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Chinese Journal of Chemical Engineering 2018年第10期26卷 2199-2205页

作者： Hongyan Shen youzhi liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering College of Chemical Engineering and Environment North University of China

Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.

关键词： Magnesium hydroxide Synthesis Polypropylene Hydrophobic property Rotating packed bed

Devolatilization of high viscous fluids with high gravity technology

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Chinese Journal of Chemical Engineering 2024年第7期71卷 249-257页

作者： Jibing Qi youzhi liu Yandong liu Taiyuan University Taiyuan 030032China Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China

Volatile organic compounds(VOCs)are generally toxic and harmful substances that can cause health and environmental *** removal of VOCs from polymers has become a key *** effective devolatilization to remove VOCs from high viscous fluids such as polymer is necessary and is of great *** this study,the devolatilization effect of a rotating packed bed(RPB)was studied by using polydimethylsiloxane as the viscous fluid and acetone as the *** devolatilization rate and liquid phase volume(KLa)have been *** results indicated that the optimum conditions were the high-gravity factor of 60,liquid flow rate of 10 L·h^(-1),and vacuum degree of 0.077 *** dimensionless correlation of KLa was established,and the deviations between predicted and experimental values were less than±28%.The high-gravity technology will result in lower mass transfer resistance in the devolatilization process,enhance the mass transfer process of acetone,and improve the removal effect of *** work provides a promising path for the removal of volatiles from polymers in combination with high-gravity *** can provide the basis for the application of RPB in viscous fluids.

关键词： High-gravity technology Devolatilization rate High viscous fluid Volatile organic compounds(VOCs)

In situ synthesis of hydrophobic magnesium hydroxide nanoparticles in a novel impinging stream-rotating packed bed reactor

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1306-1312页

作者： Hongyan Shen youzhi liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering College of Chemical Engineering and Environment North University of China

Hydrophobic Mg(OH)_2nanoparticles were successfully synthesized via an in situ surface modification method in a novel impinging stream-rotating packed bed(IS-RPB) reactor using oleic acid(C_(17)H_(33)COOH, OA) as a surface modifier, magnesium chloride hexahydrate in the presence of ethanol as a precursor, and sodium hydroxide as a precipitant. The products were characterized by Fourier transform infrared spectroscopy(FTIR), Field emission scanning electron microscopy(FESEM), X-ray diffraction(XRD), and thermogravimetry-differential scanning calorimetry(TG-DSC). Compatibility with organic solutions was determined by sedimentation tests. The prepared nanoparticles exhibited regular hexagonal lamella with an average diameter of 30 nm when OA is added to the reaction system; this result indicates that OA regulates the morphology of the Mg(OH)_*** revealed that the high-purity Mg(OH)_2product presents a brucite structure, and the I_(001)/I_(101) of hydrophobic Mg(OH)_2(0.86) was higher than that of the blank Mg(OH)_2(0.63). FTIR analysis showed that OA bonded to the surface of the Mg(OH)_2. Compared with the blank Mg(OH)_2product, the product obtained through the proposed method possesses excellent hydrophobic properties, including a high water contact angle of 101.4° and good compatibility with liquid paraffin. TG-DSC analysis indicated that the total percentage of mass loss of hydrophobic Mg(OH)_2(40.88%) was higher than that of the blank Mg(OH)_2product(33.18%). The in situ surface modification method proposed in this work presents potential use in the large-scale production of Mg(OH)_2nanoparticles.

关键词： Nanoparticles Preparation Surfactants Magnesium hydroxide Precipitation

Degradation of nitrobenzene-containing wastewater by sequential nanoscale zero valent iron-persulfate process

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Green Energy & Environment 2021年第6期6卷 910-919页

作者： Jingjuan Qiao Weizhou Jiao youzhi liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuanShanxi030051China

As nitrobenzene(NB)is structurally stable and difficult to degrade due to the presence of an electron withdrawing group(nitro group).The sequential nanoscale zero valent iron-persulfate(NZVI-Na_(2)S_(2)O_(8))process was proposed in this study for the degradation NB-containing *** results showed that the NB degradation efficiency and the total organic carbon removal efficiency in the sequential NZVINa_(2)S_(2)O_(8)process were 100%and 49.25%,respectively,at a NB concentration of 200 mg L^(-1),a NZVI concentration of 0.75 g L^(-1),a Na_(2)S_(2)O_(8)concentration of 26.8 mmol L^(-1),an initial pH of 5,and a reaction time of 30 min,which were higher than those(88.53%and 35.24%,respectively)obtained in the NZVI/Na_(2)S_(2)O_(8)*** radicals(SO_(4)·-)and hydroxyl radicals(·OH)generated in the reaction were identified directly by electron paramagnetic resonance spectroscopy and indirectly by radical capture experiments,and it was shown that both SO_(4)^(·-)and·OH played a major role in the sequential NZVI-Na_(2)S_(2)O_(8)*** possible pathways involved in the reduction of NB to aniline(AN)and the further oxidative degradation of AN were determined by gas chromatography-mass spectrometry.

关键词： Nanoscale zero valent iron Impinging stream-rotating packed bed Sequential NZVI-Na2S2O8process Nitrobenzene Degradation pathways

The turbulent behavior of novel free triple-impinging jets with large jet spacing by means of particle image velocimetry

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Chinese Journal of Chemical Engineering 2016年第6期24卷 757-766页

作者： Jun Zhang youzhi liu Ying Luo Shanxi Province Key Laboratory of Higee-oriented Chemical Engineering North University of China

A novel reactor that achieves rapid liquid–liquid mixing via free triple-impinging jets(FTIJs) is developed to improve mixing efficiency at unequal flow rates for liquid–liquid reactions. The flow characteristics of FTIJs were investigated using particle image velocimetry(PIV). The instantaneous and mean velocities data at different Reynolds numbers(Re) were analyzed to provide insights into the velocity distributions in FTIJs. The effect of jet spacing on the stagnation points, instantaneous velocity, mean velocity, profiles of the x- and ycomponents of mean velocity, and turbulent kinetic energy(TKE) distributions of FTIJs were investigated at Re = 4100 with a volumetric flow rate ratio of 0.5. The characteristics of the turbulent flows are similar for all jet spacings tested. Two stagnation points are observed, which are independent of jet spacing and are not located in the center of the flow field. However, velocity and TKE distributions are strongly dependent on the jet *** jet spacing increases the expansion angle and the values of TKE, leading to strong turbulence, improving momentum transfer and mixing efficiency in FTIJs. The present study shows that optimization of the operating parameters is helpful for designing FTIJs.

关键词： Expansion angleFree triple-impinging jetsTurbulent kinetic energyPIV

Oxidation of benzyl alcohols to ketones and aldehydes by O3 process enhanced using high-gravity technology

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Chinese Journal of Chemical Engineering 2020年第3期28卷 808-814页

作者： Wenqiang Gao Lei Du Weizhou Jiao youzhi liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China Department of Chemistry and Chemical Engineering Luliang UniversityLuliang033000China

In this study,a practical process for ozonization of benzyl alcohols to ketones and aldehydes in a rotating packed bed(RPB-O3)reactor has been *** 1-phenylethanol as a model reactant,the performance of RPB-O3 process in different solvents has been compared with the commonly used stirred tank reactor(STR-O3).Ethyl acetate was the optimum solvent for the conversion of 1-phenylenthanol to acetophenone in RPB-O3 process,with 78%yield after 30 *** a parallel STR-O3 experiment,the yield of acetophenone was50%.Other experimental variables,i.e.O3 concentration,reaction time,high-gravity factor and liquid flow rate were also *** highest yield of acetophenone was obtained using O3 concentration of 80 mg·L-1,reaction time of 30 min,high gravity factor of 40 and liquid flow rate of 120 L·*** the optimized reaction conditions,a series of structurally diverse primary and secondary alcohols was oxidized with(19%–92%)*** ozonization mechanism was studied by Electron Paramagnetic Resonance(EPR)spectroscopy,monitoring the radical species formed upon self-decomposition of *** characteristic quadruple peak with the 1:2:2:1 intensity ratio that corresponds to hydroxyl radicals(·OH)was observed in the electron paramagnetic resonance(EPR)spectrum,indicating an indirect oxidation mechanism of alcohols via·OH radical.

关键词： Ozone Benzyl alcohols Aldehydes and ketones High-gravity technology

Catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-Mn-Cu/γ-Al2O_(3) in a rotating packed bed

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Chinese Journal of Chemical Engineering 2022年第5期35卷 133-142页

作者： Weizhou Jiao Xingyue Wei Shengjuan Shao youzhi liu Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering National Demonstration Center for Experimental Comprehensive Chemical Engineering EducationNorth University of ChinaShanxi 030051China Key Laboratory of Industrial Ecology and Environmental Engineering(MOE) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China

This study investigated catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-MnCu/γ-Al_(2)O_(3)(Cat)in a rotating packed bed(RPB)for the first *** results showed that the value of the overall decomposition rate constant of ozone(K_(c))and overall volumetric mass transfer coefficient(K_(L)a)are 4.28×10^(-3) s^(-1) and 11.60×10^(-3) s^(-1) respectively at an initial pH of 6,βof 40,Co3(g)of 60 mg·L^(-1)and Q_(L) of 85 L·h^(-1) in deionized water,***,the K_(c) and K_(L)a values of Fenhe water are0.88×10^(-3) s^(-1) and 2.51×10^(-3) s^(-1) lower than deionized water,*** addition,the K_(c) and K_(L)a values in deionized water for the Cat/O_(3)-RPB system are 44.86%and 47.41%higher than that for the Cat/O_(3)-BR(bubbling reactor)system,respectively,indicating that the high gravity technology can facilitate the decomposition and mass transfer of ozone in heterogeneous catalytic ozonation and provide some insights into the industrial wastewater.

关键词： Rotating packed bed Ozone Heterogeneous catalysis Overall decomposition rate constant Overall volumetric mass transfer coefficient

TiO_2–SA–Arg nanoparticles stabilized Pickering emulsion for photocatalytic degradation of nitrobenzene in a rotating annular reactor

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Chinese Journal of Chemical Engineering 2017年第2期25卷 223-231页

作者： Shiguang Zhang Lei Li youzhi liu Qiaoling Zhang Shanxi Province Key Laboratory of Higee-Orienred Chemical Engineering North University of ChinaTaiyuan 030051China

Pickering emulsions stabilized by salicylic acid and arginine modified titanium dioxide （TiO2-SA-Arg） nanopar- tides were prepared in this study for photocatalytic degradation of nitrobenzene in a rotating annular reactor, and the effects of various design parameters of the rotating annular reactor, initial nitrobenzene concentration, catalyst amount, and solution pH on the degradation rate of nitrobenzene were investigated. Meanwhile, the degradation mechanism of nitrobenzene was proposed. The results show that increasing the aeration rate, the rotational speed, and light intensity results in a higher photocatalytic degradation rate of nitrobenzene owing to the effective clearance of electrons and a high quantity of oxidative free radicals. The degradation of nitroben- zene in the rotating annular reactor follows the pseudo first-order kinetics, but it is not well described by the Langmuir-Hinshdwood equation. Aeration has a significant effect on the photocatalytic degradation pathway of nitrobenzene. Because nitrobenzene can undergo reduction reaction as electron acceptors and oxidative deg- radation initiated by hydroxyl free radicals, the photocatalytic degradation of nitrobenzene follows the reduction mechanism under no aeration, but the oxidation mechanism under aeration.

关键词： NanoparticlesEmulsionsWaste waterWaste treatmentRenewable energyReaction kinetics

Numerical simulation and experimental study of the characteristics of packing feature size on liquid flow in a rotating packed bed

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Chinese Journal of Chemical Engineering 2021年第6期34卷 22-31页

作者： Xifan Duan Zhiguo Yuan youzhi liu Hangtian Li Weizhou Jiao Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China

Rotating packed bed has high efficiency of gas-liquid mass *** it is significant to investigate fluid motion in rotating packed *** simulations of the effects of packing feature size on liquid flow characteristics in a rotating packed bed are reported in this *** particle image velocimetry is compared with the numerical simulations to validate the turbulent *** show that the liquid exists in the packing zone in the form of droplet and liquid line,and the cavity is *** the radial thickness of the packing is less than 0.101 m,liquid line and droplets appear in the *** rotational speed and radial thickness of the packing increase,the average diameter of the droplets becomes smaller,and the droplet size distribution becomes *** the initial velocity of the liquid increases,the average droplet diameter increases and the uniformity of particle size distribution become *** droplet velocity increases with the radial thickness of the packing increasing,and gradually decreases when it reaches the cavity *** effect of packing thickness is most substantial through linear *** predicted and simulated values are within±15%.The cumulative volume distribution curves of the experimental and simulated droplets are consistent with the R-R distribution.

关键词： Chemical process strengthening equipment Rotating packed bed Computational fluid dynamics Particle image velocimetry Sieve packing

An integrated technology for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity environment

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Chinese Journal of Chemical Engineering 2024年第8期72卷 117-125页

作者： Kangrui Nie Ruize Shang Fuming Miao liuxiang Wang youzhi liu Weizhou Jiao Shanxi Province Key Laboratory of Chemical Process Intensification and School of Chemistry and Chemical Engineering North University of ChinaTaiyuan 030051China

In this study,an integrated technology is proposed for the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3)in a high-gravity *** effects of absorbent type,high-gravity factor,gas/liquid ratio,and initial BaCl2concentration on the absorption rate and amount of CO_(2)and the preparation of BaCO_(3)are *** results reveal that the absorption rate and amount of CO_(2)follow the order of ethyl alkanolamine(MEA)>diethanol amine(DEA)>N-methyldiethanolamine(MDEA),and thus MEA is the most effective absorbent for CO_(2)*** absorption rate and amount of CO_(2)under high gravity are higher than that under normal ***,the absorption rate at 75 min under high gravity is approximately 2 times that under normal *** is because the centrifugal force resulting from the high-speed rotation of the packing can greatly increase gas-liquid mass transfer and *** particle size of BaCO_(3)prepared in the rotating packed bed is in the range of 57.2—89 nm,which is much smaller than that prepared in the bubbling reactor(>100.3 nm),and it also has higher purity(99.6%)and larger specific surface area(14.119 m^(2)·g^(-1)).It is concluded that the high-gravity technology has the potential to increase the absorption and utilization of CO_(2)in alkanolamine solution for the preparation of BaCO_(3).This study provides new insights into carbon emissions reduction and carbon utilization.

关键词： High-gravity technology Wet absorption CO_(2)capture Enhanced mass transfer CO_(2)utilization Barium carbonate