HYDROPROCESSING PROCESS FOR THE IMPROVEMENT OF THE CATALYST LIFE

Abstract

This invention relates to a hydroprocessing process for the improvement of catalyst life. Such inventive process is carried out with intermittent or discontinuous addition of a co-feed stream when hydroprocessing petroleum based feedstock or an oxygen containing feedstock. More specifically, it has been found that intermittent or discontinuous addition of the co-feed stream such as carbon monoxide, carbon dioxide, or their precursors to the hydrogen stream can reduce the long term deactivation, extend the life and increase run length of a cobalt/molybdenum hydrotreating catalyst.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional application which claims benefit under 35 USC §119(e) to U.S. Provisional Application Ser. No. 61/360,333 filed Jun. 30, 2010, entitled “HYDROPROCESSING PROCESS FOR THE IMPROVEMENT OF THE CATALYST LIFE,” which is incorporated herein in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

FIELD OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvement of the catalyst life.

BACKGROUND OF THE DISCLOSURE

Hydroprocessing in general refers to a process of contacting a feedstock with hydrogen at an elevated temperature and pressure using catalyst which may vary according to the types of the feedstock, the purpose and the condition of the process.

A classic example of hydroprocessing is the so called hydrotreating process, which refers to a process of contacting a petroleum feedstock with hydrogen at an elevated temperature and pressure using hydrotreating catalyst to, for example, remove or lower the sulfur contaminant from the feedstock. Hydrotreating itself can have different purposes and conditions such as but not limited to hydrogenation, hydrodesulfurization and hydrodenitrogenation, hydrodeoxygenation, and aromatics saturation.

In recent years, laboratory and commercial tests have demonstrated that vegetable oils and/or animal fats can be added to a refinery hydrotreater to produce transportation fuels. However, unlike the petroleum based feedstock, it is found that carbon monoxide and carbon dioxide can be generated in the process of hydrotreating vegetable oils and/or animal fats.

Since it is well known in the literature (Topics in Catalysis (2009) 52:229-240, Bjorn Donnis et al.) that co-feeding CO or CO₂ with H₂ inhibits sulfur removal. It is therefore highly desirable to 1) understand the impact of the CO and CO₂ generated from the process of hydrotreating vegetable oils and/or animal fats oil on catalyst activity, and 2) improve the process and catalyst for hydroprocessing vegetable oils and/or animal fat oil including extending the life of the hydroprocessing catalyst.

BRIEF SUMMARY OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvement of the catalyst life. Such inventive process is carried out with intermittent or discontinuous addition of a co-feed stream when hydroprocessing a petroleum based feedstock or an oxygen containing feedstock. More specifically, it has been found that intermittent or discontinuous addition of the co-feed stream such as carbon monoxide, carbon dioxide, or their precursors to the hydrogen stream can reduce the long term deactivation, extend the life and increase run length of a cobalt/molybdenum hydrotreating catalyst.

One embodiment of the invention relates to a process comprising the steps of a) providing a petroleum based hydrocarbon feedstock; b) providing a hydroprocessing catalyst; c) providing a co-feed stream; and d) contacting the petroleum based hydrocarbon feedstock with the hydroprocessing catalyst under hydroprocessing conditions with intermittent or discontinuous addition of the co-feed stream. The co-feed stream refers to CO, CO₂, or their precursor.

Another embodiment of the invention relates to a process comprising the steps of a) providing an oxygen containing feedstock; b) providing a hydroprocessing catalyst; c) providing a co-feed stream; d) contacting the oxygen containing feedstock with the hydroprocessing catalyst under hydroprocessing conditions with intermittent or discontinuous addition of the co-feed stream. The co-feed stream refers to CO, CO₂, or their precursor.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a graph showing the effect of CO, CO₂ on Product Sulfur.

DETAILED DESCRIPTION OF THE DISCLOSURE

This invention relates to a hydroprocessing process for the improvement of the catalyst life. Such inventive process is carried out with intermittent or discontinuous addition of a co-feed stream when hydroprocessing a petroleum based feedstock or an oxygen containing feedstock. More specifically, it has been found that intermittent or discontinuous addition of the co-feed stream such as carbon monoxide, carbon dioxide, or their precursors to the hydrogen stream can reduce the long term deactivation, extend the life and increase run length of a cobalt/molybdenum hydrotreating catalyst.

Turning now to the detailed description of the preferred arrangement or arrangements of the present invention, it should be understood that the inventive features and concepts may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow.

According to the first embodiment of the current invention, there is provided a process for hydroprocessing a petroleum based hydrocarbon feedstock to make fuel product by contacting the petroleum based hydrocarbon with hydroprocessing catalyst under hydroprocessing conditions with intermittent or discontinuous addition of a co-feed stream. The co-feed stream refers to CO, CO₂, or their precursor.

According to the 2^nd embodiment of the current invention, there is provided a process for hydroprocessing an oxygen containing feedstock to make fuel product by contacting the oxygen containing feedstock with hydroprocessing catalyst under hydroprocessing conditions with intermittent or discontinuous addition of a co-feed stream. The co-feed stream refers to CO, CO₂, or their precursor.

The term “hydroprocessing” in general refers to a process for contacting a feedstock with a treating gas at an elevated temperature and pressure using catalyst which may vary according to the types of the feedstock, the purpose and the condition of the process. Hydroprocessing conditions include temperatures in the range from about 250 to about 800° F. and pressure in the range from about 100 psig to about 2500 psig.

Hydroprocessing in general is carried out in the presence of a catalytically effective amount of hydroprocessing catalyst containing metals. Such catalysts generally involve a carrier such as a refractory inorganic oxide having deposited thereon a metal that may be selected from Groups 3-10 of the Periodic Table based on the IUPAC format having Groups 1-18. According to one embodiment of the invention, the metal is selected from Groups 3-10. According to another embodiment, the metal is selected from Groups 6 and 8-10 including but not limited to Mo, W, Ni, Co, and Ru. Unsupported hydroprocessing catalysts can also be used in hydroprocessing process.

Commercial hydroprocessing catalysts are readily available from a variety of sources including ALBEMARLE, ADVANCED REFINING TECHNOLOGIES (ART), PGM CATALYSTS & CHEMICALS, AMERICAN ELEMENTS, EURECAT, FISCHER, HALDOR TOPSOE, HEADWATER, SIGMA, and other chemical suppliers. Catalysts may be microsized, nanosized, fluidized or other catalyst forms dependent upon the reactor size, shape and conditions under which the reaction is run.

The term hydroprocessing includes but not limited to hydrotreating, hydrocracking, and any process in which a hydrocarbon feed is reacted with a treating gas (e.g. hydrogen for hydrotreating process).

Hydrotreating process refers to a process of contacting a petroleum feedstock or oxygen containing feedstock with hydrogen at an elevated temperature and pressure using hydrotreating catalyst to, for example, remove or lower the sulfur contaminant from the feedstock. Hydrotreating itself can have different purposes and conditions such as hydrogenation, and hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO) and aromatics saturation.

Hydrotreating process conditions include temperatures in the range from about 250 to about 800° F., pressure in the range from about 100 psig to about 2500 psig. The hydrogen treat gas rate in the range of about 100 to 10,000 scf/B (standard cubic feed gas per barrel of liquid) and a liquid hourly space velocity in the range of about 0.1 to about 10 hr.⁻¹.

The hydrotreating process in general is carried out in the presence of catalyst containing at least one metal from Groups 6, 8, 9 and 10 of the Periodic Table, based on the IUPAC format having Groups 1-18. In one embodiment, such catalysts include Co, Mo, Ni, W, and Ru. In the case of hydrogenation, hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO), and aromatics saturation, such catalysts contain Co, Mo, Ni, W, and mixtures thereof such as Co/Mo, Ni/Mo, Ni/W and Ni/Mo/W. These catalysts are usually supported on a refractory inorganic oxide support such as alumina, silica, silica-alumina and the like. Unsupported hydroprocessing catalysts can also be used in hydroprocessing processes.

Another example of hydroprocessing is the so called hydrocracking process, which refers to a process of contacting a petroleum based or oxygen containing feedstock with hydrogen at an elevated temperature and pressure using hydrocracking catalyst, for example, NiW on Al2O3-SiO2. Hydrocracking can include several reactions such as hydrocracking, hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO) and aromatics saturation.

Hydrocracking process conditions include temperatures in the range from about 500 to about 900° F., pressures in the range from about 100 to about 2500 psig, hydrogen treat gas rate in the range of about 100 to 10,000 scf/B and a liquid hourly space velocity in the range of about 0.1 to about 10 hr⁻¹.

Hydrocracking catalysts include an acid support serving as cracking component and a hydrogenation component. The cracking component may be amorphous or crystalline. Amorphous cracking catalysts include silica-alumina. Crystalline cracking catalysts are molecular sieves including aluminosilicates such as zeolites and aluminophosphates such as SAPOs. Examples of zeolites as cracking catalysts include Y zeolite, beta zeolite and ZSM-5. Examples of SAPOs as cracking catalysts include SAPO-5, SAPO-34. Hydrogenation components include Group 6 or Group 8-10 metals or oxides include but not limited to one or more of molybdenum, tungsten, cobalt, nickel, or the oxides thereof.

Referring to the 1st embodiment of the invention, the petroleum based hydrocarbon useful for the invention includes but not limited to a full range of feeds from paraffins and light virgin naphthas to whole crudes and include both natural and synthetic feeds. Boiling points for feeds may range from about 100 to greater than about 1000° F. Examples of such feeds include C5+ paraffins, naphthas, kerosene, gasoline, heating oils, jet fuels, diesel, cycle oils, catalytically cracked light and heavy gas oils, hydrotreated gas oil, light flash distillate, vacuum gas oil, light gas oil, straight run gas oil, coker gas oil, synthetic gas oil, deasphalted oils, foots oil, slack waxes, waxes obtained from a Fischer-Tropsch synthesis process, long and short residues, and syncrudes, optionally originating from tar sand, shale oils, residue upgrading processes and etc,

Referring to the 2^nd embodiments of the invention, the oxygen containing feedstock refers to any feed molecules containing oxygen atoms. The oxygen containing feedstock useful for the invention includes but not limited to vegetable oil, animal fats, algae oil, glycols, polyols, sugar alcohols, biomass, and organic compounds containing functional groups that can be reduced (hydrogenated) such as aldehydes, ketones, esters, amides and carboxylic acids. In general, any oxygen containing feedstock may undergo the reactions, such as decarbonylation and decarboxylation to produce carbon monoxide and carbon dioxide, respectively, while undergoing a hydroprocessing process.

Refer to the 1^st and 2^nd embodiments of the invention, the co-feed stream useful for the current invention includes but not limited to CO, CO₂, or their precursor. A CO or CO₂ precursor is a compound which releases CO or CO₂ under hydroprocessing conditions. Examples of such CO or CO₂ generating precursors include carboxylic acids, carbonates, formaldehyde, glyoxal, and carbonyls. Since the oxygen containing feedstock may undergo reactions during hydroprocessing, such as decarbonylation and decarboxylation to produce carbon monoxide and carbon dioxide, respectively, therefore, any oxygen containing feedstocks, such as vegetable oil, animal fats, algae oil, glycols, polyols, sugar alcohols can also serve as CO and CO₂ precursors.

Further referring to the 1^st and 2^nd embodiment of the invention, the feedstock may be contacted with a hydroprocessing catalyst under hydroprocessing conditions including treating gas such as hydrogen. A co-feed stream may be added to the treating gas or directly to the hydroprocessing reactor. Any hydroprocessing reactor known to the people skilled in the art may be used for this invention. The co-feed stream may be added in the matter of, but not limited to, intermittent, discontinuous, pulsed, staged, or non-steady. In one embodiment such intermittent or discontinuous addition of the co-feed stream may occur as follows: co-feed is added for 1 to 10 days, followed by 1 day to 50 weeks without co-feed during the hydroprocessing process. In another embodiment such intermittent or discontinuous addition of the co-feed stream may occur for 1 to 5 days followed by 1 day to 25 weeks without co-feed. In yet another embodiment such intermittent or discontinuous addition of the co-feed stream may occur for 2 or 3 days followed by 4 days to 10 weeks without co-feed.

The following examples of certain embodiments of the invention are given. Each example is provided by way of explanation of the invention, one of many embodiments of the invention, and the following examples should not be read to limit, or define, the scope of the invention.

Example 1

Laboratory and commercial tests have demonstrated that vegetable oils and/or animal fats can be added to a refinery hydrotreater to produce transportation fuels. Since carbon monoxide and carbon dioxide can be generated from oxygen containing feedstocks such as animal fat and vegetable oils in this hydrotreating process, experiments were run to study the effects that CO and CO₂ would have on the performance of a commercially available cobalt/molybdenum catalyst. The evaluation consisted of a seven month test run on a laboratory hydrotreater using a diesel feed with 2000 ppm sulfur. The hydrotreating conditions were set to achieve a product sulfur level of about 10 ppm. The experiment was carried out at 642 F, 1400 scf/B, 600 psig, 1.0 hr⁻¹, Co/Mo catalyst and diesel feed (sulfur level of ˜2000 ppm) as base case. At these conditions, product sulfur level was about 10 ppm at the beginning of the run. During the 7 month test, CO or CO₂ was co-fed with H2 intermittently. The catalyst performance was evaluated based on the product sulfur level.

The result is shown in FIG. 1. Using a commercially available cobalt/molybdenum catalyst and a diesel feed with 2000 ppm sulfur, the product sulfur level was about 10 ppm. Not surprisingly and consistent with results reported in the literature, when CO and/or CO₂ were co-fed with H₂, the product sulfur level increased to a range from 30 to 90 ppm. However, as shown in FIG. 1, when the carbon oxides were removed from the feed, the product sulfur level returned to 10 ppm. More significantly is that the product sulfur level remained at about 10 ppm at base case conditions over this testing period while either CO or CO₂ was co-fed intermittently. There was no catalyst deactivation observed.

In other words, it was found that the intermittent feeding with either CO or CO₂ results in reduced catalyst deactivation and an increase in expected run length which is unexpected. The current invention suggests that periodically adding CO and/or CO₂ increases the useful life of the catalyst over what would be predicted using well established hydrotreating reaction models.

In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as an additional embodiment of the present invention.

Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.

Claims

1. A process comprising

a) providing a feedstock selected from a petroleum based hydrocarbon feedstock or an oxygen containing feedstock;

b) providing a hydroprocessing catalyst;

c) providing a co-feed stream; and

d) contacting said feedstock with said hydroprocessing catalyst under a hydroprocessing condition with an intermittent or a discontinuous addition of said co-feed stream.

2. The process of claim 1 wherein said petroleum based hydrocarbon feedstock is selected from a group consisting of C5+ paraffins, naphthas, kerosene, gasoline, heating oils, jet fuels, diesel, cycle oils, catalytically cracked light and heavy gas oils, hydrotreated gas oil, light flash distillate, vacuum gas oil, light gas oil, straight run gas oil, coker gas oil, synthetic gas oil, deasphalted oils, foots oil, slack waxes, waxes obtained from a Fischer-Tropsch synthesis process, long and short residues, syncrudes, optionally originating from tar sand, shale oils, residue upgrading processes, and any mixture thereof

3. The process of claim 1 wherein said oxygen containing feedstock is any feed molecules containing oxygen atoms.

4. The process of claim 1 wherein said oxygen containing feedstock is selected from a group consisting of vegetable oil, animal fat, algae oil, glycols, polyols, sugar alcohols, biomass, organic compounds, and any mixture thereof

5. The process of claim 4 wherein said biomass or organic compound contains functional groups which can be reduced or hydrogenated.

6. The process of claim 1 wherein said intermittent or discontinuous addition of said co-feed stream occurs for 1 to 10 days followed by 1 day to 50 weeks without co-feed.

7. The process of claim 1 wherein said intermittent or discontinuous addition of said co-feed stream occurs for 2 to 3 days followed by 4 to 10 weeks without co-feed.

8. The process of claim 1 wherein said co-feed stream is CO, CO2, or their precursor.

9. The process of claim 8 wherein said precursor is a compound which releases CO or CO2 under said hydroprocessing condition.

10. The process of claim 8 wherein said precursor is selected from the group consisting of carboxylic acids, carbonates, formaldehyde, glyoxalin, carbonyls, vegetable oil, animal fat, algae oil, glycols, polyols, sugar alcohols, and any mixture thereof.

11. The process of claim 1 wherein said hydroprocessing catalyst is a metal-containing hydroprocessing catalyst.

12. The process of claim 11 wherein said metal is selected from Groups 3-10 of the Periodic Table.

13. The process of claim 11 wherein said metal is selected from a group consisting of Mo, W, Ni, Co, Ru, and mixture thereof.

14. The process of claim 1 wherein said hydroprocessing catalyst is supported on an inorganic oxide support.

15. The process of claims 1 wherein said hydroprocessing condition comprises a temperature in the range from about 250 to about 800° F., a pressure in the range from about 100 to 2500 psig.

16. The process of claims 1 wherein said hydroprocessing process is a hydrotreating process carried out by a hydrotreating catalyst under a hydrotreating condition.

17. The process of claim 16 wherein said hydrotreating condition comprises a temperature in the range from about 250 to about 800° F., and a pressure in the range from about 100 to 2500 psig.

18. The process of claim 16, wherein said hydrotreating catalyst is selected from a group consisting of Co, Mo, Ni, W, and mixtures thereof

19. The process of claim 16, wherein said hydrotreating process is hydrogenation, hydrodesulphurization, hydrodenitrogenation, hydrodeoxygenation or aromatics saturation.

20. The process of claim 1 wherein said hydroprocessing process is a hydrocracking process carried out by a hydrocracking catalyst under a hydrocracking condition.

21. The process of claim 20 wherein said hydrocracking catalyst is selected from a group consisting of Co, Mo, Ni, W and any combination thereof

22. The process of claim 20 wherein said hydrocracking conditions comprises a temperature in the range from about 500 to about 900° F., and a pressure in the range from about 100 to 2500 psig.