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  1. Article ; Online: Experimental and Kinetic Study of the Catalytic Behavior of Sulfate-Treated Nanostructured Bifunctional Zirconium Oxide Catalysts in n -Heptane Hydroisomerization Reactions

    Mohammed Khalil / Bashir Y. Al-Zaidi / Zaidoon M. Shakor / Sattar J. Hussein / Ali Al-Shathr

    ChemEngineering, Vol 7, Iss 6, p

    2023  Volume 115

    Abstract: In this study, a mono-functional ZrO 2 nanomaterial was treated with sulfur and loaded with two different percentages of platinum metals (i.e., 0.5 and 1 wt%) to generate an acidic bi-functional Pt/SZrO 2 nanocatalyst for the purpose of increasing the ... ...

    Abstract In this study, a mono-functional ZrO 2 nanomaterial was treated with sulfur and loaded with two different percentages of platinum metals (i.e., 0.5 and 1 wt%) to generate an acidic bi-functional Pt/SZrO 2 nanocatalyst for the purpose of increasing the catalytic activity and selectivity together. This work aims to determine the least amount of the costly platinum metal that can be added to the catalyst to achieve the appropriate balance between the acidic and metallic sites. Both rapid deactivation of the super-acid nanaocatalyst and fast cleavage of the zero-octane n -heptane chain can consequently be prevented throughout the reaction. This can be achieved by accelerating the hydroisomerization reactions at a pressure of 5 bar to reach the highest selectivity towards producing the desired multi-branched compound in fuel. Several characterization techniques, including XRD, SEM, EDX, BET, and FTIR, have been used to evaluate the physical properties of the catalysts. The best reaction product was obtained at 230 °C compared to the other tested temperatures. The conversion, selectivity, and yield of reaction products over the surfaces of the prepared catalysts followed this order: 0.5 wt% Pt/SZrO 2 > 1 wt% Pt/SZrO 2 > 0.5 wt% Pt/ZrO 2 > 1 wt% Pt/ZrO 2 > SZrO 2 > ZrO 2 . The highest conversion, selectivity, and yield values were obtained on the surface of the 0.5 wt% Pt/SZrO 2 catalyst, which are 69.64, 81.4 and 56.68 wt%, respectively, while the lowest values were obtained on the surface of the parent ZrO 2 catalyst, which are 43.9, 61.1 and 26.82, respectively. The kinetic model and apparent activation energies were also implemented for each of the hydroisomerization, hydrogenation/dehydrogenation, and hydrocracking reactions, which track the following order: hydroisomerization < hydrogenation/dehydrogenation < hydrocracking. The lowest apparent activation energy value of 123.39 kJ/mol was found on the surface of the most active and selective 0.5% Pt/SZrO 2 nanocatalyst.
    Keywords bi-functional Pt/SZrO 2 nanocatalyst ; sulfate treatment ; Pt-metal loading by impregnation ; n -heptane hydroisomerization reactions ; kinetic model ; Chemistry ; QD1-999
    Subject code 660
    Language English
    Publishing date 2023-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Experimental and kinetic studies of the advantages of coke accumulation over Beta and Mordenite catalysts according to the pore mouth catalysis hypothesis

    Ali Al-Shathr / Bashir Y. Al-Zaidi / Amal K. Shehab / Zaidoon M. Shakoor / Safa Aal-Kaeb / Laura Quintana Gomez / Hasan Sh. Majdi / Emad N. Al-Shafei / Adnan A. AbdulRazak / James McGregor

    Catalysis Communications, Vol 181, Iss , Pp 106718- (2023)

    2023  

    Abstract: Coke formation inside heterogeneous reactors is an important industrial problem that leads to reduced catalyst efficiency. However, this study aims to prove the benefits of coke build-up in improving catalyst performance. The formation and decomposition ... ...

    Abstract Coke formation inside heterogeneous reactors is an important industrial problem that leads to reduced catalyst efficiency. However, this study aims to prove the benefits of coke build-up in improving catalyst performance. The formation and decomposition of coke on six different zeolite structures was studied. The dissociation kinetic model of the spent catalysts during the toluene alkylation with 1-heptene inside a stainless-steel autoclave reactor at different temperatures was carried out. Various techniques (XRD, XRF, TPO, CHNS and TGA-DTG) were used. It was found that the conversion and selectivity of the desired product were higher on the parent H-mordenite and the dealuminated H-beta catalysts with conversions of 85.3% and 84.67%, respectively, at a 360 min reaction time. This was attributed to the reduction of the ratio of hard:soft coke. It is confirmed that the decomposition activation energies of hard coke, 140.1–202.6 kJ/mol, are much higher energies than those of soft coke, 89.9–118.7 kJ/mol. It is also noted that the hypothesis of pore mouth catalysis is dominated by non-polyaromatic coke on the surface of the H-beta catalysts, while the hypothesis is dominated by polyaromatic coke on the surface of the H-mordenite catalysts.
    Keywords Toluene alkylation ; H-beta zeolite ; H-mordenite zeolite ; Dealuminated and desilication zeolites ; Pore mouth catalysis ; Coke kinetic decomposition ; Chemistry ; QD1-999
    Subject code 660
    Language English
    Publishing date 2023-08-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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