Pt/WO3/ZrO2 Catalysts for n-Heptane Isomerization

Shkurenok, V. A.; Смоликов, М. Д.; Yablokova, S. S.; Kir’yanov, D. I.; Белый, А. С.; Paukshtis, E. A.; Леонтьева, Н. Н.; Gulyaeva, T. I.; Шилова, А. В.; Дроздов, В. А.

doi:10.1016/j.proeng.2015.07.291

Cited by 21 publications

(9 citation statements)

References 10 publications

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“…There is a complex of active centers, each of which is responsible for a particular direction of the process, on acting surface of the polyfunctional catalyst. For example, activation of molecular hydrogen takes place at Lewis (L) and Bronsted (B) acid centers [16]. Modified with metals Bronsted centers take part in isomerization and hydrogenation reactions while metal containing Lewis centers are active in reactions of hydrogenation (M˚-L) and C-SH bond breaking [17].…”

Section: Resultsmentioning

confidence: 99%

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

et al. 2021

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The purpose of the present work is to show that light straight-run gasoline fraction can be used as feedstock for hydro-catalytic isomerization process, and the isomerized product can serve as a component for obtaining pure ecological commercial gasoline brand Euro-4 and Euro-5. Transformation of n-alkanes of Zhanazhol oil’s light gasoline fraction with boiling temperature 180°C was studied. Isomerization was carried out in a flow unit with a stationary layer of modified sample of industrial aluminum-platinum catalyst at 200-300°C and 2.0-4.0 MPa, with volume feed rate of 1.0-3.0 h-1 and circulation ratio of hydrogen containing gas circulation 1000-1500 m3/m3 of catalyst feed. Light gasoline fraction are subjected to a number of chemical transformations: n-paraffins isomerization, five-membered and six-membered cycloalkanes dehydroisomerization and hydrocracking. n-Alkanes are isomerized in iso-alkanes, naphthenic hydrocarbons are first subjected to hydrocracking with opening the cycle and forming n-alkanes, which are then isomerized into iso-alkanes. Thus, the reaction products contain isopentane, 2,3-dimethylbutane with octane number 92 and 104 correspondingly, and other iso-paraffinic hydrocarbons that lead to raise of gasoline octane number. By study of individual hydrocarbon composition of feedstock and isomerizate it is possible to establish some regularities hydrocarbons in the process of hydro-catalytic isomerization of light gasoline fraction.

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Section: Resultsmentioning

confidence: 99%

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

et al. 2021

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“…The mixed hydroxide Cr(OH) 3 -Zr(OH) 4 was prepared from ZrOCl 2 -containing Cr(NO 3 ) 3 solution by dropwise addition of an ammonia water solution under vigorous stirring up to pH 9~10. The precipitated hydrogel was aged at room temperature for 24 h and refluxed at 100 • C for 24 h. Then, it was filtered and washed with deionized water repeatedly until no chloride ions were detected.…”

Section: Catalyst Preparationmentioning

confidence: 99%

“…Current stringent environmental protection regulations have forced the implementation of severe controls for reducing aromatic, olefin, and sulfuric compounds and led to a sharp rise in the demand for clean fuels with none-aromatic and high octane number [1,2]. Heptane isomerization to branched isomers with high octane numbers is a desirable reaction for compensating for the octane number [3,4]. However, no process that is suitable for heptane fraction isomerization in industrial oil refining is currently known; since the implementation of such a process will allow for the meeting of long-term environmental requirements for commercial gasoline, it has aroused increased interest [4].…”

Section: Introductionmentioning

confidence: 99%

“…Heptane isomerization to branched isomers with high octane numbers is a desirable reaction for compensating for the octane number [3,4]. However, no process that is suitable for heptane fraction isomerization in industrial oil refining is currently known; since the implementation of such a process will allow for the meeting of long-term environmental requirements for commercial gasoline, it has aroused increased interest [4]. The main concern for the commercialization of n-heptane isomerization is that β-cleavage occurs during the isomerization reaction.…”

Section: Introductionmentioning

confidence: 99%

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Effect of the Cr2O3 Promoter on Pt/WO3-ZrO2 Catalysts for n-Heptane Isomerization

Zhang

Zhao

et al. 2018

Catalysts

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Isomerate, the product of a light naphtha Isomerization unit, is a clean, high-octane gasoline blending component, which is free of sulfur content, aromatics, and olefins. However, the isomerization of the long-chain alkanes, such as n-heptane, is pretty difficult. As a result, this process has not been commercialized yet. In recent years, much attention has been paid to Pt/WO 3 /ZrO 2 as an n-heptane isomerization catalyst due to its good thermal stability, strong acidity, simplicity of preparation, reusability and good isomerization activity. In this work, the Pt/WO 3 /ZrO 2 catalyst was modified by various loading of metal Cr to improve the catalytic performance. The effects of WO 3 content, Cr metal loading and calcination temperature on the catalyst characters and catalytic activity were studied. It is shown that Cr-Pt/WO 3 /ZrO 2 with the loading of 18 wt% WO 3 and 1.0-1.4 wt% Cr, prepared at the calcination temperature of 800 • C, has the highest activity. It was found that the octane number increases by 28 units through the isomerization of light naphtha feedstocks. In addition, the study on the stability of Cr-Pt/WO 3 /ZrO 2 indicates that the catalyst is not deactivated after 500 h of the n-heptane isomerization reaction.Arata and Hino [6] because of its good stability both in reducing and oxidizing conditions [7]. While the WO 3 /ZrO 2 type catalyst shows high selectivity in the isomerization reaction of linear alkane, the catalyst activity is relatively low and the degree of cracking is too high [8]. Thus, the catalyst needs to be modified to meet the industrial production requirements. The catalyst consisting of Pt deposited on WO 3 /ZrO 2 for n-heptane isomerization has attracted the attention of a large number of researchers as the most promising catalyst [9,10]. The structure of the WO 3 /ZrO 2 catalyst varies depending on the WO 3 content [11,12], leading to different catalyst activities. The structure and properties of this kind of catalyst can be modified by changing the WO 3 content [13]. While most researchers believe that the best catalytic activity is obtained when WO 3 is highly dispersed on the surface of the catalyst, there has been some debate about this subject. It was shown that the catalyst has better catalyst activity with the WO 3 density of seven-eight atoms·nm −2 [14,15]. Many researchers have found that the addition of small amounts of metals such as Fe, Al, In, and Ga to Pt/WO 3 /ZrO 2 enhances catalysis and stability of n-heptane isomerization, and it was demonstrated that Cr can be used as a modifier in Pt/WO 3 /ZrO 2 catalysts. Based on economic considerations, Cr metal is a more cost-effective option, and is therefore a more suitable for industrial production than Ga metal [16][17][18]. In this work, n-heptane isomerization over Cr-promoted Pt/WO 3 /ZrO 2 was studied and compared to that over Pt/WO 3 /ZrO 2 . Results and Discussion Effect of Cr 2 O 3 Loading on Pt/ WO 3 /ZrO 2 Characterization of the CatalystsThe XRD patterns of Cr-Pt/WZ catalysts with different Cr loading ...

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“…One of the main sources of pollution in large cities is the aromatic hydrocarbons produced by gasoline vehicles . Therefore, fuel quality modification and the use of high‐octane gasoline are serious environmental challenges . The conventional reaction for octane number enhancement is the hydroisomerization of n ‐alkane in the oil refining industry .…”

Section: Introductionmentioning

confidence: 99%

Effect of phosphomolybdic acid on the catalytic behavior of bifunctional Pt‐Cr/nanocrystalline Y zeolite in hydroisomerization of n‐octane

Afzali

Vaezi

Aghabarari

et al. 2019

J Chinese Chemical Soc

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In this study, Y zeolite nanocrystals were synthesized without an organic template and were used as a support for bifunctional nanocatalysts in the hydroisomerization of n‐octane. Different types of catalysts were synthesized by loading Pt, Cr, and phosphomolybdic acid (HPMo) on Y zeolite nanocrystal supports and were characterized by X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), field emission scanning electron microscope (FE‐SEM), and transmission electron microscope (TEM) analysis. The Cr‐Pt/HPMo‐Y nanocatalyst with a surface area of approx. 600 m2/g showed the best performance in the hydroisomerization of n‐octane. The optimization of n‐octane hydroisomerization over bifunctional nanocatalysts supported on nanocrystalline Y zeolite, in the presence of H2 gas, was applied based on the response surface methodology (RSM) and Box–Behnken design (BBD) template. The effect of three different process variables on the yield of iso‐alkanes as the purpose process was determined. Experiments were carried out using a fixed‐bed microreactor under different ranges of weight hourly space velocity (WHSV) (A = 0.5–1.5 hr−1), H2 to n‐C8 molar ratio (B = 1:1–3:1), and reaction temperature (C = 200–300°C). The RSM proved that the temperature variable had the greatest impact on the hydroisomerization reaction yield.

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Pt/WO3/ZrO2 Catalysts for n-Heptane Isomerization

Cited by 21 publications

References 10 publications

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

Effect of the Cr2O3 Promoter on Pt/WO3-ZrO2 Catalysts for n-Heptane Isomerization

Effect of phosphomolybdic acid on the catalytic behavior of bifunctional Pt‐Cr/nanocrystalline Y zeolite in hydroisomerization of n‐octane

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