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Effects of internals on macroscopic fluid dynamics in a bubble column

Chinese Journal of Chemical engineering 2025年第1期77卷 19-29页

作者： Shijie Liu Jin Liang Qin Li Hui Yu Haoliang Wang Xiangyang Li Chao Yang School of Chemical Engineering Sichuan UniversityChengdu 610065China CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Petroleum Molecular&Process EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

The effects of internals on liquid mixing and gas-liquid mass transfer have rarely been investigated in bubble columns,and the commonly used measurement method overestimates significantly overall gas ***,gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas ***,a stable conductivity method for liquid macromixing has been established by shielding large bubbles using#16nylon ***,the influences of internal coverage(=12.6%,18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically *** is found that the presence of internals has a notable effect on macroscopic fluid *** overall gas holdup and gas-liquid volumetric mass transfer coefficient decrease,and the macromixing time decreases with the increase of internal cross-sectional area *** are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall *** design makes maintenance easier,but in reality,the reactor performance has *** improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.

关键词： Bubble column Internals Macroscopic fluid dynamics Mixing Mass transfer

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Role of methoxy and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity of β-O-4 lignin model compounds

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green Energy & Environment 2024年第1期9卷 114-125页

作者： Yang Zhou Qiang Zeng Hongyan He Kejia Wu Fuqiao Liu Xuehui Li School of Chemistry and Chemical Engineering The Guangdong Provincial Key Laboratory of Green Chemical Product TechnologyState Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong510640China CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.

关键词： Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect

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Construction of multifunctional lanthanum manganese mixed nanoparticles mediated by ionic liquids for selective aerobic oxidation of cyclohexane

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Rare Metals 2024年第5期43卷 2205-2221页

作者： Hao Li Rui-Rui Zhang Ke-Xin Li Shuang Wei Yu-Mei Liu Rui-Xia Liu Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Selective oxidation of alkanes to produce highvalue chemicals is an essential strategy and means to realize efficient utilization of *** this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the multifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of *** 8.9%cyclohexane conversion with 90%KA oi(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild *** effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characterizations,indicating the structure-directing and template effect of ILs on the multifunctional *** formation of self-assembled spherical nanoparticles followed the"dissolution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal ***,the high reactive oxygen concentration redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorption and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping *** recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.

关键词： Ionic liquids Nanoparticle Multifunctional catalyst Cyclohexane oxidation

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Synergistic solvent extraction system of bis(pyridin-2-ylmethyl)dodecan-1-amine and dinonylnaphthalene for enhanced selective extraction of nickel and cobalt

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Chinese Journal of Chemical engineering 2025年第1期77卷 10-18页

作者： Bharat Prasad Sharma Tianzhang Wang Yufeng Liang Jinping Xiong Liangrong Yang Zheng Li Beijing Key Laboratory of Electrochemical Process and Technology of Materials Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 101408China CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Simultaneous recovery of Ni and Co from Fe(Ⅲ)and AI is a critical challenge in hydrometallurgical *** solvent extraction systems often struggle with selectivity and effective performance in mixed metal ion ***,a new synergistic solvent extraction(SSX)system comprised of a novel pyridine analog,N,N-bis(pyridin-2-ylmethyl)dodecan-1-amine(BPMDA),and dinonylnaphthalene sulfonic acid(DNNSA)with tributyl phosphate as phase modifier is *** SSX system demonstrates high extraction performance achieving>90%for Ni and>97%for Co in a singlestage extraction process,with high *** optimal conditions,the selectivity sequence is observed as Co^(2+)(>97%)>Ni^(2+)(>90%)>Mn^(2+)(<20%)>Fe^(3+)(<10%)>Mg^(2+)(<5%)>Al^(3+)(<2%)>Ca^(2+)(<1%).Spectroscopic analysis evidences the preferential binding of BPMDA with Ni and Co in the presence of DNNSA,concurrently achieving a significant reduction in the co-extraction of Fe(Ⅲ)and *** selective complexation of Ni and Co using the SSX system offers a highly efficient and selective approach for their extraction,with promising potential for applications in recovery-based processes.

关键词： Nickel and cobalt extraction Synergistic solvent extraction DNNSA Pyridine Hydrometallurgy

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Construction of Ni single-atom coordinated with doped N and S elements for mild hydrogenation of methyl acrylate to methyl propionate

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Nano Research 2025年第1期18卷 217-224页

作者： Taolue Sun Chen Jian Gang Wang Hui Zhao Guoliang Zhang Zengxi Li Chunshan Li State Key Laboratory of Mesoscience and Engineering CAS Key Laboratory of Green Process and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Huizhou Institute of Green Energy and Advanced Materials Huizhou 516081China Advanced Energy Science and Technology Guangdong Laboratory Huizhou 516081China

Although the nickel-based catalyst is able toexhibit comparative catalytic activity to noble metal formethyl acrylate hydrogenation,it requires strict reactioncondition,which can be improved by regulation ofcoordination *** this study,we constructed akind of Ni single-atom coordinated with N and S(Ni-NSC)through the pyrolysis of organic Ni-based precursors at600℃.The existence and fine structure of Ni single-atom were confirmed by the spherical electron microscopicobservation in combination with the X-ray absorption spectroscopy(XAS)*** addition,the catalytichydrogenation assessment suggested that the as-prepared Ni-NSC catalyst exhibited higher activity and stability than theNi/NSC supported catalyst prepared by incipient wetness impregnation *** remarkable catalytic activity was dueto the high dispersion and density of Ni single-atom and weak adsorption energy of intermediates on these Ni sites.

关键词： methyl acrylate mild hydrogenation Ni single-atom coordination environment adsorption energy

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Numerical simulation of vortex breakdown in a cylindrical tank with rotating bottom and free surface using level set method

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Chinese Journal of Chemical engineering 2025年第1期77卷 293-300页

作者： Zepeng Zhao Qin Li Feng Ye Haoliang Wang Jianfeng Wang Hui Yu Xiangyang Li Chao Yang School of Chemical Engineering Sichuan UniversityChengdu 610065China CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Petroleum Molecular&Process EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Ecology and Environment Zhengzhou UniversityZhengzhou 450001China

A cylindrical chamber with a rotating bottom holds significant potential for application in cell culture bioreactors due to its ability to generate more stable swirling *** order to control vortex breakdown within the chamber,this study first establishes a computational fluid dynamics simulation coupled with the level set *** by experimental results in literature,this method accurately simulates the position and shape of vortex breakdown,and also predicts the critical Reynolds numbers for the appearance and detachment of vortex breakdown bubbles from the ***,it precisely captures the gaseliquid interface and depicts the vortex breakdown phenomenon in the air above the liquid for the first ***,it predicts the impact of physical property of gaseliquid systems on vortex breakdown in response to significant changes in viscosity of microbial process systems.

关键词： Vortex breakdown Level set Microbial cultivation Micro-bioreactor

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Towards the insights into the deactivation behavior of acetylene hydrogenation catalyst

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Petroleum Science 2024年第2期21卷 1405-1414页

作者： Hai-Xia Su Yang Jiao Jian-Gong Shi Zhi-Wei Yuan Di Zhang Xu-Peng Wang Jing Ren Dan Liu Jian-Zhou Gui Hai-Yang Gao Xiao-Li Xu State Key Laboratory of Separation Membranes&Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of Material Science and EngineeringTiangong UniversityTianjin300387China Institute of Engineering Technology Sinopec Catalyst Co.LtdBeijing101100China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of ChemistryTiangong UniversityTianjin300387China

A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity *** results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.

关键词： Acetylene Hydrogenation green oil Carbon deposit Sintering Catalyst deactivation

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Direct observation of ordered-disordered structural transition of MoS_(2)-confined ionic liquids

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Chinese Journal of Chemical engineering 2024年第8期72卷 126-132页

作者： Yumiao Lu Weilu Ding Kun Li Yanlei Wang Bobo Cao Ruirui He Hongyan He CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial TechnologyZhengzhou 450000China

Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid ***,we explore the growth phenomenon of surface-confined ILs and reveal a peculiar structural transition behavior from order to disorder above a threshold *** behavior can be explained by the variation of interfacial forces with increasing distance from the solid *** structural observation of different ILs highlights the influence of the ionic structure on the growth ***,the length of the alkyl chain in the cation is found to be a determining factor for the ordering ***,the thermal stability of surface-confined ILs is investigated in depth by controlling annealing *** is found that the ordered monolayer ILs exhibit high robustness against high *** findings provide new perspectives on the properties of surface-confined ILs and open up potential avenues for manipulating the structures of nanometer-thick IL films for various applications.

关键词： Ionic liquids(ILs) Surface-confined ILs Structural transition Thermal stability Interfacial forces

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Significant enhancement in local thermal conductivity of erythritol at interface with nanoparticles due to their interaction

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Nano Research 2024年第8期17卷 7726-7736页

作者： Ning Cao Yanhui Feng Kening Yan Zihan Liu Jiawei Wan Lin Qiu School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Biochemical Engineering Key Laboratory of Biopharmaceutical Preparation and DeliveryInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

When nano-fillers are used to enhance the thermal conductivity of organic phase change materials(PCMs),the naturally formed interface is considered to hinder thermal transport of the composite ***,the effect of the interface on the thermal properties of surrounding PCM has not been fully *** this paper,three composite PCMs(Ery@SiC,Ery@SiO_(2) and Ery@Si_(3)N_(4))were prepared by melt-blending *** local thermal conductivity and reduced Young’s modulus(E^(*))of the erythritol at the interface and far away from the interface in the composite PCMs were simultaneously measured by scanning thermal microscopy(SThM).The results revealed significant enhancement in local thermal conductivity of erythritol at the interface and its obvious positive correlation with E^(*).For different composite PCMs,molecular dynamics(MD)simulations suggested that the increase in intrinsic thermal conductivity and E^(*)of erythritol is attributed to the increase in interaction energy between erythritol and nanoparticles,as more erythritol phonon vibrations transform from localized mode to delocalized mode and erythritol has a higher density at the *** findings will provide new ideas for the design of PCM for energy storage.

关键词： scanning thermal microscopy phase change materials thermal conductivity reduced Young’s modulus interaction energy phonon participation ratio

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Post-treatment of Ti-MWW zeolite with potassium fluoride for propylene epoxidation

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Frontiers of Chemical Science and engineering 2024年第8期18卷 37-47页

作者： Xintong Li Xianchen Gong Jilong Wang Shengbo Jin Hao Xu Peng Wu State Key Laboratory of Petroleum Molecular&Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China

Epoxidation of propylene to propylene oxide(PO)with hydrogen peroxide(HPPO)is an environmentally friendly and cost-efficient process in which titanosilicates are used as ***-MWW is a potential industrial catalyst for this process,which involves the addition of HPPO to *** silanol groups generated during secondary crystallization unavoidably result in ring-opening of PO and inefficient decomposition of HPPO,which diminish the PO selectivity and the lifespan of *** address this issue,we conducted post-treatment modifications of the structured Bf-Ti-MWW catalyst with potassium fluoride aqueous *** quenching the silanol groups with potassium fluoride and implanting electron-withdrawing fluoride groups into the Ti-MWW framework,both the catalytic activity and HPPO utilization efficiency were ***,the ring opening reaction of PO was *** a continuous fixed-bed liquid-phase propylene epoxidation reaction,the KF-treated structured Ti-MWW catalyst displayed an exceptionally long lifespan of 2700 h,with a PO yield of 590 g·kg^(-1)·h^(-1).

关键词： titanosilicates Ti-MWW propylene epoxidation structured catalyst KF modification

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