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Table of Content
28 December 2017, Volume 25 Issue 12
    Research progress in the SO2 resistance of the catalysts for selective catalytic reduction of NOx
    Minhua Zhang, Baojuan Huang, Haoxi Jiang, Yifei Chen
    2017, 25(12):  1695-1705.  doi:10.1016/j.cjche.2017.03.030
    Abstract ( 1637 )   PDF (971KB) ( 330 )  
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    The selective catalytic reduction (SCR) of NOx with NH3 has been proven to be an efficient technology for NOx conversion to N2. However, the catalysts used for SCR usually suffer from the problem of sulfur poisoning which seriously limits their practical application. This review summarized sulfur poisoning mechanisms of various SCR deNOx catalysts and strategies to reduce deactivation caused by SO2 such as doping metals, controlling the structures and morphologies of the catalysts, and selecting appropriate supports. The methods and procedures of catalysts preparation and the reaction conditions also have effect on SO2-resistance of the catalysts. Several novel catalyst systems that exhibited good SO2 resistance are also introduced. This paper could provide guidance for the development of highly efficient sulfur-tolerant deNOx catalysts.
    Fluid Dynamics and Transport Phenomena
    CFD simulation of solids residence time distribution in a multi-compartment fluidized bed
    Zheng Zou, Yunlong Zhao, Hu Zhao, Libo Zhang, Zhaohui Xie, Hongzhong Li, Qingshan Zhu
    2017, 25(12):  1706-1713.  doi:10.1016/j.cjche.2017.02.010
    Abstract ( 1373 )   PDF (987KB) ( 43 )  
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    The present work focuses on a numerical investigation of the solids residence time distribution (RTD) and the fluidized structure of a multi-compartment fluidized bed, in which the flow pattern is proved to be close to plug flow by using computational fluid dynamics (CFD) simulations. With the fluidizing gas velocity or the bed outlet height rising, the solids flow out of bed more quickly with a wider spread of residence time and a larger RTD variance (σ2). It is just the heterogeneous fluidized structure that beingmore prominentwith the bed height increasing induces the widely non-uniform RTD. The division of the individual internal circulation into double ones improves the flow pattern to be close to plug flow.
    Influence of nanoparticle concentrations on flow boiling heat transfer coefficients of Al2O3/R141b in micro heat exchanger by direct metal laser sintering
    Jianyang Zhou, Xiaoping Luo, Cong Deng, Mingyu Xie, Lin Zhang, Di Wu, Feng Guo
    2017, 25(12):  1714-1726.  doi:10.1016/j.cjche.2017.05.001
    Abstract ( 1186 )   PDF (1248KB) ( 29 )  
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    Al2O3/R141b+Span-80 nanorefrigerant for 0.05 wt.% to 0.4 wt.% is prepared by ultrasonic vibration to investigate the influence of nanoparticle concentrations on flow boiling heat transfer of Al2O3/R141b+Span-80 in micro heat exchanger by direct metal laser sintering. Experimental results showthat nanoparticle concentrations have significantly impact on heat transfer coefficients by homogeneity test of variances according to mathematical statistics. The heat transfer performance of Al2O3/R141b+Span-80 nanorefrigerant is enhanced after adding nanoparticles in the pure refrigerant R141b. The heat transfer coefficients of 0.05wt.%, 0.1wt.%, 0.2wt.%, 0.3 wt.% and 0.4 wt.% Al2O3/R141b+Span-80 nanorefrigerant respectively increase by 55.0%, 72.0%, 53.0%, 42.3% and 39.9% compared with the pure refrigerant R141b. The particle fluxes from viscosity gradient, non-uniform shear rate and Brownian motion cause particles to migrate in fluid especially in the process of flow boiling. Thismigrationmotion enhances heat transfer between nanoparticles and fluid. Therefore, the heat transfer performance of nanofluid is enhanced. It is important to note that the heat transfer coefficients nonlinearly increase with nanoparticle concentrations increasing. The heat transfer coefficients reach its maximum value at the mass concentration of 0.1% and then it decreases slightly. There exists an optimal mass concentration corresponding to the best heat transfer enhancement. The reason for the above phenomenon is attributed to nanoparticles deposition on the minichannel wall by Scanning Electron Microscopy observation. The channel surface wettability increases during the flow boiling experiment in themass concentration range from 0.2 wt.% to 0.4wt.%. The channel surface with wettability increasing needsmore energy to produce a bubble. Therefore, the heat transfer coefficients decrease with nanoparticle concentrations in the range from 0.2 wt.% to 0.4 wt.%. In addition, a new correlation has been proposed by fitting the experimental data considering the influence ofmass concentrations on the heat transfer performance. The new correlation can effectively predict the heat transfer coefficient.
    Transport properties of dilute ammonia-noble gas mixtures from new intermolecular potential energy functions
    Farshid Zargari, Delara Mohammad-Aghaie, Maryam Lotfi, Masoume Ghorbanipour, Mohammad Mehdi Alavianmehr, Omolbanin Shahraki
    2017, 25(12):  1727-1734.  doi:10.1016/j.cjche.2017.07.007
    Abstract ( 1100 )   PDF (798KB) ( 22 )  
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    Previously we have determined the dilute mixture transport properties of slightly polar fluorocarbons using the inverted intermolecular potential energies (Ind. Eng. Chem. Res. 45 (2006) 9211-9223). In the present paper, the corresponding states correlations for reduced viscosity collision integrals were employed to obtain effective unlike interaction potential models for dilute binarymixtures of highly polar molecule ammonia with noble gases. The inverted potentials were fitted to the Morse-Spline-van der Waals (MSV), model potential. The method of least-squares fitting was then applied to identify best consistence force parameters for each ammonia-noble gas mixture, taking advantage of experimental viscosities, diffusion coefficients and thermal conductivities. The proposed potential modelswere compared with those obtained fromother sources, in order to assess the extent of their validity.
    The potentials were later employed to calculate transport properties of the studied mixtures. Then, results were compared with those reported in the literature, which led to the acceptable agreement.
    Solid-liquid equilibrium of dimethyl terephthalate (DMT), dimethyl isophthalate (DMI) and dimethyl phthalate (DMP) in melt crystallization process
    Chunyuan Wu, Youwei Cheng, Lijun Wang, Xi Li
    2017, 25(12):  1735-1739.  doi:10.1016/j.cjche.2017.03.003
    Abstract ( 1241 )   PDF (730KB) ( 50 )  
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    The binary solid-liquid equilibrium of Dimethyl Terephthalate (DMT), Dimethyl Isophthalate (DMI) and Dimethyl Phthalate (DMP)was investigated by experiment and differential scanning calorimetry (DSC). The result demonstrated DMT/DMI and DMT/DMP systems are eutectic while DMI/DMP is a solid-solution system. The eutectic temperature of DMT/DMI system is 336.7 K and that of DMT/DMP is 271.1 K. Furthermore, a classical solid-liquid phase equilibrium model was used to fit the experimental data of the eutectic systems of DMT/DMI and DMT/ DMP and the theoretical model could describe the eutectic solid-liquid phase diagrams properly.
    Analogy between adsorption and sorption: An elementary mechanistic approach. I. Monolayer adsorption and sorption without solvent cluster formation
    Pierre Schaetzel, Sébastien Thomas, Hasna Louahlia Gualous
    2017, 25(12):  1740-1749.  doi:10.1016/j.cjche.2017.03.002
    Abstract ( 1212 )   PDF (743KB) ( 53 )  
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    The elementary mechanistic model of adsorption and sorption is based on a simple hypothesis: the adsorption sites are uniformly distributed on the surface of the pore walls in the adsorbent, the sorption sites are uniformly distributed in the volume of the polymer. In this first paperwewill analyze the simple casewhere one solute molecule is only allowed to occupy a single adsorption or sorption site. A common elementary occupation law of the free sites is assumed: the differential increase of the number of the adsorbed/sorbed molecules is proportional to the differential increase of the activity of the solute and the concentration of the free (non-occupied) sites in the solid. The proportionality coefficient is called affinity coefficient depending on the solid/solute couple and on the temperature and independent of the concentration of the solute. In adsorption the concentration of the free sites is a surface concentration on the porewalls and in sorption it is expressed by themolarity. The simple monolayer adsorption lawof Jovanovi? is obtained: n=n0(1-e-KP)where n is the number ofmoles adsorbed when the pressure is P. n0 is the total number of adsorption sites and K the affinity coefficient for adsorption. The sorption law writes: a = 1/k [φ/(1-φ)] + (1-r)/k ln[1 + 1/r φ/(1-φ)] where φ, r and k hold respectively for the volume fraction of the solvent in the polymer, for the ratio of the molar volumes of the solvent to the elementary polymer chain containing one single adsorption site and for the sorption affinity coefficient. The confrontation of these equations to experimental isotherms is satisfactory in comparison with the classical Langmuir and Flory-Huggins equations: the best results are obtained for adsorption of vapors on a 5A zeolite and for all analyzed sorption results.
    Permeation properties of CO2 and CH4 in asymmetric polyethersulfone/polyesterurethane and polyethersulfone/polyetherurethane blend membranes
    Shadi Hasanajili, Masoud Latifzadeh, Mahmoud Bahmani
    2017, 25(12):  1750-1759.  doi:10.1016/j.cjche.2017.07.011
    Abstract ( 1425 )   PDF (1324KB) ( 19 )  
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    The transport performances of carbon dioxide and methane were studied in polyethersulfone, polyethersulfone/ polyeterurethane (PES-ETPU) and polyethersulfone/polyestherurethane (PES-ESPU) blend membranes separately with different compositions. The variations in the structural characteristics of PES membrane after incorporation of ESPU and ETPU were investigated by different techniques. Additionally, the effect of pressure and composition on the permeance of CO2, CH4 and ideal selectivity of CO2/CH4 were checked on the membranes. The results revealed that themorphology of the blendmembraneswas affected by two opposite factors: thermodynamic enhancement and kinetic hindrance. The membranes with denser sponge layers were formed at lower ratio of PU/PES,whilemore porous structure with enlarged macrovoids membraneswere observed at higher PU content. The results indicated that adding PU to PES membrane, caused permeance improvement of the gases with nearly no change and/or reduction in ideal selectivity of CO2/CH4.Moreover, PES-ETPU membranes showed higher permeability and less CO2/CH4 selectivity in comparison with PES-ESPU samples. For PES-ESPU membrane containing 1.5% ESPU, CO2 permeance at 10 bar was improved up to 20% with almost no change in CO2/CH4 selectivity with respect to PES. Finally, response surface methodology was used to evaluate the effects of the operating parameters on the permeance and ideal selectivity.
    An efficient green route for hexamethylene-1,6-diisocyanate synthesis by thermal decomposition of hexamethylene-1,6-dicarbamate over Co3O4/ZSM-5 catalyst: An indirect utilization of CO2
    Muhammad Ammar, Yan Cao, Peng He, Liguo Wang, Jiaqiang Chen, Huiquan Li
    2017, 25(12):  1760-1770.  doi:10.1016/j.cjche.2017.03.032
    Abstract ( 1569 )   PDF (1003KB) ( 21 )  
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    The utilization of CO2 as rawmaterial for chemical synthesis has the potential for substantial economic and green benefits. Thermal decomposition of hexamethylene-1,6-dicarbamate (HDC) is a promising approach for indirect utilization of CO2 to produce hexamethylene-1,6-diisocyanate (HDI). In this work, a green route was developed for the synthesis of HDI by thermal decomposition of HDC over Co3O4/ZSM-5 catalyst, using chlorobenzene as lowboiling point solvent. Different metal oxide supported catalysts were prepared by incipientwetness impregnation (IWI), PEG-additive (PEG) and deposition precipitation with ammonia evaporation (DP) methods. Their catalytic performances for the thermal decomposition of HDC were tested. The catalyst screening results showed that Co3O4/ZSM-525 catalysts prepared by different methods showed different performances in the order of Co3O4/ZSM-525(PEG) N Co3O4/ZSM-525(IWI) N Co3O4/ZSM-525(DP). The physicochemical properties of Co3O4/ZSM- 525 catalyst were characterized by XRD, FTIR, N2 adsorption-desorption measurements, NH3-TPD and XPS. The superior catalytic performance of Co3O4/ZSM-525(PEG) catalyst was attributed to its relative surface content of Co3+, surface lattice oxygen content and total acidity. Under the optimized reaction conditions: 6.5% HDC concentration in chlorobenzene, 1 wt% Co3O4/ZSM-525(PEG) catalyst, 250 ℃ temperature, 2.5 h time, 800 ml·min-1 nitrogen flow rate and 1.0 MPa pressure, the HDC conversion and HDI yield could reach 100% and 92.8% respectively. The Co3O4/ZSM-525(PEG) catalyst could be facilely separated from the reaction mixture, and reused without degradation in catalytic performance. Furthermore, a possible reaction mechanism was proposed based on the physicochemical properties of the Co3O4/ZSM-525 catalysts.
    Pt-H2SO4/Zr-montmorillonite: An efficient catalyst for the polymerization of octamethylcy-clotetrasiloxane, polymethylhydrosiloxane and hexamethyldisiloxane to low-hydro silicone oil
    Yuedong Zhou, Fengfu Li, Junwei Liu, Zhi Yun, Xia Gui
    2017, 25(12):  1771-1776.  doi:10.1016/j.cjche.2017.04.004
    Abstract ( 1315 )   PDF (719KB) ( 9 )  
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    The liquid phase ring-opening of octamethylcy-clotetrasiloxane (D4) was investigated over Pt-H2SO4/Zrmontmorillonite catalyst. Montmorillonite (Mt), Zr-Mt, H2SO4/Mt, H2SO4/Zr-Mt and Pt-H2SO4/Zr-Mt were also detected for evaluation. The catalysts were characterized by X-ray fluorescence, X-ray diffraction, nitrogen adsorption-desorption, NH3-TPD and pyridine-FTIR measurements. In comparison to activate clay which is used in the industry of catalyst, Zr-Mt catalyst displayed stronger acidity and more excellent catalytic activity in the polymerization of D4, polymethylhydrosiloxane (D4H) and hexamethyldisiloxane (MM) to low-hydro silicone oil. Relative to Zr-Mt, the acidity of H2SO4/Zr-Mt was noticeably improved and the catalyst exhibited a higher capability of ring-opening of D4 conversion and yield of low-hydro silicone oil. To enhance the stability of H2SO4/Zr-Mt catalyst, a small amount of metals (Pt) was doped. The nitrogen adsorption-desorption results indicated that pore textural parameters of the Pt-H2SO4/Zr-Mt had not changed with larger specific surface area. Compared with H2SO4/Zr-Mt, the total acidity of Pt-H2SO4-Zr/Mt catalyst retained, but the content of the Brønsted acid increased and the content of the Lewis acid decreased. The Pt-H2SO4-Zr/Mt catalyst displayed higher catalyst reproducibility. After 40 h reaction of polymerization, the yield of low-hydro silicone oil decreased from 93% to 42% over H2SO4/Zr-Mt catalyst, while the yield of low-hydro silicone oil reduced from 93% to 78% over Pt-H2SO4/Zr-Mt catalyst. A sharp decrease in catalytic activity after 35 h of Pt-H2SO4/Zr-Mt catalyst was detected. Furthermore, Pt-H2SO4/Zr-Mt was completely regenerated under appropriate condition and appeared good repeatability in the D4, D4H and MM to low-hydro silicone oil.
    Influence of the post-treatment of HZSM-5 zeolite on catalytic performance for alkylation of benzene with methanol
    Qingtao Wang, Wenwen Han, Hualei Hu, Jinghui Lyu, Xiaolong Xu, Qunfeng Zhang, Hongjing Wang, Xiaonian Li
    2017, 25(12):  1777-1783.  doi:10.1016/j.cjche.2017.03.033
    Abstract ( 1302 )   PDF (776KB) ( 38 )  
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    The porousmaterialHZSM-5 zeolite with micro-mesopore hierarchical porosity was prepared by post-treatment (combined alkali treatment and acid leaching) of parent zeolite and its catalytic performance for benzene alkylation with methanol was investigated. The effect of post-treatment on the textural propertieswas characterized by various techniques (including ICP-AES, XRD, nitrogen sorption isotherms, SEM, NH3-TPD, Py-IR and TG). The results indicated that the post-treatment could modify the structural and acidic properties of HZSM-5 zeolite. In this procedure, not only additional mesopores were created by selective extraction of silicon but also the acidity was tuned. Consequently, themodified HZSM-5 zeolite showed larger external surface areawith less acid sites as compared to the parent zeolite. Itwas found out that themodified zeolite exhibited a higher benzene conversion and xylene selectivity for alkylation of benzene with methanol as well as excellent life span of the catalyst than conventional ones. This can be explained by the facts that the presence of additional mesopores improved the diffusion property in the reactions. Furthermore, the modified zeolite showed an appropriate Brønsted acidity for effective suppression of the side reaction of methanol to olefins, thus reduced the accumulation of coke on the HZSM-5 zeolite,whichwas favorable for the catalyst stability. In comparison with the parent HZSM-5 zeolite, themodified zeolite by alkali treatment and acid leaching showed better performance for the benzene alkylation with methanol.
    Preparation of Ni2P/Al-SBA-15 catalyst and its performance for benzofuran hydrodeoxygenation
    Tianhan Zhu, Hua Song, Xueya Dai, Hualin Song
    2017, 25(12):  1784-1790.  doi:10.1016/j.cjche.2017.03.027
    Abstract ( 1159 )   PDF (879KB) ( 16 )  
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    The Al-doped Ni2P/Al-SBA-15 catalyst with high hydrodeoxygenation (HDO) activity was synthesized by temperature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), NH3 temperature programmed desorption (NH3-TPD), N2 adsorption-desorption and CO uptake. The effect of Al on benzofuran (BF) HDO performance was investigated. The result indicates that the incorporation of Al into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed Ni2P particles on the catalyst. The Al also contributes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of Al can enhance the acid strength. The total deoxygenated product yield over Ni2P/Al-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 (70.9%).
    A data-derived soft-sensor method for monitoring effluent total phosphorus
    Shuguang Zhu, Honggui Han, Min Guo, Junfei Qiao
    2017, 25(12):  1791-1797.  doi:10.1016/j.cjche.2017.06.008
    Abstract ( 1528 )   PDF (630KB) ( 25 )  
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    The effluent total phosphorus (ETP) is an important parameter to evaluate the performance of wastewater treatment process (WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to obtain the reliable values of ETP online. First, a partial least square (PLS) method is introduced to select the related secondary variables of ETP based on the experimental data. Second, a radial basis function neural network (RBFNN) is developed to identify the relationship between the related secondary variables and ETP. This RBFNN easily optimizes the model parameters to improve the generalization ability of the soft-sensor. Finally, a monitoring system, based on the above PLS and RBFNN, named PLS-RBFNN-based soft-sensor system, is developed and tested in a real WWTP. Experimental results show that the proposed monitoring system can obtain the values of ETP online and own better predicting performance than some existing methods.
    MPC of distillation column with side reactors for methyl acetate
    Cuimei Bo, Jun Li, Lei Yang, Hui Yi, Jihai Tang, Xu Qiao
    2017, 25(12):  1798-1804.  doi:10.1016/j.cjche.2017.08.012
    Abstract ( 1575 )   PDF (659KB) ( 45 )  
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    This paper focuses on the dynamic control of distillation columnwith side reactors (SRC) formethyl acetate production. To obtain the optimumintegrated structure and steady state simulation, the systematic design approach based on the concept of independent reaction amount is applied to the process of SRC formethyl acetate production. In addition to the basic control loops, multi-variable model predictive control modular with methyl acetate concentration and temperature of sensitive plate is designed. Then, based on process simulation software Aspen Plus, dynamic simulation of SRC for methyl acetate production is used to verify the effectiveness of the control scheme.
    An on-line constraint softening strategy to guarantee the feasibility of dynamic controller in double-layered MPC
    Hongguang Pan, Weimin Zhong, Zaiying Wang
    2017, 25(12):  1805-1811.  doi:10.1016/j.cjche.2017.06.010
    Abstract ( 1022 )   PDF (830KB) ( 18 )  
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    A double-layered model predictive control (MPC), which is composed of a steady-state target calculation (SSTC) layer and a dynamic control layer, is a prevailing hierarchical structure in industrial process control. Based on the reason analysis of the dynamic controller infeasibility, an on-line constraints softening strategy is given. At first, a series of regions of attraction (ROA) of the dynamic controller is calculated according to the softened constraints; then a minimal ROA containing the current state is chosen and the corresponding softened constraint is adopted by the dynamic controller. Note that, the above measures are performed on-line because the centers of the above ROA are the steady-state targets calculated at each instant. The effectiveness of the presented strategy is illustrated through two examples.
    Research on fault detection method for heat pump air conditioning system under cold weather
    Liangliang Sun, Jianghua Wu, Haiqi Jia, Xuebin Liu
    2017, 25(12):  1812-1819.  doi:10.1016/j.cjche.2017.06.009
    Abstract ( 943 )   PDF (819KB) ( 25 )  
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    Building energy consumption accounts for nearly 40% of global energy consumption, HVAC (Heating, Ventilating, and Air Conditioning) systems are the major building energy consumers, and as one type of HVAC systems, the heat pump air conditioning system, which is more energy-efficient compared to the traditional air conditioning system, is being more widely used to save energy. However, in northern China, extreme climatic conditions increase the cooling and heating load of the heat pump air conditioning system and accelerate the aging of the equipment, and the sensor may detect drifted parameters owing to climate change. This non-linear drifted parameter increases the false alarm rate of the fault detection and the need for unnecessary troubleshooting. In order to overcome the impact of the device aging and the drifted parameter, a Kalman filter and SPC (statistical process control) fault detection method are introduced in this paper. In thismethod, themodel parameter and its standard variance can be estimated by Kalman filter based on the gray model and the real-time data of the air conditioning system. Further, by using SPC to construct the dynamic control limits, false alarm rate is reduced. And this paper mainly focuses on the cold machine failure in the component failure and its soft fault detection. This approach has been tested on a simulation model of the “Sino-German Energy Conservation Demonstration Center” building heat pump air-conditioning system in Shenyang, China, and the results show that the Kalman filter and SPC fault detection method is simple and highly efficient with a low false alarm rate, and it can deal with the difficulties caused by the extreme environment and the non-linear influence of the parameters, and what's more, it provides a good foundation for dynamic fault diagnosis and fault prediction analysis.
    Experimental and modeling investigation of dynamic interfacial tension of asphaltenic-acidic crude oil/aqueous phase containing different ions
    Mostafa Lashkarbolooki, Shahab Ayatollahi
    2017, 25(12):  1820-1830.  doi:10.1016/j.cjche.2017.02.004
    Abstract ( 1003 )   PDF (946KB) ( 56 )  
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    In this way, after experimentalmeasurement of interfacial tension, different models includingmono-exponential decay, dynamic adsorptionmodels and empirical equation are used to correlate this time-dependent behavior of interfacial tension (IFT). During the modeling approach, the induction, adsorption, equilibrium, and mesoequilibrium times as well as diffusivity of surface active components known as natural surfactant including asphaltene and resin from crude oil to the interface are obtained. In addition, the surface excess concentration of surface active components at the interface and Gibbs adsorption isothermare utilized to analyze the measured dynamic IFTs. Finally, the mechanisms of crude oil/aqueous solution IFT including (a) the activity of surfaceactive components and (b) surface excess concentration of them at fluid/fluid interface are proposed and discussed in details.
    A strong adhesive block polymer coating for antifouling of large molecular weight protein
    Xianling Meng, Xia Jiang, Peijun Ji
    2017, 25(12):  1831-1837.  doi:10.1016/j.cjche.2017.04.007
    Abstract ( 1256 )   PDF (798KB) ( 26 )  
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    Some proteins secreted by microorganisms have large molecularweights.Wereport here an approach to prepare coating by multilayer polymers for antifouling of proteins, especially the proteins with a large molecular weight. Stainless steel was used as the model substrate. The substrate was first coatedwith a hybrid polymer film, which was formed by simultaneous hydrolytic polycondensation of 3-aminopropyltriethoxysilane and polymerization of dopamine (HPAPD). After grafting the macroinitiator 2-bromoisobutyryl bromide, the block polymer brushes PMMA-b-PHEMA were grafted. Three proteins were used to test protein adsorption and antifouling behavior of the coating, including recombinant green fluorescent (54 kDa), recombinant R-transaminase (2×90 kDa), and recombinant catalase (4×98 kDa). It is demonstrated that the block polymer brushes not only can prevent the adsorption of small molecular weight proteins, but also can significantly reduce the adsorption of the large molecular weight proteins.
    Combination of a crude oil-degrading bacterial consortium under the guidance of strain tolerance and a pilot-scale degradation test
    Yilin Liu, Chen Li, Lei Huang, Yun He, Tingting Zhao, Bo Han, Xiaoqiang Jia
    2017, 25(12):  1838-1846.  doi:10.1016/j.cjche.2017.02.001
    Abstract ( 1283 )   PDF (860KB) ( 39 )  
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    Under the guidance of strain tolerance, a new combinationmethod for crude oil-degrading bacterial consortium was studied. Firstly,more than 50 efficient crude oil-degrading and biosurfactant producing bacteriawere isolated from petroleum-contaminated soil andwater in Tianjin Binhai New Area Oilfield, China. Twenty-four of them were selected for further study. These strains were identified as belonging Pseudomonas aeruginosa, Bacillus subtilis, Brevibacillus brevis, Achromobacter sp., Acinetobacter venetianus, Lysinibacillus macroides, Klebsiella oxytoca, Stenotrophomonas rhizophila, Rhodococcus sp. and Bacillus thuringiensis. A shake-flask degradation test revealed that 12 of these strains could degrade over 50% of 1% crude oil concentration in 7 d. Of these, 8 strains were able to produce biosurfactants. Furthermore, environmental tolerance experiments indicated that the majority of the strains had the ability to adapt to extreme environments including high temperatures, alkaline environments and high salinity environments. A mixed bacterial agent comprising the strains WB2, W2, W3 and HA was developed based on the environmental tolerance tests and subjected to the pilot-scale degradation test indicating that this bacterial agent could degrade 85.2% of 0.8% crude oil concentration in 60 d. Our results suggest that the application of this mixed agent could remediate crude oil polluted soils in saline and alkaline environments.
    Simultaneously energy production and dairy wastewater treatment using bioelectrochemical cells: In different environmental and hydrodynamic modes
    Masoud Hasany, Soheila Yaghmaei, Mohammad Mahdi Mardanpour, Zahra Ghasemi Naraghi
    2017, 25(12):  1847-1855.  doi:10.1016/j.cjche.2017.08.003
    Abstract ( 1321 )   PDF (890KB) ( 64 )  
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    A successful design, previously adapted for treatment of complex wastewaters in a microbial fuel cell (MFC), was used to fabricate two MFCs, with a few changes for cost reduction and ease of construction. Performance and electrochemical characteristics of MFCs were evaluated in different environmental conditions (in complete darkness and presence of light), and different flow patterns of batch and continuous in four hydraulic retention times from 8 to 30 h. Changes in chemical oxygen demand, and nitrate and phosphate concentrations were evaluated. In contrast to the microbial fuel cell operated in darkness (D-MFC) with a stable open circuit voltage of 700 mV, presence of light led to growth of other species, and consecutively low and unsteady open circuit voltage. Although the performance of theMFC subjected to light (L-MFC)was quite lowand unsteady in dynamic state (internal resistance = 100 Ω, power density = 5.15 W·m-3), it reached power density of 9.2 W·m-3 which was close to performance of D-MFC (internal resistance = 50 Ω, power density = 10.3 W·m-3). Evaluated only for D-MFC, the coulombic efficiency observed in batch mode (30%) was quite higher than the maximum acquired in continuous mode (9.6%) even at the highest hydraulic retention time. In this study, changes in phosphate and different types of nitrogen existing in dairy wastewater were investigated for the first time. At hydraulic retention time of 8 h, the orthophosphate concentration in effluent was 84% higher compared to influent. Total nitrogen and total Kjeldahl nitrogen were reduced 70% and 99% respectively at hydraulic retention time of 30 h, while nitrate and nitrite concentrations increased. The microbial electrolysis cell (MEC), revamped from D-MFC, showed the maximum gas production of 0.2 m3 H2·m-3·d-1 at 700 mV applied voltage.
    Modified molecular matrix model for predicting molecular composition of naphtha
    Kun Wang, Shiyu Li
    2017, 25(12):  1856-1862.  doi:10.1016/j.cjche.2017.01.008
    Abstract ( 987 )   PDF (714KB) ( 51 )  
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    To improve the naphtha composition prediction model based on molecular type homologous series matrix (MTHS), this paper puts forward a novelmolecular matrix to characterize the naphtha composition and the normal distribution hypothesis to better describe the molecular composition distribution within each homologous series of the molecular matrix. Through prediction calculation of eight groups of naphtha samples and eight groups of gasoline samples, it is verified that the normal distribution hypothesis is more applicable than gamma distribution hypothesis for the prediction model. According to the prediction results of the samples, the restrain range of normal distribution parameters during model computing process is summarized. With the bulk properties of naphtha samples and the value range of distribution parameters as input conditions, this study utilizes the improved novelmolecular matrix to predict the composition of naphtha samples. As the results show, the novel molecular matrix can predict more detailed composition information of naphtha and improve prediction accuracy with less unknown parameters.
    Catalytic behavior in propane aromatization using GA-MFI catalyst
    Alfredo Aloise, Enrico Catizzone, Massimo Migliori, Jànos B. Nagy, Girolamo Giordano
    2017, 25(12):  1863-1870.  doi:10.1016/j.cjche.2017.04.016
    Abstract ( 1223 )   PDF (829KB) ( 32 )  
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    Ga-Al-MFI samples were synthesized in hydrothermal conditions from gels of composition 1.08CH3NH2- 0.134TPABr-1SiO2-xAl2O3-yGa2O3-40H2O at 175 ℃ for 7 days, with x = 0.005 and 0.0025, y = 0.005, 0.010 and 0.020. The samples were characterized by XRD, BET measurements, thermal analysis (TGA-DTA) atomic absorption and high resolution solid state MAS 27Al and 71Ga NMRmeasurements. The aromatization of propane was studied as catalytic test. The activity and selectivity of the catalysts were determined for benzene, toluene and xylenes on the one hand and for methane and ethane on the other hand. The most active sample was obtained with the highest Ga/Al ratio. For this sample, the BTX selectivity obtained by aromatizationwas always higher than the hydrocracking selectivity leading tomethane and ethane. The relative amount of toluenewas higher than that of benzene and of xylenes. The samples were deactivated by coke formation thatwas revealedmore severe for the most active sample.
    Catalytic performance of hybrid Pt@ZnO NRs on carbon fibers for methanol electro-oxidation
    Dongyan Li, Chen Gu, Feng Han, Zhaoxiang Zhong, Weihong Xing
    2017, 25(12):  1871-1876.  doi:10.1016/j.cjche.2017.08.013
    Abstract ( 1328 )   PDF (870KB) ( 43 )  
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    A novel Pt@ZnO nanorod/carbon fiber (NR/CF) with hierarchical structure was prepared by atomic layer deposition combined with hydrothermal synthesis and magnetron sputtering (MS). The morphology of Pt changes from nanoparticle to nanorod bundle with controlled thickness of Pt between 10 and 50 nm. Significantly, with the increase of voltage from 0 to 0.6 V (vs. standard calomel electrode), the prompt photocurrent generated on ZnO NR/CF increases from 0.235 to 0.725 mA. Besides, the Pt@ZnO NR/CF exhibited higher electrochemical active surface area (ECSA) value, better methanol oxidation ability and CO tolerance than Pt@CF, which demonstrated the importance of the multifunctional ZnO support. As the thickness of Pt increasing from 10 to 50 nm, the ECSA values were improved proportionally, leading to the improvement of methanol oxidation ability. More importantly, UV radiation increased the density of peak current of Pt@ZnO NR/CF towards methanol oxidation by additional 42.4%, which may be due to the synergy catalysis of UV light and electricity.
    Viscosity of aqueous ionic liquids analogues as a function of water content and temperature
    Farouq S. Mjalli, Hasan Mousa
    2017, 25(12):  1877-1883.  doi:10.1016/j.cjche.2017.09.008
    Abstract ( 1448 )   PDF (715KB) ( 32 )  
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    Ionic liquids analogues known as Deep Eutectic Solvents (DESs) are gaining a surge of interest by the scientific community, and many applications involving DESs have been realized.Moisture content is one of the important factors that affects the physical and chemical characteristics of these fluids. In this work, the effect of mixing water with three common type Ⅲ DESs on their viscosity was investigated within the water mol fraction range of (0-1) and at the temperature range (298.15-353.15 K). Similar trends of viscosity variation with respect to molar composition and temperature were observed for the three studied systems. Due to the asymmetric geometry of the constituting molecules in these fluids, their viscosity could not be modeled effectively by the conventional Grunberg and Nissan model, and the Fang-He model was used to address this issue with excellent performance. All studied aqueous DES mixtures showed negative deviation in viscosity as compared to ideal mixtures. The degree of intermolecular interactions with water reaches a maximum at a composition of 30% aqueous DES solution. Reline, the most studied DES in the literature, showed the highest deviation. The information presented in thiswork on the viscosity of aqueous DES solutionsmay serve in tuning this important property for diverse industrial applications involving these novel fluids in fluid flow, chemical reactions, liquid-liquid separation and many more.