RU2416462C2 - Hydrocracking catalysts for vacuum gas-oil and demetallised mix - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to catalyst and method of hydrocarbon treatment. Catalyst is intended for treatment of VGO/DMO to transform VGO/DMO into useful hydrocarbon products with shorter chains. Note here that VGO/DMO mix comprises less than that 10 % by volume of DMO while catalyst comprises: catalytic carrier material containing mesoporous material MCM-41 wherein major portion of pores inside catalytic material feature diametre varying from 20 to 50 A, catalytic material with which catalytic carrier material is impregnated, and promoter metal on catalytic carrier material intended for increasing catalytic conversion. Note here that said catalytic carrier material with catalytic metal and promoter metal serve to convert catalytically VGO/DMO into hydrocarbon products with shorter carbon chains. Invention covers also method of catalytic conversion of VGO/DMO in the presence of above described catalyst.

EFFECT: possibility to process hydrocarbon VGO/DMO mixes into products with shorter carbon mixes.

30 cl, 5 tbl, 1 dwg, 5 ex

Description

BACKGROUND OF THE INVENTION

Links to related applications

This patent application claims priority in provisional patent application US No. 60/639909, filed December 29, 2004, which in its entirety is incorporated into this application by reference.

Technical field

This invention relates generally to the field of catalytic processing of heavy hydrocarbons to produce the desired hydrocarbon products, in particular to a new catalyst used for the catalytic processing of demetallized oil (DMO).

State of the art

The flexibility of hydrocracking as a way to improve the quality of oil has led to its phenomenal development over the past 15 years. Through catalytic processing, the feed can be converted to lower boiling or higher quality products. Hydrocarbon feeds suitable for such processing range from oil residue to naphtha. Products include materials as diverse as gasoline, kerosene, middle distillate fractions, lubricating oils, boiler fuel, and various chemicals.

Industrial hydrocracking is usually carried out in a single-stage reactor or in a two-stage reactor with sequential stages. Numerous hydrocracking catalysts have been studied to process various hydrocarbons, reduce undesirable side effects of catalytic processing, and / or increase the life of the catalyst. Development has also led to catalysts suitable for harsh environments. Continuous work is underway to increase economic efficiency. The choice of catalysts and the specific process flow will depend on many factors, such as the properties of the feed, the desired properties of the products, the size of the hydrocracking unit and various other economic considerations.

While hydrocracking studies and heavy vacuum gas oil (VGO) were previously aimed at hydrocracking, there is a need to focus on refining heavier and more diverse hydrocarbons, such as deasphalted oil (DAO) or demetallized oil (DMO), into a product suitable for gas pipelines, aviation fuels and diesel fuels in accordance with geographical and seasonal fluctuations in demand. Liquefied petroleum gas (LPG) and lubricant bases would also be desirable products. An advantage would be a catalyst that is capable of working with large hydrocarbon molecules and heavy polyaromatic molecules, in particular with DMO. A particular advantage would be a catalyst that can process the VGO / DMO feed mixture. Since it is known that the world market is leaning towards heavier hydrocarbons, a catalyst suitable for such heavy hydrocarbons would provide an advantage.

SUMMARY OF THE INVENTION

The present invention includes a catalyst and a process for processing heavy hydrocarbons using this catalyst. The catalyst is particularly suitable for the processing of demetallized oil (DMO) and is particularly suitable in the case of a VGO / DMO hydrocarbon mixture. The function of the catalyst is to catalytically convert the VGO / DMO mixture into useful hydrocarbon products having shorter chains. The catalyst includes a catalytic carrier material, a catalytic metal impregnating a catalytic carrier material, and a promoter metal on a catalytic carrier material, which serves to increase catalytic conversion. A combination of a catalytic support material and a catalytic metal, also called an active metal, and a promoter metal is exploited to catalytically convert VGO / DMO into hydrocarbon products having shorter carbon chains.

In a preferred embodiment, the catalytic metal component comprises molybdenum and the promoter metal includes nickel.

In the case of catalytic carrier materials, one preferred embodiment includes ultra-stable Y (USY) zeolite as a catalytic carrier material. As a binder for the entire catalyst obtained in this study, γ-alumina was used. The amount of γ-alumina used was approximately 70% of the total catalyst carrier for test runs. In a most preferred embodiment, the USY zeolite was present in the absence of γ zeolite.

The most preferred catalytic carrier material includes the mesoporous material MCM-41.

In another preferred embodiment, the catalytic carrier material is β-zeolite. In yet another preferred embodiment, the catalytic support material is an amorphous aluminosilicate, also called ASA. ASA has a heterogeneous structure with low acidity and a large surface area. The heterogeneous structure tends to generate acidic sites that are not accessible to large molecules, which causes the poor performance of the ASAs per se compared to the MCM-41 or to the combination of the MCM-41 and ASA. Similarly, USY- and β-zeolite carriers suffer from the disadvantages associated with the microporous nature of the carriers, which makes the catalyst less effective in the case of large molecules, since diffusion is limited. These carriers, used on their own, tend to clog quickly, thereby deactivating the catalyst. MCM-41, alone or in combination with USY- or β-zeolite carriers, is devoid of these disadvantages. In a preferred embodiment, the catalytic carrier material is exclusively superstable zeolite Y, mesoporous material MCM-41, β-zeolite, amorphous aluminosilicate, or combinations thereof. The most preferred embodiment includes a single catalytic carrier material, which essentially all is MCM-41. This material is mesoporous, that is, it is well structured and has a uniform morphology with a large surface area. It also has less acidity than beta or USY carrier materials. The invention includes the use of a suitable carrier material and a balance between the acid and metal function with a suitable distribution of metals throughout the carrier material. This is achieved due to the characteristic properties of the very well-structured morphology of the MCM-41 carrier material, which contains both acidic and metallic regions that are accessible to large hydrocarbon molecules present in VGO and DMO. For this reason, a high conversion is achieved. The advantage is that the lower acidity of the MCM-41 compared with other carrier materials increases the selectivity of conversion to middle distillate fractions and limits the formation of undesirable light gases.

In a preferred embodiment of the invention, the catalytic metal is present in the form of a sulfide. For example, molybdenum in the form of molybdenum sulfide is preferred. Similarly, when tungsten is used as the catalytic metal, tungsten sulfide is a preferred embodiment.

In a preferred embodiment, promoter metals include exclusively nickel, cobalt, or combinations thereof.

The catalyst of the invention is particularly suitable for a VGO / DMO hydrocarbon mixture containing at least 10% DMO by volume. Test runs were conducted for a VGO / DMO hydrocarbon mixture containing at least 15% DMO by volume.

The catalytic support is impregnated with a catalytic metal and a promoter metal by methods known in the art, such as co-impregnation or sequential impregnation.

A catalytic conversion process comprising heavy hydrocarbons of demetallized oil comprises the steps of introducing heavy hydrocarbon-containing demetallized oil into the reactor stage and introducing the catalyst into the reactor stage. The catalyst introduced into the reactor stage includes a catalytic carrier material, a catalytic metal impregnating the catalytic carrier material, and a promoter metal on the catalytic carrier material, which serves to increase catalytic conversion. A catalytic carrier material with a catalytic metal and a promoter metal is used to catalytically convert at least a portion of the demetallized oil into hydrocarbon products having shorter carbon chains.

In the method, a predetermined temperature of a reactor operated to achieve conversion is achieved and held. In a preferred embodiment, the predetermined temperature is at least 390 ° C. In a most preferred embodiment, the predetermined temperature is at least 400 ° C.

In a preferred embodiment, most of the pores of the catalyst support have a size in the range of 20 to 50 Å, and the catalyst support has a large surface area, as determined by the pore size distribution. Table 1 shows examples of preferred embodiments.

Table 1
Structural characteristics of the obtained catalysts Sample BET surface area (m ² / g) Pore volume (cm ³ / g) The average pore diameter (Å) NiMo-ASA 186 0.33 36 NiMo-MCM-41 324 0.40 25 NiMo-β 313 0.41 26 NiMo-USY 300 0.35 23

Brief Description of the Drawings

In order that the method of presenting the characteristic features, advantages and objectives of the invention, as well as other things that will become clearer, can be understood more fully, a more specific description of the briefly described invention can be obtained by referring to the options for its implementation, which are illustrated in the accompanying drawings that are part of this description. It should be noted, however, that the drawings illustrate only a preferred embodiment of the invention and, therefore, should not be construed as limiting the scope of the invention, as it encompasses other equally effective embodiments.

The drawing shows a schematic representation of a preferred implementation of the method using the catalyst according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Several catalysts were prepared using nickel (Ni) / molybdenum (Mo) metal charges along with the four different carrier materials mentioned above. The four catalytic compositions obtained by this method were characterized using a gas sorption analyzer, temperature programmed reduction (TPR) and temperature programmed desorption (TPD). In addition, catalytic formulations were tested in a batch reactor and compared with a commercial catalyst. The result of this study showed that a composition comprising an MCM-41 catalyst carrier, resulting in a NiMo-MCM-41 catalyst, worked better for heavy hydrocarbons, especially VGO / DMO mixtures, than a commercial catalyst. The other three catalyst compositions of the invention also had excellent performance. NiMo-MCM-41 showed the highest hydrodesulfurization (HDS) and hydrogenating activities. In addition, it gave a higher conversion and higher diesel yield than a commercial catalyst.

Most hydrocracking catalysts of commercial interest are inherently difunctional because they consist of both a hydrogenation-dehydrogenation component and an acid carrier. The reactions catalyzed by the individual components are completely different from each other. In specific catalysts, the relative strengths of the two components may vary. The balance between these two components affects the ongoing reactions and the resulting products.

table 2 The acidity of all obtained catalysts Catalyst Acidity (mmol / g) Peak Temperature (° C) NiMo-MCM-41 0.33 264 NiMo-ASA 0.50 252 NiMo-β 0.56 233 NiMo-USY 0.59 238

Table 2 shows the TPD data of ammonia for all the hydrocracking catalysts obtained. The acidity of the obtained catalysts is in the range from 0.33 mmol / g (NiMo-MCM-41) to 0.59 mmol / g (NiMo-USY). The lowest acidity of NiMo-MCM-41 is expected since MCM-41 is a silica-based material and contains a small amount of alumina. Therefore, the NiMo-MCM-41 catalyst contains less γ-alumina than the other catalysts obtained.

A catalytic metal such as molybdenum and a metal promoter provide hydrogenation-dehydrogenation functions. As noted, the metal is preferably in the form of a sulfide. Other metals of group VIA and group VIIIA are suitable as promoter metal and catalytic metal. These metals catalyze the hydrogenation of raw materials, making them more reactive to cracking and removal of heteroatoms, and also lead to a decrease in the degree of coking. They also initiate cracking, forming a reactive olefin intermediate by dehydrogenation.

Since hydrocracking of industrial raw materials must be carried out in the presence of hydrogen sulfide and organic sulfur compounds, it is preferable that the metal region be present in the form of a metal sulfide of group VIA, promoted with nickel or cobalt sulfide.

The reactions that occur during hydrocracking go in three main directions. The first direction is non-catalytic thermal cleavage of C-C bonds through the formation of hydrocarbon radicals with the addition of hydrogen (hydropyrolysis). The second direction is the monofunctional breaking of C – C bonds with the addition of hydrogen over hydrogenating components consisting of metals, oxides, or sulfides (hydrogenolysis). The third direction is bifunctional breaking of C – C bonds with the addition of hydrogen over bifunctional catalysts consisting of a hydrogenating component diffusely scattered on a porous, acidic support. In addition to the above reactions, there are other reactions that occur during hydrocracking. These may include hydrodesulfurization, hydrodenitrification, hydrodeoxygenation, olefin hydrogenation and partial aromatics hydrogenation.

Table 3
Experiment design Catalytic systems Catalyst Preparation - a commercial NiMo-MCM-41 NiMo-USY NiMo-β NiMo-ASA Binder γ-alumina, wt.% 70 70 70 70 The carrier, wt.% thirty thirty thirty thirty NiO, wt.% 2.5 2.5 2.5 2.5 MoO ₃ , wt.% 12 12 12 12 Ni, wt.% 2 2 2 2 Mo, wt.% 8 8 8 8 Atomic ratio 0.2 0.2 0.2 0.2 Catalyst Characterization Surface area, m ² / g 324 300 313 186 Pore volume, cm ³ / g 0.4 0.35 0.41 0.33 Pore Size Angstrom 25 23 26 36 Acidity, mmol / g 0.33 0.59 0.56 0.5 Catalyst Testing Batch reactor - - No. of runs 5 one one one one Temperature ° C 410 410 410 410 410 Pressure, kg / cm ² 150 150 150 150 150 The mass of raw materials, g one hundred one hundred one hundred one hundred one hundred The mass of the catalyst, g 3 3 3 3 3

The commercial catalyst used for comparison was DHC-8 from Universal Oil Products (UOP). γ-alumina was used as a binder for the entire catalyst obtained in this test above. The amount of γ-alumina used was 70% of the total catalyst support.

Table 3-2 Description of raw materials Raw Material Properties Vgo DMO VGO / DMO 85% / 15% (vol.) Density 0.92-0.93 0.96-0.97 0.93-0.94 Total nitrogen, wt. parts per million 700-900 1300-2100 1100-1200 Total sulfur, wt.% 2-3 3-3.5 2.6-2.8 Distillation by Method D2887 of the American Society for Testing Materials (ASTM Distillation, D2887) 5%, ° C 279 402 50% max ° C 472 596 495 90% max ° C 543 678 615 Ni + V, wt. parts per million <1 8.0-13.5 2-3

Table 4-7 Conversion of fractions 800-900 ° F and 900-1050 ° F for tested catalysts Conversion% The range of boiling fraction, ° F Commercial NiMo-MCM-41 NiMo-β NiMo-ASA NiMo-USY 800-900 13.37 19.23 17.57 15.78 15.04 900-1050 35.29 36.33 32,74 34.56 35.69 Generally 27.01 29.97 27.01 27.47 27.89

Among the four catalytic formulations described above that are included in this invention, the NiMo-MCM-41 catalyst has the lowest acidity and the largest surface area. This is due to the fact that the MCM-41 is a silica-based material and contains a small amount of alumina. One of the advantages of MCM-41 is that it is mesoporous and has a low acidity. The mesoporosity of the NiMo-MCM-41 catalyst along with its low acidity contributes to the highest conversion and the greatest reduction in gas yield.

Although the invention is illustrated or described only by the example of several options, specialists in this field will be clear that this is not its limitation, but various options are acceptable within the scope of the present invention.

Claims (30)

1. A catalyst for processing a hydrocarbon mixture of vacuum gas oil / demetallized oil (VGO / DMO) for the catalytic conversion of a hydrocarbon mixture of VGO / DMO into useful hydrocarbon products having shorter chains, and this hydrocarbon mixture of VGO / DMO contains at least 10% demetallized oil (DMO) by volume, and the catalyst includes: a catalytic carrier material, including the mesoporous material MCM-41, where most of the pores inside the catalytic carrier material have diameters from 20 to 50 Å, the catalytic the metal impregnated with the catalytic support material and the metal promoter on the catalytic support material, which serves to enhance the catalytic conversion, where the catalytic support material with a catalytic metal and a promoter metal is operable to catalytically convert VGO / DMO to hydrocarbon products having shorter carbon chains. 2. The catalyst according to claim 1, wherein the catalytic metal is molybdenum and the promoter metal is nickel. 3. The catalyst according to claim 1 or 2, where the catalytic carrier material includes ultra-stable Y-zeolite. 4. The catalyst according to claim 1 or 2, where the catalytic carrier material is only mesoporous material MCM-41. 5. The catalyst according to claim 1 or 2, where the catalytic carrier material comprises β-zeolite. 6. The catalyst according to claim 1 or 2, where the catalytic carrier material includes amorphous aluminosilicate. 7. The catalyst according to claim 1 or 2, where the catalytic carrier material further includes a carrier material selected from the group consisting of ultra-stable Y-zeolite, β-zeolite, amorphous aluminosilicate and combinations thereof. 8. The catalyst of claim 2, wherein at least a portion of the nickel is present in the form of nickel sulfide. 9. The catalyst according to claim 1, where the catalytic metal is selected from the group consisting of molybdenum, tungsten and combinations thereof, and where the promoter metal is selected from the group consisting of nickel, cobalt and combinations thereof. 10. The catalyst of claim 9, wherein at least a portion of the nickel is present in the form of nickel sulfide. 11. The catalyst according to claim 9, where at least part of the cobalt is present in the form of cobalt sulfide. 12. The catalyst according to any one of claims 1, 2, 8-11, where the VGO / DMO hydrocarbon mixture contains at least 15% DMO by volume. 13. The catalyst according to any one of claims 1, 2, 8-11, where the catalytic support is impregnated with a catalytic metal and a promoter metal by co-impregnation. 14. The catalyst according to any one of claims 1, 2, 8-11, where the catalytic support is impregnated with a catalytic metal and a promoter metal by sequential impregnation. 15. A method for the catalytic conversion of heavy hydrocarbons containing demetallized oil (DMO), wherein the heavy hydrocarbons are a vacuum gas oil / demetallized oil (VGO / DMO) hydrocarbon mixture containing at least 10% DMO by volume, comprising the steps of:
introducing heavy hydrocarbon-containing demetallized oil into the reactor stage, introducing the catalyst into the reactor stage, the catalyst comprising: a catalytic carrier material including mesoporous material MCM-41, where most of the pores inside the catalytic carrier material have diameters of 20 to 50 Å, the catalytic the metal impregnating the catalytic support material and the promoter metal on the catalytic support material, which serves to enhance the catalytic conversion, where the catalytic support material with the catalytic metal and promoter metal it is operable to catalytically convert at least a portion of demetallized oil into hydrocarbon products having shorter carbon chains. 16. The method of claim 15, wherein the catalytic metal component is molybdenum and the promoter metal is nickel. 17. The method according to clause 15 or 16, where the catalytic carrier material includes ultra-stable Y-zeolite. 18. The method according to clause 15 or 16, where the catalytic carrier material is only a mesoporous material MCM-41. 19. The method according to clause 15 or 16, where the catalytic carrier material comprises β-zeolite. 20. The method according to clause 15, or 16, where the catalytic carrier material includes amorphous aluminosilicate. 21. The method according to clause 15 or 16, where the catalytic carrier material further comprises a carrier material selected from the group consisting of ultra-stable Y-zeolite, β-zeolite, amorphous aluminosilicate and combinations thereof. 22. The method according to clause 15 or 16, where the catalytic component is a metal selected from the group consisting of nickel, cobalt and combinations thereof, and where the metal promoter is selected from the group consisting of molybdenum, tungsten and combinations thereof. 23. The method according to clause 15 or 16, where the VGO / DMO hydrocarbon mixture contains at least 15% DMO by volume. 24. The method of claim 22, wherein at least a portion of the nickel is present in the form of nickel sulfide. 25. The method according to item 22, where at least part of the cobalt is present in the form of cobalt sulfide. 26. The method according to any one of paragraphs.15, 16 or 25, where the catalytic support is impregnated with a catalytic metal and a promoter metal by co-impregnation. 27. The method according to any one of claims 15, 16 or 25, wherein the catalytic support is impregnated with a catalytic metal and a promoter metal by sequential impregnation. 28. The method according to any one of paragraphs.15, 16 or 25, further comprising the step of maintaining a predetermined temperature in the reactor. 29. The method of claim 28, wherein the predetermined temperature is at least 390 ° C. 30. The method according to p, where a predetermined temperature is equal to at least 400 ° C.

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