US3293172A

US3293172A - Regenerative hydrorefining of petroleum crude oil

Info

Publication number: US3293172A
Application number: US363628A
Authority: US
Inventors: William K T Gleim
Original assignee: Universal Oil Products Co
Current assignee: Universal Oil Products Co
Priority date: 1964-04-29
Filing date: 1964-04-29
Publication date: 1966-12-20
Anticipated expiration: 1983-12-20

Description

United States Patent Oflfice 3,293,172 Patented Dec. 20, 1966 3,293,172 REGENERATIV E HYDROREFINING OF PETROLEUM CRUDE OIL William K. T. Gleim, Island Lake, 111., assignor to Universal Oil Products Company, Des Plaines, 111., a corporation of Delaware No Drawing. Filed Apr. 29, 1964, Ser. No. 363,628 16 Claims. (Cl. 208-264) The present invention relates to a regenerative process for hydrorefining of petroleum crude oil, heavy vacuum gas oil, crude tower bottoms, vacuum tower bottoms, visbreaker product efiiuent, heavy cycle stocks, and other high-boiling hydrocarbon fractions and/or distillates. More specifically, the present invention is directed toward a catalytic slurry process for hydrorefining heavy hydrocarbonaceous material severely contaminated by the presence of excessive quantities of deleterious substances. The present process encompasses continuous regeneration and recirculation of the catalyst employed therein.

In one of its various embodiments, the present inveution involves a process for efiecting the decontamination, or hydrorefining, of a heavy hydrocarbon charge stock for the primary purpose of efiiecting the destructive removal of nitrogenous and sulfurous compounds, and particularly for the conversion of the pentane-insoluble portion of such charge stock into useful pentane-soluble hydrocarbon products. Crude petroleum oil, and other heavy hydrocarbon fractions and/or distillates, boiling at temperatures above the gasoline and middle-distillate boiling ranges, such as crude tower bottoms, vacuum gas oil, heavy cycle stocks, black oil, etc., generally contain nitrogenous and sulfurous compounds in large quantities; In addition, these high-boiling hydrocarbon fractions contain quantities of metallic contaminants which exhibit the tendency to exert detrimental effects upon the catalyst utilized in various processes to which the crude oil, or portion thereof, or other heavy hydrocarbonaceous material, is ultimately subjected. The more common of such metallic contaminants are nickel and vanadium, although other metals including iron, lead, arsenic, copper, etc., may be present. These metallic contaminants, as well as others, may be present within the hydrocarbonaceous material in a variety of forms: they may exist therein as metal oxides or as sulfides, introduced into the crude oil as metallic scale or particles; they may be in the form of soluble salts of such metals; usually, however, these contaminants are found to exist as organo-metallic compounds of high molecular weight, such as metal porphyrins and various derivatives thereof. Where the metallic contaminants are present as oxide or sulfide scale, they may be removed, at least in part by a relatively simple filtering technique, the water-soluble salts of such metals being removable by washing and subsequent dehydration. However, a much more severe treatment is generally required to remove, or destroy, the organo-metallic compounds, and to the extent that the resulting heavy hydrocarbonaceous fraction becomes suitable for further processing. Notwithstanding that the total concentration of these contaminants, for example metallic porphyrins, is relatively small, often less than about p.p.m., calculated as the elemental metals, subsequent processing techniques are readily adversely afiected thereby. For example, when a hydrocarbon charge stock, containing metals in excess of about 3.0 p.p.m., is subjected to a cracking process for the purpose of producing lower-boiling, normally liquid hydrocarbons, the metals become deposited upon the catalyst employed, steadily increasing in quantity until such time as the composition of the catalytic composite is changed to the extent that undesirable results are obtained.

In addition to the contaminating influences in the form of nitrogenous and sulfurous compounds, and metallic complexes, crude oils and other heavy hydrocarbon fractions generally consists of a significant quantity of highboiling, pentane-insoluble material. For example, a Wyoming sour crude oil, having a gravity of 232 API at 60 F., not only is contaminated by about 2.8% by weight of sulfur, approximately 2700 p.p.m. of total nitrogen, a total of about 100 p.p.m. of metallic porphyrins (computed as elemental nickel and vanadium), but also contains a high-boiling, pentane-insoluble asphaltenic fraction in an amount of about 8.39% by weight. Similarly, and a much more difficult charge stock to convert into valuable, useful normally liquid hydrocarbons, a crude-tower bottoms product having a gravity, API at 60 F., of 14.3, is contaminated by the presence of about 3.0% by weight of sulfur, 3830 p.p.m. of total nitrogen, p.p.m. of total metals and about 10.93% by weight of asphaltenic compounds. Asphaltenes are high molecular weight hydrocarbons considered to be coke-precursors having the tendency to become immediately deposited within the reaction zone and other process equipment, and onto the catalytic composite in the form of a gummy, high molecular weight residue. Since this in efiect constitutes a large loss of charge stock, it is economically desirable to convert such asphaltenes into pentane-soluble liquid hydrocarbon fractions. Furthermore, the presence of excessive quantities of asphaltenes appears to inhibit the activity of a catalytic composite with respect to the removal of sulfur and nitrogen by conversion thereof to hydrogen sulfide, ammonia and hydrocarbons.

The object of the present invention is to provide a more efiicient process for hydrorefining, or decontaminating, such petroleum crude oils, than the processes currently being employed. A fixed-bed catalytic process, or a fixed-fluidized bed process for the hydrorefining of highly contaminated heavy hydrocarbonaceous material, is virtually precluded due to the difiiculty in maintaining the catalyst in an active condition. Various moving-bed processes employing catalytically active metals deposited upon refractory inorganic oxide materials, such as silica and/or alumina, are extremely erosive, thereby causing plant maintenance to become diflicult and expensive. The present invention teaches the preparation of a colloidally dispersed, unsupported catalytic component useful in a regenerative slurry process. The present process yields a liquid hydrocarbon product which is more suitable for further processing, without experiencing the difficulties otherwise resulting from the presence of the above-described contaminants. The catalyst of the present invention is particularly advantageous for effecting the removal of the organo-metallic complexes, without significant product yield loss while simultaneously converting pentane-insoluble material into pentane-soluble liquid hydrocarbons, notwithstanding the high concentrations of the other contaminating influences.

Therefore, in a broad embodiment, the present invention relates to a regenerative process for hydrorefining a hydrocarbon charge stock, which process comprises the steps of: (a) admixing said charge stock with at least one organo-metallic compound selected from the metals of Group VI-B having an atomic number greater than 24, and Group V-B of the Periodic Table; (b) decomposing said organo-metallic compound in said charge stock and reacting the resulting colloidal suspension with hydrogen; (c) separating the resulting reaction mixture to provide a hydrorefined liquid product and a catalystcontaining sludge; (d) dissolving the organic-soluble mazerial contained in said sludge and combining the resultng solution with said charge stock; (e) treating the renaining portion of said sludge with a sulfurous comaound selected from the group consisting of sulfur mono: :hloride, sulfur dichloride and a mixture thereof; (f) separating the resulting insoluble coke from said Sludge; and, (g) admixing the remainder of said sludge, containing the aforesaid metals, with said charge stock.

In particular, the present invention encompasses a process for hydrorefining a hydrocarbon charge stock, which process comprises steps of: (a) admixing said :harge stock with at least one carbonyl of the metals of Group VI-B having an atomic number greater than 24, andGroup V-B of the Periodic Table; (b) heating the resulting mixture at a temperature less than about 310 C., and for a time sufficient to decompose said carbonyl within said charge stock; (c) reacting the resultingcolloidal suspension with hydrogen at a temperature within the range of from about 225 C. to about 500 C. and

under a pressure of from about 500 to about 5000 p.s.i.g.;-

( d) separating the resulting reaction mixture to provide a hydrorefined liquid product and a catalyst-containing sludge; (e) dissolving the organic-soluble material contained in said sludge and combining the resulting solution with said charge stock; (f) treating the remaining portion of said sludge, at a temperature within the range of from about 300 C. to about 500 C., with a solution of from about 0.1% to about 25.0% by weight of a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof; (g) separating the resulting insoluble coke from the thustreated sludge; and, (h) combining the resulting solidfree remainder of said sludge, containing the aforesaid metals, with said hydrocarbon charge stock and reacting the resulting colloidal suspension with hydrogen as aforesaid.

A more limited embodiment of the present invention encompasses a process for hydrorefining a petroleum crude oil containing pentane-insoluble asphaltenes, which process comprises the steps of: (a) admixing said crude oil with at least one beta-diketone complex of the metals of Group VI-B having an atomic number greater than 24, and Group V-B of the Periodic Table; (b) decomposing said beta-diketone complex in said charge stock at a temperature less than about 310 C. and reacting the resulting colloidal suspension with hydrogen and added hydrogen sulfide at a temperature within the range of from about 225 C. to about 500 C. and under a pressure of from about 500 to about 5000 p.s.i.g.; (c) separating the resulting reaction mixture to provide a hydrorefined liquid product and a catalyst-containing sludge; (d) dissolving the organic-soluble material contained in said sludge and combining the resulting solution with said charge stock; (e) treating the remaining portion of said sludge, at a temperature within the range of from about 300 C. to about 500 C., with a solution of from about 0.1% to about 25.0% by weight of a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof; (f) separating the resulting insoluble coke from the thus-treated sludge; and, (g) combining the resulting solid-free remainder of said sludge, containing the aforesaid metals, with said charge stock, and reacting the resulting colloidal suspension with hydrogen and added hydrogen sulfide as aforesaid.

From the foregoing embodiments, it is readily ascertained that the method of the present invention involves the preparation of a colloidally-dispersed catalytic component utilizing metals selected from the group consisting of the metals of Group VI-B and having an atomic number greater than 24, and Group V-B of the Periodic Table. Therefore, the catalyst prepared in accordance with the method of the present invention, may comprise one or more metallic components from the group of vanadium, niobium, tantalum, molybdenum, tungsten, and

. 4 mixtures of two or more. It will be noted that the metal selected from Group VLB, namely molybdenum and/ or tungsten, has an atomic number greater than 24. It has been found that organo-chromium compounds do not yield comparable results upon subsequent reaction with hydrogen, and in particular do not elfect a suitable degree of conversion of the pentane-insoluble material and the destructive removal of the organo-metallic contaminants such as the nickel and/or vanadium porphyrins. The catalyst is prepared by initially dissolving an organometallic complex of the selected metal, or metals, in the hydrocarbon charge stock containing a pentane-insoluble fraction which is to be converted into soluble hydrocarbons. The quantity of the organo-metallic compounds employed is such that the colloidal suspension, or dispersion, resulting when the organo-metallic compound is decomposed in the hydrocarbon charge stock, comprises from'about 1.0% to about 10.0% by weight, calculated as if the metal existed in the elemental state. Suitable organo-metallic compounds include molybdenum blue, molybdenum hexacarbonyl, phosphomolybdic acid, molybdyl acetylacetonate, silicomolybdic acid, tungsten hexacarbonyl, phosphotungstic acid, tungsten acetylacetonate, silicotungstic acid, tungsten ethylxanthate, vanadium carbonyl, phosphovanadic acid, vanadyl acetylacetonate, vanadyl ethylxanthate, other carbonyls, heteropoly acids, beta-diketone complexes, etc.

Briefly, the process is effected :by initially mixing the desired quantity of the organo-metallic compound, for example, a mixture of phosphomolybdic acid and vanadyl acetylacetonate in the hydrocarbon charge stock, in amounts such that the resulting colloidal suspension, or dispersion contains from about 1.0% to 10.0% by weight of molybdenum and vanadium, calculated as the elements thereof. In order to facilitate the formation of the colloidal suspension, upon decomposition of the organometallic compound, it is often advisable to form a solution of such organo-metallic compound in a suitable solvent such =as an alcohol, a ketone, an ester, etc., adding such solution dropwise to the hydrocarbon charge stock. The resulting mixture is then heated, preferably in the absence of free hydrogen and other well-known reducing agents, at a temperature less than about 310 C. for a time sufiicient to effect the decomposition of the organometallic compound, and to remove the solvent by distillation, thereby forming a colloidal suspension, or dispersion of the metallic component within the hydrocarbon charge stock. The colloidal dispersion is then passed into a suitable reaction zone maintained at a temperature within the range of from about 225 C. to about 500 C. and under a hydrogen pressure Within the range of about 500 to about 5000 p.s.i.g. The presence of added hydrogen sulfide, within the hydrogen atmosphere, has been found to enhance the catalytic activity of most of the organometallic compounds, and particularly the beta-diketone complexes of vanadium and tungsten, and such hydrogen sulfide is added in an amount within the range of about 1.0% to about 15.0% by volume prior to effecting the hydroretining reactions. I

In order to maintain the catalyst in its decomposed form, which is believed to be either as the elemental metal, or as a lower oxide thereof, it is necessary that the reaction zone be substantially completely free from carbon monoxide. Following the decomposition of at least some of the foregoing organo-metallic compounds, such as molybdenum hexacarbonyl, some carbon monoxide will be present in the gaseous phase; this is readily removed by venting prior to passing the mixture into the reaction zone. Where some of the carbon monoxide is dissolved in the liquid phase, it is preferred to remove the same by suitable stripping means. When effected in a continuous manner, the process may be conducted in either upward flow or downward flow. The normally liquid hydrocarbons are separated from the total reaction zone product efiluent by any suitable means, for example,

through the utilization of a centrifuge, or settling tanks, the remaining catalyst-containing sludge being treated as hereinafter set forth.

The catalyst-containing sludge is a viscous fluid consisting of the catalytic metals, originally dispersed in the charge stock, unconverted asphaltenic material, soluble hydrocarbons, porphyrinic material containing nickel and vanadium, coke and heavy carbonaceous material, etc. I have found that the unconverted asphaltenic material consists of the 10.0% to about 20.0% by weight of the originally-present asphaltenes which are significantly more resistant to conversion, and cause an inordinately large proportion of the difficulties experienced when the crude oil, or heavy fraction derived therefrom, is subjected to hydrorefining and/or hydrocracking. This asphaltenic material is that which possesses the tendency to become virtually immediately transformed into coke and gummy polymerization material, as a result of which the remaining portion of the asphaltenes fails to come into contact with the active catalyst components, thereby also becoming increasingly more diflicult to convert. It is, therefore, expedient and economical to remove about 10.0% to about 20.0%, or more, of the total asphaltenic material originally present in the hydrocarbon charge stock, from the catalyst-containing sludge, prior to recirculating the same to combine with fresh charge stock. Furthermore, the active catalytic components may then be recombined with the charge stock, to form the colloidal suspension or dispersion, thereby effecting additional refining of the charge stock.

Following the separation of the normally liquid hydrocarbons from the catalyst-containing sludge, the latter is treated with a suitable organic solvent for the purpose of dissolving residual organic-soluble material such as the pentane-soluble hydrocarbon products resulting from the conversion of the pentane-insoluble asphaltenic compounds originally present in the petroleum crude oil. Any well-known organic solvent may be employed for the dissolution of the organic-soluble material in the catalystcontaining sludge; suitable solvents include, therefore, pentane, benzene, hexane, heptane, toluene, etc. The resulting solution may be subjected to further reaction with hydrogen by recycling the same to combine with the fresh hydrocarbon charge stock. The remaining portion of the catalyst-containing sludge is then treated, in accordance with the present invention, with a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof. The unconverted asphaltenic material is at least in part converted into insoluble coke. Such conversion may be readily elfected at a relatively low temperature within the range of from about 250 C. to about 450 C. The sulfur chloride is generally employed in an amount of from about 0.1% to about 25.0% by weight of the material to be treated. An unexpected advantage is afforded, through the use of the stated sulfur chlorides, in that, at lower temperatures of about 100 C. to about 300 C., the organo-metallic contaminants are subject to destructive removal, such that the metals take on a soluble form, and are thus separated from the heavy hydrocarbon complex. The insoluble coke, resulting from the conversion of the asphaltenes, is separated from the sludge, the resulting substantially solid-free remainder of the sludge being combined with fresh hydrocarbon charge stock, and reacted with hydrogen as aforesaid. Prior to combining the metals recovered from the sludge with the fresh hydrocarbon charge stock, it may be desirable to withdraw at least a portion of such metals, generally from 0.1% to about 1.0% by weight in order to maintain the highest possible degree of catalytic activity. Consequently, a like quantity of metal is added to the hydrocarbon charge stock as the organo-metallic compound, to compensate for the quantity of metal removed from the sludge, prior to combining the latter with said charge stock. The solution recovered from the catalyst-containing sludge will contain the original metallic components utilized as the catalyst, and, in addition thereto, at least a portion of the vanadium originally existing in the charge stock as a porphyrin or a derivative thereof. Since the vanadium component, when colloidally dispersed within the charge stock, exhibits an acceptable degree of catalytic activity, very little fresh catalyst is necessary to maintain catalytic activity, and in many instances the catalyst may be considered to be self-sustaining. In any event, the metals recovered from the catalyst containing sludge are combined with fresh hydrocarbon charge stock, the mixture being heated to a temperature not above 310 C. to form the colloidal suspension of dispersion.

Although the process encompassed by the present invention may be elfected in the manner wherein the catalyst-containing sludge is treated separately, other processing schemes will be evident to those having skill in the art of petroleum refining processes, and will be advantageous in hydrorefining the more severly contaminated charge stocks. For example, when the charge stock is a vacuum tower bottoms product having a gravity of l4.7 API at 60 F., and contaminated by 3.18% by weight of sulfur, 3,900 ppm. of total nitrogen, 40 ppm. of nickel, over 400 p.p.m. of vanadium, and containing a high-boiling, pentane-insoluble asphaltenic fraction in an amount of 12.53% by weight, the process readily lends itself to multiple-stage techniques. Thus, the charge stock may be initially treated with a sulfur chloride at about 300 C., to form insoluble coke from about 15.0% of the .asphaltenes and to eliminate at least a portion of the nickel and vanadium porphyrins. After separation of the insoluble coke, the solid-free liquid portion can be reacted with hydrogen in the presence of the decomposed catalytically active organo-metallic compound in the manner hereinabove set forth. The hydrorefined liquid is separated from the catalyst-containing sludge, the latter then treated with an additional amount of a sulfur-chloride priolr; to being combined with fresh hydrocarbon charge stoc On the other hand, the catalyst-containing sludge can be added to fresh hydrocarbon charge stock, and the mixture extracted to remove the organic-soluble material. The remaining insoluble portion of the mixture is then treated at a temperature of about 300 C. with a sulfur chloride to convert asphal-tenes into insoluble coke which may be readily separated by a centrifuge system or settling tanks, the supernatant liquid being admixed with the organic-soluble material, with which mixture the colloidal dispersion of catalytic metals will be formed. It is understood that various. modifications are not intended to be removed from the broad scope of the present invention as set forth in the specification and appended claims.

Depending upon the particular organo-metallic compound selected as the catalyst source, the dispersed materia-l is believed to be the elemental metal or a lower oxide form thereof. Although analytical methods, including X-ray diffraction, have not revealed the precise physical and/or chemical state of the colloidally disperse-d material, it is believed that .the same may exist as a pseudo complex with the asphaltenic compound initial-1y present in the charge stock, or as the elemental metal or an oxide, as hereinbefore stated.

The following examples are given to illustrate the process of the present invention, and the effectiveness thereof in converting pentane-insoluble asphaltenes, while simultaneously effecting the conversion of sulfurous and nitrogeneous compounds into sulfur-free and nitrogenfree hydrocarbons and decreasing significantly the concentration of organo-metallic contaminants. It is not intended that the present invention 'be-unduly limited to the catalyst, charge stock and/or operating conditions employed in this illustration.

7 Example I The crude oil employed to illustrate the benefits afforded through the utilization of the present invention was a Wyoming sour crude oil, having a gravity of 23.2 API at 60 F., and containing about 2.8% by weight of sulfur, approximately 2700 p.p.m. of nitrogen, 18 p.p.m. of nickel andv about 81 p.p.m. of vanadium, as metal porphyrins, calculated on the basis of the elemental metal. In addition, the sour crude oil consisted of about 8.39% by weight of pentane-inso-luble asphaltenes. As hereinafter indicated, the process of the present invention effects the conversion of a significant proportion of such asphaltenes and to the degree that the same no longer exert a detrimental effect upon further processing. The colloidally dispersed catalysts were prepared by decomposing the indicated organo-rnetallic compounds Within the Wyoming sour crude oil, thereafter subjecting the mixture to conversion in a rotating autoclave at a temperature of about 400 C. and under an imposed hydrogen pressure of about 200 atmospheres. Each of the col loidal suspensions remained in the autoclave as the foregoing conditions for a period of from about four to about eight hours.

Molybdenum hexacarbonyl, in an amount of 23.3 grams, was admixed with 200 grams of the Wyoming sour crude, the mixture being charged to the rotating autoclave and heated to a temperature at 250 C. for a period of three hours. After venting to remove carbon monoxide, the autoclave was pressured to 100 atmospheres with hydro-gen and then heated to a temperature of 400 C. for a period of about four hours, the final pressure being about 200 atmospheres. The gravity, AP-Iat 60 F., of the resulting normally liquid product eflluent, following separation thereof from the catalyst-containing sludge, was 40.1, indicating a significant degree of conversion to lower-boiling hydrocarbon products. Upon analysis, this liquid product indicated the continued presence of only 7.1 p.p.m. of nitrogen, about 0.02% by weight of sulfur, about 0.10% by weight of pent-aneinsoluble asphaltenes, less than about 0.02 p.p.m. of nickel and less than about 0.02 p.p.m. of vanadium. When utilizing 23.3 grams of molybdenum hexacarbonyl decomposed in situ, in the presence of hydrogen, the final liquid product was found to contain 347 p.p.m. of nitrogen compared to 7.1 p.p.m., as hereinabove set forth.

Example II A mixture of the Wyoming sour crude and a colloidally disperse-d vanadium component was prepared by adding a solution of about 42. grams of vanadlyl acetylacetonate, in 500 grams of normal amyl alcohol, to 250 grams of the sour Wyoming crude, the mixture being stirred at a temperature of about 160 C. during the addition: the alcoholic solvent was recovered in an overhead condenser. Thereafter, 100 grams of the mixture was sealed in an 850 cc. rotating autoclave and pressured to 100 atmospheres with hydrogen. The contents were heated to a temperature of 400 C., the resulting final pressure being about 200 atmospheres, which conditions were maintained for a period of about eight hours. The bydrorefined product, consisting of normally liquid hydrocarbons, was separated from the catalyst-containing sludge and found to contain about 0.308% by weight of pentaneinsoluble asphaltenes, less than about 0.03 p.p.m. of nickel, less than about 0.6 p.p.m. of vanadium and 0.19% by weight of sulfur.

Example III A normal amyl alcohol solution of 23.2 grams of molybdenum hexacarbonyl and 42 grams of vanadyl acetylacetonate is added dropwise to 450 grams of sour Wyoming crude oil hereinabove described, the resulting mixture being intimately admixed with a vibromixer at a temperature of about 200 C., at which temperature the normal amyl alcohol is readily distilled, leaving the molybdenum and vanadium components colloidally dispersedin the crude oil. The mixture is placed Within the rotating autoclave and pressured to atmospheres with hydrogen. The temperature is increased to 400 C., the resulting pressure being about 200 atmospheres, and the autoclave maintained at these conditions for a period of about six hours. Following separation from the catalyst-containing sludge, the normally liquid product efiluent is found to have a gravity, API at 60 F., of about 35.5. Upon analysis, this normally liquid product is found to contain less than about 10 p.p.m. of nitrogen, less than 0.02% by weight of sulfur, about 0.15% by weight of pentane-insolublc asphaltenes, less than about 0.1 p.p.m. of nickel and less than about 0.1 p.p.m. of vanadium.

The catalyst-containing sludge, in an amount of about 60 grams, is admixed with about 60 cc. of benzene, the resulting mixture being stirred for a period of about one-half hour. Following centrifugal separation, the henzene solvent and organic-soluble portion of the sludge is admixed with fresh crude oil, the insoluble portion of the sludge, in an amount of about 50 grams being slurried with about 500 milliliters of a solution of 10.0 grams of sulfur monochloride. The insoluble sludge and sulfur monochloride solution are intimately admixed for a period of about one hour at a temperature of about 300 C., for the purpose of converting asphaltenic material to coke and liquid hydrocarbons. The resulting mixture is subjected to centrifugal separation to remove the coke, follow ing which the supernatant liquid is added dropwise to the mixture of fresh crude oil and benzene solution of the organic-soluble matter. The centrifuged solids, remaining after extracting the supernatant liquid therefrom, are in an amount of about 5.0 grams.

The mixture of crude oil and benzene-soluble material is heated to a temperature of about C., the supernatant liquid being added dropwise thereto. The resulting colloidal dispersion is placed within the rotating autoclave and pressured to 100 atmospheres with hydrogen as before. The autoclave is heated to a temperature of 400 C. for a period of about eight hours, the final pressure being about 200 atmospheres. The total reaction zone product efiiuent is passed into a centrifugal separator from which the normally liquid hydrocarbon product, substantially free from solids, is removed. This liquid product contains less than about 10 p.p.m. of total nitrogen, less than about 0.10% by weight of sulfur, about 0.02% by weight of pentane-insoluble asphaltenes, less than about 0.10 p.p.m. of nickel and less than about 0.10 p.p.m. of vanadium.

Example III A vacuum tower bottoms products having a gravity of 14.7 API at 60 F., and contaminated by 3.18% by weight of sulfur, 3,900 p.p.m. of nitrogen, over 450 p.p.m. of nickel and vanadium, is admixed, in an amount of 200 grams, with 40.0 grams (20.0% by weight) of sulfur dichloride, the mixture being placed in a rotating autoclave having a capacity of 1800 cc. The contents of the autoclave are pressured with sufi'icient hydrogen to insure a final pressure of 200 atmospheres after being heated to a temperature of 350 C., these conditions being maintained for a period of eight hours. After depressuring and cooling, the contents of the autoclave are subjected to centrifugal separation to remove the insoluble coke particles. The resulting supernatant liquid, upon analysis, indicates about 60.0% removal of the asphaltenic material, and a decrease in the amount of nickel and vanadium to about 200 p.p.m.

Phosphomolybdic acid, in an amount of 10.0% by weight (calculated as elemental molybdenum), based upon the quantity of supernatant liquid, is added dropwise as an isopropyl alcohol solution to the supernatant liquid at a temperature of 160 C. The resulting colloidal suspension is placed in the rotating autoclave, being maintained therein at a temperature of 425 C. and under a hydrogen pressure of 200 atmospheres for a period of eight hours. After cooling and depressuring, the contents of the autoclave are centrifuged to remove the catalystcontaining sludge from the normally liquid hydrocarbons, the latter, upon analysis, indicating less than about 0.3 p.p.m. of total metals, about 0.1% by weight of sulfur, less than about 10 p.p.m. of nitrogen and about 0.01% by weight of asphaltenes.

The catalyst-containing sludge is admixed with an additional 200 grams of vacuum tower bottoms product, the mixture commingled with 20.0% by weight of sulfur monochloride, and placed in the rotating autoclave. After eight hours at a temperature of 350 C. and a hydrogen pressure of 200 atmospheres, the contents of the autoclave are centrifuged to provide a supernatant liquid which, upon analysis, indicates about 60.0% removal of asphaltenic material. An additional amount of phosphomolybdic acid, about 1.0% by weight, as elemental molybdenum, is added to the supernatant liquid, and the resulting colloidal dispersion is placed in the autoclave for a period of eight hours at a temperature of 425 C. and a pressure of 200 atmospheres. After separation of the catalyst-containing sludge, the normally liquid hydrocarbon product indicates a gravity of about 295 API at 60 F., about 0.1% by weight of sulfur, less than about 10 p.p.m. of total nitrogen and less than about 0.01% by weight of asphaltenes.

The foregoing specification and examples clearly illustrate the advantages afforded the hydrorefining of petroleum crude oils through the utilization of the regenerative process of the present invention. It is of particular interest to note that the concentration of nickel and vanadium, existing as organo-metallic complexes, as well as the pentane-insoluble asphaltenes, have been decreased to a level permitting subsequent utilization of the crude oil for further processing, and that at least a portion of the crude oil was converted to lower-boiling hydrocarbon products. Furthermore, the catalyst-containing sludge, following partial conversion to insoluble coke -as hereinbefore set forth, is readily utilized in the formation of a colloidal dispersion to be reacted with hydrogen in the manner hereinbefore set forth.

I claim as my invention:

1. A regenerative process for hydrorefining a hydrocarhon charge stock containing asphaltenes which comprises the steps of:

(a) admixing said charge stock with at least one organo-metallic compound of a metal selected from the metals of Group VIB having an atomic number greater than 24, and Group V-B of the Periodic Table;

(b) decomposing said organo-metallic compound in said charge stock and reacting the resulting colloidal suspension with hydrogen;

(c) separating the resulting reaction mixture to provide a hydrorefined liquid product and a catalystcontaining sludge;

(d) contacting the sludge with an organic solvent to dissolve the organic-soluble material contained in said sludge and combining the resulting solution with said charge stock;

(e) treating the remaining portion of said catalyst-containing sludge at a temperature of from about 100 C. to about 500 C. with a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof to convert asphaltenes contained therein to insoluble coke;

(f) separating the resulting insoluble coke from said sludge; and,

(g) admixing the remainder of said sludge, containing the aforesaid metal, with said charge stock.

2. A process for hydrorefining a hydrocarbon charge stock containing asphaltenes which comprises the steps of:

(a) admixing said charge stock with at least one organo-rnetallic compound of a metal selected from the metals of Group VI-B having an atomic number greater than 24, and Group V-B of the Periodic Table;

(b) decomposing said organo-metallic compound in said charge stock at a temperature below about 310 C., reacting the resulting colloidal suspension with hydrogen at a temperature above'about 225 C. and at a pressure greater than 500 pounds per square inch gauge;

(e) treating the remaining portion of said sludge at a temperature of from about C. to about 500 C. with a solution of from about 0.1% to about 25.0% by weight of a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof to convert asphaltenes contained therein to insoluble coke;

(f) separating insoluble coke from the thus-treated sludge; and,

(g) admixing the resulting coke-free remainder of said sludge, containing the aforesaid metal, with said charge stock.

3. The process of claim 2 further characterized in that the mixture of said charge stock and decomposed organometallic compound is reacted with hydrogen at a temperature within the range of from about 225 to about 500 C. and under a pressure of from about 500 to 5000 pounds per square inch gauge.

4. The process of claim 2 further characterized in that said organo-metallic compound comprises an organomolybdenum compound.

5. The process of claim 2 further characterized in that said organo-metallic compound comprises an organotungstic compound.

6. The process of claim 2 further characterized in that said organo-rnet-allic compound comprises an organovanadic compound.

' 7. A processfor hydrorefining a hydrocarbon charge stock containing asphaltenes which comprises the steps of:

(a) admixing said charge stock with at least one carbonyl of a metal selected from the metals of Group VI-B having an atomic number greater than 24, I

and Group V-B of the Periodic Table;

(b) heating the resulting mixture at a temperature less than about 310 C. and for a time sufficient to decompose said carbonyl within said charge stock;

(c) reacting the resulting colloidal suspension with hydrogen at a temperature within the range of from about 225 C. to about 500 C. and under a pressure of from about 500 to about 5000 pounds per square inch gauge;

(d) separating the resulting reaction mixture to provide a hydrorefined liquid product and a catalyst-containing sludge;

(e) contacting the sludge with an organic solvent to dissolve the organic-soluble material contained in said sludge, combining the resulting solution with said charge stock;

(f) treating the remaining portion of said sludge, at a temperature within the range of from about 300 C. to about 500 C., with a solution of from about 0.1% to about 25 .O% by weight of a sulfurous compound selected from the group consisting of sulfur 1 1 monochloride, sulfur dichloride and a mixture thereof to convert asphaltenes contained therein to insoluble .coke;

(g) separating the resulting insoluble coke thus-treated sludge; and,

(h) combining the resulting coke-free remainder of said sludge, containing the aforesaid metal, with said hydrocarbon charge stock and reacting the resultant colloidal suspension with hydrogen as aforesaid.

8. The process of claim 7 further characterized in that aid sludge is treated with said sulfurous compound under I. hydrogen pressure of from about 100 to about 300 itmospheres.

9. A process for hydro-refining a petroleum crude oil :ontaining pentaue-insoluble asphaltenes which comprises he steps of:

(a) admixing said crude oil with at least one heteropoly acid of a metal selected from the metals of Group VI-B having an atomic number greater than 24, and Group V-B of the Periodic Table;

(b) heating the resulting mixture at 'a. temperature less than about 310 C. and for a time Sufficient to decompose said heteropoly acid in said charge stock;

() reacting the rtsulting colloidal suspension with hydrogen at a temperature of from about 225 C. to about 500 C. and at a pressure within the range of about 500 to about 5000 pounds per square inch gauge;

(d) separating the resulting reaction mixture to provide from the a hydrorefined liquid product and a catalyst-contain ing sludge;

(e) contacting the sludge with an organic solvent to dissolve the organic-soluble matter contained in said sludge and combining the resulting solution with said-charge stock;

(f) treating the remaining portion of said sludge, at a temperature Within the range of from about 300 C. to about 500 C., with a solution of from about 0.1% to about 25.0% by weight of a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and-a mixture ther of toconvert asphaltenes contained therein to insoluble coke;

(g) separating the resulting insoluble coke from the thus-treated sludge; and,

(h) combining the resulting coke-free remainder of said sludge, containing the aforesaid metal, with said petroleum crude oil and reacting the resultant colloidal suspension with hydrogen as aforesaid.

10. The process of claim 9 further characterized in that said heteropoly acid comprises silicomolybdic acid.

11. The process of claim 7 further characterized in that said carbonyl comprises molybdenum hexacarbonyl.

12. A process for hydrorefining a hydrocarbon charge stock containing asphaltenes which comprises the steps of:

(a) admixing said charge stock with at least one betadiketone complex of a metal selected from the metals vide a hydrorefined liquid product and a catalystcontaining sludge;

(e) treating the remaining portion of said sludge, at a temperature Within the range of from about 300 C. to about 500 C., with a solution of from about 0.1% to about 25.0% by Weight of a sulfurous compound selected from the group consisting of sulfur monochloride, sulfur dichloride and a mixture thereof to convert asphaltenes contained therein to insoluble coke;

(f) separating the resulting insoluble coke from the thus-treated sludge; and,

(g) combining the resulting coke-free remainder of said sludge, containing the aforesaid metal, with said hydrocarbon charge stock and reacting the resultant colloidal suspension with hydrogen as aforesaid.

13. The process of claim 12 further characterized in that the mixture of said charge stock and decomposed beta-diketone complex is reacted with hydrogen and added hydrogen sulfide at a temperature Within the range 'of' from about 225 C. to about 500 C. and under a pressure of from about 500 to 5000 pounds per square inch gauge.

14. The process of claim 12 further characterized in that said beta-diketone complex comprises vanadyl'acetyl- :acet-onate.

15. The process of claim 12 further charcaterized in that said beta-diketone complex comprises molybdyl acetylacetonate.

16. The process of claim 9 further characterized in that said heteropoly acid comprises phosphomolybdic acid.

References Cited by the Examiner UNITED STATES PATENTS 3 ,l65,463 l/ 1965 Gleim et al .,208264 DELBERT E. GANTZ, Primary Examiner. S. P, JONES, Assistant Examiner.

Claims

1. A REGENERATIVE PROCESS FOR HYDROREFINING A HYDROCARBON CHARGE STOCK CONTAINING ASPHALTENES WHICH COMPRISES THE STEPS OF: (A) ADMIXING SAID CHARGE STOCK WITH AT LEAST ONE ORGANO-METALLIC COMPOUND OF A METAL SELECTED FROM THE METALS OF GROUP VI-B HAVING AN ATOMIC NUMBER GREATER THAN 24, AND GROUP V-B OF THE PERIODIC TABLE; (B) DECOMPOSING SAID ORGANO-METALLIC COMPOUND IN SAID CHARGE STOCK AND REACTING THE RESULTING COLLOIDAL SUSPENSION WITH HYDROGEN; (C) SEPARATING THE RESULTING REACTION MIXTURE TO PROVIDE A HYDROREFINED LIQUID PRODUCT AND A CATALYSTCONTAINING SLUDGE; (D) CONTACTING THE SLUDGE WITH AN ORGANIC SOLVENT TO DISSOLVE THE ORGANIC-SOLUBLE MATERIAL CONTAINED IN SAID SLUDGE AND COMBINING THE RESULTING SOLUTION WITH SAID CHARGE STOCK; (E) TREATING THE REMAINING PORTION OF SAID CATALYST-CONTAINING SLUDGE AT A TEMPERATURE OF FROM ABOUT 100* C. TO ABOUT 500*C. WITH A SULFUROUS COMPOUND SELECTED FROM THE GROUP CONSISTING OF SULFUR MONOCHLORIDE, SULFUR DICHLORIDE AND A MIXTURE THEREOF TO CONVERT ASPHALTENES CONTAINED THEREIN TO INSOLUBLE COKE; (F) SEPARATING THE RESULTING INSOLUBLE COKE FROM SAID SLUDGE; AND, (G) ADMIXING THE REMAINDER OF SAID SLUDGE, CONTAINING THE AFORESAID METAL, WITH SAID CHARGE STOCK.