Hydroprocessing Catalysts Research Articles

石炭液化油水素化処理触媒の活性低下挙動とその対策

The deactivation behavior of molybdenum catalysts used for hydrotreating coal-derived liquids is reviewed to obtain information for the design concept for long-life catalysts. Causes for the catalyst deactivation are fundamentally similar to those for catalysts us-ed in petroleum hydroprocessing. However, the deactivation patterns for the catalysts in coal-derived liquid hydroprocessing was different from that found in petroleum hydroprocessing. This is mainly due to differences between coal liquid and petroleum feeds. Characterization of spent catalysts revealed certain differences in features of metal and carbonaceous deposits resulting from the use of coal liquids and petroleum. The changes in physical and chemical pro-perties of used hydroprocessing catalysts are discussed for coal liquids and petroleum, respec-tively. Changes in the local structure of active metals were found to decrease catalyst activity during coal liquid hydrotreating. Based on understanding of the catalyst deactivation, remedies for catalyst deactivation in connection with the development new types longife catalysts are also discussed.

Hydroprocessing catalysis by supported ruthenium sulphide

Ruthenium sulphide catalysed hydrodenitrogenation (HDN) of quinoline and hydrodesulphurization (HDS) of benzothiophene were studied using a batch autoclave (cold filled with 3448 kPa of hydrogen), at 350 400 ° C and 300 350 ° C , respectively. Ruthenium from various precursors—[Ru Cl 3 xH 2O], [Ru 3(CO) 12], [Ru(NH 3) 6] 3+—was supported on Y-zeolite and γ-Al 2O 3, and then sulphided. The catalysts were highly active for HDN but not for HDS by comparison with a conventional NiMo Al 2O 3 formulation. The results were attained with metal loadings (~5%) much lower than those used in conventional hydroprocessing catalysts. Physical combination of the most active catalyst, ruthenium sulphide supported on Y-zeolite, with sulphided nickel molybdate on alumina resulted in a catalyst system with greatly enhanced activity for HDN.

ANALYSIS OF RESIDUUM DEMETALATION BY SIZE EXCLUSION CHROMATOGRAPHY WITH ELEMENT SPECIFIC DETECTION

ABSTRACT We analyzed thermally treated heavy residua by element specific size exclusion chromatography (SEC-ICF) to elucidate the fate of the V and Ni compounds. Thermal treatment, in addition to removing metals, significantly reduces the size of the remaining metal-containing compounds.We thermally treated the distillable and nondistillable metals separately. The distilled metals, primarily petroporphyrins, were completely removed under moderate conditions. The non-volatile metal-containing components, which constituted most of the Ni and V, were either removed, or reduced in size.when treating heavy residua over commercial fixed-bed hydroprocessing catalysts, the metal-containing molecules in the size range of the catalyst pore are preferentially removed. Those larger than the pore size appear to demetalate more slowly.The results argue demetalation is a function of the ligand structure and size of the metal-containing species and not necessarily the coordination sphere around the metal center.

The interaction of vanadium and nickel porphyrins and metal-free porphyrins with molybdenum-based hydroprocessing catalysts: relevance to catalyst deactivation and catalytic demetallization

The poisoning of a Co-Mo-alumina hydrodesulphurization (HDS) catalyst by metal-free, vanadium and nickel etio- and tetraphenyl porphyrins and the binding and reactivity of the porphyrins on oxide and sulfide surfaces is described. The surface interactions of porphyrins were studied by adsorption from solution, and UV-visible diffuse-reflectance and ESR spectroscopy. Metalloporphyrins undergo demetallation at acidic sites. The porphyrin ring is oxidized at a meso-carbon by oxomolybdenum(VI) species and adsorbed oxygen to a cation radical and an oxophlorin. During HDS porphyrin bound to the catalyst is hydrogenated at the meso-carbon to phlorin. Interaction of the porphyrins with surfaces is similar to that of polynuclear aromatic hydrocarbons. The relevance of these results to catalyst deactivation and catalytic demetallation is discussed.

Characterization of sulphided molybdenum-containing hydroprocessing catalysts by oxygen and hydrogen chemisorption

Low-temperature oxygen (–78 °C) and hydrogen (300 °C) chemisorption have been applied to characterize a series of sulphided Mo/Al and Co–Mo/Al hydroprocessing catalysts containing up to 12% Mo. Three commercial Co–Mo/Al catalysts have also been studied. Attention has been focussed mainly on the merit of oxygen chemisorption as a surface-specific probe for characterizing hydroprocessing catalysts. From the results it appears that while oxygen chemisorbed at –78 °C can titrate the number of coordinately unsaturated sites (CUS) irrespective of the nature of the support they are on, it cannot distinguish between two CUS with different intrinsic hydrodesulphurization (HDS) activity (arising either because of carrier–catalyst interaction or because of the influence of a promoter) or between a hydrogenation (HYD) and a HDS site.Hydrogen-chemisorption results are also found to throw some light on the structural growth of MoS2 crystallites on the support. The results strongly indicate that hydrogen first dissociates on the CUS on the edge planes of MoS2 prior to its migration to the basal planes where it remains as SH groups. There is also evidence that the van der Waals gap between two MoS2‘sandwiches’ cannot accommodate hydrogen.

Fundamental Studies of Transition Metal Sulfide Hydrodesulfurization Catalysts

Abstract Hydroprocessing catalysts based upon the transition metal sulfides have been widely used for over 60 years and catalysts such as Co/Mo/Al2O3 remain the industry “workhorses” in hydroprocessing of petroleum-based feedstocks [1]. Such applications include sulfur removal (hydrodesulfurization), nitrogen removal (hydrogenitrogenation), and product quality improvement (hydrotreating, hydroconversion). Original interest (prior to World War II) in these catalysts centered on their activityin the hydrogenation of coal liquids which contain considerable amounts of sulfur, thus maintaining the transition metal in the sulfided state. It was quickly discovered that Co, Ni, Mo, and W sulfides and their mixtures were the most active and least expensive of the transition metal sulfides [2]. Later (post-World War II) their major uses shifted to hydroprocessing of sulfur- and nitrogen-containing petroleum-based feedstocks with Co- and Ni-promoted Mo and W catalysts usually supported on Al2O3. However, as petroleu...

Thermal and steam stability of commercial hydroprocessing catalysts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal and steam stability of commercial hydroprocessing catalystsP. Donald Hopkins and Bernard L. MeyersCite this: Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 3, 421–426Publication Date (Print):September 1, 1983Publication History Published online1 May 2002Published inissue 1 September 1983https://doi.org/10.1021/i300011a007RIGHTS & PERMISSIONSArticle Views136Altmetric-Citations22LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (756 KB) Get e-Alerts