to oxy-fuel technology with CO2 storage can help reduce carbon footprint. However, there are expected differences in ash formation under oxy-fuel conditions, leading to additional challenges in ash handling and environmental concerns.
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
Energy & Fuels
Dali Kong, Shuai Wang, Kun Luo, Jiahui Yu, Jianren Fan
Summary: The methanation process in a bubbling fluidized bed (BFB) reactor is studied using computational fluid dynamics-discrete element method (CFD-DEM) with thermochemical sub-models. A novel algorithm is developed for bubble identification and statistics. The effects of key operating parameters on bubble behaviors are quantified and the underlying mechanism of mesoscale bubble behaviors is elucidated. The results show that the bubble dynamics can be well captured by the algorithm and the interphase heat and mass transfer can be enhanced by adjusting the operating parameters.
Review
Energy & Fuels
Chen Ge, Shiyuan Li, Linwei Wang
Summary: Oxy-fuel circulating fluidized bed combustion (Oxy-CFBC) is a promising and sustainable technology for carbon capture, utilization, and sequestration in coal-fired power plants. In the past 15 years, research on Oxy-CFBC has rapidly developed, from lab-scale to industrial-scale facilities. This paper reviews the research status of Oxy-CFBC, including models, heat transfer, combustion characteristics, pollutant formation and emission, and system optimization. It also analyzes different fuels and the differences in NOx emission and desulfurization mechanism between air combustion and oxy-combustion modes. The review highlights the importance of gas staging and oxygen staging in reducing NO emissions, and discusses new generation technologies and challenges for future research and industrial application of Oxy-CFBC.
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)