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    Kinetic Study on a Commercial Amorphous Hydrocracking Catalyst by Weighted Lumping Strategy

    Sadighi, Sepehr, Ahmad, Arshad, Irandoukht, Akbar
    International Journal of Chemical Reactor Engineering, 2010, Vol.8(1) [Peer Reviewed Journal]
    Walter de Gruyter GmbH
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    Title: Kinetic Study on a Commercial Amorphous Hydrocracking Catalyst by Weighted Lumping Strategy
    Author: Sadighi, Sepehr; Ahmad, Arshad; Irandoukht, Akbar
    Publisher: De Gruyter
    Subject: Hydrocracking ; Vacuum Gas Oil ; Lump Kinetic Model ; Amorphous
    Description: Hydrocracking is an important upgrading process in the petroleum refinery, and it is generally used to process feedstocks ranging from vacuum gas oil (VGO) to vacuum residue. In this work, hydrocracking of VGO using a dual functional amorphous catalyst was carried out at a pilot scale unit under the following reaction conditions: liquid hourly space velocity (LHSV) from 1 to 1.5 hr-1 and reaction temperatures of 360-440°C at the constant pressure and hydrogen to oil, 156 bar and 1780 Nm3/m3, respectively. The effluent of the reactor was characterized to dry gas, naphtha, kerosene, diesel and unconverted VGO or residue. The pilot tests demonstrated that performing experiments beyond the temperature, recommended by catalyst vendor, lead the process to unstable hydrocracking. To describe the yield of hydrocracking products a five-lump discrete lumping approach with ten reactions was proposed. At first, the kinetic model contained twenty kinetic constants which were estimated by using the conventional objective function. The estimated parameters showed that the tendency of the catalyst to convert VGO to gas and naphtha was negligible whilst rate constants for hydrocracking of VGO to middle distillates were considerably high which was compatible with the nature of amorphous hydrocracking catalysts. After evaluating the magnitude of reaction rates and eliminating the ignorable constants, the network was reduced to six reactions in which only nine parameters were needed. The predictions indicated that the latter network could fit the yield of products more acceptable as if the average absolute deviation between experimental and calculated yields was descended from 16.25% to 12.6%. Then, to have a better prediction, a weighted objective function was used in which weight factors were calculated by a proposed weighted least square expression. The results confirmed that this approach could reduce average absolute deviation of model to 10.75%, and it created a fairly even distribution of deviation between hydrocracking products.
    Is part of: International Journal of Chemical Reactor Engineering, 2010, Vol.8(1)
    Identifier: 1542-6580 (E-ISSN); 10.2202/1542-6580.2193 (DOI)

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    The effect of molybdenum on the characteristics and catalytic properties of M/Cs 1.5 H 1.5 PW 12 O 40 /Al 2 O 3 (M = Ni or/and Mo) nanocatalysts in the hydrocracking of n -decane

    Amirmoghadam, Hoda, Sadr, Moayad, Aghabozorg, Hamidreza, Salehirad, Fathoallah, Irandoukht, Akbar
    Reaction Kinetics, Mechanisms and Catalysis, 2018, Vol.125(2), pp.983-994 [Peer Reviewed Journal]
    Springer Science & Business Media B.V.
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    Title: The effect of molybdenum on the characteristics and catalytic properties of M/Cs 1.5 H 1.5 PW 12 O 40 /Al 2 O 3 (M = Ni or/and Mo) nanocatalysts in the hydrocracking of n -decane
    Author: Amirmoghadam, Hoda; Sadr, Moayad; Aghabozorg, Hamidreza; Salehirad, Fathoallah; Irandoukht, Akbar
    Subject: Heteropoly acid ; Molybdenum ; Nanocatalyst ; Hydrocracking ; Nickel ; Alumina
    Description: In this research, M/Cs 1.5 H 1.5 PW/Al 2 O 3 (M = Ni or/and Mo) nanocatalysts were prepared via 2 steps with the impregnation method and the effect of molybdenum on the characteristic and catalytic properties of the prepared samples was studied. The synthesized samples were characterized by X-ray diffraction (XRD), temperature programmed reduction, temperature programmed desorption (TPD), and energy dispersive X-ray spectroscopy techniques. Morphology of the samples was studied by field emission scanning electron microscope (FESEM) and surface area, pore volume and pore size of the compounds were measured by BET method. In the XRD patterns of the prepared catalysts, the H 3 PW 12 O 40 phase was observed. The FESEM images showed that the synthesized particles were in nanoscale. The results of TPD studies indicated that the total acid site of Ni–Mo/Cs 1.5 H 1.5 PW/Al 2 O 3 catalyst was more than the others. The catalytic activity of the nanocatalysts in hydrocracking of n -decane indicated that Ni–Mo/Cs 1.5 H 1.5 PW/Al 2 O 3 nanocatalyst had the highest catalytic activity.
    Is part of: Reaction Kinetics, Mechanisms and Catalysis, 2018, Vol.125(2), pp.983-994
    Identifier: 1878-5190 (ISSN); 1878-5204 (E-ISSN); 10.1007/s11144-018-1456-3 (DOI)

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    Investigation the effects of Al-grafting and calcination temperature on acidity and physicochemical properties of silica SBA-15

    Orouj Reza, Rashidzadeh Mehdi, Irandoukht Akbar, Sadighi Sepehr
    Journal of the Serbian Chemical Society, 01 January 2020, Vol.85(10), pp.1345-1356 [Peer Reviewed Journal]
    Directory of Open Access Journals (DOAJ)
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    Title: Investigation the effects of Al-grafting and calcination temperature on acidity and physicochemical properties of silica SBA-15
    Author: Orouj Reza; Rashidzadeh Mehdi; Irandoukht Akbar; Sadighi Sepehr
    Subject: Silica Sba-15 ; Post-Synthesis Al-Grafting ; Acidity ; Physicochemical Properties ; Chemistry
    Description: In this study, the effect of calcination temperature and Si/Al mole ratio on acidity and physicochemical properties of silica SBA-15 were investigated. Silica SBA-15 samples were calcined at 350, 450 and 550°C, and then post-synthesis, the Al-grafting method was applied to incorporate aluminum species into their framework with Si/Al mole ratio of 10 and 30. Characterizations using small angle XRD and N2 adsorption–desorption techniques indicated that the hexagonal mesoporous structure was retained after performing Al-grafting even at the high aluminum loading. Moreover, FTIR results implied that the aluminum species were incorporated into the SBA-15 framework. NH3-TPD results showed that by decreasing Si/Al mole ratio at all calcination temperatures, the number of weak acid sites increased in comparison to those of the pure SBA-15 samples. Additionally, the maximum total acidity of synthesized samples was observed at the calcination temperature of 450°C with Si/Al mole ratio of...
    Is part of: Journal of the Serbian Chemical Society, 01 January 2020, Vol.85(10), pp.1345-1356
    Identifier: 0352-5139 (ISSN); 1820-7421 (E-ISSN); 10.2298/JSC191129021O (DOI)