Modelling of alkane dehydrogenation under transient and steady state conditions over a chromia catalyst using isotopic labelling

Jackson, S. David; Grenfell, John Lee; Matheson, Isobel M.; Webb, G.

doi:10.1016/s0167-2991(99)80143-8

Cited by 9 publications

(7 citation statements)

References 6 publications

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“…Mechanisms for the PDH reaction and subsequent catalyst deactivation on several catalysts have been studied extensively. Most kinetic studies reported in the literature are, however, not complete since either the catalyst deactivation phenomenon is ignored, or the activity of the catalyst is assumed to be independent of coke formation [19][20][21][22]. Among the few complete kinetic studies, to the best of our knowledge, Larsson et al [23] combined the kinetics of PDH (a simple power law model) with the kinetics of coke formation.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Modelling of Propane Dehydrogenation over a Pt–Sn/hierarchical SAPO-34 Zeolite Catalyst, Including Catalyst Deactivation

Komasi

Fatemi

Mousavi

2017

Progress in Reaction Kinetics and Mechanism

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Pt–Sn/hierarchical SAPO-34 was synthesised and kinetically modelled as an efficient and selective catalyst for propylene production through propane dehydrogenation. The kinetics of the reaction network were studied in an integral fixed-bed reactor at three temperatures of 550, 600 and 650 °C and weight hourly space velocities of 4 and 8 h−1 with a feed containing hydrogen and propane with relative molar ratios of 0.2, 0.5 and 0.8, at normal pressure. The experiments were performed in accordance with the full factorial experimental design. The kinetic models were constructed on the basis of different mechanisms and various deactivation models. The kinetics and deactivation parameters were simultaneously predicted and optimised using genetic algorithm optimisation. It was further proven that the Langmuir–Hinshelwood model can well predict propane dehydrogenation kinetics through lumping together all the possible dehydrogenation steps and also by assuming the surface reaction as the rate-determining step. A coke formation kinetic model has also shown appropriate results, confirming the experimental data by equal consideration of both monolayer and multilayer coke deposition kinetic orders and an exponential deactivation model.

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Section: Introductionmentioning

confidence: 99%

Kinetic Modelling of Propane Dehydrogenation over a Pt–Sn/hierarchical SAPO-34 Zeolite Catalyst, Including Catalyst Deactivation

Komasi

Fatemi

Mousavi

2017

Progress in Reaction Kinetics and Mechanism

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“…Supported chromium oxide catalysts are used for many industrial catalytic processes . Chromium oxide supported on alumina is used as a catalyst for propane and butane dehydrogenation. − Determination of the surface structure under reaction conditions is important for a complete understanding of the catalyst system.…”

Section: Introductionmentioning

confidence: 99%

“…1 Chromium oxide supported on alumina is used as a catalyst for propane and butane dehydrogenation. [2][3][4][5][6][7][8][9][10][11] Determination of the surface structure under reaction conditions is important for a complete understanding of the catalyst system.…”

Section: Introductionmentioning

confidence: 99%

In Situ Ultraviolet Raman Spectroscopy of the Reduction of Chromia on Alumina Catalysts

2004

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A fluidized bed in situ cell is used to examine the chromia on alumina catalyst surface. The loading is varied from 1 to 20% chromium oxide on alumina. The structure of the surface is monitored as a function of temperature, reduction, and hydration. This is the first study to use ultraviolet excitation to study a reduced chromium catalyst surface. Reduction of the sample in hydrogen gas leads to the formation of noncrystalline Cr(3+) species. Addition of potassium to the surface reduces the size of the chromia clusters.

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“…The equilibrium conversion of the process is limited by the reaction temperature and as that increases so does conversion [28]. Hence to accommodate the thermodynamic limitations typical reaction temperatures are C550°C: at these temperatures all C-H bonds in an alkane have equal chance to react [29][30][31][32]. However, at such high temperatures secondary reactions such as cracking and carbon deposition are also favoured; therefore, the reaction tends to get less selective as temperature and conversion increase.…”

Section: Dehydrogenation and Hydrogenation Processes In Trans-hydrogementioning

confidence: 99%

“…The logic that underlies this is the evidence that dehydrogenation is the more difficult reaction. Although alkanes can exchange hydrogen at low temperatures on a catalyst surface [30,31,37] indicating that breaking the first C-H bond in an alkane is not necessarily difficult, removal of the second hydrogen is rate determining and thermodynamic limits ensure that high temperatures are needed [38,39]. In contrast the addition of hydrogen to an alkyne or alkadiene is thermodynamically favoured at most temperatures.…”

Section: Catalytic Processes For Trans-hydrogenationmentioning

confidence: 99%

Catalytic upgrading of refinery cracked products by trans-hydrogenation: a review

Garba

Jackson

2016

Appl Petrochem Res

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The production of high premium fuel is an issue of priority to every refinery. The trans-hydrogenation process is devised to convert two low valued refinery cracked products to premium products; the conversion processes involve the combination of dehydrogenation and hydrogenation reaction as a single step process. The paper reviews the recent literature on the use of catalysts to convert low value refinery products (i.e. alkanes and alkynes or alkadienes) to alkenes (olefins) by trans-hydrogenation. Catalysts based on VO x , CrO x and Pt all supported on alumina have been used for the process. However, further studies are still required to ascertain the actual reaction mechanism, mitigating carbon deposition and catalyst deactivation, and the role of different catalysts to optimize the reaction desired products.

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Modelling of alkane dehydrogenation under transient and steady state conditions over a chromia catalyst using isotopic labelling

Cited by 9 publications

References 6 publications

Kinetic Modelling of Propane Dehydrogenation over a Pt–Sn/hierarchical SAPO-34 Zeolite Catalyst, Including Catalyst Deactivation

Kinetic Modelling of Propane Dehydrogenation over a Pt–Sn/hierarchical SAPO-34 Zeolite Catalyst, Including Catalyst Deactivation

In Situ Ultraviolet Raman Spectroscopy of the Reduction of Chromia on Alumina Catalysts

Catalytic upgrading of refinery cracked products by trans-hydrogenation: a review

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