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Table of Content
28 October 2021, Volume 38 Issue 10
    Knowledge expression, numerical modeling and optimization application of ethylene thermal cracking: From the perspective of intelligent manufacturing
    Kexin Bi, Shuyuan Zhang, Chen Zhang, Haoran Li, Xinye Huang, Haoyu Liu, Tong Qiu
    2021, 38(10):  1-17.  doi:10.1016/j.cjche.2021.03.033
    Abstract ( 184 )   PDF (7201KB) ( 242 )  
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    Applications of process systems engineering (PSE) in plants and enterprises are boosting industrial reform from automation to digitization and intelligence. For ethylene thermal cracking, knowledge expression, numerical modeling and intelligent optimization are key steps for intelligent manufacturing. This paper provides an overview of progress and contributions to the PSE-aided production of thermal cracking; introduces the frameworks, methods and algorithms that have been proposed over the past 10 years and discusses the advantages, limitations and applications in industrial practice. An entire set of molecular-level modeling approaches from feedstocks to products, including feedstock molecular reconstruction, reaction-network auto-generation and cracking unit simulation are described. Multi-level control and optimization methods are exhibited, including at the operational, cycle, plant and enterprise level. Relevant software packages are introduced. Finally, an outlook in terms of future directions is presented.
    Low-temperature conversion of methane to oxygenates by supported metal catalysts: From nanoparticles to single atoms
    Geqian Fang, Jian Lin, Xiaodong Wang
    2021, 38(10):  18-29.  doi:10.1016/j.cjche.2021.04.034
    Abstract ( 135 )   PDF (7633KB) ( 203 )  
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    Direct cost-effective conversion of abundant methane to high value-added oxygenates (methanol, formic acid, acetic acid, etc.) under mild conditions is prospective for optimizing the structure of energy resources. However, the CH bond of products is more reactive than that of high thermodynamic stable methane. Exploring an appropriate approach to eliminate the “seesaw effect” between methane conversion and oxygenate selectivity is significant. In this review, we briefly summarize the research progress in the past decade on low-temperature direct conversion of methane to oxygenates in gas-solid-liquid phase over various transition metal (Fe, Cu, Rh, Pd, AuPd, etc.) based nanoparticle or single-atom catalyst. Furthermore, the prospects of catalyst design and catalysis process are also discussed.
    Recent advances in amino acid-metal coordinated nanomaterials for biomedical applications
    Shaobo Wang, Yunchao Zhao, Zeyu Zhang, Yalong Zhang, Linlin Li
    2021, 38(10):  30-42.  doi:10.1016/j.cjche.2021.03.013
    Abstract ( 136 )   PDF (9998KB) ( 278 )  
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    Metal and amino acid (AA), as two kinds of entities, have been widely involved in biomaterials and nanomedicines. Recently, the marriage of them has developed new nanoformulations, amino acid-metal coordinated nanomaterials (AMCNs), which show great biomedical application potential in cancer therapy, antibacterial applications, biomedical imaging, etc. With the respective characteristics of metal and AA with rich biological and chemical properties, AMCNs can not only act as drug carriers with specific tumor targeting ability, but also realize synergistic therapy and imaging-guided therapy. Although the design and synthesis of amino acid-metal coordinated nanomaterials have been in-depth investigated, there are few systematic reviews on their biomedical application. In this review, we give a comprehensive summary of recent progresses in the design, fabrication, and biomedical applications of AMCNs. We also propose the future outlooks and challenges in aforementioned field. We expect that this review would contribute some inspiration for future research and development for amino acid metal coordinated nanomaterials.
    Fluid Dynamics and Transport Phenomena
    Coalescence dynamics of two droplets of different viscosities in T-junction microchannel with a funnel-typed expansion chamber
    Weixi Guo, Chunying Zhu, Taotao Fu, Youguang Ma
    2021, 38(10):  43-52.  doi:10.1016/j.cjche.2021.03.012
    Abstract ( 98 )   PDF (7243KB) ( 236 )  
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    The coalescence behavior of two droplets with different viscosities in the funnel-typed expansion chamber in T-junction microchannel was investigated experimentally and compared with droplet coalescence of the same viscosity. Four types of coalescence regimes were observed: contact non-coalescence, squeeze non-coalescence, two-droplet coalescence and pinch-off coalescence. For droplet coalescence of different viscosities, the operating range of non-coalescence becomes narrowed compared to the droplet coalescence of same viscosity, and it shrinks with increasing viscosity ratio η of two droplets, indicating that the difference in the viscosity of two droplets is conducive to coalescence, especially when 1<η<6. Furthermore, the influences of viscosity ratio and droplet size on the film drainage time (Tdr) and critical capillary number (Cac) were studied systematically. It was found that the film drainage time declined with the increase of average droplet size, which abided by power-law relation with the size difference and viscosity ratio of the two droplets: Tdr ~ (ld)0.25±0.04 and Tdr ~ (η)-0.1±0.02. For droplet coalescence of same viscosity, the relation of critical capillary number with two-phase viscosity ratio and dimensionless droplet size is Cac = 0.48λ0.26l-2.64, while for droplet coalescence of different viscosities, the scaling of critical capillary number with dimensionless average droplet size, dimensionless droplet size difference and viscosity ratio of two droplets is Cac = 0.11η-0.07ls-2.23ld0.16.
    Effects of piperacillin synthesis on the interfacial tensions and droplet sizes
    Yu Xie, Guoming Huang, Weiguo Hu, Yujun Wang
    2021, 38(10):  53-62.  doi:10.1016/j.cjche.2021.05.025
    Abstract ( 96 )   PDF (5896KB) ( 266 )  
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    Piperacillin is a polar organic substance, and can reduce the interfacial tension of oil and water when dissolved in water. In this study, changes in dichloromethane-water interfacial tensions and microdroplet sizes during piperacillin synthesis from an aqueous solution of ampicillin and dichloromethane solution of 4-ethyl-2,3-dioxo-1-piperazine carbonyl chloride (EDPC) were observed using a pendent drop technique and a coaxial ring tube system with embedded high-speed camera, respectively. It was found that the rapid N-acylation reaction caused the piperacillin at the interface to synthesize rapidly and diffuse out slowly, resulting in the interfacial tension decreased from 19.5 mN·m-1 to 7.2 mN·m-1 rapidly and then increased slowly as the concentrations of ampicillin and EDPC were 0.05 mol·L-1 and 0.1 mol·L-1. Meanwhile, the increase in the concentration of EDPC increased the peak concentration of piperacillin at the interface, and the addition of ethyl acetate to the ampicillin solution promoted mass transfer and reduced the aggregation of piperacillin effectively. During synthesis, the interfacial tension decreased, leading to a change in droplet sizes in the micro-reaction system. The two-phase reaction was carried out in a coaxial ring tube, with ampicillin and EDPC solutions as continuous and dispersed phases, respectively. The reaction reduced the dripping flow area, and the addition of ethyl acetate to the ampicillin solution slightly affected the division of the flow pattern. Under the same flow conditions, the droplet sizes of the reaction group were smaller than those of the no reaction group. The experimental results demonstrated that the increase of the continuous phase, decrease in the dispersed phase flow rate, or increase in EDPC concentration making droplet sizes smaller, and the addition of ethyl acetate slightly affected droplet sizes. These findings are important for the design and optimization of piperacillin synthesis reactors.
    Study on gas-liquid flow characteristics in stirred tank with dual-impeller based on CFD-PBM coupled model
    Songsong Wang, Qiuxiang Bu, Deyu Luan, Ying Zhang, Longbin Li, Zhaorui Wang, Wenhao Shi
    2021, 38(10):  63-75.  doi:10.1016/j.cjche.2020.10.026
    Abstract ( 95 )   PDF (18019KB) ( 465 )  
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    Study on gas-liquid flow in stirred tank with two combinations of dual-impeller (six-bent-bladed turbine (6BT)+six-inclined-blade down-pumping turbine (6ITD), the six-bent-bladed turbine (6BT)+six-inclined-blade up-pumping turbine (6ITU)) was conducted using computational fluid dynamics (CFD) and population balance model (PBM) (CFD-PBM) coupled model. The local bubble size was captured by particle image velocimetry (PIV) measurement. The gas holdup, bubble size distribution and gas-liquid interfacial area were explored at different conditions through numerical simulation. The results showed that the 4 mm bubbles accounted for the largest proportion of 33% at the gas flow rates Q = 0.76 m3·h-1 and 22% at Q = 1.52 m3·h-1 for combined impeller of 6BT + 6ITU, while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT + 6ITD combination, i.e. 25% at Q = 0.76 m3·h-1 and 22% at Q = 1.52 m3·h-1, respectively, which indicated that 6BT + 6ITU could reduce bubble size effectively and promote gas dispersion. In addition, the gas holdup around impellers was increased obviously with the speed compared with gas flow rate. So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size, which embodied the advantages of 6BT + 6ITU combination in gas-liquid mixing.
    Separation Science and Engineering
    Enhanced coalescence separation of oil-in-water emulsions using electrospun PVDF nanofibers
    Yujie Yang, Lei Li, Qian Zhang, Wenwen Chen, Song Lin, Zaiqian Wang, Wangliang Li
    2021, 38(10):  76-83.  doi:10.1016/j.cjche.2020.08.037
    Abstract ( 102 )   PDF (10972KB) ( 202 )  
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    A novel and high-efficiency coalescence membrane enhanced by nano-sized polyvinylidene fluoride (PVDF) nanofibers based on polyester (PET) substrate was fabricated using electrospinning method. The properties of the electrospun nanofibers such as roughness and surface morphology greatly affected the oil droplet interception efficiency and surface wettability of the membrane. A series of coalescence units were prepared with different layers of nanofibrous membrane and the separation efficiencies at different initial concentrations, flow rates, and oil types were tested. It is very interesting that the obtained nanofibrous membrane exhibited superoleophilicity in air but poor oleophilicity under water, which was beneficial to the coalescence process. The coalescence unit with four membrane layers had excellent performances under different initial concentrations and flow rates. The separation efficiency of the 4-layers unit remained above 98.2% when the initial concentration reached up to 2000 mg·L-1. Furthermore, the unit also exhibited good performance with the increasing oil density and viscosity, which is promising for large-scale oil wastewater treatment.
    Polyethersulfone-polyvinylpyrrolidone composite membranes: Effects of polyvinylpyrrolidone content and polydopamine coating on membrane morphology, structure and performances
    Yanna Wu, Jianxian Zeng, Yajie Zeng, Hu Zhou, Guoqing Liu, Jian Jian, Jie Ding
    2021, 38(10):  84-97.  doi:10.1016/j.cjche.2020.09.012
    Abstract ( 106 )   PDF (15116KB) ( 173 )  
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    Hydrophilic modification is a promising method to inhibit fouling formation on ultrafiltration membrane. In this work, different mass concentrations (1%-16%) of hydrophilic polyvinylpyrrolidone were incorporated into polyethersulfone (PES) membranes fabricated by none-solvent induced phase separation. Then, polydopamine (PDA) coating on the surface of prepared membrane was carried out at pH 8.5. The morphology and structure, surface hydrophilicity, permeation flux, BSA rejection, antifouling and stability performances of PES and PDA/PES modified membranes were investigated in detail. The results indicated that PDA was successfully attached onto the membranes. Membrane hydrophilicity was evaluated by water contact angle measurement. The contact angles of modified membranes reduced remarkably, suggesting that the membrane hydrophilicities were significantly increased. The results of filtration tests, which were done by dead-end filtration of bovine serum albumin solution, showed that the properties of permeability and fouling resistance were obviously improved by PDA modification. When polyvinylpyrrolidone mass content reached 10%, flux recovery ratio of modified membrane was up to 91.23%, and its BSA rejection were over 70%. The results of stability tests showed that the modified membranes had good mechanical stability and chemical stability. This facile fabrication procedure and outstanding performances suggested that the modified membranes had a potential in treating fouling.
    Catalysis, Kinetics and Reaction Engineering
    Engineering the efficient three-dimension hollow cubic carbon from vacuum residuum with enhanced mass transfer ability towards H2O2 production
    Zhaohui Chen, Yasi Mo, Dong Lin, Yongxiao Tuo, Xiang Feng, Yibin Liu, Xiaobo Chen, De Chen, Chaohe Yang
    2021, 38(10):  98-105.  doi:10.1016/j.cjche.2020.08.040
    Abstract ( 87 )   PDF (6414KB) ( 255 )  
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    Constructing efficient carbon material with enhanced mass transfer ability from vacuum residuum (VR) is of prime industrial and scientific significance. Herein, we demonstrated a one-pot synthesis of metal-free and highly symmetric hollow carbon cubes (HCCs) using cost-efficient vacuum residuum (VR) as a C/N/S source. By multi-techniques such as TEM, SEM, Raman, XPS, and XRD, it is found that the CTAB surfactant plays an important role in emulsifying and forming oil-in-water suspension particles. Subsequently, high aromatics contents in VR favor the formation of HCCs shell by graphitization on the surface of NaCl template. Notably, heavy metals (e.g., V, Ni) are not enriched in carbon skeleton due to the unique graphitization mechanism. This metal-free HCCs catalyst showed good catalytic stability and high selectivity towards direct and local electrochemical production of hydrogen peroxide (H2O2) through two-electron O2 reduction due to enhanced mass transfer ability. The results provide a novel avenue to synthesize metal-free cubic carbon material from low-cost and plentiful VR, which are essential to the design of more efficient catalysts for O2 reduction to H2O2.
    Enhanced stability of Fe-modified CuO-ZnO-ZrO2-Al2O3/HZSM-5 bifunctional catalysts for dimethyl ether synthesis from CO2 hydrogenation
    Xiao Fan, Shoujie Ren, Baitang Jin, Shiguang Li, Miao Yu, Xinhua Liang
    2021, 38(10):  106-113.  doi:10.1016/j.cjche.2020.11.031
    Abstract ( 80 )   PDF (5286KB) ( 217 )  
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    A series of iron (Fe) modified CuO-ZnO-ZrO2-Al2O3 (CZZA) catalysts, with various Fe loadings, were prepared using a co-precipitation method. A bifunctional catalyst, consisting of Fe-modified CZZA and HZSM-5, was studied for dimethyl ether (DME) synthesis via CO2 hydrogenation. The effects of Fe loading, reaction temperature, reaction pressure, space velocity, and concentrations of precursor for the synthesis of the Fe-modified CZZA catalyst on the catalytic activity of DME synthesis were investigated. Long-term stability tests showed that Fe modification of the CZZA catalyst improved the catalyst stability for DME synthesis via CO2 hydrogenation. The activity loss, in terms of DME yield, was significantly reduced from 4.2% to 1.4% in a 100 h run of reaction, when the Fe loading amount was 0.5 (molar ratio of Fe to Cu). An analysis of hydrogen temperature programmed reduction revealed that the introduction of Fe improved the reducibility of the catalysts, due to assisted adsorption of H2 on iron oxide. The good stability of Fe-modified CZZA catalysts in the DME formation was most likely attributed to oxygen spillover that was introduced by the addition of iron oxide. This could have inhibited the oxidation of the Cu surface and enhanced the thermal stability of copper during long-term reactions.
    Aqueous-phase hydrogenation of levulinic acid over carbon layer protected silica-supported cobalt-ruthenium catalysts
    Lihua Qian, Guojun Lan, Xiaoyan Liu, Zhenqing Li, Ying Li
    2021, 38(10):  114-122.  doi:10.1016/j.cjche.2021.07.004
    Abstract ( 108 )   PDF (8475KB) ( 108 )  
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    The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) by using water as solvent is a crucial process in the production of fine chemicals from biomass. An ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica (CoRu@C/SiO2) is prepared by using tannis-ligated cobalt-ruthenium complex on silica as precursors, and applied for catalyzed synthesis of GVL from LA. Because of the synergistic effect between cobalt and ruthenium, the addition of small amounts of Ru to Co catalysts can increase the catalytic activity in the aqueous hydrogenation of LA. The ultrathin carbon layer covered on the CoRu bimetallic catalyst can greatly reduce the leaching of active metals. The CoRu@C/SiO2 catalyst achieves high stability and is reused up to 5 runs without significant loss of performance in aqueous hydrogenation of levulinic acid.
    Syngas production from chemical looping reforming of ethanol over iron-based oxygen carriers: Theoretical analysis and experimental investigation
    Atif Abdalazeez, Wenju Wang, Siddig Abuelgasim
    2021, 38(10):  123-131.  doi:10.1016/j.cjche.2021.02.012
    Abstract ( 105 )   PDF (10059KB) ( 25 )  
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    Chemical looping reforming (CLR) is a recent trend for syngas production, which has several merits compared to the conventional manner. One of the most important issues for CLR is to find low-cost material as oxygen carriers, so iron is a promising candidate. This paper contributes to testing the thermodynamic ability of iron-based oxygen carrier for chemical looping reforming of ethanol (CLRE). Iron thermodynamically investigated in temperature 100-1300 ℃ and excess oxygen number (Φ) 0-4. It was found that the temperature and Φ have an apparent effect on the gaseous composition produced from the process. Increases in temperature within the range of 100-1300 ℃ enhanced syngas generated and reduced coke formation and CH4. Whereas, increased Φ, particularly at higher temperatures, had also enhanced syngas production as well as reduced coke formation. However, increasing Φ for values beyond one had decreased syngas and not significantly reduced coke deposition. Moreover, an experimental investigation was carried out in a fixed bed reactor for more in-depth verification of iron ability as an oxygen carrier through using magnetite ore (mainly Fe3O4). It found that the effect of temperature on syngas production was consistent with that calculated thermodynamically, as syngas increased with raising the temperature through the CLRE.
    Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics
    Zhaoxiang Zhang, Fei Guo, Wei Song, Xiaohong Jia, Yuming Wang
    2021, 38(10):  132-144.  doi:10.1016/j.cjche.2020.09.023
    Abstract ( 83 )   PDF (8465KB) ( 40 )  
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    Based on the theory of first-order reaction kinetics, a thermal reaction kinetic model in integral form has been derive. To make the model more applicable, the effects of time and the conversion degree on the reaction rate parameters were considered. Two types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate, and two types of correction methods are provided. The model was explained and verified using published experimental data of different polymer thermal reaction systems, and its effectiveness and wide adaptability were confirmed. For the given kinetic model, only one parameter needs to be determined. The proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process.
    Ca- and Mg-rich waste as high active carrier for chemical looping gasification of biomass
    Xin Niu, Laihong Shen
    2021, 38(10):  145-154.  doi:10.1016/j.cjche.2020.09.024
    Abstract ( 78 )   PDF (1822KB) ( 46 )  
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    Chemical looping gasification (CLG) is a promising technology for high-quality syngas production. One key issue to successful CLG is the selection of high-performance oxygen carrier. In this study, several Ca- and Mg-rich steelmaking wastes from steel industry, such as blast furnace slag (BF slag), blast furnace dust (BF dust) and Linz-Donawitz converter slag (LD slag), were used as oxygen carriers in chemical looping gasification of biomass. The results showed that the reducibility of Ca- and Mg-rich waste, especially LD slag and BF dust, was superior to that of hematite. Considering long-term operation, the cyclic stability of steelmaking waste was tested. BF dust showed a poor stability, while the other carrier (hematite, BF slag or LD slag) presented an excellent stability during multiple redox cycles in spite of partial sintering and agglomeration. Moreover, the effects of supply oxygen coefficient (O/B ratio) and reaction temperature on CLG of biomass were investigated. The results revealed that Ca- and Mg-rich waste exhibited a higher syngas production compared to hematite. The higher performance could be attributed to the improved reduction rate of Fe2O3 and gasification rate of biomass by Ca or Mg in steelmaking waste. In addition, LD slag exhibited the higher gas value at the O/B ratio of 1 at 900 ℃. As a consequence, LD slag was an appropriate oxygen carrier for CLG of biomass in terms of perfect reducibility, superior cyclic stability and high reactivity.
    High efficient removal of HCN over porous CuO/CeO2 micro-nano spheres at lower temperature range
    Zhihao Yi, Jie Sun, Jigang Li, Tian Zhou, Shouping Wei, Hongjia Xie, Yulin Yang
    2021, 38(10):  155-164.  doi:10.1016/j.cjche.2020.08.029
    Abstract ( 89 )   PDF (7797KB) ( 27 )  
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    The porous CeO2 flowerlike micro-nano spheres based materials were prepared to remove HCN effectively at lower temperature range. The CeO2 and a serious of porous flowerlike ceria based materials loaded with metal species including Cu, Ag, Ni, Co and Fe were synthesized by hydrothermal method and precipitation method respectively. The physicochemical properties were probed by means of XRD, H2-TPR, BET, SEM and XPS. The removal ability for 130?mg·m-3 HCN over CuO/CeO2 showed the highest activity, the breakthrough time of which was more than 70?min at the condition of 30?℃, 120,000?h-1 and 5?% (volume) H2O, owe to a higher relative atomic ratio of oxygen vacancies and Oβ, the stronger interaction between metal particle and support, the optimum redox properties. The reaction mechanism was speculated by detecting the reaction products selectivity at different reaction temperature. It was shown that the reaction system for removal of HCN over CuO/CeO2 catalytic material involved chemisorption, catalytic hydrolysis, catalytic oxidation as well as NH3-SCR reactions.
    Promoting di-isobutene selectivity over ZnO/ZrO2-SO4 in isobutene oligomerization
    Jiyuan Li, Mifen Cui, Zhuxiu Zhang, Xian Chen, Qing Liu, Zhaoyang Fei, Jihai Tang, Xu Qiao
    2021, 38(10):  165-171.  doi:10.1016/j.cjche.2020.08.039
    Abstract ( 84 )   PDF (5020KB) ( 81 )  
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    Isooctane attracts great interest in recent years because of its promising potential as friendly-environmental gasoline, which is obtained by dimerization of isobutene with a hydrogenation step. Herein, a solid acid catalyst sulfated zirconia modified by ZnO was prepared. The oligomerization of isobutene had been investigated over ZrO2-SO4 and ZnO(X)/ZrO2-SO4 catalyst in order to find efficient catalysts for the production of isobutene oligomers. The presence of ZnO obviously enhanced the dimerization of isobutene and ZnO(X)/ZrO2-SO4 exhibited the highest di-isobutene yield of 60%. Kinetic studies showed the higher trimerization-to-dimerization activation energy ratios of ZnO(X)/ZrO2-SO4 than those of ZrO2-SO4 from 353 to 393 K. In addition, reaction rate of dimerization was higher than trimerization over ZnO(X)/ZrO2-SO4. The high L/B ratio manifested the capability to enhance the selectivity of C8 in isobutene dimerization. Furthermore, ZnO(X)/ZrO2-SO4 exhibited stable conversion for the dimerization of isobutene.
    Study on attrition of spherical-shaped Mo/HZSM-5 catalyst for methane dehydro-aromatization in a gas-solid fluidized bed
    Xinzhuang Zhang, Yunda Han, Dapeng Li, Zhanguo Zhang, Xiaoxun Ma
    2021, 38(10):  172-183.  doi:10.1016/j.cjche.2021.03.025
    Abstract ( 105 )   PDF (9269KB) ( 78 )  
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    As a potential methane efficient conversion process, non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance, especially in the states of high temperature, long-time rapid movement and chemical reaction. Existing evaluation methods for attrition resistance, such as ASTM D5757 and Jet Cup test, are targeted for fresh catalysts at ambient temperature, which cannot well reflect the real process. In this study, spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing, in which the catalyst attrition under different system temperatures, running time and process factors was investigated with percent mass loss (PML), particle size-mass distribution (PSMD) and scanning electron microscope (SEM). Carbon deposition on the catalyst before and after activation, aromatization and regeneration was analyzed by thermogravimetry (TG), and the attrited catalysts were evaluated for methane dehydro-aromatization (MDA). The results show that the surface abrasion and body breakage of catalyst particles occur continuously, with the increase of system temperature and running time, and make the PML rise gradually. The process factors of activation, aromatization and regeneration can cause the catalyst attrition and carbon deposits, which broaden the PSMD in varying degrees, and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature. Catalyst attrition has a certain influence on its catalytic performance, and the main reasons point to particle breakage and fine powder escape.
    Chemical Engineering Thermodynamics
    Thermodynamic modeling of gas solubility in aqueous sodium chloride solution
    Li Sun, Jierong Liang
    2021, 38(10):  184-195.  doi:10.1016/j.cjche.2020.09.056
    Abstract ( 91 )   PDF (2404KB) ( 71 )  
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    An electrolyte Equation of State is presented by combining the Cubic Plus Association Equation of State, Mean Spherical Approximation and the Born equation. This new model uses experimental relative static permittivity, intend to predict well the activity coefficients of individual ions (ACI) and liquid densities of aqueous solutions. This new model is applied to model water + NaCl binary system and water + gas + NaCl ternary systems. The cation/anion-water interaction parameters of are obtained by fitting the experimental data of ACI, mean ionic activity coefficients (MIAC) and liquid densities of water + NaCl binary system. The cation/anion-gas interaction parameters are obtained by fitting the experimental data of gas solubilities in aqueous NaCl solutions. The modeling results show that this new model can correlate well with the phase equilibrium and volumetric properties. Without gas, predictions for ACI, MIAC, and liquid densities present relative average deviations of 1.3%, 3.6% and 1.4% compared to experimental reference values. For most gas-containing systems, predictions for gas solubilities present relative average deviations lower than 7.0%. Further, the contributions of ACI, and salting effects of NaCl on gases are analyzed and discussed.
    Solubility measurement and thermodynamic properties of sulfamonomethoxine in pure solvents and sulfamonomethoxine hydrate in acetone + water binary solvent at different temperature
    Yanmin Shen, Wenju Liu, Paifeng Shi, Chao Wang
    2021, 38(10):  196-204.  doi:10.1016/j.cjche.2020.10.037
    Abstract ( 88 )   PDF (901KB) ( 63 )  
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    The experimental solubility of sulfamonomethoxine in six different pure solvents (methanol, ethanol, 1-propanol, l-butanol, ethyl acetate and acetone) and sulfamonomethoxine hydrate in acetone + water mixture solvents were measured from 294.55 K to 362.15 K by a laser dynamic method under atmospheric pressure. Experimental results indicated that the solubility data of sulfamonomethoxine increased with temperature increasing in pure solvents and the solubility followed this order: acetone > methanol > ethanol > ethyl acetate > 1-propanol > 1-butanol, but solubility in ethyl acetate was not affected significantly by temperature. In acetone + water mixture solvent, the solubility of sulfamonomethoxine hydrate increased with temperature and the acetone concentration. Thermodynamic equations were applied to correlate solubility data of sulfamonomethoxine and sulfamonomethoxine hydrate including the modified Apelblat equation, λh equation, Wilson equation, NRTL equation, Van’t Hoff-Jouyban Acree equation and modified Apel-Jouyban-Acree equation. Furthermore, thermodynamic properties ΔGd, ΔHd and ΔSd of sulfamonomethoxine and sulfamonomethoxine hydrate in dissolution process were obtained and discussed with the modified Van’t Hoff equation and Gibbs equation.
    Biotechnology and Bioengineering
    Development of genipin crosslinked gelatin matrices on surface interaction: Enhancing the biocompatibility by attenuating sterile inflammation
    Qiang-Song Wang, Gui-Fang Wang, Hai-Yun Zhang, Fa-Quan Zhao, Yuan-Lu Cui
    2021, 38(10):  205-215.  doi:10.1016/j.cjche.2021.03.022
    Abstract ( 67 )   PDF (10307KB) ( 18 )  
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    The inflammation can be stimulated by the surgical implantation and biomaterial presence through the foreign body via bio-interface. Macrophages play a key role in the interaction of host tissue to implant surfaces. In present study, the immuno-inflammatory responses of genipin crosslinked gelatin matrices (GCGM) to macrophages in vitro and the host tissue surfaces in rats were investigated. The results showed that the mechanical properties, swelling and degradation of gelatin matrices were improved by the crosslinking of genipin at physiological conditions. The macrophage on the surface of GCGM could avoid to be activated. The interaction of macrophage and GCGM suggested that GCGM could reduce the inflammatory response with downregulating the production and mRNA expression of pro-inflammatory cytokines. The anti-inflammatory effect of GCGM was demonstrated to be related to inhibit nuclear factor kappa-B (NF-κB) signaling pathway. Furthermore, gelatin matrices crosslinked with genipin could decrease the acute and chronic inflammatory response interacting with host tissue surfaces to enhance the biocompatibility in rats. These results showed that GCGM could avoid to active macrophages and were endowed with anti-inflammatory properties, suggesting the significant potential for clinical success with the development of immunomodulatory biomaterials.
    Enhancing gene editing efficiency for cells by CRISPR/Cas9 system-loaded multilayered nanoparticles assembled via microfluidics
    Xuanyu Li, Qiang Feng, Ziwei Han, Xingyu Jiang
    2021, 38(10):  216-220.  doi:10.1016/j.cjche.2021.02.009
    Abstract ( 80 )   PDF (2511KB) ( 80 )  
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    Most non-viral carriers for in vitro delivery of nucleic acids suffer from low efficiency of introducing mRNA and other nucleic acids, especially large mRNA. Cas9 protein is the nuclease part of the powerful gene-editing tool, CRISPR/Cas9 system, Cas9 mRNA is particularly large, thus presents a big challenge for delivery. We assembled a multilayered biodegradable nanocarrier to load Cas9 mRNA inside to protect Cas9 mRNA from degradation. We used a microfluidic chip to synthesize a small, positively charged, and degradable core to attract negatively charged Cas9 mRNA. The microfluidic assembly allows the core to be small enough to incorporate into a cationic liposome. The multilayered nanocarriers elevated the delivery efficiency of Cas9 mRNA by over 2 folds and increased the expression by over 5 folds compared to commercially used non-viral carriers. In addition, the multilayered nanocarriers do not require reduced serum medium for transfection. When using the standard complete medium for transfection, the multilayered nanocarriers could increase the expression of Cas9 mRNA by over 15 folds compared to commercially used non-viral carriers. The co-delivery of Cas9 mRNA and sgRNA via LRC elevated the gene-editing efficiency by 3 folds compared to that via commercially used non-viral carriers. Based on the higher transfection efficiency of Cas9 mRNA/sgRNA than commercially used non-viral carriers, these multilayered nanocarriers may have a good prospect as efficient commercial delivery carriers for Cas9 mRNA/sgRNA and other nucleic acids.
    Hollow mesoporous polyaniline nanoparticles with high drug payload and robust photothermal capability for cancer combination therapy
    Yinfeng Zhang, Fang Fang, Yongjie Chen, Min Li, Li Li, Wenyue Li, Jinfeng Zhang
    2021, 38(10):  221-228.  doi:10.1016/j.cjche.2021.03.011
    Abstract ( 103 )   PDF (5859KB) ( 67 )  
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    In recent years, synergistic chemo-photothermal therapy has revealed promising potential in treatments against various kinds of cancer. However, the development of superb photothermal agents with high drug loading capacity is still highly required. In this work, a hollow mesoporous polyaniline nanoparticle (HPANI NP) has been developed for encapsulating chemotherapeutic drug doxorubicin (DOX) with an remarkable drug loading content as high as 37.5%. Additional PEG modification endowed the drug-loaded HPANI NPs with improved water-dispersibility and bioavailability. Such PEG-HPANI-DOX NPs exhibited strong NIR absorbance and robust photothermal conversion capacity, exhibiting highly efficient synergistic cancer treatment. More interestingly, the responsively released DOX molecules could emit strong red fluorescence, which could be employed to monitor the cellular endocytosis and drug release profile of PEG-HPANI-DOX NPs. Finally, the as-fabricated NPs showed good biocompatibility and low toxicity, serving as a promising nanoagent for highly efficient drug delivery and cancer combination therapy.
    Glycopolymer N-halamine-modified biochars with high specificity for Escherichia coli eradication
    Qinggele Borjihan, Quanfu Yao, Huihui Qu, Haixia Wu, Ying Liu, Alideertu Dong
    2021, 38(10):  229-236.  doi:10.1016/j.cjche.2021.04.010
    Abstract ( 81 )   PDF (10074KB) ( 16 )  
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    Antibiotic-resistant bacteria contamination in environments imposes great threats to human life health. This research aims to develop novel targeted antibacterial biochars for achieving high selectivity to kill pathogenic Escherichia coli (E. coli). The glycopolymer N-halamine-modified biochars (i.e., BCPMA-Cl) were synthesized by the modification of biochars with poly[2-(methacrylamido) glucopyranose-co-acrylamide] (P(MAG-co-AM), followed by chlorination treatment. Based on the results of FTIR, turbidity, XPS, and UV-vis, BCPMA-Cl was successfully synthesized and demonstrated to be able to eliminate Staphylococcus aureus (S. aureus) and E. coli. Especially, BCPMA-Cl possessed extremely potent to specific-killing 104 CFU·ml-1 of E. coli with lower hemolytic activity (<5%). Additionally, the antibacterial mechanisms of BCPMA-Cl against bacteria were contact-killing and release-killing contributed by active chlorine (i.e., Cl+). Therefore, this work provided a cost-effective and facile approach for preparation of functional biochars used for bacteria-specific therapeutic applications via livestock pollutants as well as showing a promising strategy to avoid bacterial resistance.
    Nickel-Carnosine complex: A new carrier for enzymes immobilization by affinity adsorption
    Junyang Xu, Yanjun Jiang, Liya Zhou, Li Ma, Zhihong Huang, Jiafu Shi, Jing Gao, Ying He
    2021, 38(10):  237-246.  doi:10.1016/j.cjche.2021.04.019
    Abstract ( 73 )   PDF (6592KB) ( 114 )  
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    Immobilization is an effective method to promote the application of enzyme industry for improving the stability and realizing recovery of enzyme. To some extent, the performance of immobilized enzyme depends on the choice of carrier material. Therefore, the development of new carrier materials has been one of the key issues concerned by enzyme immobilization researchers. In this work, a novel organic-inorganic hybrid material, nickel-carnosine complex (NiCar), was synthesized for the first time by solvothermal method. The obtained NiCar exhibits spherical morphology, hierarchical porosity and abundant unsaturated coordination nickel ions, which provide excellent anchoring sites for the immobilization of proteins. His-tagged organophosphate-degrading enzyme (OpdA) and ω-transaminase (ω-TA) were used as model enzymes to evaluate the performance of NiCar as a carrier. By a simple adsorption process, the enzyme molecules can be fixed on the particles of NiCar, and the stability and reusability are significantly improved. The analysis of protein adsorption on NiCar verified that the affinity adsorption between the imidazole functional group on the protein and the unsaturated coordination nickel ions on NiCar was the main force in the immobilization process, which provided an idea way for the development of new enzyme immobilization carriers.
    Reusable high performance of calcined Mg/Al hydrotalcite for the removal of Navy Blue and Yellow F3G dyes
    Sri Juari Santosa, Dwi Puji Astuti
    2021, 38(10):  247-254.  doi:10.1016/j.cjche.2020.08.038
    Abstract ( 88 )   PDF (2538KB) ( 48 )  
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    Water pollution with dye chemicals from apparel industries is a serious problem in the world. Since most of dyes are potentially have toxic and carcinogenic effects on human, it is important to remove them before they are discharged to the environment. Among many methods available for dyes removal in water, adsorption is the easiest and economically feasible that has no major obstacle for practical applications. In the present study, we tested calcined Mg/Al hydrotalcite (Mg/Al CHT) prepared by co-precipitation technique as an adsorbent for the removal of Navy Blue (NB) and Yellow F3G (YF3G) dyes. Mg/Al CHT was characterized by using a Fourier transform infrared (FTIR) spectrometer, an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The results showed that Mg/Al CHT was highly effective as an adsorbent for the removal of NB and YF3G under mild-acidic condition (pH 4) with removal capacities (b) according to Langmuir isotherm model were 7.97×10-4 and 5.80×10-4 mol·g-1, respectively. Kinetics study showed that the adsorption of NB and YF3D on Mg/Al CHT followed pseudo-second order with rate constant (kp2) 11.57×103 and 11.75×103 g·mol-1·min-1, respectively. The spent adsorbent can be easily regenerated by simply calcining it at 450 ℃ for 3 h. Adsorption test on the mixture of NB and YF3G showed that the adsorption capacity of Mg/Al CHT was eightfold higher than that of Mg/Al HT and the value was maintained with repeated use.
    Effect of different treatments on electrokinetic remediation of Zn, Pb and Cd from a contaminated calcareous soil
    Hossein Beyrami
    2021, 38(10):  255-265.  doi:10.1016/j.cjche.2020.09.011
    Abstract ( 73 )   PDF (2233KB) ( 39 )  
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    Electrokinetic remediation is a promising method to decontamination of the heavy metals from soils. In this paper, the remediation of a contaminated calcareous soil with Zn, Cd and Pb sampled from around Zanjan province of Iran, was investigated using electrokinetic method. In this paper, the soil contain a high concentration of Zn (1400 mg·kg-1), Cd (15 mg·kg-1) and Pb (250 mg·kg-1). Electrokinetic decontamination consists of two series of experiments as follows: (1) the effect of five treatments including the use of distilled water, acetic acid and EDTA electrolyte solutions, and approaching anodes systems, and the circulation flow of electrolyte at two different voltage gradient (i.e. 1.33 and 2.66 V·cm-1), and (2) the effect of moisture content (saturated, FC and 0.7FC, FC indicated soil moisture at “Field Capacity”) with a voltage gradient of 1.33 V·cm-1. After applying electric current for 5 days, the results of experiments indicated that the removal efficiency of heavy metals can be increased by raising the voltage gradient. In this matter, the highest remediation can be observed among different treatments in EDTA (Ethylene diamine tetra acetic acid) treatment (40.11%, 43.10% and 24.7% for Zn, Cd and Pb, respectively). Moreover, the heavy metals removal at the saturated moisture was at the highest level so that 32.62% cadmium, 31.33% zinc and 18.82% lead being removed after 120 h of electric current application. By decreasing moisture to 0.7FC, the removal percentage for the three heavy metals obtained 20.97%, 18.44% and 12.25%, respectively. Furthermore, Cd had the highest removal, and Zn and Pb were next among the three heavy metals in question.
    Materials and Product Engineering
    Polymeric ionic liquids (PILs) with high acid density: Tunable catalytic performance for biodiesel production
    Xiaocheng Lin, Youjie Huang, Ling Li, Changshen Ye, Jie Chen, Ting Qiu
    2021, 38(10):  266-275.  doi:10.1016/j.cjche.2021.04.006
    Abstract ( 74 )   PDF (11579KB) ( 99 )  
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    A series of polymeric ionic liquids (PILs) used as effective heterogeneous catalysts for biodiesel production via esterification of free fatty acids (FFAs) were effectively prepared by the reaction of poly (ethylene imine) (PEI) polymers with different molecular weight and 1,3-propanesultone, followed by the further acidification with differential effective acids, i.e. H2SO4, CF3SO3H, CH3SO3H or p-toluenesulfonic acid (p-TSA). Ultrahigh acidity and catalytic performance were achieved and could be fine-tuned by simply adjusting the molecular weight of PEI and by further treatment of acids. Specifically, under the optimal conditions (i.e. reaction temperature was 70 ℃, reaction time was 2.0 h, catalyst dosage was 3.15% (mass), and alcohol/acid molar ratio was 14:1) acquired through the Box-BEHNKEN response surface methodology, a high oleic acid conversion of 98.42% could be obtained over the optimal PIL, PEI(70000)-PS-p-TSA. Additionally, our PILs also showed high generality for esterification of other FFAs, with general high conversion over 90% noted in each case even under much milder reaction conditions compared to other conventional catalysts.
    Controllably tailoring external surface sites of nanosheet HZSM-5 for maximizing light olefins in catalytic cracking of n-decane
    Tiantian Zhu, Hairui Liang, Bofeng Zhang, Yajie Tian, Guozhu Liu
    2021, 38(10):  276-285.  doi:10.1016/j.cjche.2021.04.015
    Abstract ( 100 )   PDF (9146KB) ( 113 )  
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    A series of triphenylethoxysilane (TPEOS)-modified nanosheet HZSM-5 catalysts (ZN-x, x = 4%, 8% and 16%, mass) were synthesized by chemical liquid deposition to selectively change external acidity distributions. TPEOS modification was found to passivate some external Brønsted and Lewis acid sites by 37.8%, in which Brønsted acid sites (BAS) were found more easily sacrificed by breaking the surface AlO bond of bridging hydroxyl groups and forming SiOSi bonds. The selectivity of ZN-8 catalyst for light olefins (ethylene, propylene and butene) in n-decane catalytic cracking is up to 26% (450 ℃, WHSV = 10.95 h-1), which is ca. 78% higher than that of parent one. The better performance was attributed to the appropriate external acid density in ZN-8, which inhibits bimolecular hydrogen transfer reaction of light olefins on the adjacent acid sites, resulting in more olefins, few coke precursors and thus an excellent catalytic stability.
    Rational design and synthesis of upconversion luminescence-based optomagnetic multifunctional nanorattles for drug delivery
    Xuhua Liang, Yanyan Zhao, Min Cheng, Fei Zhang
    2021, 38(10):  286-293.  doi:10.1016/j.cjche.2021.05.021
    Abstract ( 116 )   PDF (4574KB) ( 88 )  
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    Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging, disease diagnosis and targeted delivery of drugs. To explore a mesoporous nanostructure with excellent water dispersibility and high drug-loading capacity, a novel nanorattle-structured Fe3O4@SiO2@NaYF4:Yb,Er magnetic upconversion nanorattle (MUCNR) was successfully designed by using Fe3O4 as core and NaYF4:Yb,Er nanocrystals as shell. The microstructures and crystal phase of the as-prepared MUCNRs were evaluated by transmission electron microscopy, X-ray powder diffraction and N2 adsorption/desorption isotherms. The Kirkendall effect was adapted to explain the formation mechanism of the MUCNRs. The loading content and encapsulation efficiency of doxorubicin hydrochloride (DOX) could reach as high as 18.2% and 60.7%, respectively. Moreover, the DOX loading MUCNR (DOX-MUCNR) system showed excellent sustained drug release and strong pH-dependent performance, which was conducive to drug release at the slightly acidic microenvironment of tumor. Microcalorimetry was used to quantify the interactions between the carrier structure and drug release rate directly. The heat release rates in the heat-flow diagrams are basically consistent with the DOX release rate, thereby showing that microcalorimetry assay not only provides a unique thermodynamic explanation for the structure-activity relationship of Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs but also provides powerful guidance to avoid the blind selection or design of drug carriers. Therefore, our work firmly provided a comprehensive perspective for using Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs as a remarkable magnetic targeted drug carrier.