Article
Energy & Fuels
Antonio Soria-Verdugo, Eduardo Cano-Pleite, Alberto Passalacqua, Rodney O. Fox
Summary: The effect of biomass particle shape on the conversion of beech wood during pyrolysis in a bubbling fluidized bed was investigated. The experimental results demonstrated that the pyrolysis velocity of the particles was proportional to their characteristic heat transfer length. The pyrolysis time ranged from 43 to 85 s at 500°C and from 27 to 53 s at 600°C.
Article
Energy & Fuels
Yunlei Cui, Yaning Zhang, Longfei Cui, Qingang Xiong, Ehab Mostafa
Summary: Conversion of plastic wastes into value added fuels is a good way for sustainable development. In this study, microwave-assisted fluidized bed reactor pyrolysis of polypropylene plastic for pyrolysis gas production was experimentally investigated. The effects of pyrolysis temperature, fluidizing velocity, and microwave power on the pyrolysis gas products were analyzed. An optimal pyrolysis gas yield of 76.1 wt% was obtained when the pyrolysis temperature was 900°C, fluidizing velocity was 2.36 x 10-3 m/s and microwave power was 800 W, and the pyrolysis gas was rich in C3H6, CH4, and C3H8 with a higher heating value of 51.8 MJ/m3. The produced gas has great potentials in applications, such as fuel cells.
Article
Engineering, Chemical
Juliette Palier, Alain Le-Bail, Catherine Loisel, Patricia Le-Bail
Summary: This study found that mixing cake batter without baking powder under pressure of 0.3 and 0.5 bar of CO2 yielded the best results, with a specific volume of 2.5 mL/g which was 89% of the specific volume of control cake with baking powders. The improvement was mainly attributed to the solubilization of CO2 in the liquid phase of the batter.
JOURNAL OF FOOD ENGINEERING
(2022)
Article
Chemistry, Physical
Peter Serles, Michel Hache, Jason Tam, Alianna Maguire, Tao Li, Guorui Wang, Keith Sebastian, Jun Lou, Charles Jia, Pulickel M. Ajayan, Jane Howe, Yu Zou, Tobin Filleter
Summary: Rapid production of nanoscale carbon-based designs with complex 3D geometry has been enabled by the combination of nano-3D printing via two-photon polymerization and post-pyrolysis. This article evaluates the mechanical performance of pyrolyzed carbon designed with modified printing parameters and provides structural insight towards creating a reliable and robust carbon material.
Article
Engineering, Environmental
Min Yang
Summary: In this study, one-dimensional longitudinal mixing models were developed to analyze the mixing processes of an oxidation ditch and an aeration tank. The analysis showed that the mixing in the oxidation ditch resembled that of a continuous stirred tank reactor (CSTR) in a mode of circulation flow and dispersion, while the mixing in the aeration tank resembled that of a CSTR in a mode of dispersion. The complete mixing times of both systems were evaluated and compared.
WATER ENVIRONMENT RESEARCH
(2022)
Article
Thermodynamics
Yusuf H. Bello, Mahmoud A. Ahmed, Shinichi Ookawara, Ahmed E. Elwardany
Summary: An improved biomass conversion in a lab-scale fluidized bed reactor (FBR) is achieved by optimizing the air distributor orifice size and number. Different methods of introducing air yield different results in gas holdup, with increasing the orifice number showing positive effects on gas holdup.
Article
Thermodynamics
Thoharudin, Shu-San Hsiau, Yi-Shun Chen, Shouyin Yang
Summary: This study simplified a comprehensive multistep kinetic mechanism of fast biomass pyrolysis in a fluidized bed reactor and found that particle size and fluidization velocity have a significant impact on the pyrolysis process.
ENERGY CONVERSION AND MANAGEMENT
(2022)
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
Fatemeh Tashakori-Asfestani, Saman Kazemi, Reza Zarghami, Navid Mostoufi
Summary: This study investigates the effects of four inter-particle forces on particle mixing in a fluidized bed. Each force's impact on axial mixing of particles was examined and compared to a bed without inter-particle force. The results showed that hydrogen bond force had the most significant influence on bubble size and particle mixing. The presence of inter-particle force increased the bubble phase fraction and diffusivity due to the formation of larger bubbles. The Ashton mixing index was evaluated, indicating that while diffusivity was higher with inter-particle force, mixing time was longer due to slower mixing at the particle scale.
Article
Physics, Applied
Qian Chen, Lulu Cao, Jinji Li, Qiang Fu, Yonghui Zhu, Qingjie Guo, Ruobai Liu, Tian Li, Wen Zhang, Jun Du, Jianguo Zheng, Zhaocong Huang, Ping Kwan Johnny Wong, Bin Fang, Zhongming Zeng, Ya Zhai
Summary: A reliable method to enhance the spin mixing conductance at the ferromagnetic/non-magnetic material interface through rare-earth doping in the non-magnetic layer is reported. The doping of rare-earth enables effective tuning of the interface, leading to improved spin injection and manipulation efficiency.
APPLIED PHYSICS LETTERS
(2022)
Article
Energy & Fuels
Miao Yang, Seyed Morteza Mousavi, Hesammedin Fatehi, Xue-Song Bai
Summary: This paper investigates biomass gasification in lab-scale fluidized bed gasifiers using the MP-PIC model coupled with the DKM and a new pyrolysis model. The results show that the DKM improves the robustness of the model and the new pyrolysis model enhances the sensitivity of gasification product yields to operating temperature. The simulation results agree well with experimental data and reveal the effects of steam/biomass ratio and operating temperature on gas product formation. The steam/biomass ratio has a minor effect on pyrolysis and heterogeneous reactions, while the gasifier temperature has a crucial impact on these processes and carbon conversion.
Article
Green & Sustainable Science & Technology
Bouabdellah Abed, Abdelouahab Benzerdjeb, Abdeljellil Benmansour, Habib Achache, Rabia Ferhat, Abderrahmene Debz, Alaxender M. Gorlov
Summary: Renewable energies and cross-flow turbines are gaining increasing interest, with numerical methods proving to be useful in evaluating and predicting turbine performance. The study presents numerical results for a Darrieus turbine, showing good agreement with experimental results and highlighting the potential for faster and more cost-effective performance evaluation.
Article
Chemistry, Analytical
Saqib Shahzad, Muhammad Nadeem, Adnan Hamid, Li Fei, Atta Ullah
Summary: This study investigates the hydrodynamics of gas-solid flows in fluidized bed reactors by simulating monodisperse and bidisperse systems with different particle sizes and solid volume fractions. The results show that slip velocity, heterogeneity index, and mixing index are influenced by the size distribution and solid volume fraction.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Agricultural Engineering
Yuan Liu, Shiliang Wu, Huiyan Zhang, Rui Xiao
Summary: Combining torrefaction with fast pyrolysis is a feasible method for producing long-chain ether precursors. Structural characterization results showed that torrefaction led to a decrease in crystallinity index and the elimination of hydroxyls, ether bonds, etc., but an increase in carbonyls. The production of small-molecule gases was reduced after torrefaction, while the yield of targeted compounds in bio-oil significantly improved, with 240CS providing the highest carbon yield.
BIORESOURCE TECHNOLOGY
(2021)
Article
Engineering, Environmental
Tove Djerf, David Pallares, Filip Johnsson, Gaetano Sardina, Henrik Strom
Summary: This study investigates the back-mixing of solids in the transport zone of large-scale circulating fluidized bed (CFB) boilers and identifies the core-to-wall layer mass transfer as the governing mechanism. Pe-numbers may not straightforwardly describe lateral solid dispersion, and a Pe-number < 26 is needed to match the measured back-mixing rates in large-scale CFB boilers. A mathematical expression for the core-to-wall layer mass transfer coefficient based on a Sherwood number correlation shows better agreement with large-scale measurements than expressions in the literature.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.