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Covalent organic frameworks-incorporated thin film composite membranes prepared by interfacial polymerization for efficient CO_(2) separation

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Chinese Journal of chemical engineering 2022年第3期35卷 152-160页

作者： Haoqing Xu Wenyan Feng Menglong Sheng Ye Yuan Bo Wang Jixiao Wang Zhi Wang chemical engineering Research Center School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Tianjin Key Laboratory of Membrane Science and Desalination Technology State Key Laboratory of Chemical EngineeringCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin 300350China Life and Health Research Institute School of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China

Thin film composite(TFC)membranes with nanofillers additives for CO_(2)separation show promising applications in energy and environment-related ***,the poor compatibility between nanofillers and polymers in TFC membranes is the main *** this work,covalent organic frameworks(COFs,TpPa-1)with rich ANHA groups were incorporated into polyamide(PA)segment via in situ interfacial polymerization to prepare defect-free TFC membranes for CO_(2)/N_(2)*** formed covalent bonds between TpPa-1 and PA strengthen the interaction between nanofillers and polymers,thereby enhancing ***,the incorporated COFs disturb the rigid structure of the PA layer,and provide fast CO_(2)transfer *** incorporated COFs also increase the content of effective carriers,which enhances the CO_(2)facilitated ***,in CO_(2)/N_(2)mixed gas separation test,the optimal TFC(TpPa_(0.025)-PIP-TMC/m PSf)membrane exhibits high CO_(2)permeance of 854 GPU and high CO_(2)/N_(2)selectivity of 148 at 0.15 MPa,CO_(2)permeance of 456 GPU(gas permeation unit)and CO_(2)/N_(2)selectivity of 92 at 0.5 *** addition,the Tp Pa_(0.025)-PIP-TMC/m PSf membrane also achieves high permselectivty in CO_(2)/CH_(4)mixed gas separation ***,the optimal TFC membrane showes good stability in the simulated flue gas test,revealing the application potential for CO_(2)capture from flue gas.

关键词： Covalent organic frameworks CO_(2)/N_(2)separation In situ interfacial polymerization Compatibility Covalent bonds

Effects of Formulation Parameters and Process Variables on the Properties of Granules Obtained by Reactive Granulation

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Transactions of Tianjin University 2018年第3期24卷 224-233页

作者： Leping Dang Xiaojun Lang Xu Li Hongyuan Wei school of chemical engineering and Technology Tianjin University

In this work, granulation between dodecyl-benzenesulfonic acid and sodium carbonate was investigated in a laboratory-scale high shear mixer. The effects offormulation parameters and process variables, including primary carbonate size, binder content, impeller speed, and operating temperature, were correlated to the properties ofthe product granules. Design ofexperiment and analysis ofvariance were combined to analyze the experimentaldata, and results showed that larger granule sizes with fewer fine particles can be obtained by employing higher binder contents and larger sodium carbonate sizes. The shear force ofthe impeller can extensively break oversized granules. The binder content exerted a contrasting effect on the flowability ofgranules formed with two kinds ofsodium carbonate, likely because ofdifferences in the liquid saturation ofthe solids. The dissolution rate determined by in-line size analysis showed that high binder contents were beneficialto dissolution performance, and the relationships between Hunter color and tested parameters were evaluated. The results ofthis work can be used as a reliable guidance for process controland optimization in powder detergent manufacturing.

关键词： Dry neutralization Granulation Size Flowability Dissolution rate Color

Shortcut Method of Design and Energy-Saving Analysis of Sargent Dividing Wall Column

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China Petroleum Processing & Petrochemical Technology 2018年第4期20卷 99-108页

作者： Fang Jing Cheng Xiaomin Li Xiaochun Xiang Ning Li Chunli school of chemical engineering Hebei University of Technology

The Sargent dividing wall column can implement four products separation sequences in one column based on Fully Thermally Coupled Distillation Column. The initial design parameters are required for the design optimization or dynamic control of the Sargent dividing wall column, and in order to make the rigorous simulation of the Sargent dividing wall column more conducive to convergence, a ten column model for complex Sargent column is established in this paper,and the shortcut design method of this model is proposed. The internal minimum vapor and liquid flow are obtained by the Underwood equations and the mass balance method and the V-min method. The separation for a 4-component shortcut mixture of pentane, hexane, heptane and octane was considered, while the initial values of design parameters and the ratio of vapor-liquid distribution of each column were calculated by using the shortcut design method of a ten column model. And by comparing the shortcut calculations with rigorous simulation results, the practicality and reliability of shortcut calculations were verified. The reason for energy saving was analyzed based on back-mixing. A virtual heat exchanger is proposed to make the Sargent dividing wall column more energy efficient.

关键词： Sargent dividing wall column shortcut design method energy saving virtual heat exchangers

The dynamic surface evolution of halide perovskites induced by external energy stimulation

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National Science Review 2024年第4期11卷 185-194页

作者： Feiyu Cheng Pengdong Wang Chenzhe Xu Qingliang Liao Suicai Zhang Haochun Sun Wenqiang Fan Guodong Liu Zhiyun Li Yaping Kong Li Wang Fangsen Li Zhuo Kang Yue Zhang Academy for Advanced Interdisciplinary Science and Technology State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing Key Laboratory for Advanced Energy Materials and Technologies Key Laboratory of Advanced Materials and Devices for Post-Moore ChipsMinistry of EducationBeijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology Beijing Vacuum Interconnected Nanotech Workstation(Nano-X) Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of Sciences Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

Tracking the dynamic surface evolution of metal halide perovskite is crucial for understanding the corresponding fundamental principles of photoelectric properties and intrinsic instability. However, due to the volatility elements and soft lattice nature of perovskites, several important dynamic behaviors remain unclear. Here, an ultra-high vacuum（UHV） interconnection system integrated by surface-sensitive probing techniques has been developed to investigate the freshly cleaved surface of CH3NH3PbBr3in situ under given energy stimulation. On this basis, the detailed three-step chemical decomposition pathway of perovskites has been clarified. Meanwhile, the evolution of crystal structure from cubic phase to tetragonal phase on the perovskite surface has been revealed under energy stimulation. Accompanied by chemical composition and crystal structure evolution, electronic structure changes including energy level position,hole effective mass, and Rashba splitting have also been accurately determined. These findings provide a clear perspective on the physical origin of optoelectronic properties and the decomposition mechanism of perovskites.

关键词： metal halide perovskite external energy stimulation surface dynamic evolution surface electronic structure ultra-high vacuum interconnection system

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硅基催化结构合成的策略(英文)

催化学报 2008年第11期29卷 1187-1192页

作者： Harold H. KUNG Mayfair C. KUNG chemical and biological engineering Department Northwestern University

Two approaches to synthesize silicon-based catalytic structures that aim at capturing the properties and functionalities of natural enzymes are described in this brief review:unit-by-unit synthesis of macromolecular units and templating/imprinting synthesis of nanocages. The unit-by-unit approach mimics the peptide synthesis method,offers atomic control of the structure,but is inefficient in synthesizing large structures such as nanocages. The templating/imprinting method is more suitable for nanocages at the sacrifice of atomic control,and the nanocages obtained are shown to possess properties exhibited by enzyme cavities.

关键词：合成工艺化学结构催化过程催化剂

Steam reforming of ethanol over Ni/Ce_(0.7)Pr_(0.3)O_2 catalyst

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Journal of Rare Earths 2012年第7期30卷 670-675页

作者：王红张丽娟袁木朝子徐婷玉刘源 school of chemical engineering Inner Mongolia University of Technology Tianjin Key Laboratory of Applied Catalysis Science and Engi-neering Department of Catalysis Science and TechnologySchool of Chemical EngineeringTianjin University

NiO/Ce0.7Pr0.3O2 catalysts were prepared by co-precipitation method and used for steam reforming of ethanol to produce hydrogen. The influence of nickel content and the doping of Pr on the catalytic performance were investigated. The catalysts were characterized by using temperature programmed reduction （TPR）, X-ray diffraction （XRD） and thermal analysis techniques. 15 wt.%NiO/Ce0.7Pr0.3O2 catalyst was highly active and selective for steam reforming of ethanol to produce hydrogen. With the doping of Pr, the anti-carbon deposition property of the catalyst and the anti-sintering stability of metal nickel were effectively improved. The improvement of the anti-carbon deposition is attributed to generation of oxygen vacancies resulted from the Pr doping; while the improvement of anti sintering is ascribed to the intensified interaction between the nickel species and the support which is owing to the Pr-doping resulted incorporation of some nickel ions into ceria lattice.

关键词： cerium praseodymium ethanol steam reforming nickel doping rare earths

Isolation, Purification, and Characterization of Exopolysaccharide Produced by Leuconostoc Citreum N21 from Dried Milk Cake

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Transactions of Tianjin University 2019年第2期25卷 161-168页

作者： Yanfang Yang Fang Feng Qingqing Zhou Fangkun Zhao Renpeng Du Zhijiang Zhou Ye Han school of chemical engineering and Technology Tianjin University

A strain with high production of exopolysaccharide(EPS) was isolated from dried milk cake(a traditional fermented food from Inner Mongolia). The strain was called N21 and later identified as Leuconostoc citreum( Leu. citreum). The strain was cultured in Man-Rogosa-Sharpe medium containing 50 g/L of sucrose for 48 h at 30 °C and the EPS purified, with a yield of 24.5 g/L. An average molecular weight of 6.07 × 10~6 g/mol was determined by high-performance size-exclusion chromatography. The structure of the purified EPS was investigated through gas chromatography, ~1H and ^(13)C nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. The results demonstrated a polysaccharide composed of D-glucopyranose units in a linear chain with consecutive α(1 → 6) linkages. No branching was found in the structure of the exopolysaccharide. The purified EPS showed high water solubility and emulsibility. Based on the thermogravimetric curve, the degradation temperature of the EPS was 308.47 °C, which suggested that the dextran in the study exhibited high thermal stability. The results indicated that Leu. citreum N21 could be widely used to produce linear EPS and that the EPS has potential applications in food science and processing as a food additive.

关键词： Exopolysaccharide Dextran Characterization Leuconostoc citreum Structure

In Situ Growth of 3D Hierarchical ZnO@Ni_xCo_(1-x)(OH)_y Core/Shell Nanowire/Nanosheet Arrays on Ni Foam for High-Performance Aqueous Hybrid Supercapacitors

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Transactions of Tianjin University 2018年第3期24卷 201-211页

作者： Fumin Wang Mengchao Liu Xubin Zhang Guojun Lv Mingshuai Sun school of chemical engineering and Technology Tianjin University

In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two-step protocol including a wet chemical process followed by electro-deposition. We then characterized its composition, structure and surface morphology by X-ray diff raction, energy-dispersive X-ray spectrometry(EDS), X-ray photoelectron spectroscopy, scanning electron microscopy(SEM), transmission electron microscopy, EDS elemental mapping. Our electrochemical measurements show that the ZnO@Ni_(0.67)Co_(0.33)(OH)_y electrode material exhibited a noticeably high specific capacity of as much as 255(mA ·h)/g at 1 A/g. Additionally, it demonstrated a superior rate capability, as well as an excellent cycling stability with 81.6% capacity retention over 2000 cycles at 5 A/g. This sample delivered a high energy density of 64 W·h/kg and a power density of 250 W/kg at a current density of 1 A/g. With such remarkable electrochemical properties, we expect the 3D hierarchical hybrid electrode material presented in this work to have promising applications for the next generation of energy storage systems.

关键词： ZnO@NixCo1-x(OH)y Core/shell nanowire/nanosheet array Supercapacitor Ni foam

Effects of Different Draft Baffles on the Hydrodynamics in Internal-Loop Airlift Reactors

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Transactions of Tianjin University 2015年第5期21卷 446-452页

作者：郄思远高飞刘晨黄哲庆刘春江 school of chemical engineering and Technology Tianjin University

In this paper, a 2-D airlift reactor was developed. The streamline and hydrodynamic parameters were measured in a 2-D airlift loop reactor(ALR)with different draft baffles. Three regimes were observed under different conditions. Particle image velocimetry(PIV)measurement showed that the liquid velocity distribution in horizontal direction presented different profiles in the three regimes. The length, the height and the spacing of draft baffles were applied in the experiments to optimize the ALR structure. It was found that the draft tube structure is of great importance in determining the hydrodynamics of ALRs. Additionally, the experimental results may serve as a step to the further optimization and design of ALR.

关键词： internal-loop airlift reactor hydrodynamics draft baffle structure particle image velocimetry