JPS582997B2 - Method for hydrogenation treatment of heavy hydrocarbon streams - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heavy hydrocarbon stream containing asphaltene materials, metals, nitrogen compounds and sulfur compounds.
Hydrocarbon streams) in the presence of hydrogen.

It is widely known that various organometallic compounds and asphaltenes are present in petroleum crude oil and other petroleum hydrocarbon streams, such as petroleum hydrocarbon residues tar sands derived hydrocarbon streams and coal derived hydrocarbon streams. Are known.

The metals most commonly found in such hydrocarbon streams are nickel, vanadium and iron.

Such metals are highly detrimental to various petroleum refining operations such as hydrocracking, hydrodesulfurization and catalytic cracking.

Metals and asphaltenes plug the voids in the catalyst bed and also reduce catalyst life.

Various metals deposited on the catalyst tend to poison or render it inactive.

Furthermore, asphaltenes tend to reduce the susceptibility of hydrocarbons to desulfurization.

When catalysts such as desulfurization catalysts or fluidized bed cranking catalysts are exposed to metals and asphaltenes,
This catalyst will quickly become inactive and may have to be quickly removed from a particular reactor or replaced with fresh catalyst.

Hydrogenation treatment (
Hydrotreating (hydrotreating) methods are known that do not involve appreciable asphaltene precipitation and reactor clogging of such feedstocks, and also provide effective removal of metals and other contaminants such as sulfur and nitrogen compounds. It is less conventional to use fixed bed catalytic methods for the accompanying conversions.

While the heavy portions of hydrocarbon streams were once used as low-quality fuels or as feedstock for asphalt-type materials, current politics and economics have shifted to hydrotreating such materials to remove attendant contaminants from them. There is a need to obtain a higher proportion of usable materials from such raw materials.

hydrogenating a petroleum hydrocarbon stream in the presence of a hydrogenating component and a catalyst consisting of a suitable support material such as alumina, alumina-silica or silica-alumina;
That is, it is well known that hydrogenation desulfurization, hydrogenation denitrification and/or hydrogenation cracking can be carried out.

Hydrogenating ingredients are Webster's Seventh New
Collegiate Dictionary (WEBSTER')
S SEVENTH NEW COLLEGIATED
ICTIONARY>, G, & C. Merriam Company, Springfield, Massachusetts, USA (G, & C. Merriam Company,
Springfield, Massachusetts
e, U, S. A,) (1963), page 628 of the Periodic Table of Elements, Group Ⅰ of the Periodic Table of Elements and (
or) consisting of one or more metals from Group Ⅰ.

Combinations of metals such as cobalt and molybdenum, nickel and molybdenum, cobalt, nickel and molybdenum, and nickel and tungsten have been found to be useful.

For example, U.S. Pat. No. 3,340,180 discloses that a heavy hydrocarbon stream containing sulfur, asphalt-based materials, and metal-containing compounds as contaminants is made of a combination of such metals and activated alumina, the pore size of which is 0 angstrom units. Å] (Onm) to less than 5% of its pore volume with radius greater than 100 Å (10 nm) to 300 Å (30 nm), and 80 Å (8 nm)
m) teaches that it may be hydrogenated in the presence of a catalyst having pores of larger radius less than 10% of its pore volume.

U.S. Pat. No. 4,016,067 describes that heavy hydrocarbon streams can be demetallized and desulfurized in the presence of a dual catalyst system in which the first catalyst is delta and/or Data Comprising Group I metals and Group I metals, preferably molybdenum and cobalt, in composite with an alumina support having the indicated content of alumina, approximately 100 Å (10 nm) to 200 Å (20 nm)
) have at least 60% of its pore volume, at least about 5% of its pore volume have pores larger than 500 Å (50 nm), and have a surface area of up to about 110 square meters per duram (m2/g). and the second catalyst consists of a similar hydrogenating component composited with a refractory substrate, preferably alumina, with a 30 Å (
at least 50%, preferably at least 60%, of the pore volume is occupied by pores having a diameter of 3 nm) to 100 Å (10 nm), and at least 1
It has a surface area of 50 m/g.

U.S. Pat. No. 2,890,162 consists of an active catalyst component on alumina, with the majority of pores ranging from 60 Å (6 nm) to 40 Å.
It has a diameter of 0 Å (40 nm) and a diameter of 1000 Å (100 nm).
m) Catalysts which may have pores with larger diameters can be used for desulfurization, hydrocracking, hydroforming of naphthenic hydrocarbons, alkylation, modification of nandene, isomerization of paraffins etc., hydrogenation, dehydrogenation and various This patent teaches that suitable active ingredients and promoters are suitable for hydrofining operations of the type, as well as hydrocracking of residual oils and other asphalt-containing materials. Among the metals listed are molybdenum and chromium.

British Patent No. 1,051,341 discloses a process for the hydrodealkylation of certain aromatics, consisting of an oxide or sulfide of a group metal supported on alumina, with a .5 milliliters (ml/g) to 1
．． Porosity of 8ml/g and 138m/g to 200
m2/g and at least 85% of the total porosity
A catalyst is used which is occupied by pores having a diameter of 150 Å (15 nm) to 550 Å (55 nm).

U.S. Pat. No. 3,245,919 and U.S. Pat. No. 3,267,025 describe hydrocarbon conversion processes such as reforming, hydrocracking, hydrodesulfurization, isomerization, hydrogenation, and dehydrogenation, in which bohemite alumina products are Group I and II metals, such as chromium, molybdenum, tungsten, iron, nickel, cobalt, and platinum group metals, their compounds and A catalyst having a catalytic amount of a metal component selected from the mixture and having a pore structure having a total of at least about 0.5 cc/g of pores larger than 80 nanometers (8 nm) is used.

U.S. Pat. No. 3,630,888 comprises a promoter selected from elements of Groups B and II of the Periodic Table, their oxides and combinations thereof, and a specific catalyst agent consisting of silica, alumina and combinations thereof; 0.40 per Durham
It has a pore volume larger than a cubic centimeter (CC/g), and the pore volume consists of micropores and access channels that are gap-likely spaced through the micropore structure. the first portion of the closely spaced grooves has a diameter of about 100 Å (10 nm) to about 1000 nm (100 nm) and occupies 10% to 40% of the pore volume; The second part of the groove has a diameter greater than 100 nm (100 nm) and occupies 10% to 40% of the pore volume, and the remaining part of the pore volume has a diameter of more than 100 nm (100 nm).
micropores with diameters smaller than 200 nm), the remainder of which accounts for 20% to 80% of the total pore volume, teaches the treatment of residual hydrocarbon feedstock in the presence of a catalyst. .

U.S. Pat. No. 3,114,701 describes a hydrofining process in which the nitrogen compounds are chromium and/or molybdenum oxides in combination with iron, cobalt and/or nickel oxides on a porous oxide support such as alumina or silica alumina. The use of catalysts containing high concentrations of nickel and molybdenum on predominantly alumina supports, while suitable for removal from petroleum hydrocarbons in the presence of a variety of catalysts, has become more common at 180 °F (82 °C ) to about 1050° F. (566° C.) is described.

U.S. Pat. No. 2,843,552 discloses that a catalyst containing appreciable amounts of chromia along with alumina providing a very good attrition resistant catalyst can have molybdenum oxides impregnated therein and that this catalyst can be used for reforming, desulfurization and isomerization. It states that it can be used in the conversion method.

U.S. Pat. No. 2,577,823 discloses redn oil containing 1% to 6.5% sulfur in the form of organic sulfur compounds.
Hydrodesulfurization of heavy hydrocarbon fractions, such as ced crude, can be carried out over chromium, molybdenum and aluminum oxide catalysts, which contain chromium and molybdenum oxides on preformed alumina. It teaches that it is made by simultaneous precipitation at a pH of 8.

U.S. Pat. No. 3,265,615 discloses a method for making supported catalysts in which a high surface area catalyst support, such as alumina, is impregnated with ammonium molybdate;
It is then reduced by soaking in an aqueous solution of chromium sulfate, drying the treated catalyst overnight, and then treating with hydrogen at stepwise temperatures: 550°F (228°F).
0.5 hours at 750°F (399°C); and 0.5 hours at 950°F (510°C).

The reduced material is sulfurized and heated to 650°F (343°C).
) to 930°F (499°C) boiling point is hydrofined.

U.S. Pat. No. 3,956,105 describes a method for hydrogenating petroleum hydrocarbon fractions such as residual fuel oil, which may contain alumina, silica, zirconia, doria, boria, chromia, magnesia and complexes thereof. A catalyst consisting of a refractory inorganic oxide, a Group (1) B metal (chromium, molybdenum, tungsten) and a Group (1) metal (nickel, cobalt) is used.

The catalyst is prepared by dry mixing finely divided Group B metals, Group II metal compounds, and refractory inorganic oxides, peptizing the mixture, forming an extrudable dough, extruding, and baking. Manufacture.

US Pat. No. 3,640,817 discloses a two-step process for treating asphaltene-containing hydrocarbons.

Both catalysts in this process are selected from the group consisting of molybdenum, tungsten, chromium, iron, cobalt, nickel and platinum group metals on a porous support material such as alumina, silica, zirconia, magnesia, titania and mixtures thereof. or more metal components,
The first catalyst has 50% or more of its pore volume characterized by pores having a pore diameter greater than about 1000 nm (100 nm), and the second catalyst has pores characterized by pores having a pore diameter greater than about 1000 nm (100 nm);
50% or less of the micropores have pores characterized by having a pore diameter larger than 50% of the micropores.

US Pat. No. 3,957,622 teaches a two-step hydroconversion process for asphaltene-containing black oils.

Desulfurization takes place in the first stage on a catalyst having pores, characterized by pores having a pore diameter greater than about 1000 nm (100 nm), in a proportion of up to 50% of its pore volume.

Accelerated conversion and desulfurization of asphaltene moieties are secondary
The process is carried out on a catalyst having a proportion of 50% or more of its micropore volume of pores characterized by pores having a pore diameter greater than 1000 Å (100 nm).

Each catalyst is alumina, silica, zirconia, magnesia,
One or more metal components selected from the group consisting of molybdenum, tungsten, chromium, iron, cobalt, nickel, platinum group metals and mixtures thereof on a support material of titania, boria, strontia, hafnia or mixtures thereof. Become.

French Patent No. 2,281,972 describes the preparation of catalysts consisting of oxides of cobalt, molybdenum and (or nickel) on a substrate of aluminum oxide and 3 to 15% by weight of chromium oxide and the purification of their hydrocarbon fractions. teaches the use in hydrodesulfurization of fuel oils obtained by vacuum distillation or residual oils obtained by atmospheric distillation.

This substrate can be produced by co-precipitation of chromium and aluminum compounds.

U.S. Patent No. 3,162,596 is an integrated method,
Residual hydrocarbon oil containing metal contaminants (nickel and vanadium) is first removed using a hydrogen-providing diluent or with one or more hydrogenation-promoting metals supported on a solid support typified by silica or alumina. hydrogenated over a catalyst containing 100% chloride and then distilled under reduced pressure to produce primarily about 110%
A method is taught for separating a heavy gas oil fraction containing reduced amounts of metals from an undistilled residue boiling at 0°F (593°C) and containing asphaltic materials.

This heavy gas oil fraction is then catalytically cracked.

U.S. Pat. No. 3,180,820 describes the upgrading of heavy hydrocarbon feedstocks in a two-zone hydrodesulphurization process, in which each zone consists of scales from groups VB, ■B, and ■ of the periodic table. A solid hydrogenation catalyst containing one or more metals is used.

Both catalysts may be supported or unsupported.

In a preferred embodiment, the first zone contains an unsupported catalyst mono-oil slurry and the second zone contains the supported catalyst in the form of a fixed bed, slurry or fluidized bed.

Supports for supported catalysts include alumina, silica, zirconia, magnesia, titania, doria, boria, strontia, hafnia, as well as silica-alumina, silica-zirconia, silica-magnesia, alumina-titania and silica-magnesia-zillionia, among others. A porous refractory inorganic oxide support containing a composite of two or more oxides.

This patent states that the supported catalyst suitable for use in the present invention is about 5
Surface area of 0m2/g to 700m2/g, approximately 20 people (
2 nm) to 600 nm (60 nm) and a pore volume of about 0.10 ml/g to 20 ml/g.

U.S. Pat. No. 3,977,961 and U.S. Pat. No. 3,985,684 describe a process for the hydroconversion of heavy oils and residues using one or two catalysts, including alumina, silica, zirconia, Catalysts containing Group B metals and/or Group ■ metals on refractory inorganic oxides such as magnesia, boria, phosphates, titania, ceria, and thoria each contain a Group A metal such as germanium. can have a very high surface area and also a very high pore volume.

The first catalyst has a diameter of 1/50 inch (0.051 cm).
) have a proportion of at least about 20% of its pore volume of pores with an absolute diameter within the range of about 100 ionm to about 200 ionm (20 nm); The catalyst is approximately 1/50 inch (0.051 cm)
) to about 1/25 inch (0.102 Cm).
the catalyst has pores having an absolute diameter in the range of from about 1/25 inch (0.102 cm) to about 1/8 inch, representing at least 15% of its total pore volume; (0.32 cm), the pores have an absolute diameter in the range of about 175 nm (17,5 nm) to about 275 λ (27,5 nm), at least 15 nm of the total pore volume. % and also have a surface area of about 200 m2/g to about 600 m2/g and a pore volume of about 0.8 cc/g to about 3.0 cc/g.

The second catalyst has pores having an absolute diameter within the range of about 100 pores (10 nm) to about 200 pores (20 nm) for at least 55% of its total pore volume and 5oA for less than 10% of its pore volume. - (5 nm-) pores with a pore diameter of less than about 25% of its total pore volume.
It has pores with a pore diameter of 30 nm+, and also has a surface area of about 200 m2/g to about 600 m2/P and a pore volume of about 0.6 cc/g to about 1.5 CC/g.

These patents also teach sending the effluent from such processing to a catalytic cracking device or a hydrogen cracking device.

US Pat. No. 4,054,508 discloses a process for demetallizing and desulfurizing residual oil fractions, which uses two catalysts in three zones.

The oil is comprised of Group B metal and iron group metal oxides complexed with an alumina support in the first zone, and at least 60% of the pore volume is between 100 nanometers (10 nm) and 200 nanometers (20 nm).
500 nm) diameter pores and in which at least about 5% of the pore volume is pores having a diameter greater than 500 nm (50 nm), and in a second zone composited with the alumina support. oxides of group I B metals and iron group metals having a surface area of at least 150 m2/g and at least 50% of its pore volume
m) to 100 nm (i0 nm) in diameter, and then in a third zone with a small portion of the first catalyst.

According to the invention, a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds and sulfur compounds is hydrogenated (h
The hydrotreating method has now been discovered and developed.

The process of the invention uses a catalyst with special physical properties and a hydrogenating component containing molybdenum and chromium and optionally cobalt.

Broadly speaking, in accordance with the present invention, a method is provided for the hydrogenation of heavy hydrocarbon streams containing metals, asphaltenes, nitrogen compounds, and sulfur compounds.

The process involves the hydrogenation of heavy hydrocarbon streams in the presence of hydrogen under suitable conditions with molybdenum and chromium, their oxides, their sulfides and mixtures thereof on large pore catalytically active alumina. The process consists of contacting the catalyst with a catalyst containing a chemical component.

Molybdenum can be present in an amount ranging from about 5% to about 15% by weight based on the total catalyst weight calculated as MoO3 and chromium from about 5% to about 15% by weight based on the total catalyst weight calculated as Cr203. It may be present in an amount within the range of about 20% by weight.

The catalyst has a pore volume in the range of about 0.4 CC/g to about Q.8 cc/g, about 150 m2/g to about 300 m2
/g and an average pore diameter within the range of about 100 nm (10 nm) to about 200 nm (20 nm).

The catalyst further comprises cobalt and/or its oxide,
and/or may contain sulfides thereof.

When present, cobalt is present in an amount ranging from about 0.1% to about 5% by weight, based on the total weight of the catalyst, calculated as CoO.

The catalyst used in the process of the present invention is prepared by annealing alumina (pseudopoumite) in air at about 800°F (427°C) to about 1400°F (760°C) for about 0.5 to about 2 hours, and It can be produced by forming alumina and then impregnating the gamma alumina with one or more aqueous solutions containing pyrolyzable salts of molybdenum and chromium.

The catalyst used in the process of the present invention has pores having a diameter smaller than 50A (5 nm) in a proportion of about 0% to about 10% of its pore volume and about 30% to about 80% of its pore volume. 50 people (5nm) to about 100 people (10nm)
pores having a diameter within the range of from about 100 nanometers (10 nm) to about 150 nanometers (15 nm) at a proportion of about 10% to about 50% of the pore volume; 150 at a rate of about 0% to about 10% of the volume
It has pores with a diameter larger than λ (15 nm).

The method of the present invention uses hydrogen partial pressures in the range of about 1000 psia (6.9 MPa) to about 3000 psia (20.7 MPa), about 700°F (371°C) to about 820°C.
Average catalyst bed temperature in the range of °F (438 °C), about 0.1
Hydrocarbon capacity/hour/catalyst capacity or approximately 3 hydrocarbon capacities/
hourly liquid hourly space velocity (LHSV) within hours/catalyst capacity
, and approximately 2000 standard cubic feet of hydrogen/hydrocarbon 1
Barrel (SCFB) (356m3/m3) or approx.
It is carried out at a hydrogen circulation rate or hydrogen addition rate within the range of 5000 SCFB (2672 m2/m2).

The accompanying drawings are simplified flow sheets of preferred embodiments of the method of the invention.

The present invention relates to a new process for the hydrogenation of heavy hydrocarbon feedstocks.

Such feedstocks will contain asphaltenes, metals, nitrogen compounds and sulfur compounds.

The feedstock to be treated by the process of the invention contains small amounts of nickel and vanadium, such as less than 40 ppm up to more than 1000 ppm (total amount of nickel and vanadium) and up to about 25% by weight of asphaltenes. You should understand what you will do.

If the feedstock has too high a total nickel and vanadium content or contains excessively high amounts of asphaltenes, this feedstock should be pre-treated to reduce the excess amount of this particular contaminant. I can do it.

Such pretreatment may include a hydrogenation treatment suitable to remove metals from the feedstock and/or convert asphaltenes in the feedstock to reduce this contaminant to a sufficient degree; Any suitable relatively inexpensive catalyst may be used for such treatment.

The contaminants will adversely affect the subsequent processing of such feedstocks if they are not reduced to acceptable levels.

Typical feedstocks that may be satisfactorily treated in the process of the present invention often contain substantial amounts of components that boil above 1000°F (538°C).Examples of 3 Representative Feedstocks includes crude oil, top crude oil, petroleum hydrocarbon residue oil,
There are hydrocarbon streams derived from atmospheric residues, vacuum residues, oils obtained from tar sands and residues derived from tar sands oils, and coals.

Such hydrocarbon streams contain organometallic compounds that have a deleterious effect on various purification processes that utilize catalysts to convert the particular hydrocarbon stream being processed.

Metal contaminants found in such feedstocks include, but are not limited to, iron, vanadium, and nickel.

Nickel is present in most crude oil and residue fractions in the form of soluble organometallic compounds.

The presence of nickel-porphyrin complexes and other nickel-organometallic complexes, even at relatively small concentrations of such complexes, greatly complicates the refining and utility of heavy hydrocarbon cuts.

It is known that in the presence of significant amounts of such organometallic nickel compounds, the cranking catalyst rapidly deteriorates and its selectivity changes.

Appreciable amounts of such organometallic nickel compounds in the feedstock to be hydrotreated or hydrocracking have a deleterious effect on such processing.

The catalyst becomes inactive and the nickel compounds are deposited in the interstices between the catalyst particles, clogging the fixed bed reactor or increasing its pressure drop.

Iron-containing compounds and vanadium-containing compounds are present in substantially all crude oil together with the high Conradson carbon asphaltic and/or asphaltenic portions of the crude oil.

Of course, when crude oil is topped and the fraction boiling below about 450°F (232°C) to 600°F (316°C) is removed, such metals become concentrated in the remaining bottoms. It is.

When such a residue is further processed, the presence of such metals has an adverse effect on the processing catalyst.

It must be pointed out that nickel-containing compounds have a detrimental effect to a greater extent on cracking catalysts than iron-containing compounds.

If oil containing such metals were used as a fuel, it would have poor performance as a fuel oil in industrial furnaces because these metals corrode the metal surfaces of the furnace.

Metal contaminants such as vanadium, nickel, and iron are often present in rather small quantities in various hydrocarbon streams, but these are often present in amounts of 40 to 50 ppm by weight.
It is found at concentrations in excess of 1000 ppm, even more often in excess of 1000 ppm.

Of course, other materials may also be present in a particular hydrocarbon stream.

Such metals exist as oxides or sulfides of specific metals, or as high molecular weight organometallic compounds including metal naphthenates and metal porphyrins and their derivatives.

In either case, the feed stream may be subjected to a demetalization treatment prior to use in the process of the invention if the total amount of nickel and vanadium is excessive.

Broadly speaking, in accordance with the process of the present invention, a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds and sulfur compounds is processed to reduce metals, asphaltenes, nitrogen compounds and sulfur compounds in a heavy hydrocarbon stream. A method of hydrogenating is provided.

The process comprises contacting the hydrocarbon stream with a catalyst in the presence of hydrogen under suitable conditions, wherein the catalyst comprises molybdenum and chromium metals, their oxides, on large pore catalytically active alumina. , their sulfides, or mixtures thereof, and the molybdenum is about 5% based on the total catalyst weight calculated as MoO3.
% to about 15 wt.%, chromium is present in an amount from about 5 wt.% to about 20 wt.%, based on the total weight of the catalyst, calculated as Cr203, and the catalyst is present in an amount of about 0.5 wt.% to about 15 wt.%. Pore volume within the range of 4 CC/g to about 0.8 cc/g, surface area within the range of about 150 m/f to about 300 m/g, and about 10 nm to about 20
It is characterized in that it has an average pore diameter in the range of 0 (20 nm).

The process of the present invention may be characterized in that the catalyst contains cobalt metal, its oxide, its sulfide or a mixture thereof as the hydrogenating component of the catalyst, cobalt being calculated as Coo in the total weight of the catalyst. present in an amount within the range of about 0.1% to about 5% by weight based on

As used herein, all numbers given for surface area are obtained by the BET nitrogen adsorption method; pore volume
) are obtained by nitrogen adsorption; and it should be understood that all values shown for mean pore diameter are calculated by the formula: In the formula A. P. D. = Average pore diameter P, V. in Å. = Pore volume S, A. in CC/g. = surface area in m2/g.

Furthermore, the pore size distribution was obtained with a Digisorb 2500 by nitrogen desorption technique.

In the process of the invention, the catalyst has good demetalization activity, moderate desulfurization activity, and also high temperature and/or about 1
It has good deactivation stability when used at moderate pressures such as 200 psig (8.37 MPa).

The hydrogenating component of the catalyst used in the process of the invention consists of specific components consisting of molybdenum and chromium.

In one embodiment of the process according to the invention, the hydrogenating component of the catalyst consists essentially of molybdenum and chromium, their oxides, their sulfides or mixtures thereof.

In accordance with this embodiment, metals in a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds and sulfur compounds,
A method for hydrotreating this hydrocarbon stream to reduce the content of asphaltenes, nitrogen compounds and sulfur compounds is provided.

The process consists of contacting the stream under suitable conditions with a catalyst in the presence of hydrogen, the catalyst containing the metals molybdenum and chromium, their oxides, on large pore catalytically active alumina, sulfides or mixtures thereof, molybdenum is present in an amount ranging from about 5% to about 15% by weight of the total catalyst weight, calculated as MoO3, and chromium is present in an amount ranging from about 5% to about 15% by weight of the total catalyst weight, calculated as Cr203. is present in an amount within the range of about 5% to about 20% by weight, and the catalyst is present in an amount ranging from about 0.4 cc/g to about 0.4 cc/g.
having a pore volume within the range of 8 cc/g, a surface area within the range of about 150 m/g to about 300 m/g, and an average pore diameter within the range of about 100 onm to about 200 onm. This method is characterized by the following.

Optionally, the catalyst used in the process of the invention may also contain cobalt as a hydrogenating component.

Molybdenum and chromium and, if present, cobalt are present in elemental form, as metal oxides, as metal sulfides, or as mixtures thereof.

Molybdenum is present in an amount ranging from about 5% to about 15% by weight, based on total catalyst weight, calculated as Mo03.

Chromium is present in an amount ranging from about 5% to about 20% by weight, based on total catalyst weight, calculated as Cr203.

When present, cobalt is present in an amount ranging from about 0.1% to about 5% by weight, based on total catalyst weight, calculated as CoO.

Molybdenum is preferably present in an amount from about 7% to about 13% by weight based on the total catalyst weight calculated as Mo03 and chromium from about 6% to about 15% by weight based on the total catalyst weight calculated as Cr203. %, and the cobalt is present in an amount ranging from about 1% to about 3% by weight, based on the total catalyst weight, calculated as CoO.
Preferably, it is present in an amount within the range of % by weight.

Accordingly, a method is provided for hydrotreating a heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds and sulfur compounds to reduce the content of metals, asphaltenes, nitrogen compounds and sulfur compounds in the stream. Ru.

The process consists of contacting the stream in the presence of hydrogen with a catalyst under suitable conditions, the catalyst containing oxides of molybdenum, chromium, and cobalt on large pore catalytically active alumina; sulfides or mixtures thereof, with molybdenum present in an amount ranging from about 5% to about 15% by weight, based on the total catalyst weight, calculated as MoO3, and chromium, based on the total catalyst weight, calculated as Cr203. cobalt is present in an amount within the range of about 0% to about 5% by weight, based on the total catalyst weight, calculated as CoO, and Moreover, this catalyst is about 0.4 cc/g to about 0.4 cc/g.
Pore volume within the range of 8 CC/g, surface area within the range of about 150 m2/g to about 300 m2/g and about 100 m2/g (
10 nm) to about 200 nm (20 nm).

Any suitable catalytically active large pore alumina is used as the catalyst used in the process of the invention.

A typical example of such alumina is American Cyanamid Comp.
Aero-1 manufactured by any
There is 00 alumina.

Alumina has a pore volume greater than 0.4cc/g, 150m2
It should have a surface area greater than /g/g and an average pore diameter greater than 100 nm (10 nm).

Typically, the catalyst compositions used in the process of the invention can be prepared by impregnating various metals onto a suitable catalytically active large pore alumina.

This impregnation may be accomplished using a solution of one or more thermally decomposable compounds of the appropriate metal.

If a single solution of metal is used, impregnation can be carried out by co-impregnation.

Alternatively, impregnation can be accomplished by sequentially impregnating the various metals from two or more solutions of thermally decomposable compounds of suitable metals.

Impregnated support at least 250°F (121°C)
2 hours at a temperature of at least 1000° F. (538° C.) for at least 2 hours.

Preferably, the catalyst used in the process of the present invention is prepared by first heating pseudo-boehmite in still air from about 800°F (427°C) to about 140°C.
It is produced by quenching at a temperature of 0°F (760°C) for about 0.5 hours to about 2 hours to produce gamma alumina.

This gamma-alumina is then cobalt (if present)
, and one or more aqueous solutions containing thermally decomposable salts of molybdenum and chromium.

The finished catalyst used in the process of the invention is approximately 0.4C
Pore volume in the range of about 1 C/g to about 0.8 cc/g, about 1
A surface area in the range of 50 m/g to about 300 m/g and about 100 m/g to about 200 m/g and about 100 m/g to about 200 m/g
m).

The catalyst has a pore volume in the range of about 0.5 CC/g to about 0.7 cc/g, about 150 m2/g to about 250 m2/g.
It is preferred to have a surface area within the range of 110 mm (110 mm) to about 150 mm (15 nm).

The catalyst used in the process of the present invention has pores having a diameter of less than 5 nm (5 nm) in a proportion of from about 0% to about 10% of its pore volume and in a proportion of from about 30% to about 80% of its pore volume. About 50 people (5 nm) to about 100 people (10 nm)
) with a diameter within the range of approximately 10% of the pore volume.
pores having a diameter in the range of about 100 pores (10 nm) to about 150 pores (15 nm) in a proportion of from about 50% to about 50%;
and about 0% to about 10% of its pore volume.
It should have pores with a diameter greater than 0 (1.5 nm).

The process of the present invention is particularly useful for the hydrogenation of heavy hydrocarbon streams such as petroleum residues, atmospheric residues, vacuum residues, tar sands oils, tar sands residues, and liquids derived from coal.

Furthermore, the process of the invention can be used for the satisfactory hydrogenation of petroleum hydrocarbon distillates such as gas oil, circulating stock and furnace oil.

If the amounts of nickel and vanadium are excessive or the concentration of asphaltenes is too high, the feedstock may be used in the mains after pre-treatment of the feed atoms to reduce these excesses to a more tolerable level. Should be used in the method of invention.

Operating conditions for the hydrogenation of heavy hydrocarbon streams such as petroleum hydrocarbon residue oils are approximately 1000 psia (6.9 MPa).
a) a hydrogen partial pressure in the range of from about 3000 psia (20.7 MPa) to about 700°F (371°C) to about 8
Average catalyst bed temperature in the range of 20°F (438°C), about 0
．． LHSV within the range of 1 hydrocarbon volume/hr/catalyst volume to about 3 hydrocarbon volumes/hr/catalyst volume, and about 200
08CFB (356m3/m3) or about 15000S
Includes hydrogenation rates within the range of CFB (2672 m3/m3).

Preferably, the operating conditions are approximately 1200 psia (8.2
7 MPa) to about 2000 psia (13.8 MPa
), an average catalyst bed temperature in the range of about 730°F (388°C) to about 810°F (432°C), LHSV in the range of about 0.4 to about 1, and about 50
00SCFB (890m3/m3) or about 10000
Includes hydrogen circulation rates or hydrogen addition rates within the range of SCFB (1780 m3/m3).

If the process of the present invention is to be used to treat hydrocarbon distillate oils, operating conditions are approximately 200 psia (1.4 M
hydrogen partial pressure within the range of about 3000 psia (20,7 MPa), average catalyst bed temperature within the range of about 600°F (316°C) to about 800°F (427°C), about 0.4 hydrocarbon LHSV within the range of volumes/hour/catalyst capacity to about 6 hydrocarbon volumes/hour/catalyst capacity and about 100
0SCFB (178m3/m3) or about 10000S
The hydrogen circulation rate or hydrogen addition rate is within the range of CFB (1780m3/m3).

Suitable operating conditions for the hydrogenation of hydrocarbon distillate oils are approximately 20
0 psia (1.4 MPa) to about 1200 psia
Hydrogen partial pressure in the range of (8.27 MPa), approximately 600°F
(316°C) to about 750°F (399°C), L within the range of about 0.5 hydrocarbon volumes/hour/catalyst capacity to about 4 hydrocarbon volumes/hour/catalyst capacity.
HSV and approximately 10008CFB (178m3/m3)
and about 6000 SCFB (1069 m3/m3).

Preferred embodiments of the method of the invention are illustrated in the accompanying drawings.

This figure is a simplified flow sheet, including pumps,
Various types of auxiliary equipment such as compressors, heat exchangers and valves are not shown.

These omissions are reasonable and help simplify the drawings, as those of ordinary skill in the art will readily recognize the need for and location of such auxiliary equipment.

This reaction scheme is provided for illustrative purposes only and is not intended to limit the scope of the invention.

Referring to the drawing, approximately 4% by weight of sulfur and 0.5% by weight of nitrogen.
Arabia light vacuum distillation residue oil containing less than 100 ppm of nickel and vanadium is sent from a supply source 10 via line 11 to pump 12 and pumped via line 13.

A hydrogen-containing recycle gas stream, described below, is passed from line 14 to line 13 and mixed with the hydrocarbon feed stream to form a mixed hydrogen-hydrocarbon stream.

The mixed hydrogen-hydrocarbon stream is then sent from line 13 to furnace 15 where it is heated between about 760°F (404°C) and about 780°C.
Heat to a temperature within the range of 416°C.

The heated stream is then sent to reaction zone 17 via line 16.

reaction zone 17 consists of one or more reactors;
Each has one or more fixed beds of catalyst.

The catalyst is approximately 5% based on the total catalyst weight calculated as Mo03.
% to about 15% by weight molybdenum and Cr20
from about 5% to about 20% by weight of chromium based on total catalyst weight, calculated as 3, on large pore catalytically active alumina.

Molybdenum/and chromium exist in elemental form, either as metal oxides, as metal sulfides, or as mixtures thereof.

The catalyst has a pore volume in the range of about 0.4 cc/g to about 0, 8 cc/g, and about 150 m2/g to about 300 m2/g.
surface area within the range of about 100 Å (10 nm) to about 2
00 Å (20 nm), and about 0% to about 10% of the pore volume has a pore diameter in the range of about 0 Å (Onm) to about 50 Å (5 nm), and about 30% of the pore volume % to about 80% is about 50 Å (5 nm) to about 1
00 Å (10 nm), about 10% to about 50% of the pore volume has a pore diameter in the range of about 100 Å (10 nm) to about 150 Å (15 nm), and the pore volume About 0% to about 10% of 150 people (15n
m) have a pore size distribution with larger pore diameters.

The operating conditions used in this reaction scheme are approximately 1200 psia
(8.27 MPa) to about 1600 psia (11.
average catalyst bed temperature in the range of about 760°F (404°C) to about 780°F (416°C), about 0.4 volume hydrocarbon/hour/catalyst volume to about 0.8
LHSV within the range of Capacity Hydrocarbons/hr/Catalyst Capacity and from about 5000 SCFB (890 m3/m3) to about 8
000 SCFB (1425 m3/m3).

The effluent from reaction zone 17 is sent via line 18 to a high temperature, high pressure, gas-liquid separator 19 where the reactor pressure and
6°C).

A separator 19 separates the hydrogen-containing gas from the remainder of the effluent.

Hydrogen-containing gas leaves separator 19 via line 20.

It is allowed to cool and then sent to a light hydrocarbon separator 21 where the concentrated light hydrocarbons are separated from the hydrogen-containing gas and removed via line 22.

Hydrogen-containing gas is recovered via line 23 and passed through a scrubber (
gas scrubbing tower) where the hydrogen sulfide is removed or washed from the gas.

Hydrogen sulfide is removed from the treatment system via line 25.

The scrubber-scrubbed hydrogen-containing gas is then passed to line 14 where it can optionally be combined with formed hydrogen sent via line 26.

The hydrogen-containing gas stream is then added to the hydrocarbon feed stream in line 13 as described above.

The liquid portion of the effluent is passed from the high temperature, high pressure, gas-liquid separator 19 via line 27 to a hot flash drum 28.

In the flash drum 28, the pressure is reduced to atmospheric pressure and the temperature of the contents is reduced to about 700°F (371°C) to about 800°C.
The temperature should be within the range of F (427°C).

The flash drum 28 is used to store materials such as naphtha as well as fuel oils from approximately 550°F (288°C) to 600°F (30°C).
Light hydrocarbons, including distillates boiling at temperatures up to 16 °C), are flushed from the remainder of the product and passed through line 2.
9 from the processing system.

From about 1% to about 4% by weight based on the hydrocarbon feedstock
of C4-material, about 2% to 5% by weight of naphtha [C
5-360°F (C5-182°C)] and about 1
365°F-650°F from 0% to about 15% by weight
Light hydrocarbons, such as those containing materials at (182° C.-343° C.), can be separated into their various components and sent to storage or to separate processing equipment.

Heavier materials separated from light hydrocarbons, i.e., materials that boil at temperatures above about 600°F (316°C), may be about 60% to about 90% by weight based on the hydrocarbon feedstock.
% by weight and are removed from the flash drum 28 via line 30 for use as a feedstock for other processing or as a low monosulfur, heavy industrial oil.

Such liquid materials contain about 0.6% to about 1.2% by weight sulfur, about 1.0% to about 3.0% by weight asphaltenes, and about 5ppm to about 15ppm nickel and vanadium. .

Furthermore, 5 of the materials at 1000°F+ (538°C+)
More than 0% converts to 1000°F-(538°C-) material.

This liquid effluent is sent via line 33 to a vacuum column 34;
Here, vacuum gas oil (VGO) is separated from the low sulfur residual oil fuel.

VGO is sent from the vacuum tower 34 to a storage location via line 35.
or to conventional contact cracking equipment (not shown).

The low sulfur residual oil fuel can be sent from vacuum column 34 via line 36 to storage or other processing equipment for use as an energy source.

Alternatively, material boiling above 600° F. (316° C.) recovered from flash drum 28 via line 30 may be sent via line 37 to an existing catalytic cracking device (not shown).

The following examples are presented to further aid in understanding the invention and are presented for illustrative purposes only and are not intended to limit the scope of the invention.

Example 1 8.3% by weight Mo03 and 8.3% by weight based on total catalyst weight.
A catalyst (hereinafter referred to as catalyst A) having 3% by weight Cr203 on large pore catalytically active alumina was prepared.

American Cya
Aero (A) obtained from Namid Company
A 40.8 g sample of ero)-100 alumina is impregnated with a solution containing ammonium dichromate and ammonium molybdate.

Aero 100 alumina is 14-20 mesh (1.1
7 to 0.83 mm) and approximately 1200°F.
(649° C.) in air for 2 hours.

The solution used for impregnation was 6.8 g of ammonium dichromate and 5.0 g of ammonium molybdate in 40 ml of distilled water.
It was produced by dissolving 3g.

The impregnated alumina was dried under a heat lamp in still air overnight to remove excess moisture.

The dried material is then heated to 1000°F (538°F) in still air.
The shrimp were roasted for 2 hours at a temperature of

This finished catalyst (catalyst A) is a specific example of a catalyst for use in the process of the invention.

Example 2 For comparison purposes, commercially available catalysts are
Obtained from Cyanamid Company.

This commercially available catalyst is designated HDS-2A and is produced by American Cyanamid Co. on an alumina support.
It was specified that it contained 3% by weight and 13% by weight of M003.

This catalyst will be referred to as catalyst B hereinafter.

Example 3 A second hydrotreating catalyst was used for comparison purposes.

This catalyst was manufactured by Nalco Chemical.
ical Company).

This catalyst (hereinafter referred to as catalyst C) was coated with C on an alumina support.
It was specified as containing approximately 3% by weight oO and 13% by weight MO0.

The properties of catalysts A, B and C are shown in Table 1 below.

Furthermore, the physical properties of the alumina used as a support for Catalyst A are also shown in Table 1.

This support material is designated as Catalyst D.

This introduction of metal into alumina affects the pore size distribution of alumina,
There was no obvious effect on pore volume, surface area or average pore diameter.

Example 4 Three separate catalysts were prepared to demonstrate the effect of different concentrations of chromia on a catalyst consisting of about 9% molybdenum and an Aero 100 alumina support.

These catalysts were manufactured according to the manufacturing method described in Example 1 above.

However, only the appropriate amount of metal was used to obtain the desired composition of the finished catalyst.

These three catalysts are hereinafter referred to as catalysts E, F and G,
These were made using the same type of Aero-100 alumina used to make Catalyst A.

The chemical composition and physical properties of these catalysts are also shown in Table 1 above.

It can be seen that the introduction of metals on or into the alumina also does not have a significant effect on the physical properties of the alumina.

Example 5 Arabya light vacuum distillation residue oil (Ara
bian light vacuum resin).

The suitable properties of this feedstock are shown in Table 2 below.

Each test was conducted on a bench scale test apparatus with automatic controls for pressure, flow rate of reaction components, and temperature.

The reactor was constructed from stainless steel heavy-walled tubing with an internal diameter of 3/8 inch (0.95 cm).

1/8 inch (0.32 cm) outer diameter thermal wall
a well) extending through the center of the reactor.

The reactor was heated by an electrically heated steel block.

The hydrocarbon feedstock was supplied to the unit by a Ruska pump, a positive discharge pump.

A 14-20 mesh (1.17-0.83 mm) catalyst material was supported on 8-10 mesh (2.38-2.00 mm) aluminum grains.

Approximately 20 cubic centimeters of catalyst was used as the catalyst bed in each test.

This amount of catalyst provides a catalyst bed about 10 inches (25.4 cm) to about 12 inches (30.5 cm) in length.

10 inches (25.4 cm) of 8-10 mesh (2.38-2.00 mm) alundum grains
A layer was placed over the catalyst bed in the reactor for each test.

The catalyst used was located in the annular space between the hot and inner walls of the reactor with a 3/8 inch (0.95 cm) inside diameter.

Prior to use, each catalyst was immersed in still air for approx. Shrimp roasted at 1000°F (538°C) for 1 hour.

It was then cooled in a desiccator and added to a suitable reactor.

The catalyst was then subjected to the following pretreatments.

The reactor was placed in a reactor block at a temperature of 300°F (449°C).

500 psig of gas containing 8 mol% hydrogen sulfide in hydrogen
(3.5 MPa) pressure and approximately 300°F (149°C
) at a temperature of ■Standard cubic feet per hour [SCFH] (
28.3 l/h) over the catalyst.

After 10 to 15 minutes of such treatment, the temperature of the block was raised to below 400°C.

After at least another hour has passed and at least 1 standard cubic foot (28.3 L) of gas mixture has passed through the system, reduce the temperature of the block to 700°F (371°C).
I raised it to .

The gas mixture was then passed through the catalyst bed for at least an additional hour and in an amount of at least 1 standard cubic foot (28.3 l).

At this point, turn off the gas mixture and apply hydrogen to 1200 psi.
g (8.37 MPa) into the apparatus, approximately 0.6
Hydrogen flow was created at a rate of SCFH (17 l/hr) and the temperature was then increased to an average catalyst bed temperature of 760°F (404°C).

A hydrocarbon stream was then produced at a rate to obtain an LHSV of 0.59 hydrocarbon capacity/hour/catalyst capacity.

The effluent from the reaction zone is collected in a liquid product receiver, while the gas formed is sent through the product receiver to a pressure control valve and then to a wet test meter.
) was properly discharged.

After 1 to 3 days, the average catalyst bed temperature is 780°F.
(416°C).

After additional time, for example 3 to 5 days, the average catalyst bed temperature increased to about 800°F (427°C).

Selected samples from the product receiver were obtained and analyzed for pertinent information.

The results of these tests are shown in Table 3 below.

These data are based on LHSV of 0.59 hydrocarbon volume/hour/catalyst volume, 800°F (42
7°C) and 1200 psig (8.37 MPa
) from samples taken during operations carried out for 5 to 9 days.

The results shown in Table 3 demonstrate the superiority of the experiment using Catalyst A, an embodiment of the process according to the invention, compared to the two experiments using different catalysts.

The data show that the process of the present invention has better nickel removal, about as good vanadium removal, better asphaltene conversion, and better 1000°F (538°C + ) shows a high conversion rate of the material, but a lower sulfur removal rate.

Accordingly, the process of the present invention is useful in treating heavy hydrocarbon streams for demetallization, desulfurization, asphaltene conversion, and
It is a suitable method for converting 0°F+ (538°C) materials.

Furthermore, data from experiments 1, 4, 5 and 6 show that the presence of Cr203 in the catalyst results in better metal removal, sulfur removal,
Asphaltene conversion and 1000°F+ (538°C+
) has been shown to promote the conversion of substances to -1000°F (538°C) substances.

Example 6 Co0 1.1 wt% based on total catalyst weight, M0038
．． 2% by weight of Cr203 and 8.2% by weight of Cr203 on large pore catalytically active alumina (hereinafter referred to as catalyst H).
) was created.

Aero 100 handcrafted by American Cyanamid
A 63.8 g sample of alumina was impregnated with a solution containing ammonium dichromate and ammonium molybdate.

Aero 100 alumina is 14-20 mesh (1.1
7-0.83 mm) in the form of a substance, about 120 mm in air.
The shrimp were pre-roasted at a temperature of 0°F (649°C).

The solution used for impregnation was prepared by dissolving 10.6 g of ammonium dichromate and 8.32 g of ammonium molybdate in 80 ml of distilled water.

The alumina to be impregnated was added to this solution and the resulting mixture was left overnight.

The impregnated alumina was then dried under a heat lamp in still air for about 2 hours to remove excess moisture.

The dried material was then heated to 1000°F (538°C) in still air.
) for 2 hours.

Half of this calcined material was impregnated with a solution of cobalt nitrate.

This solution was prepared using Co(No3)2.6H in 40 ml of distilled water.
20 by dissolving 1.2 g.

The mixture of roasted material and solution was left overnight.

This material was then dried under a heat lamp in still air for approximately 2 hours.

The dried material was roasted in still air at a temperature of 1000°F (538°C) for 2 hours.

The finished catalyst (Catalyst H) is a preferred embodiment of a catalyst for use in the process of the invention.

Its properties are shown in Table 4 below.

Example 7 Co0 3.1 wt% based on total catalyst weight, Mo038
．． A second catalyst (hereinafter referred to as catalyst ①) was prepared containing 1% by weight of Cr and 8.1% by weight of 20 g of Cr on an Aero 100 alumina support.

This catalyst was manufactured by the manufacturing method described above in Example 6.
Appropriate amounts of metal were used to provide the desired composition.

This catalyst (catalyst ①) is another specific example of a catalyst used in the process of the present invention.

Its properties are shown in Table 4 below. Each was tested for their relative conversion ability to light vacuum distillation residues.

Each test was performed as described above in Example 5.

The results of these tests are shown in Table 5 below.

Table 5 also shows the test results from Experiments 1, 2 and 3 described above in Table 3.

These results are a preferred embodiment of the method of the present invention, and show that Experiment 5, which uses a preferred embodiment of the catalyst used in the method of the present invention, has an overall superior performance compared to other test runs. It proves that.

This catalyst has good desulfurization, good nickel removal, good vanadium removal, good asphaltene conversion, and 10
00°F+ (538°C+) 1000°F-(53
8℃-) It has the ability to convert into substances.

In Experiment 8, which is another specific example of the method of the present invention, a larger amount of CoO (Co0
3.1% by weight), but higher amounts can also be used in the process of the invention.
Still within the wide range of 0.1% to 5% by weight of O.

Increased amounts of cobalt improve desulfurization activity and increase metal removal rates, asphaltene conversion rates, and 1000°F+ (538°C+
) somewhat lowers the conversion rate of material to 1000°F-(538°C-) material.

Experiment 1 uses a catalyst that does not contain cobalt in its hydrogenating components, but does contain chromium and molybdenum.

In the absence of cobalt, there is less sulfur removal, slightly improved metal removal, less asphaltene conversion, and 1000°F+ (538°C+
) The conversion rate of the substance becomes smaller.

Runs 2 and 3 are comparative tests using prior art catalysts.

These two experiments essentially achieved the same amount of desulfurization as achieved by the method of the present invention.

However, these catalysts have poorer metal removal, asphaltene conversion and 1000°F+ (538°C+)
Provided a conversion of material to 1000° F. (538° C.) material.

In view of the above, the process of the present invention provides a new and novel method for the hydrogenation of heavy hydrocarbon streams.

The use of small amounts of cobalt in the catalyst in combination with metals from Group B of the Periodic Table of the Elements, namely chromium and molybdenum, makes the method of using this catalyst extremely useful for processing such heavy hydrocarbons. What makes it effective is the unexpected.

[Brief explanation of the drawing]

The accompanying figure is a simplified flow sheet of a preferred embodiment of the method of the invention.

Claims (1)

[Scope of Claims] 1. A heavy hydrocarbon stream containing metals, asphaltenes, nitrogen compounds, and sulfur compounds is contacted with a catalyst in the presence of hydrogen under suitable conditions to remove the metals, asphaltenes, and nitrogen in the stream. Compounds and sulfur metals, asphaltenes,
In a hydrogenation process for reducing the content of nitrogen and sulfur compounds, the hydrogenation component is formed by a large pore catalyst, the catalyst comprising molybdenum and chromium metals, their oxides, their sulfides, or mixtures thereof. on alumina that is active in the
o03 and chromium is present in an amount within the range of about 5% to about 15% by weight based on the total weight of the catalyst, calculated as Cr
Approximately 5% by weight based on the total weight of the catalyst calculated as 203
and about 20% by weight, and the catalyst has a pore volume of about 0.4 cc/g to about 0.8 cc/g, about 150 m/g to about 300 m/g.
and an average pore diameter within the range of about 100 Å (1 onm) to about 200 Å (20 nm). 2 Pseudobomite in still air at approximately 800°F
(427°C) to about 1400°F (760°C) for a time in the range of about 0.5 hour to about 2 hours to form gamma alumina, which is then exposed to the heat of the metal. A method according to claim 1, further characterized in that the catalyst is prepared by impregnation with an aqueous solution of one or more decomposable compounds. 3. The catalyst has pores having a diameter smaller than 50 Å (5 nm) from about θ% to about 10% of its pore volume;
about 30% to about 80% of its pore volume have pores with diameters in the range of about 5 nm) to about 100 Å (10 nm);
) and about 0% to about 10% of its pore volume have pores with diameters greater than 150 Å (15 nm). A method according to claim 1, further characterized in that: 4. The hydrogenating component of the catalyst contains metallic cobalt, its oxide, its sulfide, or mixtures thereof, such that the cobalt is from about 0.1% by weight to about 0.1% by weight, based on the total weight of the catalyst, calculated as Coo. A method according to claim 1, further characterized in that it is present in an amount within the range of 5% by weight. 5. The catalyst has from about 0% to about 10% of its pore volume pores with diameters smaller than 50 Å (5 nm);
from about 30% to about 80% of its pore volume have pores having a diameter within the range of about 100 Å (10 nm) to about 150 Å (15 nm);
from about 10% to about 50% of its pore volume, and from about 0% to about 10% of its pore volume, having pores with a diameter greater than 150 nm (15 nm).
3. The method of claim 2, further comprising: 6 Pseudobomite in still air at approximately 800°F
(427°C) to about 1400°F (760°C) for a period of time ranging from about 0.5 hour to about 2 hours to produce gamma alumina, which is then combined with molybdenum and chromium. 5. The method of claim 4, further characterized in that the catalyst is made by impregnating one or more aqueous solutions containing a thermally decomposable salt of. 7. The catalyst has from about 0% to about 10% of its pore volume pores having a diameter smaller than 50 nm (5 nm);
about 30% to about 80% of its pore volume have pores with diameters in the range of 5 nm) to about 100λ (10 nm);
) have pores having a diameter within the range of about 10% to about 50% of its pore volume, and have pores larger than 150 nm (15 nm) about 0% to about 10% of its pore volume. 5. The method of claim 4, further characterized by: 8 The catalyst has pores with a diameter smaller than 50 Å (5 nm) from about 0% to about 10% of its pore volume, and
5 nm) to about 100 pores (10 nm) for about 30% to about 80% of its pore volume, and about 100λ
(10 nm) to about 150 Å (15 nm), and pores with diameters greater than 150 Å (15 nm) to about 0% to about 50% of the pore volume. 7. The method of claim 6, further characterized in that it has 10%.