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  • Controlling morphology and catalysis capability of Sn/Ce porous coordination polymers by cerium coordination for catalytic conversion of glucose to 5-hydroxymethylfurfural
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-25
    Siyu Sun; Xingyuan Lu; Xianling Meng; Peijun Ji

    A novel porous coordination polymer (namely SnCe) has been synthesized by simultaneous coordination of Tin (Sn (IV)) and cerium (Ce (III/IV)) with the two ligands 5-sulfoisophthalic acid (SPA) and 1,3,5-benzenetricarboxylic acid (BTC). The morphology and surface area of SnCe can be controlled by the cerium-involved interfacial coordination, by taking advantage of the discrepancy of coordination ability between the two metal ions. The shape and size of the SnCes has a close relationship with the molar ratio of Sn to Ce. The mechanism of the formation of SnCe was investigated by electron microscopy measurement (scanning electron microscope) and XRD patterns. The catalysis capability was also controlled, with Sn (IV) and Ce (III/IV) as the Lewis acid sites and the sulfonate groups of SPA as the Brønsted acid sites. The Lewis acid sites can catalyze isomerization of glucose into fructose, and the Brønsted acid sites can catalyze the dehydration of fructose to 5-hydroxymethylfurfural (HMF) with a high efficiency. Thus, SnCe combines the bifunctional catalysis capability for producing HMF (an important platform chemical) from glucose. This work found that the morphology of catalyst has an effect on the catalyst capability. At the similar reaction conditions, the catalyst exhibits higher conversion and selectivity than those reported.

  • Treatment of simulated chromium-contaminated wastewater using polyethylenimine-modified zero-valent iron nanoparticles
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-21
    Ndumiso Vukile Mdlovu; Kuen-Song Lin; Zong-Wei Chen; Yeu-Jye Liu; Ncobile Bagezile Mdlovu

    The treatment of hexavalent chromium (Cr(VI)) contaminated water is considered the highest priority in the environmental field. Cr(VI) is a known carcinogen and is toxic even at parts per billion levels. In recent years, zero-valent iron nanoparticles (nZVI) have been regarded the best candidate for the decontamination of heavy metals such as chromium (Cr) in contaminated groundwater. Surface modification of nZVI has proven to enhance its stability and mobility in groundwater. In this work, the decontamination of a Cr-contaminant (Cr(VI)) through reductive reaction with polyethylenimine (PEI) coated nZVI (PEI–nZVI) was studied. Characterization was conducted using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and X-ray absorption near edge structure (XANES). The XRD patterns indicated that the nZVI product after Cr-contaminated water treatment corresponds to Fe3O4. Interestingly, the XANES and XPS analyses revealed the reduction of toxic Cr(VI) to less toxic Cr(III) with concurrent oxidization of nZVI to form Fe2O3, Fe3O4, or FeO. A Cr(VI) degradation efficiency of over 99.9% was observed within 10 min for the Cr concentration range 150–300 ppm. Cr(VI) was significantly adsorbed onto the surface of the nZVI nanoparticles; this could represent a cost-effective process for the in-situ remediation of Cr-contaminated groundwater. Owing to its excellent performance for the removal of Cr(VI), the environmentally friendly PEI–nZVI core-shell nanoparticle signifies an effective method for Cr(VI) decontamination.

  • Investigation into an energy-saving mechanism for advanced stripper configurations in post-combustion carbon capture
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-15
    Jialin Liu

    In a standard post-combustion carbon capture (PCC) process, the regeneration energy of CO2 lean solvent constitutes the majority of overall energy consumption. The energy reduction achieved by advanced stripper configurations, such as the cold-split bypass (CSB), interheated (IH) stripper, and lean vapor compression (LVC), have been reported in relevant literature. Energy-saving performance may be enhanced by combining the different modifications. In this study, the energy-saving mechanism for advanced stripper configurations was investigated using a standard amine-based process, in which 30 wt% monoethanolamine (MEA) aqueous solution was applied. Contrary to the literature reviewed, the energy-saving performance attained by combining the different modifications was limited. This was due to the major contribution of energy reduction in the various modifications sharing the similar mechanism. In addition, this study demonstrated that the overall energy required, as needed by the heat recovery in the cross-flow heat exchanger (HX) and the reboiler duty, is dominated by overhead vapor generation. Reducing the amount of vapor generated may effectively relieve the overall energy burden. Thus, when energy reduction is reliant on a HX with a poor heat recovery system, the energy-saving purpose is not fulfilled. Therefore, a successful energy-saving design may significantly reduce the amount of vapor generated, whilst maintaining a reliable heat recovery.

  • The role of nanofiller size and polymer chain configuration on the properties of polypropylene/graphite nanoplates composites
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-14
    Mojtaba Ajorloo; Mohammad Fasihi; Hadi Khoramishad

    This study aimed to evaluate the impacts of different polypropylene (PP) chain configurations, i.e., linear and branched form, on the rheological, mechanical, and electrical properties of PP-based, graphite nanoplates (GnP)-reinforced nanocomposites. The incorporation of GnP with different particle size gave us constructive information about the influences of filler's dimension on the abovementioned properties. A solid-state shear pulverization (SSSP) technique followed by conventional melt mixing was employed to get GnP-filled samples prepared for better filler dispersion. Due to higher interfacial surface area, the obtained mechanical properties from finer GnP were more satisfying. However, the electrical and rheological percolation thresholds (the formation of conductive pathways) took place at a lower content of larger GnP, which is mainly due to its higher aspect ratio compared to GnP. Replacement of linear PP with branched one did not lead to conspicuous alterations in tensile modulus and strength. Based on rheological evaluations, however, the presence of side branches hindered the development of GnP sound network throughout PP matrix, so that in comparison to linear PP-based sample the augmentation of electrical conductivity of branched PP-based composites against filler loading demonstrated slower rates.

  • The effective photocatalytic water splitting to simultaneously produce H2 and H2O2 over Pt loaded K-g-C3N4 catalyst
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-13
    Shaozheng Hu; Xiaolong Sun; Yanfeng Zhao; Wei Li; Hui Wang; Guang Wu

    In this work, for the first time, we prepared Pt loaded K+ doped graphitic carbon nitride (g-C3N4) catalyst for photocatalytic water splitting to produce H2 and H2O2 simultaneously without any sacrificial agent. Both products are high-value chemicals and in gas-liquid two phases, which avoid the trouble of separation. XRD, N2 adsorption, UV–Vis, SEM, TEM, PL, XPS and ESR were used to characterize the as-prepared catalysts. The CB and VB of as-prepared catalysts can be adjusted from -1.29 V and + 1.4 V for g-C3N4 to -0.18 V and + 2.3 V for KCN(8) by controlling the K+ concentration. The reaction result indicates that a moderate band position is significantly important for effective photocatalytic water splitting to simultaneously produce H2 and H2O2. After loading of Pt to promote the electron-hole separation efficiency, Pt-KCN(5) displays the H2 and H2O2 production abilities of 550 μmol·g−1·h−1 and 620 μmol·g−1, simultaneously. This work opens a new window for photocatalytic water splitting research.

  • Near-visible-light-driven noble metal-free of reduced graphene oxide nanosheets over CeO2 nanowires for hydrogen production
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-09
    Fang Liu; Xinhong Wang; Linus Zhang; Kenneth M. Persson; Bor-Yann Chen; Yang Hsu; Chang Tang Chang

    This study is the first to use a newly-developed material via hydrothermal method, cerium oxide nanowires doped with reduced graphene oxide (CNW-RGO) for reductive H2 production. The detailed characteristics of the CNW-RGO materials were investigated to explore the capabilities of reductive production. The mean diameter of the CNWs was uniform at 22 nm. Owing to RGO-doping, the energy gap between the valence and conduction bands tended to become narrower that demonstrated by the density functional theory calculation (DFT). Furthermore, the optimum hydrogen production was 7.14 mmol g−1 by the CNW-RGO with a RGO content of 4 wt.% under the visible-light irradiation. This result was consistent with the turnover frequency (TOF) predictions. The introduction of RGO sheets effectively mediated the transfer of photogenerated electrons from the CNW to the sheets. Therefore, it could act as an electron trap to stimulate charge separation, which was corroborated by X-ray photoelectron spectroscopy (XPS) analysis. As indicated by comparative assessment, methanol was the most promising sacrificial agent in the system. Additionally, the formation of the methoxy group after the reaction was clearly demonstrated by Fourier-transform infrared (FTIR) spectroscopy. The number of hydroxyl groups on the alcohols directly determined their activity in reductive production.

  • Improving pressure durability and fractionation property via reinforced PES loose nanofiltration hollow fiber membranes for textile wastewater treatment
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-08
    Zhiyong Chu; Kaikai Chen; Changfa Xiao; Dawei Ji; Haoyang Ling; Muyang Li; Hailiang Liu

    Loose nanofiltration (NF) hollow fiber membranes with excellent dye rejection and high inorganic salt transmission are promising for textile wastewater treatment. Herein, a novel kind of reinforced PES loose NF hollow fiber membranes with robust twisted fiber bundle was fabricated by a facile dry-wet spinning process. The SEM results indicate that the favorable interfacial bonding layer was formed between the separation and supporting layer for the sake of endowing the membranes with high longitudinal strength and lateral pressure resistance. For one thing, the tensile strength of the PST membranes was up to 185.7 MPa, a considerably higher than FEP hollow fiber membrane prepared by melt spinning process (18.5 MPa). Moreover, the PST-1 membranes show almost no deformation, compared to sever deformation of FEP hollow fiber membrane after 100 h at high pressure operation. For another, the prepared PST membranes display stable pure water flux of 52.3 L·m−2·h−1 under 0.6 MPa. Specifically, the PST membranes exhibit excellent fractionation efficiency of dye/salt mixtures, along with high dye rejection of 99.9% and low salt rejection (<7%). These results indicate that the robust reinforced PES loose NF hollow fiber membranes with permeation stability have great potential application for practical textile wastewater treatment.

  • Dardagan Fruit extract as eco-friendly corrosion inhibitor for mild steel in 1 M HCl: Electrochemical and surface morphological studies
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-08
    A. Sedik; D. Lerari; A. Salci; S. Athmani; K. Bachari; İ.H. Gecibesler; R. Solmaz

    In this study, Dardagan Fruit (DF) from Bingӧl - Turkey was tested as inhibitor corrosion for mild steel protection in 1 M HCl solution using electrochemical techniques. The surface of mild steel was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Elemental composition of the surface after exposing to test solutions was analyzed with the help of energy dispersive X-ray spectroscopy (EDX). Contact angle measurements were also performed to get information about the surface properties. Spectroscopic studies were performed to determine major components, chemical structure and adsorption mechanism of the extract. The excess surface charge of mild steel was determined using electrochemical impedance spectroscopy (EIS) and an inhibition mechanism was proposed. It was found that DF has good corrosion protection ability. The inhibition of corrosion rate reduces when concentration of DF and exposure time are increased and reaches 92% after 1 h and 97% after 6 h immersion to 3000 ppm inhibitor containing corrosive media. The high protection ability was assigned to formation of a homogenously distributed protective film over the metal.

  • Effect of tartaric acid on the adsorption of Pb (Ⅱ) via humin: Kinetics and mechanism
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-07
    Yuping Chen; Zipeng Yang; Qianxin Zhang; Daijun Fu; Ping Chen; Ruobai Li; Haijin Liu; Yalan Wang; Yang Liu; Wenying Lv; Guoguang Liu

    Tartaric acid (TA) is an important component of plant rhizosphere secretion, having a certain influence on the adsorption and desorption behavior of heavy metals in soil. Humin could serve as an environmentally compatible passivator of heavy metal in soil. The aims of this study were to simulate the adsorption of Pb (II) via humin in a soil solution, explore the effects of TA on the adsorption of Pb (II) by humin and elucidate the mechanism of its influence. The results indicated that the adsorption of Pb (II) on the surface of humin within and without TA was consistent with the Langmuir isotherm equation and the pseudo-secondary kinetic model (R2 > 0.99). The effect of TA on adsorption was related to the concentration of TA. With the increasing of TA concentration, the adsorption of Pb (II) by humin showed a peak change and the adsorption amount reached the maximum with 0.5 mmol L−1 humin, is 192.31 mg L−1 with 0.1 mmol TA. Basing on adsorption experiments and characterization of FTIR, SEM, EDX and XPS. It revealed that the oxygenated groups of TA can be combined with humin by hydrogen bonding, in the low concentration TA (less than 0.5 mmol L−1), which is equivalent to an increment of the carboxyl group on the surface of humin, thus adsorption amount was increased. The increasing of the concentration of TA led to an increment of free TA in the solution, which would complex with the lead ions in the solution, and indirectly reduce the amount of Pb(II) adsorption on the humin.

  • Improving the removal efficiency of fine particulate matters in air pollution control devices: Design and performance of an electrostatic aerosol particle agglomerator
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-07
    Wen-Yinn Lin; Ta-Chih Hsiao; Bi-Ling Hong

    Removing submicron particles in the size range from 0.1 to 1.0 µm from gas streams is difficult because they cannot be efficiently captured neither through inertial separation nor by diffusion utilized in air pollution control devices. Electrostatic agglomeration is an effective and practical method for improving the removal efficiency of fine particulate matters. For optimizing the performance of electrostatic agglomerators, in addition to the intensity and frequency of an alternating electric field and the particle residence time, an electrostatic aerosol particle agglomerator was designed and established to experimentally evaluate the influence of particle charges on its performance in this study. The results demonstrate that the performance of the electrostatic aerosol agglomerator can be greatly improved in terms of increasing the particle charges from 9 to 19 (e−/particle). Combined with the low frequency of an AC electric field, the agglomeration efficiency can be further enhanced. The highest agglomeration efficiency of 40.2% is achieved in the submicron size range at AC frequency of 45 Hz. Furthermore, the oscillating distance (cm/Hz) is proposed and estimated for correlating the agglomeration efficiency under various testing conditions. It was found that the agglomeration efficiency can be described by a simple power-law equation using this parameter.

  • Statistical process fault isolation using robust nonnegative garrote
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-03
    Jian-Guo Wang; Xue-Zhi Cai; Yuan Yao; Chunhui Zhao; Bang-Hua Yang; Shi-Wei Ma; Sen Wang

    Fault isolation is an essential procedure in multivariate statistical process monitoring, which is used to locate the detected fault. Fault isolation identifies the crucial variables responsible for the detected fault. Accurate isolation results are useful for process engineers in diagnosing the root cause of the fault. Recent studies have revealed the equivalence between the fault isolation task and the variable selection problem in discriminant analysis. Inspired by this idea, a nonnegative garrote-based fault isolation strategy is developed to identify the criticality of each process variable to the detected fault, which is further revised to a more robust version by adopting a robust nonnegative garrote. The critical variables can be identified even when the historical process data are contaminated by outliers using the method proposed in this study. The Tennessee Eastman process was used to illustrate the validity of the proposed method.

  • Photothermal conversion of graphene/layered manganese oxide 2D/2D composites for room-temperature catalytic purification of gaseous formaldehyde
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-03
    Zhongsen Wang; Huijia Yu; Long Zhang; Limin Guo; Xiaoping Dong

    Manganese oxides (MnOx) are one kind of the most used thermo-catalysts for catalytic oxidation of gaseous organic pollutants, but this process will cause excessive energy consumption. Herein, the photothermal effect of graphene oxide (GO) was utilized to convert the inexpensive solar energy to thermal energy, which subsequently drives the thermo-catalysis of MnOx for degrading gaseous formaldehyde at ambient condition. For achieving high thermal conducting ability, an intimately hybridized 2D/2D composite of GO/MnOx was hydrothermally prepared. Comparing with the GO, the MnOx and the mechanically mixed GO/MnOx, the hydrothermally synthesized composite exhibited significantly improved performance for HCHO removal under the xenon lamp illumination, and the HCHO concentration was rapidly decreased from ∼160 ppm to ∼10 ppm in 20 min. Experimental results using different illumination conditions indicated that the photothermal conversion was mainly from near infrared radiation (NIR). The Mars-van Krevelen mechanism was employed to explain the catalytic process of HCHO removal, where the adsorbed oxygen molecule and lattice oxygen atom were simultaneously activated under irradiation. This work develops an excellent catalyst for effective removal of HCHO, and meanwhile demonstrates that combination of carbonaceous materials with high photothermal conversion capability is a promising strategy to promote the low-temperature catalytic performance of thermo-catalysts.

  • Highly efficient iron based MOFs mediated catalysts for Fischer–Tropsch synthesis: Effect of reduction atmosphere
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2020-01-03
    Mehar U Nisa; Yao Chen; Xin Li; Zhenhua Li

    Catalyst activation is an important and influencing step while determining FTS activity. Taking into account the crucialness of how reduction atmosphere effects the FTS product selectivity, stability, catalytic activity, textural and morphological properties, MOFs mediated Fe-based catalyst ([email protected]) were reduced under five different reduction atmospheres i.e. R-1 (pure CO), R-2 (H2/CO = 1/4), R-3 (H2/CO = 1/2), R-4 (H2/CO = 4) and R-5 (pure hydrogen) and then analyzed under several characterization (SEM, TEM, PXRD, N2 physisorption, Raman and TG) to unravel the facts and investigate the effects behind differently reduced catalysts and how they took part in FTS catalytic reaction. However, three folds higher CO conversion was yielded by purely CO reduced [email protected] catalyst while H2 and syngas reduced catalysts yielded more stable reaction coupled to low activity and very high C5+ selectivity. Moreover, CO pretreatment gave majorly oxide phase (magnetite, Fe3O4), syngas activation yielded large amount of iron carbides (Fe3C) while H2 reduced catalyst produced metallic iron. Thus, a strong relationship between reducing gases and FTS catalytic activity was found.

  • Microwave plasma treated composites of Cu/Cu2O nanoparticles on electrospun poly(N-vinylpyrrolidone) fibers as highly effective photocatalysts for reduction of organic dyes and 4-nitrophenol
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-31
    Saitong Muneekaew; Kai-Cheng Chang; Alfin Kurniawan; Yuki Shirosaki; Meng-Jiy Wang

    Self-standing photocatalytic materials based on transition-metal decorated electrospun fiber mat have attracted considerable attention for photodegradation of toxic refractory organic pollutants in the environment. In this study, poly(N-vinylpyrrolidone)/copper(II) nitrate fibers (Cu/PVP-F) were prepared by electrospinning of PVP/Cu(NO3)2 solution followed by crosslinking using microwave-induced argon plasma (MAP) to produce Cu/Cu2O composites on the surface of fibers. The optimization for the electrospinning fibers was conducted such that the optimized electrospun composite fibers exhibited excellent visible light photocatalytic activity, corresponding to the narrowest band gap energy based on photoluminescence analyses. Moreover, the experimental results showed that the electro-spinning Cu/PVP-F fibers treated with MAP revealed the highest rate of photodegradation efficacy toward methyl orange (MO) and 4-nitrophenol (4- NP), that could be employed in the subsequent photocatalysis cycles with good recovery.

  • Construction of novel 2D/1D g-C3N4/CaTiO3 heterojunction with face-to-face contact for boosting photodegradation of triphenylmethane dyes under simulated sunlight
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-25
    Xin Chen; Xiufang He; Xia Yang; Zhansheng Wu; Yunfeng Li

    Novel binary coupled 2D/1D g-C3N4/CaTiO3 composite photocatalysts with face-to-face contact were synthesized by a solvothermal and calcination method. The properties of g-C3N4/CaTiO3 composites were characterized by XRD, SEM, TEM, BET, UV–vis/DRS, etc. The beneficial band position tuning via coupling g-C3N4 with CaTiO3, and its 2D/1D face-to-face contacted pattern transfer electrons rapidly and retard photogenerated electrons-holes recombination. The photocatalytic ability was evaluated by using crystal violet (CV) and malachite green (MG). The as-prepared g-C3N4/2CTO sample shows the highest photocatalytic activity, and the degradation rate of CV and MG can reach up to 99.76% and 95.02% under simulate sunlight owing to the impressive synergic effect between 2D/1D g-C3N4/CaTiO3 face-to-face contact pattern. The free radical scavenging experiments demonstrate that the ·O2− and h+ are the main active species. Further, the degradation intermediates of CV and MG detected by GC–MS found both containing phenol, 2,2-Methylenebis(6-Tert-Butyl-4-Methylphenol) (MTBM). Hence, they may have a similar degradation pathway, which provided a significant guideline for the degradation of triphenylmethane dyes. Our prepared novel 2D/1D face-to-face contact pattern nanocomposite is expected to be a fresh scheme for high-efficiency refractory pollutants degradation under sunlight.

  • Quality modeling and monitoring for the linear-nonlinear-coexistence process
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-24
    Bo Zhao; Bing Song; Hongbo Shi; Shuai Tan

    Linear and nonlinear relationships may exist simultaneously across process variables and quality variables. If only the linear model is established, the nonlinear structure may be neglected. If only the nonlinear model is constructed, the model accuracy and monitoring performance may be degraded. Thus, the quality monitoring method considering both linear and nonlinear relationships needs to be presented. In this paper, a serial ridge regression (SRR) method is proposed for quality monitoring in the linear-nonlinear-coexistence process. Firstly, linear features are extracted to construct the linear-quality-feature subspace, and the remaining information constitutes the complementary feature subspace. Then, the nonlinear-quality-features are further extracted from the complementary feature subspace via kernel-based strategy. Thereafter, in order to obtain more direct and clear monitoring results, the quality monitoring index is developed based on Bayesian inference. Case studies in a numerical simulation, continuous stirred tank reactor (CSTR) process and TE process demonstrate that the SRR-based method significantly outperforms partial least squares (PLS), ridge regression (RR) and kernel ridge regression (KRR)-based methods, in terms of higher fault detection rates, lower false alarm rates and better fault sensitivity. It helps the operator to detect faults earlier and avoid unnecessary downtime and maintenance.

  • Facilely-fabricated smart hydroxyl-surfaces with rapidly switchable wettability for water and oil: Reversibility between superoleophilicity and near superoleophobicity
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-24
    Ssu-Wei Hu; Vickramjeet Singh; Yu-Jane Sheng; Heng-Kwong Tsao

    Smart surfaces with switchable wettability for both aqueous and non-aqueous drops have aroused much interest because of their potential applications. In this work, a facile approach for the creation of tunable surface wettability on hydroxyl surfaces with rapid switch at ambient temperature is developed. Both surface hydrophobicity and oleophobicity are enhanced after a fluoro-surfactant solution rinse which acts as a stimulus. The reversal of surface wettability can be achieved simply by a rinse of aqueous solution of hexadecyltrimethylammonium bromide. This rapid wettability-switching property may be attributed to surface modification by physisorbed monolayer of fluoro-surfactant. When adopting a simple but effective pretreatment associated with surface roughening and oxidation, an extreme wettability change (between superhydrophilicity and superhydrophobicity) for both water and hexadecane drops can be achieved. This novel route is found to be durable and can be applied to a variety of surface materials including metal, ceramics, and polymer.

  • Surface passivation of zinc ferrite nanorod photoanodes by spray-deposited silicon oxide layer for enhanced solar water splitting
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-24
    Haiqing Ma; Mahadeo A. Mahadik; Sa Rang Kim; Miao Wang; Hyeon Ih Ryu; Hee Suk Chung; Weon Sik Chae; Hyunwoong Park; Jum Suk Jang

    ZnFe2O4 nanorods (NR's) were prepared by a chemical conversion method from β-FeOOH NRs grown on FTO substrates. To activate their photoactivity of ZnFe2O4 NRs for solar water splitting, the surface passivation was achieved with SiO2 layer via facile and effective spray pyrolysis method. The presence of SiO2 layer enhances the photocurrent density of the Pristine ZnFe2O4 from 143 µA/cm2 to 212 µA/cm2 at 1.23 VRHE for 0.25 mM Si–ZnFe2O4, representing two time increment in the photocurrent density. The influences of amount of Si precursor (Tetraethyl orthosilicate) solutions on the physical properties and the passivation effect of SiO2/ZnFe2O4 interfaces were investigated. This improved photoresponse of the Si-treated ZnFe2O4 NRs was attributed to the excellent charge transfer electrode/electrolyte interface. The effectively improved charge transfer properties of the Si-treated ZnFe2O4 NRs were demonstrated by the electrochemical impedance spectroscopy (EIS), Mott–Schottky (MS) and intensity-modulated photocurrent spectroscopy (IMPS) analyses.

  • The role of ultrasound in enzymatic degradation mechanism
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-24
    Sankar Chakma; Pritam Kumar Dikshit; Manju Nagar Galodiya; Ardhendu Sekhar Giri; Vijayanand S. Moholkar

    In this study, an attempt was made to investigate the mechanistic insight to identify the links between enzymatic and sonolysis processes through degradation mechanism. Experimental results revealed that ultrasound and cavitation increase the number of collision in enzymatic process through intense convection in the medium generated by transient cavitation, and enhances degradation efficiency by increasing interaction between enzyme and organic molecules. The formation of pH· radicals in Bisphenol-A degradation is significant and it needs external binding agent such as polyethylene glycol (PEG) to prevent the blocking of reactive sites of enzymes. On the other hand, Ciprofloxacin is susceptible to enzyme, and thus the degradation enhancement is not much significant in sono-enzymatic process. The highest degradation rates at optimum condition of pH 7.0 and 25 °C were 66.52% and 68.41% for Bisphenol-A and Ciprofloxacin, respectively. The antimicrobial activity test and the LCMS results revealed that the intermediates (acetic acid, ethyl alcohol and other products with –OH group) formed during sono-enzymatic reaction are less toxic as compared to that formed in enzymatic process. This essentially means that the enzymatic process initiates the degradation reaction and ultrasound helps towards complete mineralization by degrading the intermediates. To the best of our knowledge, this is the first report on detailed degradation mechanism of Bisphenol-A and Ciprofloxacin using enzymatic and sono-enzymatic processes.

  • Quantitative simultaneous determination of pentoxifylline and paracetamol in drug and biological samples at graphene nanoflakes modified electrode
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-20
    S. Meenakshi; K. Pandian; S.C.B. Gopinath

    Simultaneous voltammetry determination of pentoxifylline (PTX) and paracetamol (PAR) were investigated by using graphene nanoflakes modified glassy carbon electrode (GrNF/GCE) in drug and biological samples. The synthesized flake was characterized using various analytical methods and the electron transfer behavior of GrNF was confirmed by CV and EIS techniques. Electrocatalytic oxidation of PTX and PAR at GrNF/GCE occurred at a potential of +1.220 V and + 0.190 V. The peak to peak separation (900 mV) was obtained for PTX and PAR at GrNF/GCE using DPV method. Amperometry technique was carried out to measure the current response of PTX and PAR and its dynamic ranges from 0.2 × 10−8–300 × 10−6 M (0.9938) and 0.1 × 10−8–150 × 10−6 M (0.9982). The LOD of PTX and PAR were determined to be 0.75 and 0.43 nM (S/N = 3), respectively. This system provides high-level sensitivity in the presence of an excess concentration of easily oxidizable interfering biological molecules and it shows a better reproducibility and repeatability. The present system has been effectively applied for the PTX and PAR determination in real samples.

  • Trifluoroethylene bond enrichment in P(VDF-TrFE) copolymers with enhanced ferroelectric behaviors by plasma fluorination on bottom electrode
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-12
    Jer-Chyi Wang; Yi-Pei Jiang; Yu-Jie Lin; Shun-Hsiang Chan; Ming-Chung Wu

    CF4 plasma treatment on n+-Si wafers as bottom electrodes (BEs) of poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) metal-ferroelectric-metal (MFM) capacitors has been investigated in this study. Prior to the fabrication of MFM capacitors, comprehensive material analyses are administered to identify the incorporation of fluorine atoms into P(VDF-TrFE) copolymers, revealing an enrichment in C2HF3 (trifluoroethylene) bonds and an improvement in the crystallinity of the film. The P(VDF-TrFE) MFM capacitors with CF4-plasma-treated n+-Si wafers show a shallower charge trapping level of 0.154–0.226 eV extracted from the Frenkel–Poole (F–P) emission at 213–273 K for the BE injection compared to that for the top electrode (TE) injection, which is ascribed to the passivation of deep traps by the fluorine atoms that diffused from the n+-Si wafers. Thus, asymmetric remanent polarization and a negative internal bias field are obtained because of the significant increase in the β-phase at the bottom of the P(VDF-TrFE) films. With the CF4 plasma treatment for 1 min, the P(VDF-TrFE) MFM capacitors demonstrate a remanent polarization (2Pr) of 6.58 µC/cm2, a coercive electric field (Ec) of 0.47 MV/cm and stability for more than 3 × 104 cycles with negligible fatigue, making the fluorine-incorporated P(VDF-TrFE) copolymers suitable for future high-performance nonvolatile memory applications.

  • Sol–gel ZnO modified by organic dye molecules for efficient inverted polymer solar cells
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-11
    Chen-Hsueh Lin, Che-Wei Huang, Po-Hsin Wang, Tzung-Fang Guo, Ten-Chin Wen

    ZnO layer was modified with the addition of Cationic dyes including Crystal Violet (CV)/Ethyl violet (EV) in sol–gel process for an electron transport layer in inverted polymer solar cells (PSCs). X-ray photoelectron spectra showed the presence of CV/EV at the top of ZnO surface. Besides, oxygen defect was significantly reduced by CV/EV modification due to the chloride occupation. Furthermore, the amount of CV/EV decreased progressively from ZnO surface to bottom, being evidenced by depth profile. With modification, the ZnO surface became smoother and more hydrophobic to improve the contact with active layer. Meanwhile, CV/EV participated in the crystallization which resulted in the larger ZnO crystal grain size. Interface dipole after modification would slightly reduce the work function of ZnO and the energy barrier between ZnO and active layer via Ultraviolet Photoelectron Spectroscopy and External Quantum Efficiency analysis. Accordingly, inverted PSCs possessed better morphology, better electron extraction ability with ZnO modified by CV and EV respectively, rendering the power conversion efficiency up to 8.80% and 9.06% in comparison to the pristine ZnO (7.59%). In conclusion, we demonstrate a facile way to improve morphological and electrical properties of ZnO layer by simply adding CV/EV in sol–gel ZnO to fabricate high performance PSCs.

  • Synthesis of polymeric ionic liquids mircrospheres/Pd nanoparticles/CeO2 core-shell structure catalyst for catalytic oxidation of benzyl alcohol
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-12-02
    Yangjin Wu, Yiwei Zhang, Xushuai Lv, Chunfeng Mao, Yuming Zhou, Wenting Wu, Hui Zhang, Ziwei Huang

    New catalysts based on polymeric ionic liquids were synthesized and applied into selective oxidation of benzyl alcohol. Polymeric ionic liquid microspheres (PILM) were prepared by radical polymerization, and then the cations in the imidazole ring were exchanged with the metal anions. After that, the metal anions were reduced to Pd nanoparticles that was supported on the surface of PILM. This metal loading method favored the maximum amount of supported Pd nanoparticles that were uniformly distributed on the surface of PILM. In addition, the introduction of CeO2 prevented the aggregation of Pd nanoparticles and finally formed PILM/Pd/CeO2 catalysts with a core-shell structure. The performance of the PILM/Pd/CeO2 catalysts was evaluated by changing the [K2CO3] : [alcohol] molar ratio, reaction temperature and oxygen flow rate in the oxidation reaction of benzyl alcohol. The conversion and selectivity under the optimal reaction conditions reached 48% and 98% respectively The catalysts were effective and reusable after 5 cycles of experiments. In the end, a mechanism underlying the reaction pathway in benzyl alcohol oxidation was put forward.

  • Experimental and numerical study of surfactant solution spontaneous imbibition in shale oil reservoirs
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-27
    Jiawei Tu, James J. Sheng

    Experimental and simulation studies have thus far demonstrated that surfactant-based Enhanced Oil Recovery (EOR) is a feasible method to improve recoveries from initially oil-wet or mixed-wet Unconventional Oil Reservoirs (UORs). The summarized principle is that surfactant triggers spontaneous imbibition by either Interfacial Tension (IFT) reduction or wettability alteration. Several related studies have focused on the effectiveness of different surfactants or their combinations on the final oil recoveries from selected rock/fluid samples. However, the relative significance of each mechanism is not clear yet. In this work, by following both experimental and numerical simulation approach, we attempt to separately investigate the effect of IFT reduction and wettability alteration on the performance of surfactant based EOR in UORs. Further, the relative importance of each function is addressed while determining the dominating mechanism. Both experimental and simulation results showed that achieving a water-wet status is crucial for higher oil recoveries in shale and tight reservoirs. The effects of IFT reduction could be detrimental to the recovery once the wettability is altered to water-wet due to a lower capillary driven force. Therefore, to design a successful surfactant EOR case in UORs, a surfactant must have the capability of altering the wetness to a more water-wet status. Meanwhile, maintaining a relatively high IFT is also significant. Results from this paper will provide a general suggestion on surfactant selection to enhance oil recovery in UORs.

  • Preparation of porous phosphine oxide-incorporated polymer membranes for selective removal of p-cresol from simulated serum: A preliminary study
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-26
    Hung-Ling Yu, Chun-Chieh Fu, Yu-Sheng Hsiao, Chu-Chun Chien, Ruey-Shin Juang

    This preliminary study aims to prepare porous extractant-incorporated membranes (EIMs) containing base polymer cellulose triacetate (CTA), tri-n-octylphosphine oxide (TOPO), and trioctylammonium chloride (Aliquat 336) prepared by non-solvent induced phase inversion for selective removal of p-cresol from simulated serum. The surface morphology and pore structure of the EIMs were investigated using a field emission scanning electron microscope (FE-SEM) and nitrogen sorptiometer, respectively. The functional groups and chemical composition of the EIMs were characterized by the Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectrometry (XPS), respectively. The interactions between uremic toxins (p-cresol, creatinine, and urea) and TOPO or Aliquat 336, studied independently by liquid-liquid extraction, were ascribed to hydrogen bonding. Batch tests showed that the addition of TOPO strongly favored p-cresol adsorption; for example, an adsorption capacity of 2.08 mmol/g of the EIM composed of 54.5 wt% CTA, 27.3 wt% Aliquat 336, and 18.2 wt% TOPO was obtained at 37°C, compared to a negligibly small capacity for creatinine and urea. Cross-flow dynamic experiments revealed that the maximum adsorption of p-cresol in a multi-component serum was 0.75 mmol/g of the EIM under the conditions studied. The high adsorption selectivity for p-cresol may make the prepared EIMs promising and potential for efficient removal of p-cresol from simulated serum.

  • Predictions of undesirable air–sand flow behaviors in a dual fluidized bed cold flow system via a CFD full-loop model
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-23
    Cong-Binh Dinh, Shu-San Hsiau, Chien-Yuan Su, Meng-Yuan Tsai, Yi-Shun Chen, Huy-Bich Nguyen, Hou-Peng Wan

    A two-dimensional computational fluid dynamics (CFD) multiphase flow model based on a laboratory-scale dual fluidized bed cold flow system has been developed to study the unsteady flow characteristics in that system. Different sizes of silica sand as multiple solid phases were simulated to thoroughly describe the actual sand flow, and hence enhance the accuracy of the simulation results. The fluidizing air velocity and sand bed height in the riser were found to have strong influences on the results of solid volume fraction, system pressure, and sand circulation rate. It was noteworthy that when the initial sand height and air inlet velocity in the riser were increased over their critical values, an undesirable reverse flow could occur in the system, causing pressure imbalance and unstable system operation. Therefore, the saturated carrying ability of the fluidizing air should be carefully considered to prevent those unexpected phenomena. The proposed CFD model could provide valuable predictions and insights into the sand flow behaviors for the optimization of the design and operation of practical systems.

  • Green electrospun nanofiber membranes filter prepared from novel biomass thermoplastic copolyester: Morphologies and filtration properties
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-22
    Chia-Jung Cho, Yu-Sheng Chang, Yan-Zhen Lin, Dai-Hua Jiang, Wei-Hung Chen, Wen-Yinn Lin, Chin-Wen Chen, Syang-Peng Rwei, Chi-Ching Kuo

    High-performance and eco-friendly nonwoven-nanofiber filters comprising renewably sourced bio-based polyesters were fabricated by electrospinning (ES). Typical commercial nonwoven filters are thick, with uneven fiber distributions and low recovery. Bio-based polymers made of raw plant materials have soft textures. Over 75% of the polyester used herein was sourced renewable. We observed variations in its morphology under different operating conditions in scanning electron microscope images by tuning the operating parameters of ES and using different DMF/CHCl3 solvent ratios. We produced various types of ES nanofibers with uniform fiber diameters ranging from 400 to 2000 nm, which increased filter efficiency and helped overcome existing shortcomings in filter applications. A scanning mobility particle sizer and NaCl aerosol particles of sizes 30–300 nm were used to test the prepared nanofiber filters. Owing to their high specific surface areas/volume ratios and small-fiber diameters, the nanofiber filters with fiber diameters smaller than 500 nm forcefully resisted the majority of suspended particles. The averaged penetration ability of ES fiber was decreased from 30% to 4%, with increasing heating temperature and annealing time. Thicker ES fibers with beaded morphologies exhibited average penetration <0.8% and lower pressure drop, which enhanced the filter quality and single-fiber efficiency.

  • Production of recombinant human epidermal growth factor in Bacillus subtilis
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-20
    Heng-Hui Su, Jian-Chy Chen, Po-Ting Chen

    Human epidermal growth factor (hEGF) is a crucial factor in wound healing, and therefore has wide applications in the pharmaceutical and cosmetics industries. To improve the production of hEGF protein for the industrial scale, we established an hEGF gene construct for recombinant secretion by Bacillus subtilis. Examination of the secretion abilities of various signal peptides (SPs) revealed six SPs that could effectively guide hEGF secretion from B. subtilis into the culture medium. The highest production level was obtained when the hEGF gene was fused with the xynD SP (lipo type). Two copies of the hEGF expression cassette had the same effect on improving production yield as isopropyl-β-d-1-thiogalactopyranoside (IPTG) induction, and the highest yield of hEGF can reach 360 ± 9.41 mg/L. Moreover, high-purity hEGF was obtained using a His-tagged purification system. Overall, these results demonstrate that B. subtilis is a suitable cell factory for hEGF production with improved yield compared to previous systems.

  • Hollow hydroxyapatite microspheres modified by CdS nanoparticles for efficiently photocatalytic degradation of tetracycline
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-20
    Xiaofang Lei, Tianhong Xu, Weifeng Yao, Qiang Wu, Rongjiang Zou

    A novel CdS nanoparticles/hollow hydroxyapatite microsphere (CdS/HAP) photocatalysts, with excellent photocatalytic performance, was firstly prepared by using a facile hydrothermal method under low temperature. The CdS/HAP composite catalysts were explored by various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), Brunauer Emmett-Teller (BET) and photoelectrochemical measurements. The photocatalytic ability of the as-prepared composite catalysts was investigated by using tetracycline (TC) as a model contaminant. Compared to pure CdS and HAP, the CdS (10 wt.%)/HAP composite exhibited much higher photocatalytic removal efficiency with 90.2% degradation of TC in 30 min, where the best conditions were an initial pH at 5 and catalyst dosage of 0.50 g/L. Moreover, a probable reaction mechanism of CdS/HAP composite was evaluated based on the analysis of electron spin resonance (ESR) and trapping experiments. It was worth pointing out that the CdS nanoparticles can promote the photo-generated charges separation of HAP microspheres, and thus to improve the photocatalytic degradation performance of the catalysts. It can be inferred that the CdS/HAP composite's photocatalytic superiority could be used for applications in the removal of many hazard pollutants.

  • Novel Co1-xS/C-3 supported on N-doped ketjen black as an efficient electrocatalyst for oxygen reduction reaction in alkaline media
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-20
    Zhen Chen, Guangli Li, Yuejun Liu, Pu Shi, Fuzhi Li

    Highly efficient and low-cost catalysts are greatly desirable for oxygen reduction reaction (ORR) in the cathode of metal-air batteries. Herein, a novel Co1-xS/C-3/N-KB catalyst is prepared by a facile process with cheap raw materials. The electrocatalytic performance of Co1-xS/C-3/N-KB for ORR are investigated systematically. As results, Co1-xS/C-3/N-KB exhibits a half-wave potential of 0.72 V and a limiting current density of 6.0 mA·cm−2, comparable to the commercial Pt/C. Moreover, by means of Koutecky–Levich and RRDE techniques, the catalyst is confirmed to catalyze ORR at a four-electron pathway. Besides, chronoamperometric studies indicate a better catalytic stability of Co1-xS/C-3/N-KB than that of Pt/C with the current density retention rates of 93.4% and 88.3%, respectively. In addition, during the accelerated durability test, Co1-xS/C-3/N-KB shows only 11.5 mV negative shift of half-wave potential after 5000 cycles, even better than Pt/C (34.6 mV negative shift). When used as cathode catalyst for primary Al-air battery, the Co1-xS/C-3/N-KB catalyst exhibited excellent discharge voltage and better stability than Pt/C. The excellent ORR catalytic activity and stability of Co1-xS/C-3/N-KB can be due to the synergistic effect between the Co1-xS/C active sites and the N-KB support, which is not only beneficial to oxygen adsorption but also promotes efficient electron transfer, thus facilitating the oxygen reduction process. Besides, the coated/doped carbon and doped nitrogen in Co1-xS/C particles also have certain contribution, enhancing the electronic conductivity and catalytic stability, therefore facilitating the electronic transfer inside Co1-xS/C active particles during the oxygen reduction process.

  • Electrospun Co3O4 nanofiber as an efficient heterogeneous catalyst for activating peroxymonosulfate in water
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-19
    Meng-Chia Li, Shaoping Tong, Jyun-Ting Lin, Kun-Yi Andrew Lin, Yi-Feng Lin

    Even though Co3O4 is the most conventional heterogeneous catalyst for activating peroxymonosulfate (PMS), Co3O4 nanoparticles (NPs) aggregate severely, especially in water, losing their catalytic activities. In the present study, an electrospinning technique is employed to prepare Co3O4 nanofiber (CONF), in which severe aggregation of Co3O4 NPs can be prevented as Co3O4 NPs are specifically configured into fibers, rendering a much higher surface area and porosity than conventional Co3O4 NPs. When decolorization of Acid Red 27 (AR) is employed as a model test for PMS activation, CONF exhibits considerably higher catalytic activities than the commercial Co3O4 NPs for activating PMS to decolorize AR completely in 15 min with a rate constant of 0.210 min−1. The Ea of AR decolorization by CONF-activated PMS is 43.5 kJ/mol, which is also lower than several reported studies. CONF can be also re-used to activate PMS over multiple cycles. AR degradation is confirmed to involve with sulfate radicals via examining effects of radical scavengers and Electron Paramagnetic Resonance analysis. The findings obtained in this study successfully demonstrate that the electrospinning technique can be utilized to prepare nanoscale fibrous Co3O4 with improved physical and chemical properties for catalytic advanced oxidation applications.

  • Fault detection and diagnosis via standardized k nearest neighbor for multimode process
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-18
    Bing Song, Shuai Tan, Hongbo Shi, Bo Zhao

    For the multimode process, the scale information of every single mode never be considered in the distance calculation between the data and its neighbors in k nearest neighbor (kNN). This work proposes a standardized kNN (SkNN) based fault detection method, where a standardized distance is developed to characterize the distance between the data and its neighbors taking the scale information within mode and mode to mode into consideration. In addition, compared with the kNN based fault diagnosis method, the importance of various neighbors is considered through constructing the weights and giving to different neighbors in the SkNN based fault diagnosis method. Moreover, when there is more than one fault variable, in order to eliminate the influence of other fault variables on current reconstructed variable and reduce the computational complexity, concurrent reconstructed strategy and greedy algorithm are used in the SkNN based fault diagnosis method. At last, an industrial case study is employed to prove the effectiveness and advantage of the proposed SkNN based fault detection and diagnosis method.

  • Flower-like visible light driven antifouling membrane with robust regeneration for high efficient oil/water separation
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-15
    Yangyang Chen, Atian Xie, Jiuyun Cui, Jihui Lang, Chunxiang Li, Yongsheng Yan, Jiangdong Dai

    Oily wastewater has increasing in recent decades due to industrial production and domestic wastewater. Conventional techniques for oil/water separation such as adsorption, magnetic and combustion suffer from high cost, low efficiency and low regenerability, especially, a large number of oil droplets are embedded in the inner of the membrane, blocking the hole of the membrane so that the membrane cannot be reused. To solve these problems, we synthesized a flower-like visible light driven antifouling membrane, the resultant membrane manifested excellent superhydrophilicity with WCA was 0° and underwater superoleophobicity with underwater OCA was 158° More importantly, the developed membrane exhibited a favorable separation efficiency of 99.5% to separate a serious of oil/water mixtures. Remarkably, the membrane presented superior antifouling performance which maintained separation efficiency of 99% under visible driven even after 140 oil/water separations cycles. The avant-garde membrane was investigated in the work hope to become a promising candidate for oil/water separation.

  • Recovery of uranium (VI) from aqueous solutions by the polyethyleneimine-functionalized reduced graphene oxide/molybdenum disulfide composition aerogels
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-13
    Dongxuan Guo, Xiumei Song, Lulu Zhang, Weiwen Chen, Daiwei Chu, Lichao Tan

    In this work, we have developed a facile route for the fabrication of polyethyleneimine-functionalized reduced graphene oxide/molybdenum disulfide composition aerogels (PEI-rGO/MoS2 CAs). The as-obtained nanomaterial (PEI-rGO/MoS2 CAs) is characterized by using scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy measurements. The different parameters regulating the adsorption of uranium (VI) such as contact time, pH and temperature are texted. The results show that the adsorption processes of uranium (VI) onto PEI-rGO/MoS2 CAs-3 are spontaneous and endothermic and well follow pseudo-second-order and Langmuir isotherm model. The equilibrium time and maximum adsorption capacity of PEI-rGO/MoS2 CAs-3 are 350 min and 184.53 mg g−1. Therefore, PEI-rGO/MoS2 CAs holds the potential as promising adsorbent for the adsorption of uranium (VI).

  • Determination of how tetracycline influences nitrogen removal performance, community structure, and functional genes of biofilm systems
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-13
    Tingting Li, Cheng Liu, Jie Lu, Gajendra Kumar Gaurav, Wei Chen

    Antibiotic and antibiotic resistance genes (ARGs) have frequently detected in the effluent from wastewater treatment plants. Biological activated carbon (BAC) filter as a tertiary process was used to study the influence of tetracycline (TC) on nitrogen removal efficiency during exposure to tetracycline at different concentrations (0, 0.01, 0.1, 1, 5 mg/L) in an easily separated biofilm (interstitial organism) and inner biofilm (carbon-attached organism). High throughput sequencing and QPCR showed that exposure of 5 mg/L tetracycline increased the denitrifying genes (DNGs) and genera containing denitrification function (e.g., Acidovorax, Flavobacterium, unclassified_f_Comamonadaceae). Moreover, DNGs were mainly located in carbon-attached organisms, while the resistance genes were primarily found in interstitial organisms. The presence of TC stimulated the generation of resistance genes and DNGs, leading to enhanced nitrogen removal. Approximately 90% of the total resistance genes in interstitial organisms and 85% of the TC were effectively removed in the developed biofilm system. Overall, the results indicated that the biofilm system was a good choice for treatment of sewage treatment with a certain amount of TC and control over the contamination of resistance genes.

  • Intensification on drawdown process of floating particles by circle package fractal impellers
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-12
    Deyin Gu, Xiaohui Shi, Zuohua Liu

    The floating particle drawdown and dispersion characteristics in a stirred tank with four pitched-blade impellers, fractal impellers, and circle package fractal impellers were studied using computational fluid dynamics (CFD) simulation. The effects of impeller type, impeller speed, impeller spacing, impeller submergence, initial floating particle concentration, and floating particle diameter on the floating particle dispersion quality were investigated. Results showed that the floating particle dispersion degree was improved with an increment in the impeller speed, in term of axial solid concentration profile, solid concentration distribution, and cloud height. The impeller spacing of T2/3 and impeller submergence of T/6 were appropriate for the floating particle drawdown process in this work. Higher initial floating particle concentration was easier to achieve a higher floating particle dispersion degree. Smaller particle diameter resulted in smaller buoyancy and more uniform distribution. Meanwhile, circle package fractal impeller can reduce the power consumption compared with four pitched-blade impeller and fractal impeller at the same impeller speed, and enhance the solid integrated velocity and the level of homogeneity for floating particle dispersion process under the constant power consumption. In addition, the just drawdown speed (Njd) and correlation equation for Njd in the three different impeller systems were obtained.

  • Robust extended Kalman filter based state estimation for nonlinear dynamic processes with measurements corrupted by gross errors
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-09
    Guiting Hu, Zhengjiang Zhang, Antonios Armaou, Zhengbing Yan

    The quality of on-line measurement data usually cannot meet the demands of practical process monitoring and control due to the influence of measurement noise. Although extended Kalman filter (EKF) is able to improve the quality by reconciling the measurement data to fit the dynamic process model describing nonlinear and Gaussian processes, it rarely considers the presence of different types of gross errors, such as outliers, bias and drift. However, the three types of gross errors often simultaneously appear in dynamic process systems. We propose a robust EKF combined with measurement compensation (MC-REKF) approach, in which a statistical test method is used to detect the abnormal measurement data, where gross error identification is accomplished within a moving window. Subsequently, the magnitudes of gross errors are estimated and used for measurement compensation. Finally, the compensated measurements are updated to re-estimate the accurate states via EKF. The effectiveness of the proposed MC-REKF is demonstrated through a complex nonlinear dynamic chemical process system, namely the free radical polymerization of styrene. With three different types of gross errors, the mean squared error (MSE) of reconciled measurements based on the MC-REKF decreases 37 fold compared to EKF. The magnitude of the residuals between the estimated states and the true states falls below 1.0E−6 when using the MC-REKF. The implementation results imply that the proposed MC-REKF can identify and estimate different types of gross errors and finally decreases their influence on state estimation and measurement reconciliation.

  • Development of a green process for DME production based on the methane tri-reforming
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-08
    M. Farsi, M. Fekri Lari, M.R. Rahimpour

    The main object of this research is CO2 conversion to dimethyl ether (DME) based on the coupling methane tri-reforming and DME synthesis units and investigation the performance of developed process by a detail mathematical model. In the developed process, CH4 and CO2 as low-cost feedstocks are converted to DME as green and economic energy carrier that has a lower environment, infrastructure, and transportation issues compared to CH4. In the proposed process, the syngas produced through methane tri-reforming feeds to the DME reactor without any rigorous separation. To investigate the efficiency of the developed process, the conversion section of plant is modeled based on the mass and energy balance equations considering heat and mass transfer resistances, while the separation unit is simulated by an equilibrium-based model. In the next step, an optimization problem is formulated to calculate the optimal operating conditions of process to achieve maximum DME production considering process limitations. The simulation results show that considering some quench points on the tri-reformer to distribute the feed stream along the reactor increases DME production capacity from 150.9 to 243.5 ton day−1.

  • Investigation of imidazole derivatives as corrosion inhibitors of copper in sulfuric acid: Combination of experimental and theoretical researches
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-07
    Ting Yan, Shengtao Zhang, Li Feng, Yujie Qiang, Lansi Lu, Denglin Fu, Yanan Wen, Jida Chen, Wenpo Li, Bochuan Tan

    Levamisole (LMS) and 4-phenylimidazole (PIZ), used as corrosion inhibitors of copper in sulfuric acid solution were explored by electrochemical tests, morphology analysis and theoretical calculation. At the concentration of 8 mM, the maximum corrosion inhibition efficiencies of LMS and PIZ are 99.03% and 95.84%, respectively. All test data found that LMS had better corrosion inhibition performance than PIZ. LMS is a cathodic corrosion inhibitor, while PIZ belongs to a mixed-type corrosion inhibitor. Electrochemical results indicate that the corrosion inhibition efficiency has the same trend when the concentration of corrosion inhibitor increases. Scanning electron microscope and atomic force microscope were applied to research the surface morphology of copper samples under different conditions. X-ray photoelectron spectroscopy and Langmuir adsorption isotherm model were utilized to explain adsorption means. What is more, Langmuir adsorption isotherm model indicates the coexistence of physisorption and chemisorption for the two inhibitors. Besides, the adsorption between LMS and copper is more prone to chemical adsorption. The mechanism of metallic copper and corrosion inhibitors was explored through quantum chemistry studies and molecular dynamics simulation.

  • Composite NF membranes with anti-bacterial activity prepared by electrostatic self-assembly for dye recycle
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-07
    Zhenfu Gao, Songbai Liu, Zhan Wang, Shaocheng Yu

    Composite nanofiltration (NF) membranes with anti-bacterial activity were prepared by electrostatic self-assembly. A novel composite (Ag+-PEI/ Cu2+-PEI/ Fe3+-PEI) was obtained by the chelate reaction of polyethylenimine (PEI) with metal ion, which constituted the main component of the separation layer of the prepared membrane. Three composite (Ag+-PEI/ Cu2+-PEI/ Fe3+-PEI) NF membranes prepared at optimized condition exhibited excellent permeability (121 L·m−2·h−1·MPa−1/71 L·m−2·h−1·MPa−1/ 73 L·m−2·h−1·MPa−1) and high rejection (96.5%/ 94.5%/ 91.6%) for acid fuchsin as well as low rejection (31.5%/ 27.5%/ 23.7%) for MgSO4. Meanwhile, the higher flux recovery ratio (FRR) of dye was observed for the Fe3+-PEI membrane (FRRFe=91.5%) than that for others ((FRRCu=83.2%) and (FRRAg=76.4%)). Furthermore, these three NF membranes also presented good hydrophilicity (59°/39°/35°), excellent anti-bacterial activity (up to 95% against E. coil and over 90% against S. aureus) and good long-term stability in our trails. These results were of great significance for dye recycle in industrial field.

  • Porous organic polymer derived metal-free carbon composite as an electrocatalyst for CO2 reduction and water splitting
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-06
    Venkatachalam Rajagopal, Murugavel Kathiresan, Perumal Manivel, Vembu Suryanarayanan, David Velayutham, Kuo-Chuan Ho

    A hybrid porous organic polymer (POP) comprising of phenylenediamine, phloroglucinol and triazine was synthesized, carbonized at different temperatures and characterized. Solid state 13C and 15N CP-MAS NMR spectra of the POP showed evidences for the presence of the three moieties in varying composition. Raman analysis of the carbonized samples exhibited varying degrees of graphitization and powder X-ray diffraction (PXRD) analysis showed patterns corresponding to N-doped amorphous carbon. Surface morphological characteristics obtained from SEM and TEM analysis confirm different morphologies with slight variations in the particle size and porosity. Further, the electrocatalytic activities of the prepared metal-free catalysts were evaluated. Sample carbonized at 700°C (PPT-700) showed excellent catalytic activity towards electrocarboxylation of 4-bromoacetophenone in 0.1 M TBABF4/DMF and OER in 1 M KOH as indicated by their onset potential and current density, whereas the sample calcined at 900°C (PPT-900) exhibited excellent HER activity in 1 M H2SO4. The catalytic activity of PPT-700 towards electrocarboxylation and OER activity is ascribed to the presence of pyridinic, pyrrolic and quaternary nitrogen's, whereas the presence of pyridinic and pyrrolic nitrogen's are responsible for the enhanced HER activity of PPT-900 sample as evident from XPS.

  • Cadmium removal from water by enhanced adsorption on iron-embedded granular acicular mullite ceramic network
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-06
    Qiuhong Zhou, Tianyu Long, Jing He, Jinsong Guo, Junmin Gao

    Iron-embedded granular acicular mullite was synthesized and used to remove Cd(II) from water. Characterization of iron-embedded acicular mullite and its adsorption behavior for Cd(II) were studied with the commercial ceramsite as a comparison. Iron oxyhydroxide is successfully embedded into acicular mullite, but mainly hematite loaded on its counterpart. After iron embedment, the specific surface area, iron content and pore volume of acicular mullite vastly increase. The adsorption isothermal fits well by the Langmuir-Freundlich model. Based on the model, the maximum adsorption capacity (Qg) for Cd(II) on iron-embedded mullite is 2.808 mg/g, which is 8 times higher than the virgin acicular mullite and 3 times higher than the commercial ceramsite. Moreover, site energy distribution for Cd(II) adsorbed on iron-embedded mullite and commercial ceramsite were calculated to explore the adsorption mechanisms. The average site energy (µ(E*)) of Cd(II) adsorption on all samples is similar but the energy distribution frequency function F(Em*) for Cd(II) adsorption on iron-embedded acicular mullite was 8 times higher than its counterpart. Consequently, this iron-embedded acicular mullite is efficient for the removal of Cd(II) in water and could be applied as advanced filter media on large scale.

  • The investigation of de-icing and uni-directional droplet driven on a soft liquid-metal chip controlled through electrical current
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-06
    Lei Wang, Shihui Zhan, Peng Qin, Shousheng Tang, Jing Yang, Wenbo Yu, Yongping Hou, Jing Liu

    To realize the functions of de-icing and self-propelling of droplet, one soft and superhydrophobic microfluidic chip (SMC) equipped with the liquid metal was successfully fabricated in this work. After modification via nanostructures and lower surface free energy cover, the SMC surface shows self-cleaning performance. The surface not only could realize self-propelling of droplet at room temperature but also uni-directional de-icing even −30 °C after melting. The results indicate the driving force is induced by the thermal gradient, which is generated by resistance heating of liquid metal (GaIn24.5). This study is significant for extending the applications of microfluidic chip in low temperature condition.

  • Synthesis of a novel magnetic multi-amine decorated resin for the adsorption of tetracycline and copper
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-06
    Wei Wang, Zengyin Zhu, Mancheng Zhang, Shui Wang, Changsheng Qu

    A magnetic multi-amine decorated resin (MmAR-G) was prepared via polymerization, post-crosslinking, and amination reactions for adsorption and coadsorption of tetracycline (TC) and copper (Cu). The results showed that MmAR-G had relatively higher specific surface area, larger pore size, and abundant chelating groups (amino, carbonyl, and hydroxyl groups). Compare with other multi-amine resins, MmAR-G showed maximum uptake for both TC (0.104 mmol/g) and Cu2+ (0.385 mmol/g). The higher specific surface area and protonated amine led to higher TC adsorption capacity. The extra hydroxyl introduced by epoxide-opening reaction when amination, carboxyl, neutral and protonated amines can chelate with Cu2+ and enhance the adsorption, which was demonstrated by the XPS characterization. In the presence of NaCl, the competing adsorption of Cl−decreased the TC adsorption remarkably, and the restrain of the hydrogen bond formation provided more chelation groups and facilitated Cu2+ removal. In binary solutes systems, the formation of Cu-TC complexes decreased TC and Cu2+ adsorption onto MmAR-G by reducing the affinity. Still, the cumulative adsorption amount for TC and Cu2+ onto MmAR-G was highest (0.376 mmol/g). The results showed that MmAR-G was a promising adsorbent for remove and coremove organics and heavy metals in wastewater.

  • Voltammetric sensor based on Pt nanoparticles suported MWCNT for determination of pesticide clomazone in water samples
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-11-02
    Marjan S. Ranđelović, Milan Z. Momčilović, Jelena S. Milićević, Rada D. Đurović-Pejčev, Sajjad S. Mofarah, Charles C. Sorrel

    Novel electrochemical sensor based on Pt supported multiwalled carbon nanotubes is used for determination of pesticide clomazone in aqueous media via differential pulse stripping voltammetry (DPSV). Since clomazone is stable and readily soluble in water, it is often found in water sources. Hence, its determination in the environment is of utmost importance. Herein, clomazone is determined in 0.1 M phosphate buffer solution at pH 7.0 in the concentration range of 0.61–20.56 ng cm−3, with LOQ = 0.61 and LOD = 0.38. These results are in the same range with HPLC/DAD, which is used as comparative method. It is shown that DPSV is a facile and efficient way for determination of clomazone in contrast to precise but field-impractical HPLC. Mechanistic approach in explaining electrode processes is correlated to structural aspects of the synthesized sensor. HRTEM data reveals a uniform distribution of Pt nanoparticles on the MWCNT support as a source of crucial, structural and electronic changes. Furthermore, characterisation of Raman results indicates the existence of structural defects, which is believed to be the leading reason for improvement in sensing response.

  • Effect of Ni–Co morphology on kinetics for Fischer–Tropsch reaction in a fixed-bed reactor
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-31
    Amir Eshraghi, Ali Akbar Mirzaei, Rahbar Rahimi, Hossein Atashi

    In order to investigate the effect of catalyst morphology on the kinetics modeling and mechanism of Fischer–Tropsch Synthesis (FTS), experiments were conducted on single-phase face-centered cubic NiCo2O4 catalysts with different morphologies in a fixed-bed reactor under identical operating conditions. A simple template-free hydrothermal method is presented for the preparation of NiCo2O4 nanowires (NiCo-NWs). In addition, hierarchical NiCo2O4 hollow microspheres (NiCo-HMS) and hierarchical NiCo2O4 microspheres (NiCo-MS) are prepared by hydrothermal method. Characterization of catalysts was carried out using BET, SEM, EDX, XRD and TEM techniques. The findings revealed that CO dissociation is closely dependent on the morphology of catalysts, and proceeds via H-assisted route over NiCo-NWs, but direct CO dissociation route occurs over NiCo-HMS and NiCo-MS. The kinetics models of all three catalysts were able to correctly predict the experimental rate data. The obtained kinetics parameters for FTS catalytic process over NiCo-NWs, NiCo-HMS and NiCo-MS are in good agreement with the literature reports.

  • Fabrication of compressible polyolefin monoliths and their applications
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-31
    Guowei Wang, Jingyuan Niu, Taka-Aki Asoh, Hiroshi Uyama

    In this study, we contribute the facile fabrication of tough polyolefin monoliths from their polymer solutions using a phase separation method. Compressive stress–strain tests demonstrate that the monoliths have excellent mechanical properties. The monoliths show macroporous structures where the pore sizes can be tuned from sub-1 to 16 µm by adjusting the fabrication conditions. The monoliths exhibit high hydrophobicity/ oleophilicity and good resistance toward different chemicals. Based on the above properties, we applied the monoliths to the selective absorption of oil from an oil/water mixture. By simply squeezing the monoliths, the absorbed oil can be recovered. The monoliths are useful for more than 10 cycles of absorption and recovery, showing a good stability for industrial-scale oil spill treatment.

  • Ultrasound assisted green synthesis of silver nanoparticle attached activated carbon for levofloxacin adsorption
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-31
    Şeyda Karadirek, Hikmet Okkay

    The ultrasound assisted green synthesis method was investigated to produce an antibacterial adsorbent for levofloxacin removal from wastewater. The effects of AgNO3/corncob extract ratio, reaction time and US power on synthesis of AgNPs were evaluated. The optimum conditions for the synthesis of silver nanoparticle having the maximum yield were obtained (AgNO3/corncob extract ratio: 1:1 v/v, reaction time: 35 min. US power: 46 W). Silver nanoparticles were synthesized by using corncob extract as reducing agent and deposited to activated carbon under sonication. The specific surface area of silver nanoparticle attached activated carbon increased 33% compared to that of activated carbon due to the pore development effect of ultrasound irradiation. The superior adsorption capacity of silver nanoparticle attached activated carbon can be attributed to its large specific surface area (1842.62 m2/g) and average pore diameter (1.18 nm). The adsorption of levofloxacin to activated carbon or silver nanoparticle attached activated carbon showed the best correlation with Langmuir isotherm and pseudo-second order kinetic model.

  • Superhydrophilic anti-corrosive and superhydrophobic durable TiO2/Ti mesh for oil/water separation
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-29
    Xue Zhou, Sirong Yu, Jun Wang, Jie Zang, Zhexin Lv

    The effective oil/water separation is important in the treatment of oily wastewater. Recently, materials with superwetting have become research hotspots due to their high oil/water separation efficiency and wide application. Here, TiO2/Ti mesh with both superhydrophilicity and superhydrophobicity was successfully fabricated to separate oil/water mixtures. Superhydrophilic TiO2 nanotube film was prepared on Ti mesh by anodic oxidation. The superhydrophilic TiO2/Ti mesh showed good oil/water separation property for various oil/water mixtures. Besides, the superhydrophilic TiO2/Ti mesh exhibited anti-corrosive separation property that had high separation efficiency for oil/strong acid/alkali/salt solution mixtures. After surface modification with lauric acid, the superhydrophilic TiO2/Ti mesh converted to superhydrophobic. The superhydrophobic TiO2/Ti mesh indicated good durability under different conditions that it showed thermal stability under 150°C, anti-icing property at -20°C and mechanical stability under abrasion and bending test. Moreover, the superhydrophobic TiO2/Ti mesh could also separate various oil/water mixtures efficiently.

  • A study on the uniqueness of advancing contact angle for a sessile drop of surfactant solutions
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-29
    Thu Thi Yen Le, Siam Hussain, Shi-Yow Lin

    This study investigated the uniqueness of advancing contact angle (CA) by examining the evaporation process of a sessile drop of surfactant solution [sodium dodecyl sulfate (SDS), hexaethylene glycol monododecyl ether (C12E6) and Triton X-100 (TX-100)] on parafilm. The sessile drop was formed from a pendant drop that had reached its equilibrium surface tension in an atmosphere with ∼100% humidity. The relaxation of the drop profile and wetting diameter were recorded from the moment the drop touched the parafilm, and the data were then analyzed to determine the advancing CA. The results showed that for SDS solution drops, only one advancing CA was observed at each SDS concentration. However, the experimental data of TX-100 and C12E6 solution drops indicated the presence of two distinct regions that showed a near-constant CA with a quasi-equilibrium advance of the triple line; hence matching the definition of an advancing CA. The possibility of the existence of two advancing CA was further explored and the presence of two advancing CA for the sessile drops of TX-100 and C12E6 solution was verified by closely examining the advance of the triple line.

  • Battery-active monoclinic Li2MnSiO4 synthesized via temperature programmed reaction
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-28
    K. Shree Kesavan, M.S. Michael, S.R.S. Prabaharan

    Hitherto, synthesis of a single-phase Li2MnSiO4 has been perceived to be a challenging task owing to the formation energy possessed by different polymorphs is very close. In this context, we report a facile synthesis protocol by optimizing the synthesis conditions such as gas atmosphere, annealing temperature and time to obtain a phase pure crystalline monoclinic phase of Li2MnSiO4 (m-Li2MnSiO4). During the process, to avoid the formation of mixed phases of Li2MnSiO4, the dried precursor substance is subjected to following heat treatment conditions: (1) dried precursor is heated at ambient atmosphere followed by annealing; (2) maintaining a controlled flow of either O2 gas purging adapting a temperature-programmed reaction (TPR). Analysis of X-ray powder patterns reveal that during the process of heat treatment, the controlled purging of O2 is imperative to achieve battery-active monoclinic Li2MnSiO4. Perhaps the formation of m-Li2MnSiO4 occurs during the decomposition of starting material at ∼ 300 °C itself as evident from TGA/DSC analysis further annealing is essential to improve its crystallinity. The controlled flow of O2 purging results in mono dispersion of nanoparticles (TEM analysis) whereas the conventional method of annealing leads to the agglomeration of nanoparticles. Interestingly, m-Li2MnSiO4 product thus obtained exhibit mesoporosity irrespective of synthesis conditions employed. The superior electrochemical performance observed in m-Li2MnSiO4 prepared via temperature-programmed reaction (TPR) is attributed to its higher surface area, high pore volume and mono dispersion of nanoparticles. The degradation of capacity of m-Li2MnSiO4 when the lower voltage is extended to 2.5 V is owing to the formation Mn2O3.

  • Controlled fabrication of the dandelion-like SUZ-4 zeolite with the addition of ethyl acetate
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-26
    Shan Gao, Jindong Shang, Junfang Zhang, Zan Gao

    A beautiful dandelion-like microspheric SUZ-4 zeolite was created by the addition of ethyl acetate and using industrial by-product silica fume (SF) as silica source. The morphology of the SUZ-4 zeolite can be transformed from traditional rod to dandelion-like by adjusting the ethyl acetate dose and the pre-crystallization time of the synthesis gel. The effect of the ethyl acetate on the peculiar morphology formation and the construction mechanism were proposed as follow: Under the influence of ethyl acetate, the template in the system does not work, and the nuclei formed during the pre-crystallization are more liable to assemble in “tip-to-tip” orientation to form spheres, instead of growing on the facet with low density to form dispersed rods without ethyl acetate. On the other hand, the microscopic analyses indicated that, the dandelion-like microspheres are formed by the aggregation of little SUZ-4 crystals, which are not dense, allowing access to their interiors. Hence, the dandelion-like SUZ-4 zeolite displayed much better adsorption ability for methylene blue in water, compared with the rod-like one.

  • Superhydrophobic ceramic hollow fiber membrane planted by ZnO nanorod-array for high-salinity water desalination
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-26
    Tao Wang, Yanbin Yun, Manxiang Wang, Chunli Li, Guicheng Liu, Woochul Yang

    To solve the problems of membrane material tolerance and membrane fouling, a micro/nano hierarchial structure with low surface energy was constructed above the exterior surface of a ceramic hollow fiber membrane using ZnO nanorod arrays and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDTS) coatings, which make it superhydrophobic and self-cleaning. The surface morphology, chemical functional groups, and water contact angel of the modified membranes were identified. The results show that large quantity of ZnO nanorods possess desirable characteristics (i.e. superhydrophobicity, exceptional thermal and mechanical stability, and water contact angle of 160.12°) were detected on the ceramic membrane. The novel membrane shows excellent self-cleaning performance and good desalination ability in the utilization of vacuum membrane distillation (VMD) system for high-salinity water desalination.

  • Fabrication of CdS@1T-MoS2 core-shell nanostructure for enhanced visible-light-driven photocatalytic H2 evolution from water splitting
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-26
    Zhongqin Lian, Yichen Liu, Hong Liu, Hualei Zhou, Zhidong Chang, Wenjun Li

    CdS@1T-MoS2 composites with core-shell structure were synthesized through a hydrothermal treatment followed by a solvothermal treatment. Nanosized CdS particles were coated by a thin 1T-MoS2 shell to form efficient heterojunction, as demonstrated by transmission electron microscopy images and X-ray photoelectron spectroscopy. Under visible-light irradiation, CdS@1T-MoS2 composites with the MoS2/CdS weight ratio of 0.5 exhibit the highest photocatalytic performance and the H2 evolution rate reached 2.67 mmol h−1 g−1, which is 50 times that of single 1T-MoS2 and 10 times that of single CdS. 1T-MoS2, as a cocatalyst, donates the composites fast charge transfer ability and the high H2 evolution activity, while the intimate heterojunction between CdS core and 1T-MoS2 shell greatly increase the separation efficiency of photo-induced electron-hole pairs, as demonstrated by the electrochemical and PL results, resulting in the remarkable photocatalytic performance of the composites. This study supplies a facile and efficient strategy to develop the photocatalysts with boosted performance for hydrogen energy application.

  • Kinetics of ammonia synthesis over Ru/Pr2O3
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-25
    Kazuya Imamura, Shin-ichiro Miyahara, Yukiko Kawano, Katsutoshi Sato, Yuta Nakasaka, Katsutoshi Nagaoka

    We investigated the kinetics of NH3 synthesis over a catalyst consisting of low-crystalline Ru nano-layers supported on Pr2O3. We determined the reaction orders with respect to N2, H2, and NH3 at various temperatures and pressures over Ru/Pr2O3, as well as Ru/CeO2 and Ru/MgO. The reaction orders with respect to N2 were always almost unity for all the catalysts under all the reaction conditions, indicating that the rate-determining step was NN bond cleavage. In contrast, the reaction orders with respect to H2 differed among the catalysts and decreased with increasing pressure and increased with increasing temperature. Under all conditions, the reaction order with respect to H2 was largest over Ru/Pr2O3 and smallest over Ru/MgO, indicating that hydrogen poisoning of the Ru surface was retarded to a greater extent over Ru/Pr2O3 than over Ru/MgO. In agreement with the trends of the H2 reaction orders, the NH3 synthesis rates over Ru/Pr2O3 at 400 °C rose drastically (64 mmol h−1 g−1) as the pressure was increased from 0.1 to 3.0 MPa. Furthermore, decreasing the feed gas H2/N2 ratio at 3.0 MPa effectively increased the NH3 synthesis rate over Ru/Pr2O3, which reached 45 mmol h−1 g−1 at 350 °C at a H2/N2 ratio of 1/0.5.

  • Green production of bioactive components from herbal origins through one-pot oxidation/polymerization reactions and application as a corrosion inhibitor for mild steel in HCl solution
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-24
    Motahhare Keramatinia, Bahram Ramezanzadeh, Mohammad Mahdavian

    Biopolymers such as polydopamine and polyserotonin are effective corrosion inhibitors for the acidic-induced corrosion of steel. Despite the excellent corrosion inhibition activity of these compounds, they are not cost-effective and readily available in a large scale. In this study, for the first time, a cheap and easy methodology was followed for obtaining the modified Nettle extract including the oxidized/dimerized bio-active products such as serotonin and histamine. The Nettle extract (NTE) and oxidized Nettle extract components (ONTE) were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), UV-visible spectroscopy, and thermal gravimetric analysis (TGA). The NTE was oxidized under the alkaline condition at an ambient temperature. Finally, 600 ppm NTE and ONTE were separately added to 1 mol L−1 HCl solution to reduce the steel corrosion rate. The corrosion inhibition activity of the utilized inhibitors was assessed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The surface features were examined by SEM, atomic force microscope (AFM), and water contact angle test. The obtained results displayed that the ONTE inhibitor resulted in the higher inhibition efficiency than the NTE. The maximum inhibition efficiency, i.e. 93.40%, was obtained in the case of the acidic solution inhibited by 600 ppm ONTE after 1.5 h. Results of the polarization test and surface analyses proved the ONTE inhibitor components adsorption on the active metal sites, especially on the anodic areas. In studying of effects of temperature on the corrosion rate of mild steel the positive effect of ONTE on the mild steel corrosion mitigation was noticed. It was shown that the adsorption of the inhibitor on the metal surface obeyed the Langmuir isotherm in both physisorption and chemisorption forms.

  • Synergistic influence of anisotropic 3D carbon nanotube-graphene hybrid mixed matrix membranes on stability and gas permeation characteristics
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-23
    Suchhanda S. Swain, Lakshmi Unnikrishnan, Smita Mohanty, Sanjay K. Nayak

    Long-term gas separation performance and stability are the predominant factors enabling successful implementation of mixed matrix membranes (MMMs) for large-scale industrial applications. This study highlights the integration of CNT and graphene into Polysulfone (PSf) matrix and studied the synergistic effect on the permeation characteristics of O2/N2 pair. An electrical alignment technique has adopted for the preparation of the MMMs by solution casting method. Also, the parent counterparts, including PSf/CNT and PSf/rGO systems have prepared. FTIR, UV, and EDS established the existence of membrane-forming materials. The electron micrographs confirmed uniform dispersion of the filler phase within the PSf matrix, thereby indicating an effectual increase in the permeation characteristics. The hybrid system exhibited improved mechanical and thermal stability against other tested membranes. The prepared membranes showed excellent O2 permeation with higher selectivity for N2, despite the minimal difference in molecular size. The hybrid system rendered uniform permeation coefficient for 120 h; also displayed excellent hydrothermal and chemical stabilities, thus establishing commercial potential.

  • New features of non-linear time-dependent two-level atoms
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-22
    Mehdi Akremi, S.T. Korashy, T.M. El-Shahat, R. Nekhili, Inamuddin, Mohammad Rahimi-Gorji, Ilyas Khan

    In this paper, two-level atoms interacting with a single-mode radiation field alongside important properties are presented. The model presented discusses multi-photon process and it has also a nonlinear Kerr-medium and Stark-shift. In addition, the coupling parameter is discussed in a time-dependent fashion. The results show that Stark-shift, time-dependent coupling parameter, and nonlinear Kerr-medium play significant roles regarding the evolution of the von-Neumann entropy and the system's geometric phases. We've used accessible parameters to examine these observations, and some new results are obtained. Remarkably, the geometric phase shows high sensitivity to any change of the considered parameters.

  • A numerical investigation of the effect of natural gas substitution ratio (NGSR) on the in-cylinder chemical reaction and emissions formation process in natural gas (NG)-diesel dual fuel engine
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-19
    Yongxiang Zhang, Jianqin Fu, Jun Shu, Mingke Xie, Feng Zhou, Jingping Liu, Dongjian Zeng

    In this research, a newly proposed method combining Chemkin with CONVERGE was used to study the transient in-cylinder chemical reaction process in NG-diesel dual fuel engine. The selected mechanism was verified by comparing the results of CONVERGE with experimental data, and then the calibrated model of CONVERGE was used to provide boundary conditions for Chemkin. On this basis, the detailed combustion process was simulated at different natural gas substitution ratio (NGSR). The results show that, the chain branching reaction, long-chain to short-chain reaction, and reactions associated with OH radicals have significant impacts on temperature. It can also be found that the combustion of fuel shows a distinct two-stage reaction process. During the low temperature stage, both the CO and NO emissions are little. While at the high temperature stage, the CO emissions first rapidly increase and then decrease due to the consumption reaction, and the NO emissions also have a quick increase. When the NGSR is reduced, a new path for CO generation occurs at low temperature stage, resulting in minor increase (up to 0.0019 mol fraction) of CO concentration. Meanwhile, the ignition delay is reduced significantly (by 88.5%), but the increase of diesel species does not alter the formation mechanism of emissions. All these provide guidance for improving combustion and emission performance of NG-diesel dual fuel engine.

  • Facile fabrication of hierarchically porous Ni foam@Ag-Ni catalyst for efficient hydrazine oxidation in alkaline medium
    J. Taiwan Inst. Chem. E. (IF 3.834) Pub Date : 2019-10-18
    Yang Lei, Yi Liu, Baoan Fan, Lei Mao, Danqing Yu, Yanfen Huang, Fen Guo

    With the procedure of H2 gas templated electrodeposition and subsequent galvanic replacement reaction, we successfully fabricate the Ni foam@Ag-Ni (Ni foam coated with Ag-Ni bimetals) electrode. Results show the electrodeposition time of 1.5 min produces Ni foam@Ni (Ni foam coated with Ni) with the largest mass specific surface area, and the galvanic replacement time of 8 min yields Ni foam@Ag-Ni with the most favorable catalytic activity toward hydrazine oxidation reaction (HzOR). Materials characterizations reveal the formation of Ag-Ni alloy, the presence of hierarchical pore-structure, the large superficial metallic Ni content and the low amount of Ag mass loading (0.0765 mg cm−2) in Ni foam@Ag-Ni. Electrochemical evaluations show the optimized Ni foam@Ag-Ni electrode delivers the significantly lowest onset potential toward HzOR, with a negative shift of ∼260 mV than Ni foam, ∼220 mV than Ni foam@Ni and ∼60 mV than Ni foam@Ag. Furthermore, it exerts the highest current density in 1.0 mol L–1 KOH and 25 mmol L–1 N2H4, more than 2 fold that of the Ni foam, Ni foam@Ni and Ni foam@Ag at –0.05 V versus Ag/AgCl. The superiority in micro-scale construction and surface composition also endows Ni foam@Ag-Ni electrode with the remarkable durability and considerable whole-cell performance.

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上海纽约大学William Glover