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Hua Wang
Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming, China

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Journal article
Published: 05 May 2021 in Journal of Hazardous Materials
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Electroplating sludge, a hazardous solid waste product of the electroplating industry, presents a serious environmental pollution risk. In this study, an environmentally friendly process for solidifying and recovering heavy metals from electroplating sludge using copper slag and spent cathode carbon is proposed. Combining the results of toxicity characteristic leaching procedure tests, thermodynamic analysis, chemical analysis, X-ray diffraction analysis, and electron probe microanalysis, the Cr, Ni, Cu, Fe, and F transformation mechanisms were first probed during vitrification. Under optimal experimental conditions, the Cr, Ni, and Cu recovery ratios reached 75.56 wt%, 98.41 wt%, and 99.25 wt%, and they increased by 40%, 5%, and 5%, respectively compared with the currently utilized technique. Moreover, the toxicity leaching results of the slag indicate that the Cr, F, and Cu are stable, while Ni is easily leached from the (Fe,Ni)(Fe,Cr)2O4 and alloy phases. Under the optimal metal recovery conditions, the leaching concentrations of Cr, Cu, F, and Ni were 0.57 mg/L, 4.45 mg/L, 1.52 mg/L, and 1.85 mg/L, respectively, which can be reused in other materials, minimizing the environmental risk. The electroplating sludge, copper slag, and spent cathode carbon co-treatment process achieves waste disposal with waste and significantly reduces electroplating sludge processing costs.

ACS Style

Yu Yong; Wang Hua; Hu Jianhang. Co-treatment of electroplating sludge, copper slag, and spent cathode carbon for recovering and solidifying heavy metals. Journal of Hazardous Materials 2021, 417, 126020 .

AMA Style

Yu Yong, Wang Hua, Hu Jianhang. Co-treatment of electroplating sludge, copper slag, and spent cathode carbon for recovering and solidifying heavy metals. Journal of Hazardous Materials. 2021; 417 ():126020.

Chicago/Turabian Style

Yu Yong; Wang Hua; Hu Jianhang. 2021. "Co-treatment of electroplating sludge, copper slag, and spent cathode carbon for recovering and solidifying heavy metals." Journal of Hazardous Materials 417, no. : 126020.

Original research paper
Published: 22 October 2020 in Fuel Cells
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The purpose of this study is to introduce a new method for quantifying the uniformity of temperature fields. A top‐blown gas‐stirring gas‐liquid two‐phase mixing test bench was set up, combined with an infrared imager, to obtain the temperature distribution of the gas‐liquid two‐phase mixing process. Gas‐liquid two‐phase energy conversion occurs during the physical reaction. The top‐blown gas is in direct contact with liquids of different temperatures to take away some of the heat, causing a difference in the internal temperature distribution of the liquid. The gas is air and the liquid is synthetic heat transfer oil. Using image segmentation and mathematical analogy of local discrepancy functions, the temperature distribution difference and temperature field non‐uniformity coefficient (NUC) of the rectangular region in the actual temperature field are obtained. By calculating the standard deviation of the non‐uniformity coefficient of the temperature field in each working condition, the fluctuation of the uniformity of the temperature field with time is obtained.

ACS Style

K. Yang; Z. Li; Q. Wang; X. Hu; H. Wang. Investigation on ADDIN CNKISM.UserStyleTemperature Uniformity in a Gas‐liquid Two‐phase Mixing System Stirred by Top‐blown Air ▴. Fuel Cells 2020, 21, 3 -10.

AMA Style

K. Yang, Z. Li, Q. Wang, X. Hu, H. Wang. Investigation on ADDIN CNKISM.UserStyleTemperature Uniformity in a Gas‐liquid Two‐phase Mixing System Stirred by Top‐blown Air ▴. Fuel Cells. 2020; 21 (1):3-10.

Chicago/Turabian Style

K. Yang; Z. Li; Q. Wang; X. Hu; H. Wang. 2020. "Investigation on ADDIN CNKISM.UserStyleTemperature Uniformity in a Gas‐liquid Two‐phase Mixing System Stirred by Top‐blown Air ▴." Fuel Cells 21, no. 1: 3-10.

Journal article
Published: 21 August 2020 in Renewable Energy
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Based on the multiphase particle-in-cell approach, the steam gasification of biomass in a lab-scale spouted bed gasifier is simulated to explore the particle-scale transport behavior in three distinct regions of the bed. The numerical results are firstly validated with the experimental data, followed by assessing the particle-scale features of sand and biomass species in the gasifier. The results demonstrate that biomass particles in three regions of spouted bed behave with different constituent content, heat transfer coefficient and temperature. The intensive heat transfer occurs in the spout region and fountain region. Biomass particles in the spout have a small temperature, large mass, small carbon fraction, and large volatile fraction. Heterogeneous reactions of the biomass particles mainly occur in the lower part of the fountain region but can be negligible in the spout and annulus region. The water-gas reaction is two-order of magnitude faster than the methanation reaction and Boudouard reaction. The spatial distribution of particle-scale level information of both particle species is nonuniform due to the presence of three regions and biomass accumulation. The horizontal and vertical dispersion coefficient of both sand and biomass species are at the scale of 10−4 m2/s and 10−2 m2/s, respectively.

ACS Style

Shiliang Yang; Feihu Fan; Jianhang Hu; Hua Wang. Particle-scale evaluation of the biomass steam-gasification process in a conical spouted bed gasifier. Renewable Energy 2020, 162, 844 -860.

AMA Style

Shiliang Yang, Feihu Fan, Jianhang Hu, Hua Wang. Particle-scale evaluation of the biomass steam-gasification process in a conical spouted bed gasifier. Renewable Energy. 2020; 162 ():844-860.

Chicago/Turabian Style

Shiliang Yang; Feihu Fan; Jianhang Hu; Hua Wang. 2020. "Particle-scale evaluation of the biomass steam-gasification process in a conical spouted bed gasifier." Renewable Energy 162, no. : 844-860.

Journal article
Published: 24 July 2020 in Energy
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In this work, computational fluid dynamics is adopted to simulate the steam-biomass gasification in a dual fluidized bed reactor system. Under the Eulerian-Lagrangian multiphase framework, the large eddy simulation and multiphase particle-in-cell models are selected to track the gas and solid phases, respectively. The compositions of the gaseous products numerically obtained at the gasifier outlet are compared with the experimental data for the model validation. Then, the radial and axial segregation of heat carrier with a wide particle size distribution together with the spatial variation of the microscale properties of solid phase are explored. The results show that the apparent size-induced segregation of heat carrier results in the distribution of large particles in the bottom region of both the combustor and gasifier, while the accumulation of fine particles in the freeboard of the gasifier. The mass of the heat carrier distributed in the combustor is nearly 10% of that in the gasifier. The particles in the combustor have a larger particle Reynolds number and dispersion coefficient as compared with that in the gasifier. For a specific particle size distribution, reducing the particle size enlarges the temperature, heat transfer coefficient, particle Reynolds number. Different solid residence behaviors appear in different components of the bed. A wider size distribution of heat carrier slightly enlarges the mean residence time in the combustor but obviously diminishes it in the gasifier, and also evidently reduces the solid circulation.

ACS Style

Shiliang Yang; Zhanghao Wan; Shuai Wang; Hua Wang. Computational fluid study of radial and axial segregation characteristics in a dual fluidized bed reactor system. Energy 2020, 209, 118359 .

AMA Style

Shiliang Yang, Zhanghao Wan, Shuai Wang, Hua Wang. Computational fluid study of radial and axial segregation characteristics in a dual fluidized bed reactor system. Energy. 2020; 209 ():118359.

Chicago/Turabian Style

Shiliang Yang; Zhanghao Wan; Shuai Wang; Hua Wang. 2020. "Computational fluid study of radial and axial segregation characteristics in a dual fluidized bed reactor system." Energy 209, no. : 118359.

Journal article
Published: 12 March 2020 in Energy Conversion and Management
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By coupling the heat transfer and chemical reactions, biomass-steam gasification in a lab-scale spouted gasifier is numerically simulated via the multiphase particle-in-cell approach. The proposed model is firstly validated with the experimental results. Then, the spatial distributions of biomass particles, spout-annulus boundary, the gas species, the gas-solid flux, together with the influences of operating parameters are discussed. The results demonstrate that: (i) similar to the well-known Brazil nut effect, density-induced segregation of biomass and sand species results in the accumulation of large-diameter biomass species near the bed surface. High temperature does not change the general distribution of the spout-annulus boundary; (ii) the gaseous products mainly concentrate in the fountain; enlarging the bed height and biomass diameter reduces but increases the mole fraction of CO and H2, respectively. The steam-biomass ratio has a promoting effect on the production of H2, while higher gasification temperature reduces the H2 yield; (iii) enlarging the bed height and steam-biomass ratio decreases and increases the vertical flux of both the gas and solid phase in the dense region, respectively. The increase of bed height and steam-biomass ratio reduces and enlarges the gas voidage, respectively. The results obtained in this work provide meaningful insights regarding the presence of Brazil nut effect induced by the density difference and the complicated multiphase flow in the spouting apparatus, which will be beneficial to the design and optimization of this kind of gasifier.

ACS Style

Shiliang Yang; Feihu Fan; Yonggang Wei; Jianhang Hu; Hua Wang; Shaohua Wu. Three-dimensional MP-PIC simulation of the steam gasification of biomass in a spouted bed gasifier. Energy Conversion and Management 2020, 210, 112689 .

AMA Style

Shiliang Yang, Feihu Fan, Yonggang Wei, Jianhang Hu, Hua Wang, Shaohua Wu. Three-dimensional MP-PIC simulation of the steam gasification of biomass in a spouted bed gasifier. Energy Conversion and Management. 2020; 210 ():112689.

Chicago/Turabian Style

Shiliang Yang; Feihu Fan; Yonggang Wei; Jianhang Hu; Hua Wang; Shaohua Wu. 2020. "Three-dimensional MP-PIC simulation of the steam gasification of biomass in a spouted bed gasifier." Energy Conversion and Management 210, no. : 112689.

Journal article
Published: 30 November 2019 in International Journal of Refrigeration
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The marker-controlled multiple watershed segmentation are achieved to distinguish darker continuous phase in gas-liquid two-phase flow patterns efficiently. Each plot of the Betti numbers βi is curve-fitted using a four-parameter logistics model, for characterizing mixing effects. Similarity between adjacent pixels can be quantified by the distance. The β1 of continuous phase decreases linearly at distance ≥ 2, which can be used to determine the threshold for segmentation. Repeated tests with different pixels and methods are conducted to ensure the repeatability and effectiveness of this model. More interestingly, we find that the rapid increase of β1 of bubbles swarm coincides with the evolution of β1 of continuous phase, and the median of difference of β1 between the two phases in the visible window, as a novel metric of flow regime control is obtained and correlated with average volumetric heat transfer coefficient. This dynamic image analysis method, equipped with computational homology, provides the ability of evaluation of the spatial flow structure from a two-dimensional image and can be used to control the process.

ACS Style

Jianxin Xu; Fanhan Liu; Qingtai Xiao; Junwei Huang; Yu Fei; Yunfei Yang; Yuling Zhai; Jianxin Pan; Hua Wang. Synergistic effect of flow pattern evolution of dispersed and continuous phases in direct-contact heat transfer process. International Journal of Refrigeration 2019, 112, 201 -214.

AMA Style

Jianxin Xu, Fanhan Liu, Qingtai Xiao, Junwei Huang, Yu Fei, Yunfei Yang, Yuling Zhai, Jianxin Pan, Hua Wang. Synergistic effect of flow pattern evolution of dispersed and continuous phases in direct-contact heat transfer process. International Journal of Refrigeration. 2019; 112 ():201-214.

Chicago/Turabian Style

Jianxin Xu; Fanhan Liu; Qingtai Xiao; Junwei Huang; Yu Fei; Yunfei Yang; Yuling Zhai; Jianxin Pan; Hua Wang. 2019. "Synergistic effect of flow pattern evolution of dispersed and continuous phases in direct-contact heat transfer process." International Journal of Refrigeration 112, no. : 201-214.

Journal article
Published: 25 November 2019 in Energies
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In this paper, the nonlinear dynamic characteristics of the oxygen-enriched combustion of waste oil biodiesel in semi-industrial furnaces were tested by the power spectrum, phase space reconstruction, the largest Lyapunov exponents, and the 0-1 test method. To express the influences of the system parameters, experiments were carried out under different oxygen content conditions (21%, 25%, 28%, 31%, and 33%). Higher oxygen enrichment degrees contribute to finer combustion sufficiency, which produces flames with high luminance. Flame luminance and temperature can be represented by different gray scale values of flame images. The chaotic characteristics of gray scale time series under different oxygen enrichment degrees were studied. With increased oxygen content, the chaotic characteristics of flame gradually developed from weak chaos to strong chaos. Furthermore, the flame maintained a stable combustion process in a high-temperature region. The stronger the chaotic characteristics of the flame, the better the combustion effect. It can be seen that the change of initial combustion conditions has a great influence on the whole combustion process. The results of several chaotic test methods were consistent. Using chaotic characteristics to analyze the waste oil biodiesel combustion process can digitize the combustion process, find the best combustion state, optimize, and precisely control it.

ACS Style

Shengyang Gao; Fashe Li; Qingtai Xiao; Jianxin Xu; Huage Wang; Hua Wang. Experimental Demonstration of Deterministic Chaos in a Waste Oil Biodiesel Semi-Industrial Furnace Combustion System. Energies 2019, 12, 4479 .

AMA Style

Shengyang Gao, Fashe Li, Qingtai Xiao, Jianxin Xu, Huage Wang, Hua Wang. Experimental Demonstration of Deterministic Chaos in a Waste Oil Biodiesel Semi-Industrial Furnace Combustion System. Energies. 2019; 12 (23):4479.

Chicago/Turabian Style

Shengyang Gao; Fashe Li; Qingtai Xiao; Jianxin Xu; Huage Wang; Hua Wang. 2019. "Experimental Demonstration of Deterministic Chaos in a Waste Oil Biodiesel Semi-Industrial Furnace Combustion System." Energies 12, no. 23: 4479.

Journal article
Published: 21 November 2019 in Applied Energy
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In-depth understanding of the dynamical and thermal property of bubbles is required to elucidate the phenomena occurring in a bubbling fluidized gasifier. In this work, numerical simulation is conducted for the biomass gasification in a three-dimensional bubbling fluidized bed through the multiphase particle-in-cell method. After validating the numerical results with experimental data, the impact of particle size distribution of sand material on the dynamical property (i.e., the rising velocity, spatial distribution, volume) combined with the thermal property (i.e., gas species, temperature, pressure, density, thermal conductivity) of the rising bubbles in the system are explored. The results demonstrate that large bubbles have a high mass fraction of combustible gases. Along the bed height, the bubble temperature, specific heat and thermal conductivity continuously increase while the density and pressure decrease. Compared with the boundary, the bubble interior has a higher temperature, smaller density, and more combustible gases. Enlarging the particle size distribution width increases the bubble volume, aspect ratio, mass fraction of combustible gas in the lower part of the bed, temperature and the thermal conductivity of bubbles, but decreases the rising velocity, density and pressure of the rising bubbles. The results obtained provide a new perspective regarding the effect of particle size distribution on the bubble property especially the first report regarding the thermal property of the rising bubbles in the bubbling fluidized gasifier, which will be beneficial for the in-depth understanding for the fundamental aspects and also the practical operation for this kind of apparatus.

ACS Style

Shiliang Yang; Tao Zhou; Yonggang Wei; Jianhang Hu; Hua Wang. Dynamical and thermal property of rising bubbles in the bubbling fluidized biomass gasifier with wide particle size distribution. Applied Energy 2019, 259, 114178 .

AMA Style

Shiliang Yang, Tao Zhou, Yonggang Wei, Jianhang Hu, Hua Wang. Dynamical and thermal property of rising bubbles in the bubbling fluidized biomass gasifier with wide particle size distribution. Applied Energy. 2019; 259 ():114178.

Chicago/Turabian Style

Shiliang Yang; Tao Zhou; Yonggang Wei; Jianhang Hu; Hua Wang. 2019. "Dynamical and thermal property of rising bubbles in the bubbling fluidized biomass gasifier with wide particle size distribution." Applied Energy 259, no. : 114178.

Journal article
Published: 21 November 2019 in Chem
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Summary CO2 hydrogenation to methanol with renewable H2 is an ideal process for coupling reduction of greenhouse gas and development of sustainable methanol economy, and Cu-ZnO-ZrO2 is regarded as a promising catalyst for this process. Identification of the key descriptors that control the catalytic activity and selectivity is one of the most important issues for this reaction. Here, we identify the role of water in the hydrogenation of CO2 to methanol, which strongly affects the selectivity and yield of methanol. Our results reveal that methanol is generated via the hydrolysis of methoxy formed by the hydrogenation of formate, and the desorbed water vapor facilitates the hydrolysis of methoxy. A suitable amount of water in the feed can promote the formation of methanol. The enhancement on the water vapor diffusion in catalysts by structural and/or surface modification offers a new strategy for tuning the selectivity and yield of methanol.

ACS Style

Yuhao Wang; Wengui Gao; Kongzhai Li; Yane Zheng; Zhenhua Xie; Wei Na; Jingguang G. Chen; Hua Wang. Strong Evidence of the Role of H2O in Affecting Methanol Selectivity from CO2 Hydrogenation over Cu-ZnO-ZrO2. Chem 2019, 6, 419 -430.

AMA Style

Yuhao Wang, Wengui Gao, Kongzhai Li, Yane Zheng, Zhenhua Xie, Wei Na, Jingguang G. Chen, Hua Wang. Strong Evidence of the Role of H2O in Affecting Methanol Selectivity from CO2 Hydrogenation over Cu-ZnO-ZrO2. Chem. 2019; 6 (2):419-430.

Chicago/Turabian Style

Yuhao Wang; Wengui Gao; Kongzhai Li; Yane Zheng; Zhenhua Xie; Wei Na; Jingguang G. Chen; Hua Wang. 2019. "Strong Evidence of the Role of H2O in Affecting Methanol Selectivity from CO2 Hydrogenation over Cu-ZnO-ZrO2." Chem 6, no. 2: 419-430.

Journal article
Published: 09 November 2019 in Powder Technology
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The flow characteristics of binary mixtures of cylindrical particles in the rotating drum are numerically studied by extending the DEM model developed for spherical particles to non-spherical ones. The flow patterns of the binary mixtures of cylindrical particles are similar to that of spherical ones. Enlarging the length ratio obviously increases the dynamic angle of repose throughout the drum length, which gives rise to greater total kinetic energy and corresponding fluctuation magnitude. The length difference of the constituents leads to radial segregation, with small and large cylindrical particles in the radial core and periphery, respectively. Moreover, radial segregation decreases and increases the mass of large and small particles, respectively, in the active region. Also, enlarging the length ratio clearly increases the streamwise velocity in the active region. Different from the translational velocity, the rotating velocity along the axial direction is of the same scale as the transversal ones.

ACS Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. Flow dynamics of binary mixtures of non-spherical particles in the rolling-regime rotating drum. Powder Technology 2019, 361, 930 -942.

AMA Style

Shiliang Yang, Hua Wang, Yonggang Wei, Jianhang Hu, Jia Wei Chew. Flow dynamics of binary mixtures of non-spherical particles in the rolling-regime rotating drum. Powder Technology. 2019; 361 ():930-942.

Chicago/Turabian Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. 2019. "Flow dynamics of binary mixtures of non-spherical particles in the rolling-regime rotating drum." Powder Technology 361, no. : 930-942.

Journal article
Published: 14 October 2019 in Powder Technology
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The particle-scale characteristics of the solid phase in the three distinct regions of the dual-column slot-rectangular spouted bed are studied, along with the effects of operating parameters and scaling up, via the computational fluid dynamics coupled with discrete element method (CFD-DEM). Results demonstrate that: (i) the spout-annulus interface expands from the bottom initially and then shrinks to a neck; (ii) the majority of the particles are in the annulus and the solid residence time (SRT) patterns are distinctly different in the three regions; (iii) the collision force is much larger than the fluid force, with the greatest magnitudes in the spout region and bed surface; (iv) significantly different solid dispersion patterns are observed among three directions; and (v) scaling up the capacity of the multi-chamber spouting system by horizontally aligning more chambers negligibly alters the flow pattern or the particle-scale information (e.g., SRT) during steady spouting.

ACS Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. Particle-scale characteristics of the three distinct regions in the multi-chamber slot-rectangular spouted bed. Powder Technology 2019, 360, 658 -672.

AMA Style

Shiliang Yang, Hua Wang, Yonggang Wei, Jianhang Hu, Jia Wei Chew. Particle-scale characteristics of the three distinct regions in the multi-chamber slot-rectangular spouted bed. Powder Technology. 2019; 360 ():658-672.

Chicago/Turabian Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. 2019. "Particle-scale characteristics of the three distinct regions in the multi-chamber slot-rectangular spouted bed." Powder Technology 360, no. : 658-672.

Particle technology and fluidization
Published: 12 September 2019 in AIChE Journal
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Particle shape impacts the flow behavior of granular material but this effect is still far from being fully understood. Using DEM, the current work explores the segregation phenomena of the binary mixtures of cylindrical particles (differing in length but with the same diameter) in the three‐dimensional rotating drum operating in the rolling regime, with each cylindrical particle fully represented by the superquadric equation. The important characteristics and the effect of length ratio on the flow dynamics of the binary mixtures are discussed. Some trends are in sync with those of binary mixtures of spherical particles. Unique to non‐spherical particles is the orientation of particles, with results indicating that the cylindrical particles align their major axes perpendicular to the drum axis and this behavior becomes more significant for large particles when the length ratio increases. The length‐induced radial segregation causes the orientation of large cylindrical particles to be less uniform. This article is protected by copyright. All rights reserved.

ACS Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. Segregation behavior of binary mixtures of cylindrical particles with different length ratios in the rotating drum. AIChE Journal 2019, 66, 1 .

AMA Style

Shiliang Yang, Hua Wang, Yonggang Wei, Jianhang Hu, Jia Wei Chew. Segregation behavior of binary mixtures of cylindrical particles with different length ratios in the rotating drum. AIChE Journal. 2019; 66 (1):1.

Chicago/Turabian Style

Shiliang Yang; Hua Wang; Yonggang Wei; Jianhang Hu; Jia Wei Chew. 2019. "Segregation behavior of binary mixtures of cylindrical particles with different length ratios in the rotating drum." AIChE Journal 66, no. 1: 1.

Research article
Published: 20 August 2019 in ACS Sustainable Chemistry & Engineering
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Syngas generation via thermochemical H2O-CO2 splitting relies heavily on a high-temperature decomposition of metal oxides into a reduced state. Meanwhile, typical chemical looping partial oxidation of methane to syngas suffers from the carbon deposition and the low selectivity towards syngas. To overcome these drawbacks, the partial oxidation of methane and the H2O-CO2 splitting is coupled to consist of an alternative chemical looping redox scheme for the generation of Fischer–Tropsch(F–T)-ready syngas. The usability of lattice oxygen in a redox catalyst is facilitated and its redox property is also thermodynamically optimized by using H2O and CO2 as soft oxidants, guaranteeing an effective generation of syngas from both redox steps. The carbon tolerance is greatly enhanced due to H2O or CO2 gasification in the re-oxidization step. Experimental studies confirm the redox scheme by using CeO2-LaFeO3 redox catalyst, demonstrating a generation of syngas with an H2/CO molar ratio around 2.0 in both methane partial oxidation and H2O-CO2 splitting steps over 30 repeated cycles at 850 ºC. A syngas selectivity of 95 % in methane partial oxidation and nearly 100 % conversion of CO2 to CO can be achieved. Synergistic effect and competing reaction between H2O and CO2 splittings over the reduced redox catalyst are the key factors for the control of syngas composition and the intensification of CO2 splitting. The proposed approach can potentially be applied for production of Fischer–Tropsch (F–T)-ready syngas with an increased yield without the need for gas separation when compared to the state-of-the-art thermochemical splitting or methane chemical looping partial oxidation processes.

ACS Style

Yanpeng Chen; Xing Zhu; Kongzhai Li; Yonggang Wei; Yane Zheng; Hua Wang. Chemical Looping Co-splitting of H2O–CO2 for Efficient Generation of Syngas. ACS Sustainable Chemistry & Engineering 2019, 7, 15452 -15462.

AMA Style

Yanpeng Chen, Xing Zhu, Kongzhai Li, Yonggang Wei, Yane Zheng, Hua Wang. Chemical Looping Co-splitting of H2O–CO2 for Efficient Generation of Syngas. ACS Sustainable Chemistry & Engineering. 2019; 7 (18):15452-15462.

Chicago/Turabian Style

Yanpeng Chen; Xing Zhu; Kongzhai Li; Yonggang Wei; Yane Zheng; Hua Wang. 2019. "Chemical Looping Co-splitting of H2O–CO2 for Efficient Generation of Syngas." ACS Sustainable Chemistry & Engineering 7, no. 18: 15452-15462.

Article
Published: 01 August 2019 in Journal of Central South University
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The evaluation of the mixing effect of gas-liquid two-phase flow during the top-blown gas agitation mixing is one of the difficulties in the testing field, especially in the process of using the model method to study the metallurgical top-blowing process. In order to evaluate the effect of gas-liquid two-phase flow mixing, a gas chromatography simulation based on capacitance tomography was used to visualize the flow pattern and analyze the mixed characteristics. A gas top-blown agitation test rig was set up, the gas phase was air-selected, and the liquid phase was selected from synthetic heat-conducting oil. The top-blown stirring test process was measured and imaged by electrical capacitance tomography (ECT) equipment from ECT Instruments Ltd (UK). The MATLAB program was used to identify the mixing areas of the images to obtain the distribution of gas-liquid two-phase. The flow pattern of the gas-liquid mixing region was obtained. The chaotic detection of the gas-liquid mixing process was performed by the three-state test method; the images were processed by the counting box dimension-corrosion method to obtain the mixing uniformity time of gas-liquid flow. Results show that it is feasible to use the capacitance tomography technique to visualize the gas-liquid two-phase distribution. The uniformity time quantification of the gas-liquid mixing process is also achieved. 在顶吹气体搅拌混合体系中, 气液两相流的混合效果评价是测试领域的难点之一, 特别是在使 用模型法研究冶金熔池顶吹的过程中。为了评估气液两相流的混合效果, 提出基于电容层析成像(ECT) 的气相色谱模拟来观察流型并分析混合特征。建立气体顶吹搅拌试验台, 气相选择空气, 液相选用合 成导热油。使用ECT Instruments Ltd(UK)的电容层析成像设备对顶吹搅拌过程进行测量及成像。运用 MATLAB 程序对气液混合区域进行特征识别, 获得气液两相的流型分布。运用“three-state-test(3ST)” 方法对气液混合过程进行混沌检测; 运用“腐蚀化计盒维数”法处理图像, 得到气液搅拌的混均时间。 结果表明, 利用电容层析成像技术可对气液混合体系进行流型可视化和混匀时间量化。

ACS Style

Kai Yang; Shi-Bo Wang; Xiu-Le Zhu; Jian-Xin Xu; Hua Wang. Flow pattern visualization and nonlinear analysis of gas-liquid mixing process with top-blowing gas stirring. Journal of Central South University 2019, 26, 2029 -2040.

AMA Style

Kai Yang, Shi-Bo Wang, Xiu-Le Zhu, Jian-Xin Xu, Hua Wang. Flow pattern visualization and nonlinear analysis of gas-liquid mixing process with top-blowing gas stirring. Journal of Central South University. 2019; 26 (8):2029-2040.

Chicago/Turabian Style

Kai Yang; Shi-Bo Wang; Xiu-Le Zhu; Jian-Xin Xu; Hua Wang. 2019. "Flow pattern visualization and nonlinear analysis of gas-liquid mixing process with top-blowing gas stirring." Journal of Central South University 26, no. 8: 2029-2040.

Journal article
Published: 17 June 2019 in Fuel
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Isobutyl palmitate was synthesized by the esterification of palmitic acid and isobutanol with pyridine n-butyl bisulfate ionic liquid as the catalyst in a self-designed reactor. The kinetics of the esterification and cold flow properties of biodiesel were also studied. The optimal reaction conditions for the esterification are as follows: catalyst dosage, 6%; reaction time, 60 min; molar ratio of isobutanol to palmitic acid, 5:1; and reaction temperature, 100 °C. The verification test was conducted under the optimal conditions, and the esterification rate was up to 98.79%. The kinetics of catalytic esterification was analyzed. The reaction orders was 1.49; the activation energy Ea was 57.38 kJ/mol; the frequency factor A was 2.70 × 107; and the reaction kinetics model was -dcA/dt=2.70×107e-57.38RTcA1.49. The solidifying point (SP), cold filter plugging point (CFPP), and kinematic viscosity of isobutyl palmitate obtained were 3 °C, 7 °C, and 4.93 mm2 s−1, respectively. Compared to methyl palmitate, the SP decreased by six times, and CFPP decreased by 3.28 times. Therefore, the use of branched-chain alcohol instead of methanol ester exchange descaling method can effectively reduce the SP and CFPP of biodiesel to improve cold flow properties of biodiesel.

ACS Style

Zi-Hao Ni; Fa-She Li; Hua Wang; Shuang Wang; Sheng-Yang Gao. Catalytic esterification, kinetics, and cold flow properties of isobutyl palmitate. Fuel 2019, 254, 115368 .

AMA Style

Zi-Hao Ni, Fa-She Li, Hua Wang, Shuang Wang, Sheng-Yang Gao. Catalytic esterification, kinetics, and cold flow properties of isobutyl palmitate. Fuel. 2019; 254 ():115368.

Chicago/Turabian Style

Zi-Hao Ni; Fa-She Li; Hua Wang; Shuang Wang; Sheng-Yang Gao. 2019. "Catalytic esterification, kinetics, and cold flow properties of isobutyl palmitate." Fuel 254, no. : 115368.

Journal article
Published: 11 March 2019 in Nature Communications
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The synergistic interaction among different components in complex catalysts is one of the crucial factors in determining catalytic performance. Here we report the interactions among the three components in controlling the catalytic performance of Cu–ZnO–ZrO2 (CZZ) catalyst for CO2 hydrogenation to methanol. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements under the activity test pressure (3 MPa) reveal that the CO2 hydrogenation to methanol on the CZZ catalysts follows the formate pathway. Density functional theory (DFT) calculations agree with the in situ DRIFTS measurements, showing that the ZnO–ZrO2 interfaces are the active sites for CO2 adsorption and conversion, while the presence of metallic Cu is also necessary to facilitate H2 dissociation and to provide hydrogen resource. The combined experiment and DFT results reveal that tuning the interaction between ZnO and ZrO2 can be considered as another important factor for designing high performance catalysts for methanol generation from CO2. Despite great efforts, the reaction mechanism of CO2 hydrogenation to methanol and the nature of the active sites on Cu–ZnO–ZrO2 (CZZ) catalysts are still under debate. Herein, the authors report the interactions among the three components in controlling the catalytic performance of CZZ catalyst for CO2 hydrogenation to methanol.

ACS Style

Yuhao Wang; Shyam Kattel; Wengui Gao; Kongzhai Li; Ping Liu; Jingguang G. Chen; Hua Wang. Exploring the ternary interactions in Cu–ZnO–ZrO2 catalysts for efficient CO2 hydrogenation to methanol. Nature Communications 2019, 10, 1 -10.

AMA Style

Yuhao Wang, Shyam Kattel, Wengui Gao, Kongzhai Li, Ping Liu, Jingguang G. Chen, Hua Wang. Exploring the ternary interactions in Cu–ZnO–ZrO2 catalysts for efficient CO2 hydrogenation to methanol. Nature Communications. 2019; 10 (1):1-10.

Chicago/Turabian Style

Yuhao Wang; Shyam Kattel; Wengui Gao; Kongzhai Li; Ping Liu; Jingguang G. Chen; Hua Wang. 2019. "Exploring the ternary interactions in Cu–ZnO–ZrO2 catalysts for efficient CO2 hydrogenation to methanol." Nature Communications 10, no. 1: 1-10.

Journal article
Published: 13 February 2019 in Energy
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Without an intervening wall, the direct contact evaporator (DCE) has been already technically proven to improve the overall thermal efficiency of organic Rankine cycle (ORC) used to recover low-grade heat sources and transform it into power. In the estimation of volumetric heat transfer coefficient (VHTC) which is assumed to vary with flow rate, noises signals caused by various unstable factors (e.g., measurement errors) often corrupt the time series of VHTC. For forecasting the heat transfer performance of DCE in ORC more accurately, this paper proposes a novel approach (refers as EMD-RBF-NN), which combines multi-input radial basis function (RBF) neural network (NN) and empirical mode decomposition (EMD) method. Specifically, the original VHTC time series is firstly decomposed by EMD method that is fully data-driven. Then, the proposed method models the resultant decomposition series with flow rates of two fluids (dispersed and continuous phases) and VHTC by using RBF neural network. This simple technique was illustrated by using the ORC direct contact evaporator (ORC-DCE) and data processing system. Via using the experimental datasets of ORC-DCE, this paper demonstrates that the proposed EMD-RBF-NN model that associates flow rates of two phases with VHTC improves the forecasting accuracy of VHTC noticeably comparing with existing models.

ACS Style

Junwei Huang; Qingtai Xiao; Jingjing Liu; Hua Wang. Modeling heat transfer properties in an ORC direct contact evaporator using RBF neural network combined with EMD. Energy 2019, 173, 306 -316.

AMA Style

Junwei Huang, Qingtai Xiao, Jingjing Liu, Hua Wang. Modeling heat transfer properties in an ORC direct contact evaporator using RBF neural network combined with EMD. Energy. 2019; 173 ():306-316.

Chicago/Turabian Style

Junwei Huang; Qingtai Xiao; Jingjing Liu; Hua Wang. 2019. "Modeling heat transfer properties in an ORC direct contact evaporator using RBF neural network combined with EMD." Energy 173, no. : 306-316.

Journal article
Published: 19 January 2019 in Journal of Cleaner Production
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Walnut shell is a common agricultural by-products for the production of biochar. In this study, the walnut shell was investigated by thermoanalytical methods to evaluate its thermal behavior; and the biochar was prepared from the pyrolysis at 600 °C. Biochar characterization was studied in detail, and proximate analysis result indicates that the biochar obtained from walnut shell has a high fixed carbon content, lower ash content. The biochar was used as a reductant to reduce the waste copper slag for recovering iron. The reduction process of copper slag by biochar was analyzed theoretically, and the iron in the slag was recovered efficiently by reduction and magnetic separation method. The phase transformation of the reduced slag and the kinetics of reduction process were analyzed during the reduction process with biochar. The research results suggest that biochar derived from walnut shell can be used as a green reductant to reduce iron phase in the waste copper slag and realize the clean utilization of hazardous waste.

ACS Style

Shiwei Zhou; Yonggang Wei; Bo Li; Hua Wang. Cleaner recycling of iron from waste copper slag by using walnut shell char as green reductant. Journal of Cleaner Production 2019, 217, 423 -431.

AMA Style

Shiwei Zhou, Yonggang Wei, Bo Li, Hua Wang. Cleaner recycling of iron from waste copper slag by using walnut shell char as green reductant. Journal of Cleaner Production. 2019; 217 ():423-431.

Chicago/Turabian Style

Shiwei Zhou; Yonggang Wei; Bo Li; Hua Wang. 2019. "Cleaner recycling of iron from waste copper slag by using walnut shell char as green reductant." Journal of Cleaner Production 217, no. : 423-431.

Journal article
Published: 26 October 2018 in Applied Thermal Engineering
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We propose a new method to measure uniformity of gas-liquid mixing in a direct-contact heat exchanger by moment balance and image analysis. A mapping technique is developed to project the pixels distribution from binary image to 3D domain. We present a rigorous theoretical base of the applied method based on moments and equilibrium theory. An inclination angle with direction is derived to characterize the imbalanced structure caused by heterogeneity of mass distribution, which is used to quantify the global uniformity of spatial distribution of mixtures in any irregular area. A characteristic curve obtained by local inclination angles can be used to test the homogeneous, heterogeneous and pseudo-homogeneous mixtures, leading to a useful parameter to quantify the mixing effects. The uniformity obtained by similar patterns are compared with existing methods. The experimental results show a good fitting curve between mixing effects and heat transfer performance. This test could also be applied for studying a variety of multiphase mixing problems in which assessment of uniformity is required.

ACS Style

Jianxin Xu; Qingtai Xiao; ZhiHan Lv; Junwei Huang; Ruoxiu Xiao; Jianxin Pan; Hua Wang. New metrics for measuring multiphase mixing effects in a direct-contact heat exchanger. Applied Thermal Engineering 2018, 147, 592 -601.

AMA Style

Jianxin Xu, Qingtai Xiao, ZhiHan Lv, Junwei Huang, Ruoxiu Xiao, Jianxin Pan, Hua Wang. New metrics for measuring multiphase mixing effects in a direct-contact heat exchanger. Applied Thermal Engineering. 2018; 147 ():592-601.

Chicago/Turabian Style

Jianxin Xu; Qingtai Xiao; ZhiHan Lv; Junwei Huang; Ruoxiu Xiao; Jianxin Pan; Hua Wang. 2018. "New metrics for measuring multiphase mixing effects in a direct-contact heat exchanger." Applied Thermal Engineering 147, no. : 592-601.

Article
Published: 09 August 2018 in Metallurgical and Materials Transactions A
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Copper slag, a by-product of copper pyrometallurgy, inevitably contains a certain amount of copper. Oxygen-enriched smelting technologies increase the copper content in slag indirectly because of the production of higher-grade matte. The effect of iron phase evolution on the copper content in slag during the slag cleaning process in an electric furnace was investigated using the method of combining theory with experiments. Based on the analysis, the main factors that impede the separation of slag and copper/matte were determined. Subsequently, the properties of slag were analyzed after decreasing the magnetite content within the slag. The experimental results showed that decreases in magnetite content were beneficial for the separation of copper and slag because of the decrease of slag viscosity. Nevertheless, Cu-Fe alloys formed when magnetite was completely reduced to metallic iron, and the foaming slag was formed at 1250 °C. Furthermore, the distribution of copper in the reduced slags was studied in detail.

ACS Style

Shiwei Zhou; Yonggang Wei; Bo Li; Hua Wang. Effect of Iron Phase Evolution on Copper Separation from Slag Via Coal-Based Reduction. Metallurgical and Materials Transactions A 2018, 49, 3086 -3096.

AMA Style

Shiwei Zhou, Yonggang Wei, Bo Li, Hua Wang. Effect of Iron Phase Evolution on Copper Separation from Slag Via Coal-Based Reduction. Metallurgical and Materials Transactions A. 2018; 49 (6):3086-3096.

Chicago/Turabian Style

Shiwei Zhou; Yonggang Wei; Bo Li; Hua Wang. 2018. "Effect of Iron Phase Evolution on Copper Separation from Slag Via Coal-Based Reduction." Metallurgical and Materials Transactions A 49, no. 6: 3086-3096.