Please wait a minute...
SCI和EI收录∣中国化工学会会刊
[an error occurred while processing this directive]
Table of Content
18 November 2022, Volume 51 Issue 11
    Phenylboronic acid functionalized polyacrylonitrile fiber for efficient and green synthesis of bis(indolyl)methane derivatives
    Haonan Zhang, Haotian Zhang, Minli Tao, Wenqin Zhang
    2022, 51(11):  1-9.  doi:10.1016/j.cjche.2021.08.029
    Abstract ( )   PDF (5004KB) ( )  
    References | Related Articles | Metrics
    The use of fiber as a catalyst carrier to construct heterogeneous catalysts with good catalytic activity and recycling performance has received wide attention. In this study, three phenylboronic acid functionalized polyacrylonitrile fiber (PANF) catalysts were synthesized by amination and quaternization. Fourier transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy were used to verify the successful grafting of phenylboronic acid and the structural integrity of the fiber catalyst after recycling. The activity of the catalysts was explored with the Friedel–Crafts alkylation between indole and aromatic aldehydes. The results indicate that the synthesized catalyst (PANp-BAF) in which the phenylboronic acid functional group was linked at the para position, exhibited the highest catalytic activity for the Friedel–Crafts alkylation. The substrate scope experiments confirmed that the catalyst has outstanding catalytic activity for most aromatic aldehydes, especially for those containing moderate electron donating groups. Moreover, the catalyst can be reused eight times in water without significant decrease in its catalytic activity. Further, the scale-up experiment confirmed that the fiber catalyst has a certain potential for industrial application.
    Effect of K2CO3 doping on CO2 sorption performance of silicate lithium-based sorbent prepared from citric acid treated sediment
    Junya Wang, Kai Chen, Yi Wang, Jiuming Lei, Abdullah Alsubaie, Ping Ning, Shikun Wen, Taiping Zhang, Abdulraheem S.A. Almalki, A. Alhadhrami, Zhiping Lin, Hassan Algadi, Zhanhu Guo
    2022, 51(11):  10-20.  doi:10.1016/j.cjche.2022.07.025
    Abstract ( )   PDF (9082KB) ( )  
    References | Related Articles | Metrics
    In this paper, a low-cost and environmental-friendly leaching agent citric acid (C6H8O7) was used to treat the sediment of Dianchi Lake (SDL) to synthesize lithium silicate (Li4SiO4) based CO2 sorbent. The results were compared with that treated with strong acid. Moreover, the effects of preparation conditions, sorption conditions and desorption conditions on the CO2 sorption performance of prepared Li4SiO4 were systematically studied. Under optimal conditions, the Li4SiO4 sorbent was successfully synthesized and its CO2 sorption capacity reached 31.37% (mass), which is much higher than that synthesized from SDL treated with strong acid. It is speculated that the presence of some elements after C6H8O7 treatment may promote the sorption of synthetic Li4SiO4 to CO2. In addition, after doping with K2CO3, the CO2 uptake increases from the original 12.02% and 22.12% to 23.96% and 32.41% (mass) under the 20% and 50% CO2 partial pressure, respectively. More importantly, after doping K2CO3, the synthesized Li4SiO4 has a high cyclic stability under the low CO2 partial pressure.
    Photocatalytic degradation of organic pollutants using green oil palm frond-derived carbon quantum dots/titanium dioxide as multifunctional photocatalysts under visible light radiation
    Zeng Wei Heng, Woon Chan Chong, Yean Ling Pang, Lan Ching Sim, Chai Hoon Koo
    2022, 51(11):  21-34.  doi:10.1016/j.cjche.2021.10.021
    Abstract ( )   PDF (10098KB) ( )  
    References | Related Articles | Metrics
    The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogen-doped carbon quantum dots (NCQDs) and proposed a straightforward in-situ hydrothermal method for the preparation of NCQDs/TiO2 nanocomposites. The elemental composition, morphological, structural and optical characteristics of NCQDs/TiO2 nanocomposites have been comprehensively investigated. The successful grafting of NCQDs on TiO2 matrix was confirmed by the formation of TiOC bond and the electronic coupling between the π-states of NCQDs and the conduction band of TiO2. For the first time, the oil palm frond-derived NCQDs/TiO2 was adopted in the photodegradation of methylene blue (MB) under visible-light irradiation. As a result, the photocatalytic efficiency of NCQDs/TiO2 nanocomposites (86.16%) was 2.85 times higher than its counterpart TiO2 (30.18%). The enhanced performance of nanocomposites was attributed to the pivotal roles of NCQDs serving as electron mediator and visible-light harvester. Besides, the optimal NCQDs loading was determined at 4 ml while the removal efficiency of NCQDs/TiO2-4 was the highest at a catalyst dosage of 1 g·L-1 under alkaline condition. This research work is important as it proposed a new insight to the preparation of biomass-based NCQDs/TiO2 using a facile synthetic method, which offers a green and sustainable water remediation technology.
    Dual responsive block copolymer coated hollow mesoporous silica nanoparticles for glucose-mediated transcutaneous drug delivery
    Yaping Wang, Songyue Cheng, Wendi Fan, Yikun Jiang, Jie Yang, Zaizai Tong, Guohua Jiang
    2022, 51(11):  35-42.  doi:10.1016/j.cjche.2021.07.019
    Abstract ( )   PDF (6974KB) ( )  
    References | Related Articles | Metrics
    A self-regulated anti-diabetic drug release device mimicking pancreatic cells is highly desirable for the therapy of diabetes. Herein, a glucose-mediated dual-responsive drug delivery system, which combines pH- and H2O2-responsive block copolymer grafted hollow mesoporous silica nanoparticles (HMSNs) with microneedle (MN) array patch, has been developed to achieve self-regulated administration. The poly[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl acrylate]-b-poly[2-(dimethylamino)ethyl methacrylate] (PPBEM-b-PDM) polymer serves as gate keeper to prevent drug release from the cavity of HMSNs at normoglycemic level. In contrast, the drug release rate is significantly enhanced upon H2O2 and pH stimuli due to the chemical change of H2O2 sensitive PPBEM block and acid responsive PDM block. Therefore, incorporation of anti-diabetic drug and glucose oxidase (GOx, which can oxidize glucose to gluconic acid and in-situ produce H2O2) into stimulus polymer coated HMSNs results in a glucose-mediated MN device after depositing the drug-loaded nanoparticles into MN array patch. Both in vitro and in vivo results show this MN device presents a glucose mediated self-regulated drug release characteristic, which possesses a rapid drug release at hyperglycemic level but retarded drug release at normoglycemic level. The result indicates that the fabricated smart drug delivery system is a good candidate for the therapy of diabetes.
    Numerical simulation and experimental study of gas cyclone–liquid jet separator for fine particle separation
    Liwang Wang, Erwen Chen, Liang Ma, Zhanghuang Yang, Zongzhe Li, Weihui Yang, Hualin Wang, Yulong Chang
    2022, 51(11):  43-52.  doi:10.1016/j.cjche.2021.12.015
    Abstract ( )   PDF (5640KB) ( )  
    References | Related Articles | Metrics
    To address the shortcomings of existing particulate matter trapping technology, especially the low separation efficiency of fine particles, herein, a novel gas cyclone–liquid jet separator was developed to research fine particle trapping. First, numerical simulation methods were used to investigate the flow field characteristics and dust removal efficiency of the separator under different working conditions, and to determined suitable experimental conditions for subsequent dust removal experiments. Afterward, the separation efficiency of the separator against five kinds of common particles, including g-C3N4, TiO2, SiC, talc, and SiO2, was experimentally studied. A maximum separation efficiency of 99.48% was achieved for particles larger than 13.1 μm, and 96.55% efficiency was achieved for particles larger than 2 μm. The best crushing atomization effect was achieved for the separator when uG was 10 m·s-1 and uL was 3 m·s-1, while the best separation effect was achieved when uG was 10 m·s-1 and uL was 3.75 m·s-1. Studies have shown that the gas cyclone–liquid jet separator has excellent applicability in the separation of fine particles.
    Towards recycling purpose: Converting PET plastic waste back to terephthalic acid using pH-responsive phase transfer catalyst
    Yueqing Wang, Hongxing Wang, Hongmei Chen, Hantao Liu
    2022, 51(11):  53-60.  doi:10.1016/j.cjche.2021.10.028
    Abstract ( )   PDF (4176KB) ( )  
    References | Related Articles | Metrics
    Converting polyethylene terephthalate (PET) wastes to its monomer and valuable chemicals via eco-friendly chemical method is still a challenge task. Previously, phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction. Here, we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling. The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value. Among them, [C16H33N(CH3)3]3PW12O40 (abbreviated as [CTA]3PW) exhibits the highest activity and the most suitable pH responsive values. Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET, but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid. Additionally, the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive [CTA]3PW.
    Stellerite-seeded facile synthesis of zeolite X with excellent aqueous Cd2+ and Ni2+ adsorption performance
    Yinchang Pei, Shengpeng Mo, Qinglin Xie, Nanchun Chen, Zhongxin Yang, Lili Huang, Lili Ma
    2022, 51(11):  61-74.  doi:10.1016/j.cjche.2022.06.008
    Abstract ( )   PDF (14258KB) ( )  
    References | Related Articles | Metrics
    Zeolite X was synthesized by a two-step hydrothermal method using natural stellerite zeolite as the silicon seed, and its adsorption performance for Cd2+ and Ni2+ ions was experimentally and comprehensively investigated. The effects of pH, zeolite X dosage, contact time, and temperature on adsorption performance for Cd2+ and Ni2+ ions over were studied. The adsorption process was endothermic and spontaneous, and followed the pseudo-second-order kinetic and the Langmuir isotherm models. The maximum adsorption capacitiesfor Cd2+ and Ni2+ ions at 298 K were 173.553 and 75.897 mg·g-1, respectively. Ion exchange and precipitation were the principal mechanisms for the removal of Cd2+ ions from aqueous solutions by zeolite X, followed by electrostatic adsorption. Ion exchange was the principal mechanisms for the removal of Ni2+ ions from aqueous solutions by zeolite X, followed by electrostatic adsorption and precipitation. The zeolite X converted from stellerite zeolite has a low n(Si/Al), abundant hydroxyl groups, and high crystallinity and purity, imparting a good adsorption performance for Cd2+ and Ni2+ ions. This study suggests that zeolite X converted from stellerite zeolite could be a useful environmentally-friendly and effective tool for the removal of Cd2+ and Ni2+ ions from aqueous solutions.
    Fe3O4-carbon spheres core–shell supported palladium nanoparticles: A robust and recyclable catalyst for suzuki coupling reaction
    Mohamed A. Almaradhi, Hassan M.A. Hassan, Mosaed S. Alhumaimess
    2022, 51(11):  75-85.  doi:10.1016/j.cjche.2021.11.024
    Abstract ( )   PDF (9292KB) ( )  
    References | Related Articles | Metrics
    Suzuki-Miyaura (S-M) is regarded the most powerful way for synthesis biaryls, triaryls, or incorporating of substituted aryl moieties in organic preparation by the cross-coupling of aryl boronic acid with aryl halides using the Pd catalyst. This work reports the combining of the hydrothermal and microwave-assisted protocol to convert the glucose to magnetic carbon spheres (Fe3O4-CSPs) decorated with Pd nanoparticles (NPs) as the catalyst for Suzuki-Miyaura cross-coupling reactions. The physicochemical properties in the produced composite were examined using FESEM, HRTEM, nitrogen isotherms, Raman spectroscopy, FTIR, XPS, and XRD. The as-fabricated composite Pd/Fe3O4-CSPs is mostly spherical with a core–shell structure and possesses a great surface area of 253.2 m2·g-1. Its catalytic performance demonstrates that the composite has excellent stability and high tolerance Suzuki-Miyaura cross-coupling reactions in 30 min at 80 ℃. Both activated and deactivated aryl halides provided excellent yield. The as-fabricated catalyst was recycled for up to four catalytic cycles without a substantial decline in performance. Moreover, this research offers a facile roadmap for synthesizing Pd/Fe3O4-CSPs composites and promoting the practical implementation of Pd/Fe3O4-CSPs catalysts for organic transformation processes.
    Numerical simulation of flow field and residence time of nanoparticles in a 1000-ton industrial multi-jet combustion reactor
    Jie Ju, Xianjian Duan, Bismark Sarkodie, Yanjie Hu, Hao Jiang, Chunzhong Li
    2022, 51(11):  86-99.  doi:10.1016/j.cjche.2021.12.008
    Abstract ( )   PDF (18211KB) ( )  
    References | Related Articles | Metrics
    In this work, by establishing a three-dimensional physical model of a 1000-ton industrial multi-jet combustion reactor, a hexahedral structured grid was used to discretize the model. Combined with realizable k–ε model, eddy-dissipation-concept, discrete-ordinate radiation model, hydrogen 19-step detailed reaction mechanism, air age user-defined-function, velocity field, temperature field, concentration field and gas arrival time in the reactor were numerically simulated. The Euler–Lagrange method combined with the discrete-phase-model was used to reveal the flow characteristics of particles in the reactor, and based on this, the effects of the reactor aspect ratios, central jet gas velocity and particle size on the flow field characteristics and particle back-mixing degree in the reactor were investigated. The results show that with the decrease of aspect ratio in the combustion reactors, the velocity and temperature attenuation in the reactor are intensified, the vortex phenomenon is aggravated, and the residence time distribution of nanoparticles is more dispersed. With the increase in the central jet gas velocities in reactors, the vortex lengthens along the axis, the turbulence intensity increases, and the residence time of particles decreases. The back-mixing degree and residence time of particles in the reactor also decrease with the increase in particle size. The simulation results can provide reference for the structural regulation of nanoparticles and the structural design of combustion reactor in the process of gas combustion synthesis.
    Mass transfer intensification and mechanism analysis of gas–liquid two-phase flow in the microchannel embedding triangular obstacles
    Xuanyu Nie, Chunying Zhu, Taotao Fu, Youguang Ma
    2022, 51(11):  100-108.  doi:10.1016/j.cjche.2021.09.016
    Abstract ( )   PDF (4637KB) ( )  
    References | Related Articles | Metrics
    An effective mass transfer intensification method was proposed by embedding different triangular obstacles to improve the gas–liquid mass transfer efficiency in microchannel. The influences of triangle obstacles configuration, obstacle interval and flow rate on the volumetric mass transfer coefficient, pressure drop and energy consumption were investigated experimentally. The enhancement factor was used to quantify the mass transfer enhancement effect of triangle obstacles. It was found that the isosceles or equilateral triangle obstacles are superior to the rectangular obstacles. The maximum enhancement factor of equilateral triangle obstacles was 2.35. Considering comprehensively mass transfer enhancement and energy consumption, the isosceles triangle obstacle showed the best performance, its maximum enhancement factor was 2.1, while the maximum pressure drop increased only 0.41 kPa (22%) compared to the microchannel without obstacles. Furthermore, a micro-particle image velocimetry (micro-PIV) was utilized to observe the flow field distribution and evolution, in order to understand and analyze the enhancement mechanism. The micro-PIV measurement indicated that the obstacle structure could induce the formation of vortex, which promotes convective mass transfer and thins the flow boundary layer, accordingly, the gas–liquid mass transfer efficiency is remarkably improved. This study can provide theoretical guidance and support for the design and optimization of microchannel with triangular obstacles.
    Measurement and correlation of liquid-liquid equilibrium for the ternary system (water + 1,2-dichloroethane + sulfolane) at 288.15, 298.15, and 308.15 K
    Zhansheng Li, Jiayu Song, Shouhai Zhang, Jinyan Wang, Xigao Jian
    2022, 51(11):  109-114.  doi:10.1016/j.cjche.2021.09.006
    Abstract ( )   PDF (442KB) ( )  
    References | Related Articles | Metrics
    Sulfolane is an important aprotic polar solvent. Liquid-liquid equilibrium (LLE) data for the ternary systems of water + 1,2-dichloroethane + sulfolane were measured at temperatures of 288.15, 298.15 and 308.15 K under the atmospheric pressure. The distribution coefficient and selectivity were determined from the measured LLE data, which showed that 1,2-dichloroethane is a suitable extractant for the recovery of sulfolane from its aqueous solution. The nonrandom two-liquid (NRTL) model and the universal quasi-chemical (UNIQUAC) model were utilized to correlate the experimental LLE data. The low values of RMSD indicated that the ternary system could be fitted well by the NRTL and UNIQUAC models. The consistency of the binary interaction parameters for the two thermodynamic models obtained was confirmed by the topological information contained in the Gibbs energy of mixing function (GM/RT).
    Flexibility analysis for continuous ibuprofen manufacturing processes
    Wenhui Yang, Haoyu Yin, Zhihong Yuan, Bingzhen Chen
    2022, 51(11):  115-125.  doi:10.1016/j.cjche.2021.10.019
    Abstract ( )   PDF (2455KB) ( )  
    References | Related Articles | Metrics
    Continuous ibuprofen (a widespread used analgesic drug) manufacturing is full of superiorities and is a fertile field both in industry and academia since it can not only effectively treat rheumatic and other chronic and painful diseases, but also shows great potential in dental diseases. As one of central elements of operability analysis, flexibility analysis is in charge of the quantitative assessment of the capability to guarantee the feasible operation in face of variations on uncertain parameters. In this paper, we focus on the flexibility index calculation for the continuous ibuprofen manufacturing process. We update existing state-of-the-art formulations, which traditionally lead to the max-max-max optimization problem, to approach the calculation of the flexibility index with a favorable manner. Advantages regarding the size of the mathematical model and the computational CPU time of the modified method are examined by four cases. In addition to identifying the flexibility index without any consideration of control variables, we also investigate the effects of different combinations of control variables on the flexibility property to reveal the benefits from taking recourse actions into account. Results from systematic investigations are expected to provide a solid basis for the further control system design and optimal operation of continuous ibuprofen manufacturing.
    Highly selective separation of propylene/propane mixture on cost-effectively four-carbon linkers based metal-organic frameworks
    Daofei Lv, Junhao Xu, Pingjun Zhou, Shi Tu, Feng Xu, Jian Yan, Hongxia Xi, Zewei Liu, Wenbing Yuan, Qiang Fu, Xin Chen, Qibin Xia
    2022, 51(11):  126-134.  doi:10.1016/j.cjche.2021.12.024
    Abstract ( )   PDF (10810KB) ( )  
    References | Related Articles | Metrics
    The separation of propylene and propane is an important but challenging process, primarily achieved through energy-intensive distillation technology in the petrochemical industry. Here, we reported two natural C4 linkers based metal–organic frameworks (MIP-202 and MIP-203) for C3H6/C3H8 separation. Adsorption isotherms and selectivity calculations were performed to study the adsorption performance for C3H6/C3H8 separation. Results show that C3H6/C3H8 uptake ratios (298 K, 100 kPa) for MIP-202 and MIP-203 are 2.34 and 7.4, respectively. C3H6/C3H8 uptake ratio (303 K, 100 kPa) for MIP-203 is up to 50.0. The mechanism for enhanced separation performance of C3H6/C3H8 on MIP-203 at higher temperature (303 K) was revealed by the in situ PXRD characterization. The adsorption selectivities of C3H6/C3H8 on MIP-202 and MIP-203 (298 K, 100 kPa) are 8.8 and 551.4, respectively. The mechanism for the preferential adsorption of C3H6 over C3H8 in MIP-202 and MIP-203 was revealed by the Monte Carlo simulation. The cost of organic ligands for MIP-202 and MIP-203 was lower than that of organic ligands for those top-performance MOFs. Our work sets a new benchmark for C3H6 sorbents with high adsorption selectivities.
    Analysis of the flow pattern and periodicity of gas–liquid–liquid three-phase flow in a countercurrent mixer-settler
    Minghang Zhang, Wangfeng Cai, Pei Zhu, Le Xie, Yan Wang
    2022, 51(11):  135-145.  doi:10.1016/j.cjche.2021.10.001
    Abstract ( )   PDF (10166KB) ( )  
    References | Related Articles | Metrics
    In contrast to the concurrent mixer-settler, the interaction between the mixing and settling chambers have to be taken into account in the simulation of the countercurrent mixer-settler, and no work has been reported for this equipment. In this work, a three-phase flow model based on the Eulerian multiphase model, coupled with a sliding mesh model is proposed for a countercurrent mixer-settler. Based on this, the dispersed phase distribution, flow pattern, and pressure distribution are investigated, which can help to fill the gap in the operation mechanism. In addition, the velocity vector distribution at the phase port shows an intriguing phenomenon that two types of vectors with opposite directions are distributed on the left and right sides of the same plane, which indicates that the material exchange in the mixing and settling chambers is simultaneous. Analysis of this variation at this location by a fast Fourier transform (FFT) method reveals that it is mainly influenced by the mixing chamber and is consistent with the main period of the outlet flow fluctuations. Therefore, by monitoring the fluctuation of the outlet flow and then analyzing it by the FFT method, the state of the whole tank can be determined, which makes it promising for the design of control systems for countercurrent mixer-settlers.
    Full Length Article
    Innovation and application of dyes with high fixation
    Shufen Zhang, Wei Ma, Bingtao Tang, Bin Shan
    2022, 51(11):  146-152.  doi:10.1016/j.cjche.2022.02.020
    Abstract ( )   PDF (1034KB) ( )  
    References | Related Articles | Metrics
    Reactive dyes are the main species for cotton dyeing due to their wide range of hue, satisfactory color fastness and facile application method. Aiming at increasing fixation on cotton fibers, benzimidazolone yellow reactive dyes, sulfonamide red reactive dyes and anthraquinone azo blue reactive dyes are designed. The preparation, characterization and application properties of these dyes with high fixation are introduced in detail. In order to achieve dye fixation to near 100%, macromolecular crosslinking reactive dyes are designed, their dyeing and fixing mechanism are discussed. These novel reactive dyes show promising application prospect in dyeing and printing of cotton fibers.
    A stochastic reconstruction strategy based on a stratified library of structural descriptors and its application in the molecular reconstruction of naphtha
    Guangyao Zhao, Minglei Yang, Wenli Du, Feifei Shen, Feng Qian
    2022, 51(11):  153-167.  doi:10.1016/j.cjche.2021.12.020
    Abstract ( )   PDF (9495KB) ( )  
    References | Related Articles | Metrics
    Molecular reconstruction is a rapid and reliable way to provide molecular detail of petroleum fractions, which is required in the kinetic modeling of petroleum conversation processes at the molecular level. In the typical stochastic reconstruction method, the estimation of properties of pseudo molecules that are generated by Monte Carlo sampling depends on the building of predefined molecular libraries, which is expensive and inaccessible for certain petroleum fractions. In this paper, a novel stochastic reconstruction strategy is proposed, which is based on a stratified library of structural descriptors. Properties of pseudo molecules generated in the novel strategy can be directly estimated by group contribution method in the condition of lacking predefined molecular libraries. In this strategy, the molecular building diagram comprises two steps. First, the ring structure is configured by determining the number of rings. Different from the length of chain adopted in the traditional stochastic reconstruction method, in the second step, number of structural descriptors (SDs) for binding site and chain were determined sequentially for the configuration of binding site and saturated acyclic hydrocarbon chain. These structural descriptors for binding site and chain were selected from group contribution methods. To count the number of partial overlapping sections between structural descriptors for chain, two supplementary structural descriptors were created. All possible saturated structures of hydrocarbon chains can be represented by structural descriptors at the scale of property estimation. This strategy separates the building of a predefined molecule library from the stochastic reconstruction process. The exact structures of pseudo molecules represented by structural descriptors in this work can be determined with sufficient chemical knowledge. Fifty naphtha samples are tested independently to demonstrate the performance of the proposed strategy and the results show that the estimated properties were close enough to the experimental values. This strategy will benefit the molecular management of petrochemical industries and therefore improve economic and environmental efficiencies.
    A generalized CFD model for evaluating catalytic separation process in structured porous materials
    Anshi Hong, Zisheng Zhang, Xingang Li, Xin Gao
    2022, 51(11):  168-177.  doi:10.1016/j.cjche.2021.12.004
    Abstract ( )   PDF (6167KB) ( )  
    References | Related Articles | Metrics
    A hybrid multiphase model is developed to simulate the simultaneous momentum, heat and mass transfer and heterogeneous catalyzed reaction in structured catalytic porous materials. The approach relies on the combination of the volume of fluid (VOF) and Eulerian–Eulerian models, and several plug-in field functions. The VOF method is used to capture the gas–liquid interface motion, and the Eulerian–Eulerian framework solves the temperature and chemical species concentration equations for each phase. The self-defined field functions utilize a single-domain approach to overcome convergence difficulty when applying the hybrid multiphase for a multi-domain problem. The method is then applied to investigate selective removal of specific species in multicomponent reactive evaporation process. The results show that the coupling of catalytic reaction and interface species mass transfer at the phase interface is conditional, and the coupling of catalytic reaction and momentum transfer across fluid–porous interface significantly affects the conversion rate of reactants. Based on the numerical results, a strategy is proposed for matching solid catalyst with operating condition in catalytic distillation application.
    Void fraction measurement and calculation model of vertical upward co-current air–water slug flow
    Teng Wang, Miao Gui, Jinle Zhao, Qincheng Bi, Tao Zhang
    2022, 51(11):  178-198.  doi:10.1016/j.cjche.2021.10.003
    Abstract ( )   PDF (13643KB) ( )  
    References | Related Articles | Metrics
    The focus of this paper is on the measurement and calculation model of void fraction for the vertical upward co-current air–water slug flow in a circular tube of 15 mm inner diameter. High-speed photography and optical probes were utilized, with water superficial velocity ranging from 0.089 to 0.65 m·s-1 and gas superficial velocity ranging from 0.049 to 0.65 m·s-1. A new void fraction model based on the local parameters was proposed, disposing the slug flow as a combination of Taylor bubbles and liquid slugs. In the Taylor bubble region, correction factors of liquid film thickness Cδ and nose shape CZ* were proposed to calculate αTB. In the liquid slug region, the radial void fraction distribution profiles were obtained to calculate αLS, by employing the image processing technique based on supervised machine learning. Results showed that the void fraction proportion in Taylor bubbles occupied crucial contribution to the overall void fraction. Multiple types of void fraction predictive correlations were assessed using the present data. The performance of the Schmidt model was optimal, while some models for slug flow performed not outstanding. Additionally, a predictive correlation was correlated between the central local void fraction and the cross-sectional averaged void fraction, as a straightforward form of the void fraction calculation model. The predictive correlation showed a good agreement with the present experimental data, as well as the data of Olerni et al., indicating that the new model was effective and applicable under the slug flow conditions.
    A multi-functional Ru Mo bimetallic catalyst for ultra-efficient C3 alcohols production from liquid phase hydrogenolysis of glycerol
    Guoxiao Cai, Wei Xiong, Susu Zhou, Pingle Liu, Yang Lv, Fang Hao, Hean Luo, ChangYi Kong
    2022, 51(11):  199-215.  doi:10.1016/j.cjche.2021.09.013
    Abstract ( )   PDF (21432KB) ( )  
    References | Related Articles | Metrics
    Ru and Mo bimetallic catalysts supported on active carbon modified by phosphotungstic acid (PW) were designed and applied in glycerol hydrogenolysis reaction. The physicochemical properties of the catalysts were characterized and the presence of active sites was investigated from the perspective of the glycerol hydrogenolysis performance. The MoOx is highly selective for the C—O bond cleavage of glycerol molecules, which can reasonably regulate the strong C—C bond cleavage activity of Ru nanoparticles. By using sequential deposition of Ru and Mo supported on mesoporous PW-C, the characterization results show that the combination of isolated low-valence MoOx with metal Ru particles can form “MoOx-Ru-PW”, which provides highly catalytic activity toward C—O bond cleavage, selectively producing more C3 alcohols (mainly 1,2(3)-propanediol). The glycerol conversion of 1% Mo/Ru/PW-C catalyst was 59.6%, the selectivity of C3 alcohol was 96.1%, and the selectivity of propanediol (1,2(3)-propanediol) was 94.9%. It is noteworthy that the selectivity of 1,3-propanediol reached 20.7% when the PW was 21.07% (mass). This study provides experimental evidence for the tandem dehydration and hydrogenation mechanism of the multifunctional Mo/Ru/PW-C catalyst.