Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Sulfur or compound containing same
Reexamination Certificate
2001-04-10
2003-01-21
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Sulfur or compound containing same
C502S168000, C502S219000, C502S220000, C502S221000, C502S222000, C502S223000, C502S313000, C502S314000
Reexamination Certificate
active
06509291
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for sulfiding catalysts containing an S (sulfur)-containing organic additive, in particular a hydrotreating catalyst containing an S-containing organic additive.
2. Prior Art
Hydrotreating catalysts comprise hydrogenation metal components, generally a Group VI metal component such as molybdenum and/or tungsten and a Group VIII metal component, such as nickel and/or cobalt, generally on an oxidic carrier. Before use, the hydrogenation metal components present in hydrotreating catalysts will generally be converted into their sulfides. This process is conventionally indicated as sulfidation or presulfidation. It is generally done before the catalyst is used in hydrotreating to ensure a stable reactor performance.
Hydrotreating catalysts containing S-containing organic additives are known in the art. The addition of the S-containing organic additive is often intended to preclude the necessity of a separate presulfiding step.
For example, European patent application 0 300 629 and European patent application No. 0 357 295 describe hydrotreating catalysts comprising a support impregnated with at least one member of molybdenum, tungsten, and/or Group VIII of the Periodic Table, and a mercapto-compound selected from mercaptocarboxylic acids, amino-substituted mercaptanes, di-mercaptanes, and thioacids. The S-containing additive is incorporated into the catalyst composition to obviate the necessity of presulfiding, or at least make the presulfiding less difficult. In particular, the S-containing additive is incorporated into the catalyst to obviate the necessity of dedicating the initial part of the reactor start-up to providing the catalyst with the amount of sulfur needed to attain equilibrium with the reaction environment, or to shorten the time necessary for doing so. Additionally, the necessity of spiking the feed with a sulfur-containing compound such as DMDS is lessened or obviated. Further, since all catalyst particles already contain S when they enter the unit, the homogeneity of the sulfided product will be improved.
European patent application No. 0 506 206 also describes a hydrotreating catalyst comprising an S-containing additive selected from the group of bi-mercaptanes, aminosubstituted mercaptanes, and thiocarboxylic acids. The S-containing catalyst is again intended to avoid the necessity of presulfiding. Some of the catalysts described in this reference are activated by a treatment with hydrogen at a temperature from room temperature up to 400° C., preferably 100-300° C.
Similar subject-matter is described in European patent application No. 0 338 788, and European patent application No. 0 289 211.
U.S. Pat. No. 5,139,990 describes a hydrotreating catalyst comprising a carrier and hydrogenation metal components which is treated with an aqueous medium comprising a water-soluble or water-miscible S-containing organic additive, followed by drying the resulting catalyst and activating it with hydrogen at a temperature of 100-600° C.
U.S. Pat. No. 4,636,487 describes a hydrotreating catalyst comprising a support and a hydroxymercaptide of one or more metals, which may be the reaction product of a mercaptoalcohol and one or more metal compounds. The catalyst may be activated with hydrogen at a temperature of 66-316° C.
European patent application No. 0 496 592 describes a hydrotreating catalyst comprising a carboxylic acid and an organic sulfur compound which may be a mercaptocarboxylic acid. The amount of organic sulfur compound is so low that the catalyst still needs to be presulfided. No information is given as to how this presulfidation step should be carried out.
U.S. Pat. No. 4,213,850 describes liquid phase presulfiding followed by gas phase presulfiding, where in the liquid phase presulfiding a non-spiked feed is used. U.S. Pat. No. 5,045,518 describes a process in which a catalyst is first sulfided ex situ followed by an in situ sulfidation.
Although the activity of these catalysts is good, there still is room for improvement. Additionally, it has appeared that when the catalysts of the above references are brought into the hydrotreating unit, undesirable components such as acetic acid may be formed during the start-up. Additionally it was found that the start-up procedure is rather critical to obtain good results.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is a sulfidation process in which a catalyst composition comprising at least one hydrogenation metal component of Group VI and/or Group VIII of the Periodic Table, and an S-containing organic additive is first contacted with an organic liquid, followed by the catalyst being contacted with hydrogen and a sulfur-containing compound in the gaseous phase.
In a second embodiment, our invention is a catalyst obtained by the above process.
In a third embodiment, our invention is a process for hydrotreating a hydrocarbon feed by contacting the feed with the above catalyst at hydrotreating conditions.
Other embodiments of our invention encompass details about reactant compositions, process steps and conditions, etc., all of which are hereinafter disclosed in the following discussion of each of the facets of our invention.
DETAILED DISCRIPTION OF THE INVENTION
The sulfidation process
It has appears that catalysts with a higher activity may be obtained if the catalysts are sulfided by way of the above process.
In the process according to the invention, the additive-containing catalyst is first contacted with an organic liquid. The organic liquid generally has a boiling range of about 100-550° C., preferably about 150-500° C. It generally is a petroleum fraction. By their nature, petroleum fractions comprise less than about 12 wt. % of oxygen. Petroleum fractions comprising less than about 8 wt. % of oxygen, preferably less than about 5 wt. %, more preferably less than about 2 wt. %, specifically less than about 0.5 wt. % of oxygen, may be preferred. Although the olefin content of the organic liquid is not critical to the process according to the invention, petroleum fractions with and iodine number of about 50 or less, specifically about 30 or less, may be preferred. Examples of suitable petroleum fractions include fractions comprising heavy oils, lubricating oil fractions like mineral lube oil (360° C.<BP<500° C.), atmospheric gas oils, vacuum gas oils, straight run gas oils (250° C.<BP<350° C.), white spirit (180° C.<BP<220° C.), middle distillates like diesel, jet fuel and heating oil, naphthas, and gasoline. Preferably white oil, gasoline, diesel, gas oil, or mineral lube oil is used.
The organic liquid ensures that the catalyst is able to withstand the conditions prevailing during the actual sulfidation step, that is, during the contacting of the catalyst with hydrogen and a sulfur-containing compound. The organic liquid is not particularly intended to bring sulfur into the catalyst. Nevertheless, petroleum cuts such as a gas oil or diesel may sometimes contain sulfur. Generally, the organic liquid will contain less than about 10 wt. % of sulfur, preferably less than about 5 wt. %. The amount of sulfur added with the organic liquid will be less than about 40%, preferably less than about 35% of the total amount of sulfur added to the catalyst and by way of the sulfur-containing compound applied in the gaseous phase, more preferably less than about 25%, even more preferably less than about 15%.
The amount of organic liquid used generally is about 20-500% of the catalyst pore volume which can be filled with the liquid at issue under the conditions of application of the liquid. The pore volume can easily be determined by slowly adding liquid under said conditions to a certain amount of catalyst in a closed flask while shaking and determining by visual inspection when the liquid is no longer adsorbed. Another method is to add excess liquid and to remove the excess from the catalyst, e.g., by centrifugation. The person skilled in the art of pore volume impregnation is familiar with these p
Akzo Nobel N.V.
Bell Mark L.
Hailey Patricia L
Morris Louis A.
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