Mineral oils: processes and products – Refining – Sulfur removal
Reexamination Certificate
2000-06-22
2001-09-18
Myers, Helane E. (Department: 1764)
Mineral oils: processes and products
Refining
Sulfur removal
C208S215000, C208S213000
Reexamination Certificate
active
06290841
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to catalytic hydrotreatment of hydrocarbonaceous feedstocks.
BACKGROUND OF THE INVENTION
Petroleum feedstocks are characterized by relatively high levels of contaminants, including sulfur, nitrogen, Conradson carbon residue, aromatic compounds and metals such as nickel, vanadium and iron. During catalytic hydroprocessing heterogeneous catalysts are contacted with a feedstock in the presence of hydrogen under conditions of elevated temperature and pressure to reduce the concentration of the contaminants in feedstocks. The hydrotreating process promotes reactions such as hydrodesulfurization (HDS), hydrodenitrogenation (HDN), Conradson carbon removal, hydrodemetallation (HDM) and aromatics saturation, accompanied by a boiling shift to lower boiling products. As the sulfur and nitrogen components are converted into hydrogen sulfide and ammonia, metals are deposited onto the catalyst. The results include producing ecologically clean hydrocarbon products such as fuels and protecting other downstream refining catalysts from deactivation.
Processes for removing heteroatoms from feedstocks are known in the art as are catalysts for such removal. Typically, hydroprocessing catalysts contain Group VI and/or Group VIII active metal components supported on a porous refractory oxide such as alumina, alumina-silica, silica, zeolites, titania, zirconia, boria, magnesia and their combinations. Such catalysts are often prepared by combining the active metals with the support. The supports, containing metal components, are typically dried and calcined at the temperatures ranging from about 370° C. to 600° C. to eliminate any solvent and to convert metals to the oxide form. The calcined metal oxide catalysts are then typically activated by contacting with a sulfur containing compound such as hydrogen sulfide, organic sulfur compounds or elemental sulfur to convert metal oxides into catalytically active metal sulfides.
An important and continuing aim in the refining catalyst art is to develop new high performance hydroprocessing catalysts in order to obtain high quality oil products and improve refinery economics. Variations in compositional characteristics or methods of preparation of hydroprocessing catalysts have been attempted to reach these objectives.
It is known in the art that uncalcined catalysts usually provide higher dispersion of active components thereby improving hydrotreating activities. It is essential for the uncalcined catalysts that the active components, such as Group VI and/or Group VIII metal compounds, and promoters such as phosphorous, are not converted into oxide form during a high temperature step. That is, the active compounds are maintained without chemical decomposition until sulfurizing. For example, U.S. Pat. Nos. 5,198,100, 5,336,654 and 5,338,717 disclose a method for preparing a hydrotreating catalyst by impregnating a refractory support with a salt of Group VI metals and with the Group VIII metal heteropolyacids. The catalyst is not calcined or subjected to high temperatures, thereby retaining the heteropolyacids in the original form on the support; however, complete moisture removal from the catalyst during a high vacuum drying step is required before the catalyst is sulfurized.
In general, as the activity of an uncalcined catalyst is increased, the hydrotreating conditions required to produce a given oil product become more mild. Milder conditions require less capital investment to achieve the desired product specifications, such as allowed levels of sulfur, nitrogen, Conradson carbon residue, metals and aromatics, and the catalyst's life is extended due to lower coke formation and other factors.
It has been surprisingly been found that preparation of an uncalcined catalyst using a combined volatile content reduction-sulfurizing step allows for the catalyst to be prepared at lower temperatures, in less steps and without calcination, resulting in a catalyst with excellent hydrotreating activity and stability.
SUMMARY OF THE INVENTION
The process of the invention allows one to prepare a catalyst while using a combined volatile content reduction-sulfurizing step. The process comprises:
providing a porous support;
combining said support with one or more catalytically active metals, thereby forming a catalyst precursor having a volatile content; and
reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulfur containing compound;
wherein the catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.
There is also provided a process for preparing a catalyst suitable for hydrotreatment of a hydrocarbonaceous feedstock, said process comprising:
combining a porous support with one or more catalytically reactive metals selected from Group VI and Group VIII of the Periodic Table, thereby forming a catalyst precursor having a volatile content; and
reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulfur containing compound;
wherein the catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.
Further, there is provided a process for hydrotreating a hydrocarbonaceous feedstock, said process comprising contacting said feedstock at elevated temperature and elevated pressure in the presence of hydrogen with one or more catalyst beds; wherein at least one catalyst bed contains a catalyst prepared by the process comprising combining a porous support with one or more catalytically reactive metals selected from Group VI and Group VIII of the Periodic Table, thereby forming a catalyst precursor having a volatile content and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of one or more sulfur containing compounds; and wherein the catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.
There is further provided a catalyst made by the process comprising combining a porous support with one or more catalytically active metals, thereby forming a catalyst precursor having a volatile content; and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of at least one sulfur containing compounds; wherein said catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.
REFERENCES:
patent: 3509044 (1970-04-01), Adams et al.
patent: 3686137 (1972-08-01), Gatti
patent: 3761397 (1973-09-01), Gatti
patent: 3770617 (1973-11-01), Riley et al.
patent: 4530917 (1985-07-01), Berrebi
patent: 4548920 (1985-10-01), Thompson et al.
patent: 4574120 (1986-03-01), Thompson
patent: 4636487 (1987-01-01), Parrott et al.
patent: 4960506 (1990-10-01), Halbert et al.
patent: 4981828 (1991-01-01), Takahashi et al.
patent: 4992403 (1991-02-01), Takahashi et al.
patent: 5045518 (1991-09-01), Heinerman et al.
patent: 5139990 (1992-08-01), de Jong et al.
patent: 5164354 (1992-11-01), Aldridge et al.
patent: 5198100 (1993-03-01), Aldridge et al.
patent: 5334307 (1994-08-01), Simpson et al.
patent: 5336654 (1994-08-01), Aldridge et al.
patent: 5338717 (1994-08-01), Aldridge et al.
patent: 5468372 (1995-11-01), Seamans et al.
patent: 5525211 (1996-06-01), Sudhakar et al.
patent: 5688736 (1997-11-01), Seamans et al.
patent: 5770046 (1998-06-01), Sudhakar
patent: 5851382 (1998-12-01), Sudhakar
patent: 5922638 (1999-07-01), Dufresne et al.
patent: 181035 (1986-05-01), None
patent: 9641848 (1996-12-01), None
Maitra, et al., “Novel Hydrotreating Catalysts Prepared from Heteropolyanion Complexes Impregnate
Bhan Opinder Kishan
Gabrielov Alexei Grigorievich
Myers Helane E.
Shell Oil Company
LandOfFree
Hydrotreating process using sulfur activated non-calcined... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrotreating process using sulfur activated non-calcined..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrotreating process using sulfur activated non-calcined... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2515974