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    List of Articles علی مهاجری


  • Article

    1 - Separation and Quantification of Hydrocarbons of LPG Using Novel MWCNT-Silica Gel Nanocomposite as Packed Column Adsorbent of Gas Chromatography
    Journal of Nanoanalysis , Issue 2 , Year , Winter 2014
    In this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such More
    In this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such as activated carbon and recently carbon nanotube (CNTs), have been widely used for separation of nonpolar materials. Carbon nanotubes are nanosized carbon-based sorbents that have a high surface area and a large aspect ratio and are known to be stable at high temperatures. It is, therefore, conceivable to use of their unique properties in gas chromatography. In this work, a MWCNT-Silica gel nanocomposite was prepared by Sol-Gel process and it was used as stationary phase in gas chromatography for separation of alkanes mixture. In first part, ability of silica gel adsorbent was studied and then results were compared with new MWCNT-Silica gel nanocomposite. Finally, a quantitative investigation was done on a LPG sample and propane, 2-methylpropane, n-butane, 2,2-dimethylpropane, 2-methylbutane and n-pentane were measured by standard addition. Manuscript profile

  • Article

    2 - Optimization of reaction conditions and effect of catalyst type on product distribution in Cyclooctene oxidation
    Journal of Nanoanalysis , Issue 2 , Year , Winter 2016
    Oxidation of cyclooctene was studied in presence aqueous hydrogen peroxide (30%, v/v) over nano iron oxide. The catalyst prepared by microemulsion method and characterized using various techniques including XRD, TEM and BET techniques for evaluating phase, structure and More
    Oxidation of cyclooctene was studied in presence aqueous hydrogen peroxide (30%, v/v) over nano iron oxide. The catalyst prepared by microemulsion method and characterized using various techniques including XRD, TEM and BET techniques for evaluating phase, structure and morphology and surface area. In this study, we investigated the effects of varying the catalyst content, reaction temperature, H2O2 to cyclooctene molar ratio, reaction temperature and solvent. Epoxycyclooctane was found to be the main reaction product, along with amounts of other products. The best result for epoxycyclooctane production is obtained using acetonitril as solvent at 78 oC for a 16 h reaction period with 0.32 g nano-sized iron particle catalyst. The nano-Fe2O3 catalyst has more conversion and yeild than the other iron catalysts in cyclooctene oxidation because of its high surface area and appropriate particle size. Manuscript profile

  • Article

    3 - Separation of Aromatic and Alcoholic Mixtures using Novel MWCNT-Silica Gel Nanocomposite as an Adsorbent in Gas Chromatography
    Journal of Nanoanalysis , Issue 2 , Year , Winter 2014
    The separations of alcohols with hydrophilic and hydrophobic parts, and the separation of aromatic mixtures, are extremely important processes in gas and petroleum industries. Choosing an adsorbent for performing this separation is the most important part of the process More
    The separations of alcohols with hydrophilic and hydrophobic parts, and the separation of aromatic mixtures, are extremely important processes in gas and petroleum industries. Choosing an adsorbent for performing this separation is the most important part of the process. Silica gel is used as an adsorbent is various techniques such as pressure swing adsorption (PSA) and gas and liquid chromatography. Due to the polarity of silica gel, it is used for the separation of polar molecules. Carbon materials such as activated carbon and recently carbon nanotube (CNTs) are widely used for the separation of nonpolar materials. In the course of this study, a new composite was fabricated using sol-gel methods. Multiwall carbon nanotubes (non-polar carbon-based adsorbents with high surface areas) were mixed with a silica gel base (a strong polar adsorbent). The composite was then used in the separation of mixtures of both aromatic hydrocarbons and alcohols. Manuscript profile

  • Article

    4 - Investigation of Products Distribution In Fischer-Tropsch Synthesis By Nano-sized Iron-based Catalyst
    Journal of Nanoanalysis , Issue 4 , Year , Spring 2014
    Nano-sized iron-based catalyst was prepared by the micro-emulsion method. The composition of the final nano-sized iron catalyst, in term of the atomic ratio contains: 100Fe/4Cu/2Ce. Experimental techniques of XRD, BET, TEM and TPR were used to study the phase, structure More
    Nano-sized iron-based catalyst was prepared by the micro-emulsion method. The composition of the final nano-sized iron catalyst, in term of the atomic ratio contains: 100Fe/4Cu/2Ce. Experimental techniques of XRD, BET, TEM and TPR were used to study the phase, structure and morphology of the catalyst. Fischer-Tropsch Synthesis (FTS) reaction test was performed in a fixed bed reactor at pressure of 17 bars, temperature of 270-310°C with H2/CO ratio and GHSV 2 nl.h-1.gCat-1, respectively. The temperature of the system as a key parameter was changed and its effect on the selectivity and reaction rate was analysed. The results show that the rate of both reactions including of FTS and Water-Gas Shift (WGS) are increased by increasing temperature. For this condition, CO conversion also increased up to 89.1%. Manuscript profile

  • Article

    5 - Surface chemistry improvement of carbon nanotube (CNT) supported Fischer–Tropsch nanocatalysts
    Journal of Nanoanalysis , Issue 4 , Year , Spring 2014
    Functionalization of carbon nanotube (CNT) was performed, during preparation of Fischer–Tropsch synthesis (FTS) via cobalt nanocatalysts, to modify the surface properties of CNT support. Common and functionalized CNT supported cobalt nanocatalysts were prepared us More
    Functionalization of carbon nanotube (CNT) was performed, during preparation of Fischer–Tropsch synthesis (FTS) via cobalt nanocatalysts, to modify the surface properties of CNT support. Common and functionalized CNT supported cobalt nanocatalysts were prepared using impregnation wetness method with cobalt loading of 15 wt.%. The catalysts were characterized by Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), temperature program reduction (TPR), H2 chemisorption, and transmission electron microscopy (TEM) technique. Most of the cobalt particles were homogeneously distributed inside the tubes and the rest on the outer surface of the functionalized CNT. Functionalization of CNT shifted the TPR reduction peaks to lower temperatures, improved the reduction degree, and increased the dispersion of cobalt particles and stability of catalysts. The proposed cobalt catalyst supported on functionalized CNT- (N-doped functionalized CNT) increased the FTS rate (g HC/gcat./hr), and CO conversion (%) from 0.1347, and 30 to 0.235, and 47 respectively, compared to that of the catalyst prepared by impregnation wetness method on common CNT. Catalysts supported on functionalized CNT also showed better stability. Manuscript profile