JP2003535689A - Presulfurization and preconditioning of resid hydroconversion catalysts. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for maximizing the activity of a hydrotreating and / or hydrocracking catalyst when the catalyst is added to the hydrotreating and / or hydrocracking reactor. Presulfurize. A method for improving the activity and maintaining the activity of a hydrotreating and / or hydrocracking catalyst used in a resid hydroconversion process, the method comprising the steps of: the metal oxide catalyst in the inner, exposed to flow rich in the H 2 _S and H _2, to convert the metal oxide catalyst to at least partially metal sulfide, and (b) the catalyst liquid hydrocarbons A method for performing the above steps without interrupting the continuous operation of the resid hydroconversion process, comprising adjusting by passing through a stream.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention is directed to an improved process for presulfiding metal oxide supported catalysts used in hydrotreating and / or hydrocracking (hydrocracking) hydrocarbon feedstocks, and presulfated catalysts obtained thereby. The present invention relates to compositions and hydrotreating and / or hydrocracking processes using such presulfurized metal oxide catalysts. The present invention further relates to an improved process that integrates catalyst presulfiding and residual oil hydroconversion processes.

[0002]

[Prior art]

A hydrotreating catalyst can be defined as any catalyst composition that can be used to catalyze the hydrogenation of a hydrocarbon feedstock, increase its hydrogen content, and / or remove heteroatom contaminants. . Hydrocracking catalysts may be used to catalyze the addition of hydrogen to molecules with the reaction of cracking large or complex hydrocarbon molecules to yield smaller, lower molecular weight molecules. It may be defined as a thing. The residual oil hydroconversion process is a method of converting atmospheric pressure or reduced pressure residue of petroleum under the conditions of high temperature and high pressure in the presence of hydrogen and a hydrotreatment and / or hydrocracking catalyst, It can be defined as the process of converting a feedstock to a lower molecular weight product with reduced levels of contaminants (such as sulfur and nitrogen).

The catalyst compositions used in the resid hydroconversion process are well known to those skilled in the art,
Some are commercially available. Suitable catalysts include catalysts containing nickel, cobalt, tungsten, molybdenum or combinations thereof supported on a porous support such as silica, alumina, titania or combinations thereof.

For maximum effectiveness, these metal oxide catalysts are at least partially converted to metal sulfides. The metal oxide catalyst may be sulfided by contacting it with hydrogen sulfide or a sulfur-containing oil or feedstock at elevated temperature in the reactor.

The catalyst may also be provided to end users who already have sulfur incorporated. However, these ex-situ (ex-si
tu) in the presence of a hydrocarbon feedstock, at the start of the hydrotreating reactor,
Has undergone excessive stripping of sulfur. A decrease in catalytic activity is observed as a result of sulfur stripping. Therefore, it is well known to those skilled in the art that the activity and maintenance of activity of the above metal oxide catalysts can be determined during the production process or in
) Substantially enhanced by presulfiding the catalyst during start-up of the hydroconversion process.

The hydroconversion process can operate in a fixed catalyst bed mode in which a batch of catalyst is converted to hydroconversion before the process is stopped to remove and replace the catalyst. In the reactor, it is typically used for a period of 3 to 24 months. In this fixed bed system, the catalyst can be pre-sulphurized during start-up of the equipment to achieve maximum levels of catalytic performance (hydrogenation, desulfurization, denitrification, conversion, etc.).

In the hydrotreating / hydrocracking process, the process adds and removes catalyst on a regular basis (ie daily, weekly) while the process operates at normal temperature and pressure conditions. However, the catalyst is typically as-produced (
That is, the metal oxide is added). Processes that operate in this manner include boiling bed hydrocrackers (such as the H-Oil ^™ process), moving bed hydrotreaters, operating catalyst replacement reactors (OCR) and fixed bed bottoms hydrotreaters. Including the protective reactor used in.

In the application of ebullated bed treatments using first generation low activity catalysts, minimal benefits have been identified for the presulfiding of the daily added catalysts. These catalysts achieve some presulfiding when added to the hydroconversion reactor. However,
In such operations using new second and third generation catalysts (high desulfurization, low sediment), a significant increase in desulfurization, denitrification and removal of Conradson carbon is achieved by presulfiding the added catalyst. obtain.

The benefits of catalyst presulfiding are generally well known in the prior art. For example, the use of high boiling point oils, such as vacuum gas oils, and hydrocarbon solvents that aid in the incorporation of sulfur into the catalyst is taught in US Pat. Further, U.S. Pat. No. 6,096,849 issued July 23, 1985 by Berrebi discloses a method of presulfiding a hydrotreating catalyst with an organic polysulfide.

[0010] Herrington et al., Published on Dec. 4, 1979, disclose a method for presulfiding a catalyst in which the catalyst is treated with elemental sulfur. Then hydrogen
Used as a reducing agent to convert elemental sulfur in situ to hydrogen sulfide. U.S. Pat. No. 6,037,049 issued May 16, 1978 by Kittrell et al. Discloses pretreating a catalyst with elemental sulfur in the presence of hydrogen. All of the above patents are incorporated herein by reference.

[0011]

[Patent Document 1]   U.S. Pat. No. 4,943,547.

[0012]

[Patent Document 2]   U.S. Pat. No. 4,530,917.

[0013]

[Patent Document 3]   U.S. Pat. No. 4,117,136.

[0014]

[Patent Document 4]   U.S. Pat. No. 4,089,930.

[0015]

The present invention provides for the achievement of catalyst presulfiding and preconditioning during normal factory operation, but prior to the addition of the catalyst to the catalytic reactor. An improved method has been described and the invention can be achieved in most situations with minimal modification of the device. This has the benefit of enabling the basic application and retrofitting existing equipment. Further, the present invention contemplates the hydrotreating of residual oils or the preconditioning of hydrocracking catalysts without interrupting the continuous operation of the residual oil hydroconversion process.
Importantly, the resid hydroconversion process of the present invention can operate continuously for several years while maintaining high catalytic activity.

It is an object of the present invention to treat a hydrotreating and / or hydrocracking catalyst in a manner which maximizes the activity of the catalyst when added to the hydrotreating and / or hydrocracking reactor. Pre-sulfiding.

A further object of the present invention is to prepare a new or regenerated, safe and stable presulfurized hydrotreating and / or hydrocracking catalyst.

A further object of the present invention is to provide a pre-sulphurised hydrotreating and / or hydrotreating catalyst which, upon activation in situ, provides a very active hydrotreating and / or hydrocracking catalyst. It is to provide a hydrocracking catalyst.

Another object of the present invention is a presulfurized hydrotreating and / or hydrocracking catalyst that can rapidly reach harsh hydrocracking conditions without a rapid loss of activity. Is to provide.

Another object of the present invention is to precondition the residual oil hydrotreatment or hydrocracking catalyst without interrupting the continuous operation of the residual oil hydroconversion process.

[0021]

SUMMARY OF THE INVENTION The present invention describes an improved method of presulfiding and preconditioning a bottoms hydrotreatment or hydrocracking catalyst as an integrated part of a hydroconversion process. Has been done. Furthermore, this method allows for catalysts that are added intermittently or continuously during operation without interrupting the hydroconversion process. This method is used to condition, activate or presulfurize fresh or regenerated catalyst before adding it to a hydroconversion reactor using the product stream from the hydroconversion process. To be done.

In particular, the present invention is directed to hydrotreating and / or for use in resid hydroconversion processes.
Or a method for improving the activity and maintenance of activity of a hydrocracking catalyst, comprising: (a) exposing a metal oxide catalyst to a stream rich in H ₂ S and H ₂ within a hydroconversion process. And at least partially converting the metal oxide catalyst to a metal sulfide, and (b) conditioning by passing the catalyst through a liquid hydrocarbon stream,
It is a method of performing the above steps without interrupting the continuous operation of the residual oil hydroconversion process.

More specifically, the present invention provides a method for improving the activity and maintenance of hydrotreating and / or hydrocracking catalysts used in the hydroconversion process of residual oils, comprising: The method comprises: (a) bringing a metal oxide catalyst into a stream rich in H ₂ S and H ₂ in a hydroconversion process;
By exposing the catalyst to a temperature of about 300-750 ° F., a pressure of atmospheric pressure to 3000 PSIG, and an amount of H ₂ S sufficient to increase the sulfur content of the treated catalyst to 5-15 wt%. Presulfurization, (b) a liquid hydrocarbon stream, such as atmospheric or vacuum gas oil, and H ₂ S and H ₂ to deposit low levels of carbon (1-5% by weight) on the presulfurized catalyst. ₂ and a stream rich in ₂ are passed through the catalyst for 15 minutes to 10 hours at a temperature of about 500 to 750 ° F. and a reactor pressure of atmospheric pressure to 3000 PSIG for 15 minutes to 10 hours. A method is described for carrying out the above steps without interrupting the continuous operation of the conversion process.

FIG. 2 is a schematic flow sheet of the catalyst preconditioning system. Fresh or regenerated catalyst used in this process is added to the catalyst addition vessel (22) from the catalyst feed hopper (20) in the as-received metal oxide state. Suitable catalysts for the residual oil hydroconversion process include catalysts containing nickel, cobalt, tungsten, molybdenum or combinations thereof supported on a porous support such as silica, alumina, titania or combinations thereof. . Catalyst addition container
(22) is then evacuated and / or purged with nitrogen to remove oxygen and moisture from the vessel.

The catalyst addition vessel (22) containing the fresh catalyst is then pressurized with a gas containing hydrogen and hydrogen sulfide to the pressure of the downstream medium pressure amine absorber (26) to pre-sulfide the catalyst. . This H ₂ S-rich hydrogen stream (10) may come from many sources available within the flowsheet of the resid hydroconversion process. These sources can be (i) high pressure cold separator (58), (ii) warm high pressure separator (56), or (iii) any H ₂ and H ₂ S rich recovered in this process. Including flow. These sources are shown in FIG. A stream rich in _{H 2 / H 2 S (10} ) is typically obtained with temperatures of pressure and 100 to 800 ° F for 400～3000PSIG.

Presulfiding the catalyst is preferably carried out at a temperature of about 300-750 ° F. and increasing the pressure from atmospheric pressure to a pressure close to that of the resulting stream (ie 400-3000 PSIG). Furthermore, the H ₂ S concentration in the supply gas is preferably 1 to 10% by volume. Furthermore, to ensure complete presulfiding, it is desirable to treat the catalyst with an amount of H ₂ S that is at least 50% greater than that required to convert the metal oxide to the metal sulfide state.

Grace GR-25, Criterion HDS-2443B or A
Using typical commercial hydroconversion catalysts, such as KZO Nobel KF-1303, to fully sulphurize the catalyst, about 8-15% by weight of sulfur (in the form of H ₂ S or sulfur in the liquid stream) is required. is necessary. The flow is then passed through the cooler and the vapor / liquid separator via the catalyst added to the hydrocracking reactor, then towards the amine absorber (26) for the removal of H ₂ S and then It starts towards the recovery of hydrogen.

To further enhance the activity and maintenance of activity of the catalyst, the catalyst is then exposed to a stream of hydrocarbons. The distillate hydrocarbon stream (14) is fed from a warm high pressure separator (56) or using atmospheric and / or vacuum gas oil. The same stream (14) is circulated across the catalyst in the catalyst addition vessel (22) with the stream (10) rich in H ₂ and H ₂ S. The temperature of the hydrocarbon stream is from atmospheric pressure to the pressure of the resulting stream (400-3000 PSIG), typically 500-750 ° F.

This step completes the presulfiding and preconditioning process of the present invention. At this point, a reasonably low level of carbon (coke) (typically 1-5% by weight) has been deposited on the catalyst. This coke layer has a high severity (typically 750-8).
50 ° F.) residual oil hydrocracking When the catalyst is first added to the environment,
Protects the catalyst from surface temperature exotherms.

Once the catalyst has been presulfidized and preconditioned in the manner described above, the catalyst is ready to be added to the resid hydroconversion process. The catalyst addition vessel (22) has a flow (14)
Filled with liquid hydrocarbons from and is pressurized with hydrogen to the reactor pressure. The catalyst is then carried with liquid hydrocarbons into one of the reactors (50) (52) and added to the reactor for treatment of residual oil hydrocarbons. The reactors 50, 52 are shown in both FIGS. 2 and 1, which is a schematic diagram of the overall resid hydroconversion process.

The significant effect of presulfiding the residual oil hydroconversion catalyst can be seen in FIG. The figure shows data for a commercial resid hydroconversion plant operating with 100% presulfurized catalyst initially and without the addition or removal of operating catalyst. The desulfurization performance of the first real catalyst is better than that predicted from correlations based on small scale trials. It is important to note that this model prediction is based on 100% presulphurized catalyst. Desulfurization performance decreased as the catalyst ages by feeding vacuum residue feedstock. The model predictions are 4-5 wt% HDS lower than the actual data, but follow the decreasing trend of HDS. 40
After a day, the addition of the catalyst during operation (on the catalyst not pre-sulphurized) and the removal of
It was done on a regular basis.

However, the desulfurization activity did not recover to the activity expected from the correlation since the catalyst was not pre-sulphurised. The application of the present invention is expected to restore the desulfurization activity of the catalyst to the expected level.

It is believed that the scope and limitations provided in the specification and claims particularly point out and distinctly claim the invention. However, other ranges and limitations, which carry out substantially similar functions and have similar or substantially similar results in a substantially similar manner, are defined by the specification and claims. It is understood that, as has been done, it is intended to be within the scope of the present invention.

[0034]

DETAILED DESCRIPTION OF THE INVENTION

The invention is illustrated by the examples below. These examples are provided for illustrative purposes and should not be construed as limiting the invention.

Example 1 In a residual oil hydroconversion process similar to that shown in FIG. 1, a fresh or regenerated nickel-molybdenum catalyst is shown in FIG. 2 at room temperature and atmospheric pressure via a lock hopper. It is supplied to a catalyst addition container similar to that described above. The vessel is then evacuated of air and moisture using one line and the vessel is purged with nitrogen using the other line. Then, the catalyst in the catalyst addition vessel is pre-sulfided by supplying a hydrogen purge gas rich in H ₂ S from a high pressure cold separator. In this example, streams were obtained at 130 ° F. and 2760 PSIA with 2.2% by volume H ₂ S and 7%.
It contains 5% by volume of H ₂ with the balance being mostly light hydrocarbons. The catalyst was nickel-molybdenum on alumina extrudate, Criterion HDS
It is called -2443B catalyst.

The flow is started with the process gas at 130 ° F. and atmospheric pressure, while the str
eam) is heated to the desired presulfiding temperature of about 300-750 ° F. The catalyst addition vessel is slowly pressurized to the pressure of the downstream medium pressure amine absorber. The flow is then started towards the amine absorber for the removal of H ₂ S and then towards the recovery of hydrogen. 1
For 00 lbs of fresh nickel-molybdenum catalyst, about 12 lbs. Of sulfur was passed through the catalyst bed to drive the H ₂ S and H ₂ rich process gas flow until complete presulfiding of the catalyst was achieved. to continue. Then the flow is stopped.

The heavy oil transport oil is then filled with the oil into the catalyst addition vessel, the oil is passed through the catalyst and the catalyst is heated to the range of 500-650 ° F. for transfer to the hydroconversion reactor. . The catalyst addition vessel is then pressurized with hydrogen from the hydroconversion process to the reactor conditions and the catalyst is conveyed to the hydroconversion reactor. This method is typically 1
It can be done within 2 hours. During this time, the resid hydroconversion process operates in a continuous manner at temperatures and pressures that result in the desired product yield and quality.

Example 2 In a residual oil hydroconversion process similar to that shown in FIG. 1, a fresh or regenerated nickel-molybdenum catalyst is shown in FIG. 2 at room temperature and atmospheric pressure via a lock hopper. It is supplied to a catalyst addition container similar to that described above. The vessel is then evacuated of air and moisture using one line and the vessel is purged with nitrogen using a different line.

The catalyst in the catalyst addition vessel is then presulfidized by feeding a portion of the H ₂ S-rich vapor stream exiting the warm high pressure separator (illustrated as (56) in FIG. 1). To do.
The stream was obtained at about 525 ° F. and 2800 PSIA and contains 3% by volume H ₂ S and 75% by volume H ₂ with the balance being mostly light hydrocarbons. The catalyst is nickel-molybdenum on alumina extrudate and has the name Grace GR-25 catalyst. Flow is initiated towards the catalyst addition vessel, which is pressurized to the pressure of the downstream medium pressure amine absorber.

The stream is then settled through a catalysis vessel towards a medium pressure amine absorber for H ₂ S removal and then towards hydrogen recovery. Gradually heat the catalyst to 525 °
Presulfide with a high pressure vapor stream containing H ₂ S at a temperature of F and a pressure of about 400 PSIG. About 12 for 100 pounds of new nickel-molybdenum catalyst
Continue processing until one pound of sulfur has passed through the catalyst bed to achieve complete catalyst presulfiding. At these conditions, about 8 pounds of sulfur are retained on the catalyst.

A portion of the liquid stream from the warm, high pressure separator is then mixed with the vapor stream used for presulfiding (as described above). The combined streams are then fed across the catalyst for 15 minutes to 10 hours to condition the catalyst. The catalyst contains about 1-5 wt% carbon after being exposed to the combined stream.

The flow is then terminated towards downstream equipment, the catalyst addition vessel is filled with liquid hydrocarbons, and hydrogen from the hydroconversion process (illustrated as (60) in FIG. 1) is used,
Pressurize close to reactor pressure. The catalyst is then conveyed to the hydroconversion reactor using liquid hydrocarbons obtained from the high pressure, warm separator.

The invention described herein has been disclosed in terms of specific embodiments and applications. However, these details are not meant to be limiting, and other embodiments
It will be apparent to those skilled in the art in view of this teaching. Therefore, it is to be understood that the drawings and description are illustrative of the principles of the invention and that the drawings and description should not be construed as limiting its scope.

[Brief description of drawings]

FIG. 1 is a flow sheet outlining a residual oil hydroconversion process.

FIG. 2 is a flow sheet outlining a catalyst preconditioning system.

FIG. 3 is a graph of desulfurization rate versus time showing the effect of catalyst presulfiding.

[Explanation of symbols]

(20)… Catalyst supply hopper (22) ... Catalyst addition container (26) ... Medium pressure amine absorber (50) (52) ... Reactor (56)… Warm high-pressure separator (58) ... cold high pressure separator

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] June 18, 2002 (2002.18.18)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

7. The liquid hydrocarbon stream from conditioning step (b) is selected from the group consisting of atmospheric gas oil, vacuum gas oil, and liquid hydrocarbon stream available in the process. The method described.

8. A stream rich in H ₂ S and H _{2 in} which the vapor stream for the presulfiding step (a) contains 60-90% H ₂ and 1-5% H ₂ S. The method of claim 7 , wherein:

9. Adjustment step (b) results in a 1 to 10 wt% of the coke deposited on the catalyst, the process of claim 1.

10. The method of claim 1, wherein the conditioning step (b) results in 1-5% by weight coke deposited on the catalyst.

11. Adjustment step (b), 3 00~800 ° F (149~427
The method according to claim 1, which is carried out at a temperature of ° C.

Claims (14)

[Claims] 1. A hydrotreatment and / or used in a residual oil hydroconversion process.
Or a method for improving the activity and maintenance of activity of a hydrocracking catalyst comprising: (a) a metal oxide catalyst in a hydroconversion process, a stream rich in H ₂ S and H ₂ (str).
eam) to convert the metal oxide catalyst at least partially to a metal sulfide, and (b) conditioning the catalyst by passing it through a liquid hydrocarbon stream.
ing), without interrupting the continuous operation of the residual oil hydroconversion process,
A method of performing the above steps. 2. The process is a fixed bed bottoms hydrotreating process having a guard bed, wherein the guard bed is periodically in operation and out of service, and in the bottoms feedstock. The method of claim 1, wherein the metal contamination of is removed. 3. A process according to claim 1, wherein the process is a moving bed resid hydroconversion process or an on-site catalyst replacement (OCR) used. 4. The method of claim 1, wherein the feedstock is petroleum vacuum gas oil, deasphalted oil, heavy coker gas oil, FCC slurry oil or gas oil derived from coal. 5. The method of claim 1 wherein the process is a boiling bed hydroconversion process having one, two or three reactor stages. 6. A process according to claim 1, wherein the catalyst is presulfurized such that 2-10% by weight of sulfur is deposited on the catalyst. 7. The method of claim 1 wherein no preconditioning of the presulfidized catalyst is performed to deposit low levels of carbon on the catalyst. 8. The liquid hydrocarbon stream from conditioning step (b) is selected from the group consisting of atmospheric gas oil, vacuum gas oil, and liquid hydrocarbon stream available in the process. The method described. 9. A stream rich in H ₂ S and H _{2 in} which the vapor stream for the presulfiding step (a) contains 60-90% H ₂ and 1-5% H ₂ S. The method of claim 8, wherein the method is: 10. The method of claim 1 wherein conditioning step (b) results in 1-10 wt% coke deposited on the catalyst. 11. The method of claim 1 wherein conditioning step (b) results in 1-5 wt% coke deposited on the catalyst. 12. The method of claim 1, wherein conditioning step (b) is conducted at a temperature of about 400-800 ° F. 13. The method according to claim 1, wherein the adjusting step (b) is carried out at a reactor pressure of atmospheric pressure to 3000 PSIG. 14. The method according to claim 12, wherein the adjusting step (b) is carried out at a reactor pressure of atmospheric pressure to 3000 PSIG for 15 minutes to 10 hours.