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Chinese Journal of Chemical Engineering 2019年第8期27卷 1777-1788页

作者： Dong Li aiwu zeng State Key Laboratory of Chemical Engineering School of Chemical Engineering and Technology Tianjin University

An exploration of the gas CO2 absorbed into liquid ethanol accompanied with Rayleigh convection is performed by analyzing the mass entransy dissipation;this new statistical quantity is introduced to describe the irreversibility of mass transfer potential capacity. Based on the general advection–diffusion differential equation for an unsteady mass transfer process, the variation of the included angle between the velocity vector and concentration gradient fields is investigated to reveal the underlying mechanism of interfacial convection enhancing mass transfer. Results show some identical characteristics with the qualitative analyses of the synergy effects generated by the concentration and velocity fields after interfacial convection occurring for a boundary condition of fixed surface concentration. And the equivalent mass resistance for convective mass transfer process presents the similar variation with the reciprocal of instantaneous mass transfer coefficient. Accordingly, it is reasonable to be seen that mass transfer dissipation rate could be provided to assess the convection strength and explain fundamentally how Rayleigh convection improves mass transfer performance through establishing a close relationship between the mass transfer capacity and field synergy principle from the view of mass transfer theory.

关键词： Field synergy Mass entransy dissipation Equivalent mass resistance Interfacial convection Reinforcement

Separation of n-heptane/isobutanol via eco-efficient vapor recompression-assisted distillation:process optimization and control strategy

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Frontiers of Chemical Science and Engineering 2021年第5期15卷 1169-1184页

作者： Wei Hou Qingjun Zhang aiwu zeng State Key Laboratory of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin300350China Chemical Engineering Research Center Collaborative Innovative Center of Chemical Science and EngineeringTianjin300072China

In this study,vapor recompression and heat integration assisted distillation arrangements with either the low or high pressure in the reflux drum are proposed to reduce and/or eliminate the application of the costly refrigerant for the separation of n-heptane and isobutanol *** high-pressure arrangement with vapor recompression and heat integration is the most attractive among these four intensified configurations since it can reduce total annual cost by 18.10%,CO_(2) emissions by 75.01%based on natural gas(78.78%based on heavy oil fuel),and second-law efficiency by 61.20%compared to a conventional refrigerated distillation ***,exergy destruction in each component is calculated for the heat integration configurations and is shown in pie *** results demonstrate that the high-pressure configuration presents unique advantages in terms of thermodynamic efficiency compared to the low-pressure *** addition,dynamic control investigation is performed for the economically efficient arrangement and good product compositions are well controlled through a dual-point temperature control strategy with almost negligible product offsets and quick process responses when addressing 20%step changes in production rate and feed *** that there are no composition measurement loops in our developed control schemes.

关键词： n-heptane/isobutanol vapor recompression heat integration low and/or high-pressure options

Box-Behnken experimental design for optimizing process parameters in carbonate-promoted direct thiophene carboxylation reaction with carbon dioxide

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Chinese Journal of Chemical Engineering 2022年第10期50卷 222-234页

作者： Qingjun Zhang Youguang Ma Xigang Yuan aiwu zeng State Key Laboratory of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Chemical Engineering Research Center Collaborative Innovative Center of Chemical Science and Engineering(Tianjin)Tianjin 300350China

A feasible synthesis route is developed for achieving the direct carboxylation of thiophene and CO_(2) in a relatively mild solvent-free carboxylate-assisted carbonate(semi)molten *** effects of reaction factors on the carboxylate yield are investigated in the preliminary screening experiments,and the phase behavior analysis of the reaction medium is detected through the thermal characterization analysis of insitu high temperature X-ray diffraction measurement(in-situ XRD).The application of response surface methodology(RSM)based on the Box-Behnken design(BBD)is conducted to investigate the effect of the reaction parameters,such as reaction temperatu re,carbonate proportion,CO_(2) pressure and thiophene amount,on the product *** regressed second-order polynomial model equation well correlates all the independent *** analysis of variance(ANOVA)results reveal that the quadratic effect of reaction temperature is the most effective parameter in this carboxylation reaction owing to it’s the highest contribution to the sum of square(30.18%).The optimum reaction conditions for maximum product yield are the reaction temperature of 287℃,carbonate proportion of 32.20%,CO_(2) pressure of 1.0MPa and thiophene amount of 9.35 *** under these selected experimental conditions,a high product yield(50.98%)can be achieved.

关键词： Carboxylation Solvent-free medium Molten salt Optimization Response surfacemethodology

Direct carboxylation of thiophene with CO_(2) in the solvent-free carboxylate-carbonate molten medium:Experimental and mechanistic insights

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Chinese Journal of Chemical Engineering 2022年第10期50卷 264-282页

作者： Qingjun Zhang Pengyuan Shi Xigang Yuan Youguang Ma aiwu zeng State Key Laboratory of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Chemical Engineering Research Center Collaborative Innovative Center of Chemical Science and Engineering(Tianjin)Tianjin 300350China

A feasible synthesis route is devised for realizing direct carboxylation of thiophene and CO_(2) in a relatively mild solvent-free carboxylate-assisted carbonate(semi)molten *** effects of reaction factors on product yield are investigated,and the phase behavior analysis of the reaction medium is detected through the thermal characterization *** yield varies with the alternative carboxylate co-salts,which is attributed to the difference in deprotonation capacity caused by the base effect within the ***,the detailed mechanism of this carbonate-promoted carboxylation reaction is studied,including two consecutive steps of the formation of carbanion through breaking the C-H bond(s)via the carbonate and the nucleophile attacking the weak electrophile CO_(2) to form C-C bond(s).The activation energy barrier in C-H activation step is higher than the following CO_(2) insertion step whether for the formation of the mono-and/or di-carboxylate,which is in good agreement with that of kinetic isotope effect(KIE)experiments,indicating that the C-H deprotonation is slow and the forming presumed carbanion reacts rapidly with CO_(2).Both the activation energy barriers in deprotonation steps are the minimal for the cesium cluster system since there have the weak the cesium Cs-heteroatom S(thiophene)and Cs-the broken proton interactions compared to the K2CO3 system,which is likely to enhance the acidity of C-H bond,lowering the C-H activation ***,these mechanistic insights are further assessed by investigating base and C-H substrate effects via replacing Cs2CO3 with K2CO3 and furoate(la)with thiophene monocarboxylate(1b)or benzoate(1c).

关键词： Inert CAH bond Carboxylation Solvent-free medium Base effect Density functionaltheory(DFT)study

Kinetics and Mechanism Modeling of Liquid-Phase Toluene Oxidation to Benzaldehyde Catalyzed by Mn–Mo Oxide

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Transactions of Tianjin University 2019年第1期25卷 52-65页

作者： Wang Li Qingjun Zhang aiwu zeng School of Chemical Engineering and Technology Tianjin University

In this study, liquid-phase aerobic oxidation of toluene catalyzed by Mn–Mo oxide was conducted in a 1.0 L batch reactor. The macroscopic kinetics of toluene consumption and benzaldehyde generation at 413–443 K were obtained from a combination of experimental observation and hypothetical models. The results clearly showed that both the oxidation rate of toluene and generation rate of the aromatic product were proportional to the concentration of the substrate, the partial pressure of oxygen and the surface area of the catalyst. The energy barrier of toluene oxidation to benzyl alcohol was the highest(≈ 81 kJ mol^(-1)), while that of benzyl alcohol oxidation to benzaldehyde was the lowest(≈ 57 kJ mol^(-1)). Moreover, the activation energy of further oxidation of benzaldehyde in an acetic acid solvent was only slightly lower(≈ 1.9 kJ mol^(-1)) than that of toluene oxidation. Significantly, the transformation of benzyl alcohol indeed contributed to the generation of benzaldehyde and this step conformed to a first-order parallel-consecutive model. Increased reaction temperature and residence time favored the transformation of benzyl alcohol to benzaldehyde. In addition, doping with molybdenum at Mn/Mo = 3/1 enhanced the catalytic performance of the heterogeneous catalyst and was attributed to the presence of a synergetic effect between different metal cations. Regarding the microscopic kinetics, the LH-OS-ND mechanism(Langmuir–Hinshelwood adsorption of reagents on the same type of active sites and non-dissociative adsorption of oxygen) was verified as responsible for the heterogeneous oxidation of toluene. Oxygen and benzaldehyde were weakly adsorbed(Δ H_(ads,Oxy) ≈^(-1)5 kJ mol^(-1), Δ H _(ads)0,Bald) ≈-30 kJ mol^(-1)), but showed strong mobility(Δ S_(ads,Oxy) ≈-22 J mol^(-1) K^(-1)), Δ S_(ads,Bald) ≈-39 J mol^(-1) K^(-1)). The fundamental intrinsic rates were deduced based on the LH-OS-ND mechanism and showed great consistency with the macroscopic results.

关键词： Liquid phase Oxidation of toluene Heterogeneous catalyst Benzaldehyde Kinetics LH-OS-ND mechanism

A Novel Method for Synthesizing p-Benzoquinone by Direct Catalytic Oxidation of Benzene with Hydrogen Peroxide over Copper-Doped TS-1

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Transactions of Tianjin University 2019年第5期25卷 517-526页

作者： Chenxiaodong Li Qingjun Zhang aiwu zeng State Key Laboratory of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Chemical Engineering Research Center Collaborative Innovative Center of Chemical Science and EngineeringTianjin 300072China

E xisting methods for synthesizing p -benzoquinone have drawbacks with respect to environmental protection, production scale, or industrial value. Therefore, it is imperative that a simple and environmentally friendly alternative be developed. The approach that involves preparing p -benzoquinone by the catalytic oxidation of benzene with hydrogen peroxide (H 2 O 2 ) over copper-modi ed titanium silicalite-1 (Cu/TS-1) has a certain superiority due to its green synthesis and mild reaction condi- tions. In this study, Cu/TS-1 catalyst was prepared by the wet impregnation of TS-1 with an aqueous solution of Cu(NO 3 ) 2 and then characterized by X-ray di raction, Fourier transform infrared spectroscopy, di use re ectance UV Vis spectros- copy, scanning electron microscopy, inductively coupled plasma mass spectrometry, X-ray uorescence, and analysis of the N 2 adsorption desorption isotherms. The results reveal that Cu species exist mainly in the form of amorphous CuO that is well dispersed on the surface of catalysts, with no major change in the molecular sieve framework. After optimizing the reaction conditions, a desirable p -benzoquinone selectivity (88.4%) and benzene conversion (18.3%) were obtained when the doping of Cu in Cu/TS-1 is 1.95 wt%. In addition, Cu/TS-1 can be conveniently regenerated, showing a slight decrease in catalytic capability after initial use, which then stabilizes in subsequent circulations. The satisfactory stability and low cost of synthesizing Cu/TS-1 give this method considerable potential for further industrialization.

关键词： Catalytic oxidation Benzene p -Benzoquinone Copper Titanium silicalite-1 (TS-1) Wet impregnation

Vapour–Liquid Equilibrium for N,N-Dimethylformamide + Benzene + Thiophene via Gibbs Ensemble Molecular Simulation

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Transactions of Tianjin University 2017年第1期23卷 26-34页

作者： aiwu zeng Wenqi Chen Jianjun Ma Jiang Yu State Key Laboratory of Chemical Engineering School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China

The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction *** with time-consuming experiments,molecular simulation presents great potential in research on the properties of ***,in this work,Gibbs ensemble Monte Carlo was applied to successfully predict the vapour-liquid phase equilibrium data of binary and ternary systems containing benzene,thiophene and N,Ndimethylformamide(DMF) at P=101.3 *** explicit hydrogen version of the transferable potentials for phase equilibria potential model was chosen for benzene and thiophene,whereas the OPLS potential model was selected for *** predicted phase diagrams were compared with experimental data and the UNIQUAC thermodynamic model.A good agreement was obtained,which corroborated the validity of the potential *** addition,the extraction mechanism was explored by radial distribution function(RDF) of the liquid-phase *** RDFs showed that thiophene and benzene shared a similar liquidphase structure because of the intermolecular *** distinct difference between the RDFs of DMF/benzene and those of DMF/thiophene is that the oxygen atom of DMF is more associated with hydrogen atoms of thiophene than that of benzene,which may be responsible for the extraction effect of DMF.

关键词： Gibbs ensemble Monte Carlo Vapour-liquid equilibrium DMF Benzene Thiophene Radial distribution function

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侧环式反应器流场研究

化学反应工程与工艺 2007年第6期23卷 494-498页

作者：刘振曾爱武河南科技大学化工与制药学院河南洛阳471003 天津大学化工学院化学工程联合国家重点实验室天津300072

针对同步闪蒸汽提发酵新过程,开发了侧环式反应器,并采用混合模型,利用计算流体力学(CFD)技术模拟了侧环式反应器气液两相的流场。模拟结果表明,侧环具有脱气作用,随着通气量增大,气液两相接触变差,传质效果下降,这与实验现象一致。

关键词：侧环式反应器乙醇发酵计算流体力学

气液传质过程中Marangoni对流的观测与定量分析

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化工学报 2014年第10期65卷 3760-3768页

作者：于海路曾爱武天津大学化工学院化学工程联合国家重点实验室天津300072

建立了一套气液传质装置和一套纹影系统对乙醇解吸CO2过程中产生的Marangoni对流结构进行垂直界面方向上的观察,发现解吸过程中近界面处出现均匀分布的旋涡状的对流结构,并随时间聚合发展变大。此外还利用定量纹影法考察了传质过程中的... 详细信息

建立了一套气液传质装置和一套纹影系统对乙醇解吸CO2过程中产生的Marangoni对流结构进行垂直界面方向上的观察,发现解吸过程中近界面处出现均匀分布的旋涡状的对流结构,并随时间聚合发展变大。此外还利用定量纹影法考察了传质过程中的浓度分布和界面张力梯度等信息。定量的结果表明较大的界面张力梯度位于对流胞型的边缘和中心处,驱动着界面流体的运动,并耦合浮力效应,形成了近界面环流的运动形式。这种环流运动造成了对流胞型边缘浓度较大、内部浓度小的分布,促进了相界面流体微元的更新,加强了传质过程。

关键词： Marangoni对流纹影解吸界面传质浓度分布界面张力梯度

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何光岳与光岳藏书楼

图书馆 2010年第4期 134-137页

作者：曾爱武湖南日报图书馆湖南长沙410005

何光岳先生是著名的中华民族源流史研究专家,也是著名的藏书家。长期从事远古历史和炎黄文化的研究,藏书12.7万册,其中家谱5万册。文章向读者介绍了何光岳先生及他的藏书、藏书楼和学术成就。

关键词：何光岳藏书藏书楼