The physico-chemical structure and activity of hydrodesulphurization catalysts aged by accelerated method

Zbuzek, Michal; Vráblík, Aleš; Tukač, Vratislav; Veselý, M.; Prokešová, A.; Černý, Radek

doi:10.1016/j.cattod.2014.12.040

Cited by 5 publications

(9 citation statements)

References 13 publications

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“…[18] At the smallest scale, atom probe tomography (APT) has been successfully used for studying the effect of carbon deposits at the length-scale of the active site. [19] Electron microscopy (EM) can visualize carbon deposits on length-scales from the single crystal [20][21][22] to the single catalyst particle [23] in two dimensions or carbon-based compounds in three dimensions. [24,25] Using soft X-ray scanning transmission X-ray microscopy (STXM) carbon formation can be mapped at sub-micron resolution and in-situ revealing distribution and, if combined with NEXAFS, speciation of carbon deposits on a solid catalyst.…”

Section: Introductionmentioning

confidence: 99%

3‐D X‐ray Nanotomography Reveals Different Carbon Deposition Mechanisms in a Single Catalyst Particle

et al. 2021

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Catalyst deactivation involves a complex interplay of processes taking place at different length and time scales. Understanding this phenomenon is one of the grand challenges in solid catalyst characterization. A process contributing to deactivation is carbon deposition (i. e., coking), which reduces catalyst activity by limiting diffusion and blocking active sites. However, characterizing coke formation and its effects remains challenging as it involves both the organic and inorganic phase of the catalytic process and length scales from the atomic scale to the scale of the catalyst body. Here we present a combination of hard X-ray imaging techniques able to visualize in 3-D the distribution, effect and nature of carbon deposits in the macropore space of an entire industrially used catalyst particle. Our findings provide direct evidence for coke promoting effects of metal poisons, pore clogging by coke, and a correlation between carbon nature and its location. These results provide a better understanding of the coking process, its relation to catalyst deactivation and new insights into the efficiency of the industrial scale process of fluid catalytic cracking.

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Section: Introductionmentioning

confidence: 99%

3‐D X‐ray Nanotomography Reveals Different Carbon Deposition Mechanisms in a Single Catalyst Particle

et al. 2021

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“…HDS catalyst testing units are used to predict catalyst performance and test catalyst activity. These testing units can be operated under variable conditions that correspond with the real conditions of an industrial unit [6]. The testing unit comprises two identical test reactors; therefore, it is possible to set different test conditions for each reactor.…”

Section: Introductionmentioning

confidence: 99%

“…Catalyst producers are constantly developing HDS catalysts with increasing activity. The testing of newly developed catalysts is of great importance [6]. The choice of a catalyst depends, among other things, on the properties of the feedstock and the process conditions.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, it is the most important deactivation mechanism for catalysts used for the hydrotreating of middle distillates. Other types of deactivation are caused by the deposition of metals (metal sintering), thermal degradation, or segregation of the active phase [6,8,[10][11][12]. The catalyst may be poisoned by the contaminants in the feedstock.…”

Section: Introductionmentioning

confidence: 99%

“…However, there is a way to determine the effect of normal operating conditions on the catalyst properties. The catalyst can be placed in an industrial unit using a cylindrical basket under industrial conditions for several months [6]. Pilot units have been developed to study accelerated deactivation.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

Jaklová¹,

Šindelářová²,

Kohout³

et al. 2021

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Owing to the increased use of secondary materials for diesel production, refineries must confront bad quality parameters. Therefore, catalysts with certain capabilities (to remove heteroatoms and improve quality parameters at low hydrogen consumption) and their lifetimes are required. An important parameter that influences the quality of the products and the economy of the unit is the activity of the catalyst. Prior to industrial use, the catalyst is typically tested in a pilot unit. This is necessary to obtain a considerable amount of data on the lifetime of the catalyst in the shortest feasible time. Here, deactivation steps were used to test the catalyst. Two experiments were performed to evaluate the effect of two types of accelerated deactivations on the catalyst activity and product properties. The first type of deactivation proceeded for 6 h and comprised a tripling of the amount of incoming feedstock, and the second type proceeded for 18 h without an increase in the amount of feedstock. For both cases, the pressure and hydrogen flow were minimised. Both types of accelerated deactivations had similar effects on the quality of the final products and catalyst. The only difference was in the duration of catalyst recovery after deactivation. The results were compared with those of a test in which the spontaneous deactivation of the catalyst was studied.

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2017

Handbook of Spent Hydroprocessing Catalysts

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The physico-chemical structure and activity of hydrodesulphurization catalysts aged by accelerated method

Cited by 5 publications

References 13 publications

3‐D X‐ray Nanotomography Reveals Different Carbon Deposition Mechanisms in a Single Catalyst Particle

3‐D X‐ray Nanotomography Reveals Different Carbon Deposition Mechanisms in a Single Catalyst Particle

Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

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