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Liquid-phase esterification of methacrylic acid with methanol catalyzed by cation-exchange resin in a fixed bed reactor:Experimental and kinetic studies

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Chinese Journal of Chemical engineering 2023年第6期58卷 1-10页

作者： Junyang Liu Luming Wang Yuhang Bian Chunshan Li Zengxi Li Jie Li School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing Key Laboratory of Ionic Liquids Clean Process Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Langfang Technological Center of Green Industry Langfang 065801China

The kinetic behavior of esterification between methacrylic acid and methanol catalyzed by NKC-9 resin was studied in a fixed bed *** reaction was conducted in the temperature range of 323.15 to 368.15 K with the molar ratio of reactants from 0.8 to 1.4 under certain *** measurement data were regression with the pseudo-homogeneous(P-H),Eley-Rideal(E-R),and Langmuir-Hinshelwood(L-H)heterogeneous kinetic *** adsorption experiments were implemented to gain the adsorption equilibrium constants of four *** the above three models,the L-H model exhibited the best fitting *** stability of NKC-9 was evaluated by long-term running with the yield of methyl methacrylate no decrease during 3000 h *** structure and physicochemical properties of the new and used catalyst were performed by several characterizations including thermogravimetric analysis(TG),scanning electron microscope(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FT-IR)and so on.

关键词： Kinetics Esterification Methyl methacrylate Cation-exchange resin Fix bed reactor

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Theoretical study on the stability of nanobubbles and its verification in molecular dynamics simulation

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Particuology 2024年第4期87卷 99-105页

作者： Sheng Mi Chaofeng Hou Wei Ge School of Chemical Engineering and Technology Tianjin UniversityTianjin300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing.100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

The stability of vapor nanobubbles in bulk liquid was investigated theoretically and the critical bubble size was derived from macroscale thermodynamic equations,below which the system destabilizes with sharp drop in *** critical size was quantitatively verified in molecular dynamic simulation using the Lennard-Jones model of argon,where stronger attraction between the molecules at lower density is found to contribute most to the drop of system pressure and,as the Laplace pressure on the curved bubble interface fails to balance the pressure difference across the interface,the bubbles become *** theoretical model could be extended to other systems where reliable equations of state and interfacial tension are available.

关键词： Nanobubble Stability Phase diagram Critical size

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Rare earth metal based DES assisted the VPO synthesis for n-butane selective oxidation toward maleic anhydride

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Green Energy & Environment 2023年第6期8卷 1737-1752页

作者： Muhammad Faizan Yingwei Li Xingsheng Wang Piao Song Ruirui Zhang Ruixia Liu Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemInstitute of Process Engineering Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Zhengzhou Institute of Emerging Industrial Technology Zhengzhou450000China

Deep eutectic solvents(DESs) are now considered a new class of ionic liquid analogs that have been generously used in various ***, vanadium phosphorus oxide(VPO) catalysts are synthesized in combination with a deep eutectic solvent containing rare earth metal(rE-DES), and their catalytic performance in n-butane selective oxidation to produce maleic anhydride(MA) is evaluated. The rE-DES is produced from the interaction of choline chloride(ChCl) and rare earth metal salts(Cerium, Europium, Lanthanum, and Samarium metal salt)(ChCl:rE = 1:0.5–1:3) under mild conditions. It was found that DESs served as structural modifiers and electronic promoters during VPO synthesis. It regulated the chemical state of the catalyst surface, such as the vanadium valence state, acid-base properties, and ratios of V^(4+)/V^(5+),Lat–O/Sur–O and P/V. Various characterization techniques, such as FT-IR, DSC, XRD, SEM, EDS, TEM, Raman, TGA, NH3-TPD, and XPS,were used to examine its physical and chemical characteristics. These characteristics were correlated with the catalytic performance. The VPO catalyst modified by rE-DES showed a significant enhancement of n-butane conversion and MA selectivity while suppressing the selectivity of CO and CO_(2)as well as the CO/CO_(2)ratio compared to the unpromoted VPO catalyst. Especially for Ce-DES-VPO, it increased the n-butane conversion and MA mass yield up to approximately 11% and 10%, respectively. In addition, we evaluated the catalytic performance under different activation atmospheres.

关键词： earth anhydride vanadium

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Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao Ye Ji Xu Wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid ***,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the *** this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process *** approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

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Filtration performance and modeling of granular bed for dust removal from coal pyrolytic vapors

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Chinese Journal of Chemical engineering 2024年第1期65卷 35-42页

作者： Shuaiqiang Yang Lin Du Guangchao Ding Runguo Liu Wenli Song Songgeng Li State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Petrochemical Engineering Yan’an Vocational and Technical CollegeYan’an 716000China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis *** this work,a granular bed with expanded perlites as filtration media was designed and integrated into a 10 t·d^(–1)coal pyrolysis *** testing results showed that around 97.56%dust collection efficiency was *** a result,dust content in tar was significantly *** pressure drop of the granular bed maintained in the range of 356 Pa to 489 *** dust size in the effluent after filtration exhibited a bimodal distribution,which was attributed to the heterogeneity of the dust *** effects of filtration bed on pyrolytic product yields were also discussed.A modified filtration model based on the macroscopic phenomenological theory was proposed to describe the performance of the granular *** computation results were well agreed with the experimental data.

关键词： Granular bed filtration Dust removal Pyrolysis Filtration Fixed-bed

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Porous carbon material production from microwave-assisted pyrolysis of peanut shell

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Carbon Research 2023年第1期2卷 1-17页

作者： Qiu, Tianhao Li, Chengxiang Guang, Mengmeng Zhang, Yaning School of Energy Science and Engineering Harbin Institute of Technology Harbin150001 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China

Due to the complex porous structure, biochar usually has good adsorption capacity. Therefore, compared with direct combustion, conversion of peanut shell into biochar by pyrolysis is considered to be an environmentally friendly and efficient method for agricultural solid waste disposal. In this study, biochar production from microwave-assisted pyrolysis of peanut shell was detailed. The yields, surface topographies, and pore structures (pore size distribution and micropore volume) of biochars prepared at different pyrolysis temperatures (700, 750, 800, 850, 900, and 950 °C), microwave powers (350, 400, 450, 500, and 550 W), and residence times (0.5, 1.0, 1.5, 2.0, and 3.0 h) were elaborated. The results showed that the biochar yield gradually decreased and finally stabilized to around 30% while the specific surface area improved within the range of 4.68–67.29 m2/g when the pyrolysis temperature, microwave power, or residence time increased. Biochar with micropore was first obtained at pyrolysis temperature of 800 °C, microwave power of 500 W, and residence time of 2.0 h. This study further proposed quantitative relationships between the pore structures of peanut shell based biochars and experimental conditions (pyrolysis temperature, microwave power and residence time). The results presented in this study can provide guidance for the reuse of peanut shell and the production of porous biochar. The peanut shell biochar prepared in this study can be used in soil remediation, air purification, liquid purification and other fields for its porous structural characteristics. © 2023, The Author(s).

关键词： Waste incineration

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Electrocatalytic Cleavage of C-C Bonds in Lignin Models Using Nonmetallic Catalysts at Ambient Conditions

Chem and Bio Engineering

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Chem and Bio engineering 2024年第4期1卷 357-365页

作者： Liu, Guangyong Zhai, Ziqi Lu, Yumiao Lu, JunFeng Wang, Yanlei Liang, Shijing He, Hongyan Jiang, Lilong National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou University Fujian Fuzhou350002 China CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex Systems Beijing Key Laboratory of Ionic Liquids Clean Process Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial Technology Zhengzhou450000 China

Lignin, characterized by its amorphous, heavily polymerized structure, is a primary natural source of aromatic compounds, yet its complex constitution poses considerable challenges in its transformation and utilization. Therefore, the selective cleavage of C-C bonds represents a critical and challenging step in lignin degradation, essential for the production of high-value aromatic compounds. In this study, we report a simple electrocatalytic approach for lignin valorization via C-C bond cleavage by developing a nonmetallic electrocatalyst of carbon-based materials. It is found that the hydrophilicity and hydrophobicity of the electrocatalyst have a significant effect on the degradation process. Under mild conditions, the hydrophilic carbon paper exhibits 100% substrate conversion, yielding 97% benzaldehyde and 96% quinone with ionic liquid electrolytes. The mechanism study shows that the carbon catalyst with higher surface defects favors electron transfer in the oxidative cleavage process of C-C bonds. These results signify a substantial advancement in lignin degradation, offering an environmentally friendly, metal-free electrochemical route. © 2024 The Authors. Co-published by Zhejiang University and American Chemical Society.

关键词： Quinone

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Superior triethylamine-sensing properties based on SnO2 hollow nanospheres synthesized via one-step process

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Progress in Natural Science:Materials International 2024年第4期34卷 682-689页

作者： Mingyue Xu Shu Yan Zia Ur Rehman Jianhua Hou Liangyun Zhai Shengjie Zhu Chuanbao Cao Wanfeng Xie Junyu Zhong Jun Yang State Key Laboratory of Bio-fibers and Eco-textiles School of Electronics and Information College of Materials Science and Engineering College of Chemistry and Chemical Engineering Qingdao University College of Environmental Science and Engineering Yangzhou University State Key Laboratory of Chemical Safety SINOPEC Research Institute of Safety Engineering Co. Ltd. National Registration Center for Chemicals Ministry of Emergency Management Research Center of Materials Science Beijing Institute of Technology State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences

Due to serious harm of triethylamine（TEA） to environmental safety and human health, it is significant to synthesize gas-sensitive materials with high performance for TEA detection. However, it is still a challenge to achieve high-sensitivity detection of TEA at low temperature for a sensor synthesized through an economical and efficient method. In this work, hollow-structured SnO2（HS-SnO2） nanospheres have been fabricated by a facile, low-cost hydrothermal method in one step, which exhibit superior TEA-sensing properties, including not only ultrahigh response（127.75） for 100 ppm TEA, good selectivity, but also fast response and recovery time（17/28 s）, low detection threshold（1 ppm） and robust stability at a relatively low optimum operational temperature of 225°*** excellent gas-sensitizing performances are ascribed to porous hollow structures with rich oxygen vacancies that provide abundant active sites for raising O2adsorption and reaction of TEA and oxygen species. This work offers an effective and economical strategy for fabricating high-performance TEA sensors for industrial applications.

关键词： Hollow-structured SnO2 nanospheres TEA High response Gas sensors

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Tuning the atomic configuration environment of MnN_(4) sites by Co cooperation for efficient oxygen reduction

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Journal of Energy Chemistry 2023年第7期82卷 547-559,I0012页

作者： Jing Wang Haihong Zhong Jun Yang Huiyu Li Pinggui Tang Yongjun Feng Dianqing Li State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsCollege of ChemistryBeijing University of Chemical TechnologyBeijing 100029China College of Science Hainan UniversityHaikou 570228HainanChina State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic ***,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical ***,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and *** electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic *** functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.

关键词： Dual-atom sites Oxygen reduction reaction M-Nx/C catalysts Coordination environment Electronic structure Synergistic effect

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Exploration on the stability conditions in bubble columns by noncooperative game theory

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Chinese Journal of Chemical engineering 2022年第10期50卷 75-84页

作者： Jiachen Liu Xiaoping Guan Ning Yang State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

The energy-minimization multiscale(EMMS)model,originally proposed for gas-solid fluidization,features a stability condition to close the simplified conservation *** was put forward to physically reflect the compromise of two dominant mechanisms,i.e.,the particle-dominated with minimal potential energy of particles,and the gas-dominated with the least resistance for gas to penetrate through the particle *** stability condition was then formulated as the minimization of the ratio of these two physical ***,the EMMS approach was later extended to the gas-liquid flow in bubble columns,termed dual-bubble-size *** considers the compromise of two dominant mechanisms,i.e.,the liquid-dominated regime with small bubbles,and the gas-dominated regime with large *** stability condition was then formulated as the minimization of the sum of these two physical ***,the two stability conditions were expressed in different manner,though gas-solid and gas-liquid systems bear some *** addition,both the conditions transform the original multiobjective variational problem into a single-objective *** mathematical formulation of stability condition remains therefore an open *** study utilizes noncooperative game theory and noninferior solutions to directly solve the multi-objective variational problem,aiming to explo re the different pathways of compromise of dominant *** results show that only keeping the single dominant mechanism cannot capture the jump change of gas holdup,which is associated with flow regime *** of dominant mechanisms,noninferior solutions and noncooperative game theory can predict the flow regime ***,the game between the two mechanisms makes the two-bubble structure degenerate and reduce to the single-bubble *** game of the three mechanisms restores the two-bubble *** exploration on the formulation of stability conditions may

关键词： Bubble column Flow regimes Mesoscale Noncooperative gametheory

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