JP4898069B2 - Presulfidation and preconditioning method of residual oil hydroconversion catalyst - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improved process for presulfiding a metal oxide-supported catalyst used in hydroprocessing and / or hydrocracking (hydrocracking) of hydrocarbon feedstock, and the presulfided catalyst obtained thereby The present invention relates to compositions and hydrotreating and / or hydrocracking processes using such presulfided metal oxide catalysts. The present invention further relates to an improved method of integrating catalyst presulfidation and residual hydroconversion processes.
[0002]
[Prior art]
A hydroprocessing catalyst can be defined as any catalyst composition that can be used to catalyze the hydrogenation of a hydrocarbon feedstock to increase its hydrogen content and / or remove heteroatom contaminants. . A hydrocracking catalyst is any catalyst composition that may be used to catalyze the addition of hydrogen to a molecule along with a reaction that breaks up 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 petroleum atmospheric pressure or vacuum residue under high temperature and high pressure conditions in the presence of hydrogen and hydrotreating 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).
[0003]
The catalyst compositions used in the residual oil hydroconversion process are well known to those skilled in the art and 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.
[0004]
For maximum effectiveness, these metal oxide catalysts are at least partially converted to metal sulfides. The metal oxide catalyst can be sulfided by contacting it with hydrogen sulfide or a sulfur-containing oil or feedstock at elevated temperatures in the reactor.
[0005]
The catalyst may also be provided to end users who already have incorporated sulfur. However, these ex-situ methods for presulfiding the metal oxide supported catalyst result in excessive sulfur stripping when the hydroprocessing reactor is started in the presence of a hydrocarbon feedstock. I have received it. As a result of sulfur stripping, a decrease in catalytic activity is observed. Thus, it is well known to those skilled in the art that the activity and maintenance of the metal oxide catalyst described above can presulfurize the catalyst during the production process or during the start of an in situ hydroconversion process. By doing so, it is substantially improved.
[0006]
The hydroconversion process can operate in a fixed catalyst bed mode in which a batch of catalyst is placed in the hydroconversion reactor before the process is stopped to remove and replace the catalyst. Typically, it is used for a period of 3 to 24 months. In this fixed bed system, the catalyst can be presulfided during start up of the apparatus to achieve the maximum level of catalyst performance (hydrogenation, desulfurization, denitrification, conversion, etc.).
[0007]
In the hydrotreating / hydrocracking process, this process adds and removes the catalyst on a regular basis (ie, daily, weekly), while the process operates at normal temperature and pressure conditions, Is typically added as prepared (ie, containing metal oxide). Processes that operate in this manner include boiling bed hydrocrackers (such as the H Oil ^TM process), moving bed hydrotreaters, in-service catalyst replacement reactors (OCR), and fixed bed residue hydrotreaters. Including the protective reactor used in
[0008]
In an ebullated bed application using a first generation low activity catalyst, a minimum benefit has been identified for the presulfidation of the catalyst added daily. These catalysts achieve some presulfidation when added to the hydroconversion reactor. However, in such operations using new second and third generation catalysts (high desulfurization, low sediment), the presulfidation of the added catalyst results in a significant increase in desulfurization, denitrification and Conradson carbon removal. Can be achieved.
[0009]
The benefits of catalyst presulfidation are generally well known in the prior art. For example, the use of a high boiling oil such as vacuum gas oil and a hydrocarbon solvent that aids in the incorporation of sulfur into the catalyst is taught in US Pat. Further, Patent Document 2 issued on July 23, 1985 by Berrebi discloses a method for presulfiding a hydrotreating catalyst with an organic polysulfide.
[0010]
Patent Document 3 issued on December 4, 1979 by Herrington et al. Discloses a catalyst presulfiding method in which the catalyst is treated with elemental sulfur. Hydrogen is then used as a reducing agent that converts elemental sulfur into hydrogen sulfide in situ. U.S. Patent No. 6,053,028 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 by reference into this application.
[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]
[Problems to be solved by the invention]
The present invention describes an improved method for achieving catalyst presulfidation and preconditioning during normal factory operation, but prior to catalyst addition to the catalytic reactor. The present invention can be achieved with minimal changes in the apparatus in most situations. This provides the benefit of realizing basic applications and improving existing equipment. Further, the present invention contemplates residual oil hydroprocessing or hydrocracking catalyst preconditioning without interrupting the continuous operation of the residual oil hydroconversion process. Importantly, the residue hydroconversion process of the present invention can operate continuously for several years while maintaining high catalytic activity.
[0016]
The object of the present invention is to presulfide the catalyst in a way that maximizes the activity of the catalyst when the hydrotreating and / or hydrocracking catalyst is added to the hydrotreating and / or hydrocracking reactor. That is.
[0017]
A further object of the present invention is to prepare a new or regenerated, safe and stable presulfided hydrotreating and / or hydrocracking catalyst.
[0018]
A further object of the present invention is to provide a pre-sulfided hydrotreating and / or hydrocracking that provides a highly active hydrotreating and / or hydrocracking catalyst upon in situ activation. It is to provide a catalyst.
[0019]
Another object of the present invention is to provide a pre-sulfided hydrotreating and / or hydrocracking catalyst that can quickly reach severe hydrocracking conditions without rapidly losing activity. That is.
[0020]
Another object of the present invention is to precondition the residual oil hydrotreating or hydrocracking catalyst without interrupting the continuous operation of the residual oil hydroconversion process.
[0021]
[Means for Solving the Problems]
In the present invention, an improved process for presulfiding and preconditioning a residual oil hydrotreating or hydrocracking catalyst is described as an integrated part of the hydroconversion process. In addition, the process allows for a catalyst that is added intermittently or continuously during operation without interrupting the hydroconversion process. This method is used to condition, activate or presulfide the catalyst before adding fresh or regenerated catalyst to the hydroconversion reactor using the product stream from the hydroconversion process. Is done.
[0022]
In particular, the present invention provides a method for improving the hydrotreating and / or hydrocracking catalyst activity and activity used in a residual oil hydroconversion process, wherein the method comprises:
(A) subjecting the metal oxide catalyst in a hydroconversion process to a stream rich in H ₂ S and H ₂ to at least partially convert the metal oxide catalyst to a metal sulfide; and (b And) adjusting the catalyst by passing it through a liquid hydrocarbon stream, the process being carried out without interrupting the continuous operation of the residual oil hydroconversion process.
[0023]
More specifically, the present invention provides a method for improving the activity and maintenance of the hydrotreating and / or hydrocracking catalyst used in a residual oil hydroconversion process comprising:
(A) A metal oxide catalyst in a hydroconversion process, in a H ₂ S and H ₂ rich stream, at a temperature of about 300-750 ° F., a pressure of atmospheric pressure to 3000 PSIG, and sulfur of the treated catalyst. by exposure in an amount sufficient H _{2 S} to increase the content to 5 to 15 wt%, be pre-sulfurized catalyst,
(B) A liquid hydrocarbon stream, such as atmospheric or vacuum gas oil, and a stream rich in H ₂ S and H ₂ to deposit low levels of carbon (1-5 wt%) on the presulfided catalyst. Through a catalyst 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, and the continuation of the residual oil hydroconversion process. A method is described in which the above steps are performed without interrupting general operations.
[0024]
FIG. 2 is a flow sheet outlining the catalyst preconditioning system. The new or regenerated catalyst used in this process is added from the catalyst feed hopper (20) to the catalyst addition vessel (22) in the metal oxide state as received. 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. . The catalyst addition vessel (22) is then evacuated and / or purged with nitrogen to remove oxygen and moisture from the vessel.
[0025]
The catalyst addition vessel (22) containing the new catalyst is then pressurized to the pressure of the downstream intermediate pressure amine absorber (26) with a gas containing hydrogen and hydrogen sulfide, and the catalyst is presulfided. This H ₂ S rich hydrogen stream (10) may come from a number of sources obtained within the flow sheet of the residual oil hydroconversion process. These sources can be (i) a high pressure cold separator (58), (ii) a warm high pressure separator (56), or (iii) any H ₂ and H ₂ S enriched in this process. Including flow. These sources are shown in FIG. A H ₂ / H ₂ S rich stream (10) is typically obtained at a pressure of 400-3000 PSIG and a temperature of 100-800 ° F.
[0026]
The presulfidation of the catalyst is preferably performed at a temperature of about 300-750 ° F., 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 presulfidation, 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.
[0027]
To completely sulfidize the catalyst using a typical commercial hydroconversion catalyst such as Grace GR-25, Criterion HDS-2443B or AKZO Nobel KF-1303, about 8-15 wt% sulfur (liquid flow In the form of H ₂ S or sulfur). The flow is then passed through a catalyst added to the hydrocracking reactor, through a cooler and a vapor / liquid separator, towards an amine absorber (26) for removal of H ₂ S, and then Begins with hydrogen recovery.
[0028]
In order to further enhance the activity and maintenance of the catalyst, the catalyst is then exposed to a hydrocarbon stream. The distillate hydrocarbon stream (14) is fed from a warm high pressure separator (56) or using atmospheric pressure and / or vacuum gas oil. The same stream (14) is circulated across the catalyst together with the stream (10) rich in H ₂ and H ₂ S in the catalyst addition vessel (22). The temperature of the hydrocarbon stream is about 400-800 ° F., typically 500-750 ° F., from atmospheric pressure to the pressure of the resulting stream (400-3000 PSIG).
[0029]
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) is deposited on the catalyst. This coke layer protects the catalyst from surface temperature heating when it is first added to the environment of a high severity (typically 750-850 ° F.) residual hydrocracking reactor. To do.
[0030]
Once the catalyst is presulfided and preconditioned in the manner described above, the catalyst is ready to be added to the residual hydroconversion process. The catalyst addition vessel (22) is filled with liquid hydrocarbons from stream (14) and pressurized to the reactor pressure with hydrogen. The catalyst is then carried along with the liquid hydrocarbons to one of the reactors 50, 52 and added to the reactor for treatment of the residual hydrocarbons. Reactors (50) and (52) are shown in both FIG. 2 and FIG. 1, which is a system diagram of the entire residual oil hydroconversion process.
[0031]
The remarkable effect of the presulfidation of the residual oil hydroconversion catalyst can be seen in FIG. This figure shows data for a commercial residual hydroconversion plant that uses a 100% presulfided catalyst initially and operates without the addition or removal of an operating catalyst. The initial actual catalyst desulfurization performance is superior to that predicted from correlations based on small scale tests. It is important to note that this model prediction is based on a 100% presulfided catalyst. Desulfurization performance decreased as the catalyst aged by supplying a vacuum residue feed. The model prediction is 4-5 wt% lower HDS than the actual data, but follows the decreasing trend of HDS. After 40 days, in-service catalyst addition (with non-presulfided catalyst) and removal were done on a regular basis.
[0032]
However, since the catalyst was not presulfided, the desulfurization activity did not recover to the activity expected from the correlation. The application of the present invention is expected to restore the desulfurization activity of the catalyst to the expected level.
[0033]
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 that perform substantially similar functions in substantially similar ways to achieve similar or substantially similar results are defined by this specification and the claims. As such, it is understood that it is intended to be within the scope of the present invention.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
The invention is illustrated by the following examples. These examples are provided for illustrative purposes and should not be construed as limiting the invention.
[0035]
Example 1
In a residual oil hydroconversion process similar to that shown in FIG. 1, a new or regenerated nickel-molybdenum catalyst is passed through a lock hopper at room temperature and atmospheric pressure, and the same catalyst as shown in FIG. Feed into the addition vessel. The vessel is then evacuated of air and moisture using one line and the vessel is purged with nitrogen using the other line. Next, the catalyst in the catalyst addition vessel is presulfided by supplying a hydrogen purge gas rich in H ₂ S from a high-pressure cold separator. In this example, a stream is obtained at 130 ° F. and 2760 PSIA and contains 2.2% by volume H ₂ S and 75% by volume H ₂ with the remainder being mostly light hydrocarbons. The catalyst is nickel-molybdenum on an alumina extrudate and is referred to as Criterion HDS-2443B catalyst.
[0036]
The flow is started with process gas at 130 ° F. and atmospheric pressure, while the stream is heated to the desired presulfidation temperature of about 300-750 ° F. Slowly pressurize the catalyst addition vessel 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. For a 100 pound fresh nickel-molybdenum catalyst, the H ₂ S and H ₂ rich process gas stream is flowed until about 12 pounds of sulfur has passed through the catalyst bed to achieve complete presulfidation of the catalyst. to continue. The flow is then stopped.
[0037]
The heavy oil transport oil is then filled with the oil into the catalyst addition vessel, the oil is circulated through the catalyst, and the catalyst is heated to a 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 process can typically be performed within 12 hours. During this time, the residue hydroconversion process operates in a continuous manner at temperatures and pressures that provide the desired product yield and quality.
[0038]
Example 2
In a residual oil hydroconversion process similar to that shown in FIG. 1, a new or regenerated nickel-molybdenum catalyst is passed through a lock hopper at room temperature and atmospheric pressure, and the same catalyst as shown in FIG. Feed into the addition vessel. The vessel is then evacuated with air and moisture using a single line, and the vessel is purged with nitrogen using a different line.
[0039]
The catalyst in the catalyst addition vessel is then presulfided by feeding a portion of the H ₂ S rich vapor stream exiting the warm high pressure separator (exemplified as (56) in FIG. 1). A stream is obtained at about 525 ° F. and 2800 PSIA and contains 3% by volume H ₂ S and 75% by volume H ₂ with the remainder being mostly light hydrocarbons. The catalyst is nickel-molybdenum on an alumina extrudate and has the name Grace GR-25 catalyst. The flow is started towards the catalyst addition vessel and this vessel is pressurized to the pressure of the downstream medium pressure amine absorber.
[0040]
The stream is then settled through a catalyst addition vessel towards a medium pressure amine absorber for H ₂ S removal and then towards hydrogen recovery. The catalyst is gradually heated and presulfided with a high pressure steam stream containing H ₂ S at a temperature of 525 ° F. and a pressure of about 400 PSIG. For 100 pounds of new nickel-molybdenum catalyst, processing continues until about 12 pounds of sulfur has passed through the catalyst bed to achieve complete catalyst presulfidation. Under these conditions, about 8 pounds of sulfur is retained on the catalyst.
[0041]
A portion of the liquid stream from the warm high pressure separator is then mixed with the vapor stream used for presulfidation (as described above). The combined stream is 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.
[0042]
The flow is then terminated towards the downstream equipment, the catalyst addition vessel is filled with liquid hydrocarbons, and hydrogen from the hydroconversion process (exemplified as (60) in FIG. 1) is used to pressure the reactor. Pressurize close to. The catalyst is then conveyed to the hydroconversion reactor using liquid hydrocarbons obtained from a high pressure warm separator.
[0043]
The invention described herein has been disclosed in terms of specific embodiments and applications. However, these details are not intended to be limiting and other embodiments will be apparent to those skilled in the art in view of this teaching. Accordingly, it is to be understood that the drawings and descriptions are illustrative of the principles of the present invention and that the drawings and descriptions should not be construed as limiting the scope thereof.
[Brief description of the drawings]
FIG. 1 is a flow sheet outlining a residual oil hydroconversion process.
FIG. 2 is a flow sheet outlining the catalyst preconditioning system.
FIG. 3 is a graph of desulfurization rate versus time showing the effect of catalyst presulfidation.
[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

Claims (12)

In a method for improving the activity and activity maintenance of a hydroprocessing and / or hydrocracking catalyst used in a residual oil hydroconversion process, the method comprises:
(A) subjecting the metal oxide catalyst to a stream rich in H ₂ S and H ₂ coming from a hydroconversion process to at least partially convert the metal oxide catalyst to a metal sulfide; And (b) a step of conditioning the catalyst by passing it through a liquid hydrocarbon stream, wherein the steps (a) and (b) are carried out without interrupting the operation of the residual oil hydroconversion process. How to do.   The process of claim 1, wherein the process is a moving bed residue hydroconversion process or an in-operation catalyst replacement (OCR) used.   The process 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.   The process of claim 1, wherein the process is an ebullated bed hydroconversion process having one, two or three reactor stages.   The process of claim 1 wherein the catalyst is presulfided such that 2-10 wt% sulfur is deposited on the catalyst.   The method of claim 1, wherein 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 vapor stream for the presulfidation step (a) is a H ₂ S and H ₂ rich stream containing 60-90% H ₂ and 1-5% H ₂ S. The method described.   The process of claim 1 wherein the conditioning step (b) results in 1 to 10 wt% coke deposited on the catalyst.   The process of claim 1 wherein the conditioning step (b) results in 1-5 wt% coke attached to the catalyst. Adjustment step (b), 4 00-800 at a temperature of ° F (204~427 ℃), The method of claim 1, wherein. The process according to claim 1, wherein the conditioning step (b) is carried out at a reactor pressure of from atmospheric to 3000 PSIG (20.6 MPa) . The method according to claim 10, wherein the adjusting step (b) is carried out at a reactor pressure of from atmospheric pressure to 3000 PSIG (20.6 MPa) for 15 minutes to 10 hours.

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