US3847798A

US3847798A - Oxidation and desulfurization of a hydrocarbon material

Info

Publication number: US3847798A
Application number: US00259946A
Authority: US
Inventors: J Yoo
Original assignee: Atlantic Richfield Co
Current assignee: Atlantic Richfield Co
Priority date: 1972-06-05
Filing date: 1972-06-05
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12

Abstract

A process for reducing the sulfur content of hydrocarbon material by oxidizing the sulfur impurities contained in the hydrocarbon material, contacting the oxidized sulfur-containing hydrocarbon material with at least one hydrocarbon hydrogen donor component capable of transferring hydrogen under conditions such that hydrogen transfer from said component to the oxidized sulfur-containing hydrocarbon material occurs and recovering a hydrocarbon material of reduced surfur content.

Description

1 1 Nov. 12, 1974 1 OXIDATION AND DESULFURIZATION OF A HYDROCARBON MATERIAL [75] lnventor'. Jin Sun Yoo, South Holland, [11.

[73] Assignee: Atlantic Richfield Company, New

York, NY.

[22] Filed: June 5, 1972 [21] Appl. No.: 259,946

[56] References Cited UNITED STATES PATENTS 3,341,448 9/1967 Ford et a1. 208/214 3,725,253 4/1973 Yamada 208/211 3,595,778 7/1971 Smetana et a1. 208/208 R 2,648,623 8/1953 Porter et a1 208/214 2,253,308 8/1941 Rosen 208/214 3,184,401 5/1965 Gorin t 1 208/214 2,834,717 5/1958 Shiah 208/214,

- Primary ExaminerDe1bert E. Gantz Assistant ExaminerG.-.1. Crasanakis Attorney, Agent, or FirmFrank J. Uxa

[57] ABSTRACT A process for reducing the sulfur'content of hydrocarbon material by oxidizing the sulfur impurities contained in the hydrocarbon material, contacting the oxidized sulfur-containing hydrocarbon material with at least one hydrocarbon hydrogen donorcomponent capable of transferring hydrogen under conditions such that hydrogen transfer from said component to the oxidized sulfur-containing hydrocarbon material occurs and recovering a hydrocarbon material of reduced surfur content.

16 Claims, No Drawings OXIDATION AND DESULFURIZATION OF A HYDROCARBON MATERIAL The present invention relates to an improved process for reducing the sulfur content of hydrocarbon materials. More particularly, the invention relates to the reduction in sulfur content of hydrocarbon materials involving the oxidation of sulfur impurities contained therein.

Petroleum crude oils and topped or reduced crude oils as well as other heavy hydrocarbon fractions and- /or distillates are contaminated by the presence of excessive concentrations of various known non-metallic impurities which detrimentally affect various processes to which such fractions may be subjected. Among the known non-metallic impurities is sulfur which exists in hetero-atomic compounds which have proven difficult to remove by conventional processing. The sulfur in these hydrocarbon fractions is objectionable, for example, because combustion of fuels containing this impurity results in the release of sulfur oxides which are noxious, corrosive and, therefore, present a serious problem with respect to pollution of the atmosphere.

' The prior art is replete with methods for removing the sulfur compounds. One known method involves oxidation of the hydrocarbon material followed by treating the oxidized hydrocarbon at elevated temperatures to reduce the sulfur content of the hydrocarbon mate rial. This method has proven to be of only limited utility since only a rather low degree of desulfurization is achieved. In addition, substantial loss of valuable products may result due to cracking and/or coke formation during the practice of this method. Therefore, it would be advantageous to develop a process which gives an increased degree of desulfurization while decreasing cracking or coke formation.

Therefore, one of the primary objects of the present invention is to provide a process for the improved desulfurization of sulfur-containinghydrocarbon materials.

Another object of the present invention is to provide a process for producing low sulfur-containing hydrocarbons without undue yield losses to cracking and coking. Other objects and advantages will become apparent hereinafter.

It has now been discovered that improved desulfurization of a sulfur-containing hydrocarbon material without undue yield losses to cracking and coking can be obtained by a process which comprises oxidizing at least a portion of the sulfur in a sulfur-containing hydrocarbon material, contacting the oxidized sulfurcontaining hydrocarbon material with at least one hydrocarbon hydrogen donor component capable of transferring hydrogen to said oxidized hydrocarbon material under conditions such that said hydrogen transfer occurs and recovering a hydrocarbon material of reduced sulfur content.

This invention involves the processing of various sulfur-containing hydrocarbon materials, such as those derived from petroleum sources. In general, the sulfur content of these materials may be greater than about 1% by weight. In many instances these hydrocarbon materials contain a significant amount of thiophene sulfur which is known to be difficult to remove. Typical examples of hydrocarbon materials which are suited to the present process include heavy hydrocarbon materials such as petroleum fractions containing at least a' v major amount of material boiling above about 550F., for example, crude oil and atmospheric and vacuum residues which contain about 1% by weight or more of sulfur. Additional examples of suitable hydrocarbon materials include cracked gas oils, residual fuel oils, topped or reduced crudes, crude petroleum from which the lighter fractions are absent, residues from cracking processes and sulfur-containing hydrocarbon materials from tar sands, oil shale and coal. The invention is particularly suited to those sulfur-containing heavy hydrocarbon'materials which cannot be deeply flashed without extensive carry over of sulfur-containing compounds. Typical examples of the 2,3,4, and 5-ring thiophene-containing materials found in heavy hydrocarbon materials which are difficult to remove include benzothiophene, dibenzothiophene, 5-thia-3,4- benzofluorene, tetraphenyl-thiophene, diacenaphtho (l,2-b,l ',2-d) thiophene and anthra (2,1,9-cde) thianaphthene. The hydrocarbon material may also contain non-thiophene sulfur, various sulfides, and elemental sulfur which can be removed by the process of the present invention.

The sulfur in the hydrocarbon material may be oxidized using any conventional oxidant which is able to chemically oxidize at least a portion of the sulfur contained in the hydrocarbon material.- It is preferred that the oxidant preferentially oxidize the sulfur rather than the hydrocarbon portion of the hydrocarbon material. By this is meant that the oxidation preferably occurs without substantial oxidation of carbon atoms to form, for example,.ketones, carboxyl acids or other carbonylcontaining compounds. Included among the oxidants which may be used for such oxidation are oxygen (often in the form of oxygen-containing gases, e.g., air) ozone, hydrogen peroxide, organic peroxides, organic hydroperoxides and organic peracids, as well as inorganic' peroxy compounds such as inorganic peroxides and the like. The oxidation preferably takes place in the presence of a metal-containing catalyst, described hereinafter.

Thus, the oxidation step is carried out by treating the sulfur-containing hydrocarbon material with an oxidant optionally in the presence of a metal-containing catalyst for a time sufficient to effect oxidation of at least a portion of the sulfur present in the hydrocarbon material. The concentration of oxidant is usually dependent upon the percent sulfur present in the hydrocarbon material and, in general,the mole ratio of oxidant to sulfur contained in the hydrocarbon material is from about 0.5 to about 10 atoms of active (i.e., reducable) oxygen per atom of sulfur in the hydrocarbon material, preferably from about 1 to about 8 atoms of active oxygen per atom of sulfur and more preferably from about 1.5 atoms to about 4.0-atoms of active oxygen per-atom of sulfur. Oxidants useful in the present invention include those, having one, two or more atoms of active oxygen per molecule of oxidant.

The'temperature utilized in carrying out the oxidation step can vary over a wide range. Preferably, a temperature within the range from about 20F. to about 450F. may be employed, although higher and lower temperatures can be utilized. In general, the sulfurcontaining hydrocarbon material is heated with the oxidant for a time sufficient to oxidize at least a portion of the'contained sulfur, preferably for a time within the range of from about 5 min. to about 24 hours and more preferably from about one-half hour to about 20 hours.

The time that is utilized, in general, depends upon the percent sulfur present in the heavy hydrocarbon material, the type of sulfur present and the type and amount of oxidant. The sulfur-oxidizing step of this invention, in general, may be carried out over a broad range of pressures, preferably at a pressure in the range from about 1 atmosphere to about 100 atmospheres or more.

The preferred oxidants which are utilized in carrying out the oxidation step of the process of this invention are organic peroxides, organic hydroperoxides, organic peracids and hydrogen peroxide. These oxidants are particularly preferred since such oxidants have been found to give excellent desulfurization when combined with the contacting and recovery steps described herein. In addition, the use of the preferred oxidants have been found to be selective for oxidation of the sulfur, that is, substantial amounts of oxidation products such as acids and ketones are not formed. In addition, high product yields in the oxidation step, both as to the high product yield of oxidized sulfur impurities and the high product yield of hydrocarbon material which remains after the oxidation step and, in particular after the contacting step, are obtained utilizing the preferred oxidants. The organic oxidants include by way of example hydrocarbon peroxides, hydrocarbon hydroperoxides and hydrocarbon peracids wherein the hydrocarbon radicals in general contain from about I to about 30 carbon atoms per active oxygen atom. With respect to the hydrocarbon peroxides and hydrocarbon hydroperoxides, it is particularly preferred that such hydrocarbon radical contain from about 4 to about 18 carbon atoms per active oxygen atom, i.e., per peroxide linkage, and more particularly from 4 to 16 carbon atoms per peroxide linkage. With respect to the hydrocarbon peracids, the hydrocarbon radical is defined as that radical which is attached to the carbonyl carbon and it is preferred that such hydrocarbon radical contain from 1 to about 12 carbon atoms, more preferably from 1 to about 8 carbon atoms, per active oxygen atom. It is intended that the term organic peracid include, by way of definition, performic acid.

In addition, it is contemplated within the scope of this invention that the organic oxidants can be prepared in situ, that is the peroxide, hydroperoxide or peracid can be generated in the sulfur-containing hydrocarbon material and such organic oxidant is contemplated for use within the scope of this invention.

Typical examples of hydrocarbon radicals are alkyl such as methyl, ethyl, butyl, t-butyl, pentyl, n-octyl and those aliphatic radicals which represent the hydrocarbon portion of a middle distillate or kerosene, and the like; cycloalkyl radicals such as cyclopentyl and the like; alkylated cycloalkyl radicals such as monoand polymethylcyclopentyl radicals and the like; cycloalkyl substituted alkyl radicals such as cyclopenyl methyl and ethyl and the like; aryl and alkyl phenyl substituted alkyl radicals such as benzyl, methylbenzyl, caprylbenzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, and the like; aryl radicals such as xylyl, methyl phenyl, ethyl phenyl and the like.

Typical examples of oxidants are hydroxyheptyl peroxide, cyclohexanone peroxide, t-butyl peracetate, dit-butyl diperphthalate, t-butyl-perbenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, p-methane hydroperoxide, pinane hydroperoxide, 2,5-dimethylhexane-2,5-

dihydroperoxide, tetrahydronaphthalene hydroperoxide and cumene hydroperoxide as well as organic per- V acids, such as performic acid, peracetic acid, trichloroperacetic acid, perbenzoic acid and perphthalic acid. The preferred oxidant for use in the present invention is tertiary butyl hydroperoxide.

The catalyst which may be utilized to promote the oxidation of sulfur contained in a hydrocarbon material using the preferred oxidants are catalysts selected from Group IV-B, Group V-B and Group VI-B metals. These catalysts can be incorporated into the present process by any means known to those skilled in the art, and can be included in either a homogeneous or heterogeneous catalyst system. When homogeneous metal-containing oxidation catalyst is employed, it is preferred that the catalyst metal concentration be in the range from about 5 ppm. to about 10%, more preferably from about 10 ppm. to about 500 ppm. by weight based on the weight of the sulfur-containing hydrocarbon material. In any event, the catalyst metal concentration is such as to promote the preferential oxidation of sulfur in the sulfur-containing hydrocarbon material. The catalyst can be incorporated by a variety of means and by the use of a variety of carriers. The particular catalyst carrier which is utilized is not critical with respect to the practice of this invention and can be, for example, a support medium or an anion (including complex formation) which is attached to the metal (e.g., a ligand). The preferred catalyst metals are titanium, zirconium, vanadium, tantalum, chromium, molybdenum, tungsten and mixtures thereof, with molybdenum being the more preferred catalyst metal. Illustrative ligands include halides, organic acids, alcoholates, mercaptides, sulfonates and phenolates. These metals may be also bound by a variety of complexing agents including acetonylacetonates, amines, ammonia, carbon monoxide and olefins, among others. The metals may also be introduced in the form of organometallics including ferrocene type structures. The various ligands illustrated above which are utilized solely as carriers to incorporate the metal into the process system, in general, have an organic radical attached to a functional group such as the oxygen atom of the carbonyloxy group of the acid, the oxygen of the alcohol, the sulfur of the mercaptan, the

of the sulfonate, the oxygen of the phenolic compound and the nitrogen of the amines. The organic radical attached to the afore described functional groups can be defined as a hydrocarbon radical and, in general, can contain from 1 to about 30 carbon atoms. Typical examples of hydrocarbon radicals are set forth above.

Various covalent peroxide complexes, with or without vr-ligands, of suitable metals are also effective oxidation catalysts. The preferred rr-ligands are hexamethyl phosphoamide, octamethyl phosphonamide, trialkyl-, triaryl-, and triaralkylphosphines and phosphine oxides, pyridine oxide, pyridine, 2,2'-bipyridine, dimethylforamide, dimethylacetamide, and tetramethylurea.

The metals contained in either the homogeneous or heterogeneous catalyst useful in the present invention can include an individual metal or combination of metals. These metals can be supported on a suitable material, for example, natural or synthetic alumina, silica (or combinations of both) as well as activated clays or carbon, among others. The modes of contacting the hydrocarbon material with a heterogeneous catalyst whereby the catalytic effect may be achieved may include slurry-bed reactions or continuous contacting over a stationary phase in a trickle-tube reactor or other conventional methods.

A particularly preferred catalyst for carrying out the oxidation step of the process of this invention is a molybdenum-containing catalyst prepared by a method which comprises interacting molybdenum metal with a compound selected from the group consisting of organic peroxide, organic hydroperoxide, organic peracid, hydrogen peroxide and mixtures thereof in the presence of at least one saturated alcohol having from one to four carbon atoms per molecule to solubilize at least a portion of the molybdenum metal. It is believed that the molybdenum metal interacts with the peroxy compound to form a soluble molybdenum-containing product.

Typical peroxides, hydroperoxides, and peracids useful in the preparation of the preferred molybdenumcontaining catalyst have been described previously as oxidants and, therefore, no further exemplifrcation is required. These peroxy compounds may also be substituted with groups such as halides, NH SH,

and the like which do not interfere with the catalyst forming process. The most preferred peroxy compound for use in preparing this molybdenum-containing catalyst is tertiary butyl hydroperoxide.

Hydrogen peroxide suitable for preparing the preferred molybdenum-containing catalyst is preferably used in the form of an aqueous solution containing, for example, from about to about 60%, preferably about 30%, by weight of hydrogen peroxide.

Typical examples of low molecular weight monohydroxy alcohols which are suitable for use in the preparation of the preferred molybdenum-containing catalyst include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol and tertiary butyl alcohol. The low molecular weight polyhydroxy alcohols which are suitable include ethylene glycol, propylene glycol, 1,2- butylene glycol and glycerol. In general, either monoor poly-hydroxy alcohols containing from 1 to 4 carbon atoms per molecule are suitable. In the present invention, it is preferred that the molybdenum metal be interacted with tertiary butyl hydroperoxide in the presence of tertiary butyl alcohol. If tertiary butyl alcohol is used as the saturated alcohol, it is preferred, to enhance molybdenum solubility, that the interaction mixture comprise at least one monoor poly-hydroxy alcohol having from 1 to about 16 carbon atoms per molecule, at least one primary hydroxy group, and present in an amount from about 1% to about 25% by weight of the total alcohol.

Typically, the peroxy compound comprises from about 5% to about 50% by weight of the total peroxy compound and alcohol used in catalyst preparation.

lar weight alcohol, often may be within the range from about ppm. to about 5.0%, preferably in the range 7 from about 30 ppm. to about 2.0%, by weight of the total mixture. It may be desirable to prepare the catalyst in the presence of a solvent such as benzene, tertiary butyl alcohol, ethyl acetate and the like, in order to obtain the optimum molybdenum concentration in the final catalyst mixture. However, if this type of dilution is desired, it is preferred that an excess of tertiary butyl alcohol be maintained in the catalyst mixture for this purpose.

The molybdenum metal useful in the preparation of the particularly preferred molybdenum-containing catalyst may be in the form of lumps, sheets, foil .or powder. The powdered material, e.g., having a particle size such that it passes through a 50 mesh sieve, preferably through a 200 mesh sieve, on the Standard Screen Scale, is preferable because of its lower cost and in addition, it offers the greatest surface area per unit volume and, therefore, the fastest rate of solubilization.

The molybdenum metal-peroxy compound interacting may be carried out at a wide range of temperatures, for example, within the range from about 25C. to about C. Interacting pressures should be set to avoid extensive vaporization of the peroxy compound and alcohol. Typical interacting pressures may range from about 1 psia. to about 100 psia. In many instances, atmospheric pressure may be used. After the interacting has been carried out for a desired length of time, e.g., from about 5 minutes to about 30 hours, the reaction mass may be filtered to separate the insoluble molybdenum from the catalyst mixture which mixture is thereafter suitable for use as a catalyst for the oxidation of sulfur impurities in hydrocarbon materials.

Following the oxidation step, the hydrocarbon material may be separated from lower boiling materials, such as oxidant decomposition products, solvent, various catalyst components, cracked hydrocarbons and the like. Some sulfur-containing compounds may also be removed at this point. This separation may be performed using conventional procedures, such as flashing, stripping, simple distillation and the like procedures. Alternately, the entire oxidation reaction mass may be used in the contacting step of the present process.

After at least a portion of the sulfur in the hydrocarbon material has been oxidized, the hydrocarbon is contacted with at least one component, i.e., hydrocarbon hydrogen donor, capable of transferring hydrogen to the hydrocarbon material. The ratio of oxidized sulfur-containing hydrocarbon material to hydrogen donor may vary over a broad range. For example, for 100 parts of hydrocarbon material from about 5 parts to about 2000 parts of hydrogen donor material may be used. However, in order to obtain the maximum benefits of the present invention, it is preferred to use from about 50 parts to about 1000 parts hydrogen donor material for 100 parts of oxidized sulfur-containing hydrocarbon material.

' The above-noted contacting takes place at conditions such that hydrogen is transferred from at least a portion of said hydrogen donor material to the hydrocarbon material. While carrying on this contacting step, it is preferred to maintain a sufficient pressure in the contacting zone so as to maintain a major portion of the hydrogen donor material in the liquid phase. Typical contacting pressures may be within the range from about atmospheric pressure to about 2000 psig., preferably from about 300 psig. to about 1000 psig. Contacting time may range from about min. to about 8 hours, preferably from about 30 min. to about 2 hours. Suitable contacting temperatures may range, for example, from about 500F. to about 1350F., preferably from about 650F. to about 1000F.

The hydrogen donor material may be any component or mixture of components which is capable of transferring hydrogen to the hydrocarbon material at the conditions of the contacting step described above. Included among the suitable hydrogen donor materials are mixed naphthenic-aromatic condensed ring compounds having up to about 40 carbon atoms per molecule, such as indane, C to C tetralins, decalin, di-, tetra-, and octa-hydroanthracene, C and C acenaphthenes, tetrahydroacenaphthene as well as partially hydrogenated condensed aromatic ring compounds such as anthracene, chrysene, benzopyrene, fluorenthene, phenanthrene, pyrene and triphenylene, benzoanthracene, benzophenanthrene and the like; aromatic compounds containing from about 13 to about 26 carbon atoms per molecule and having at least one alkyl substituent containing from about 7 to about 20 carbon atoms, such as cumene, di-isopropyl benzene, butyl benzene, octyl benzene, decyl benzene and the like; cycloparaffins containing from about 3 to about 15 carbon atoms per molecule and alkyl derivatives of said cycloparaffms containing at least one alkyl group having from 1 to about l5 carbon atoms such as cyclohexane, cyclopentane, cyclooctane, methyl cyclohexane, diethyl cyclohexane, methyl cyclododecane, tertiary butyl cyclohexane and the like. Mixtures of more than one of-these components may be used as the hydrogen donor material. ln addition, mixtures of components, e.g., petroleum refinery streams such as hydro-treated cycle or clarified oil and the like, which contain a significant amount of hydrogen donor materials may be employed in the above-described contacting step.

Because of economic considerations, availability and processing efficiency, the preferred hydrogen donor materials for use in the present invention include indane, C to C tetralins, decalin, di-, tetra-, and octahydroanthracene, C and C acenaphthenes, tetrahydroacenaphthene, partially hydrogenated anthracene, partially hydrogenated phenanthrene, partially hydrogenated pyrene and mixtures thereof. More preferred hydrogen donor materials include the above-noted partially hydrogenated condensed aromatic ring compounds, especially the above-noted tetralins.

The process step whereby the oxidized sulfurcontaining hydrocarbon material is contacted with at least one component capable of transferring hydrogen may be carried out in any conventional manner, e.g., batchwise, semi-batchwise or continuously. Conventional equipment, such as, stirred tanks, agitated or stirred autoclaves, heat exchangers, fired heaters and the like, may be used to perform this contacting step. This contacting step causes at least a portion of the sulfur in the oxidized sulfur-containing hydrocarbon ma terial to form compounds which can be removed by conventional techniques, e.g., flashing, distillation, to give a hydrocarbon material having reduced sulfur content. For example, after the contacting step, a mixture comprising hydrocarbon material and at least partially dehydrogenated hydrogen donor material can be separated from volatile sulfur-containing compounds by conventional operations such as flashing and stripping.

A hydrocarbon material of reduced sulfur content may be recovered from the at least partially dehydrogenated hydrogen donor material by, for example, a conventional distillation procedure. Another processing scheme involves recovering a hydrocarbon material of reduced sulfur content from the effluent of the contacting step by conventional, e.g., distillation, techniques. In this latter scheme, it may be necessary to furtherconventionally process, e.g., flash, strip, the resulting at least partially dehydrogenated hydrogen donor material to remove volatile sulfur-containing compounds. In any processing procedure, it may be necessary to conventionally remove sulfur-containing compounds from the used hydrogen donor material. Whatever procedure is used, the above-noted contacting step provides an effluent which can be conventionally processed to provide a hydrocarbon material of reduced sulfur content.

One beneficial modification of the present invention involves the hydrogenation of the dehydrogenated hydrogen donor material followed by recycle back to the above-described contacting step.

This hydrogenation operation may be performed using conventional procedures. The hydrogenation is normally performed in the presence of a catalyst and may take place in either the liquid, vapor or combined liquid vapor phases. Typical hydrogenation catalysts for use in this invention include catalysts comprising a minor amount of at least one Group IV to Group VIII metal, present as elemental metal, as a metal salt, for example, oxide, sulfide and the like, or as mixtures thereof, supported on a catalyst carrier such as silica, silica-alumina, alumina, activated clays, carbon and the like. The hydrogenation operation may be either batch, semi-batch or continuous, with continuous being preferred. Reaction temperatures within the range from about 50C to about 400C. are suitable while pressures ranging from about 0 psig. to about 1000 psig. or more may be used. Hydrogen to at least partially dehydrogenated hydrogen donor material mole ratios may range from less than about 1 to about 10 or more. Weight hourly space velocities ranging from about 0.1 to about may be used. The hydrogenation conditions may vary over a broad range depending upon the extent of hydrogenation desired, the particular material being hydrogenated, the catalyst being used and the like reaction parameters.

The following examples illustrate more clearly the process of the present invention. However, these illustrations are not to be interpreted as specific limitations on the invention.

EXAMPLES I AND H These examples illustrate the improved desulfurization of hydrocarbon material which results from practicing the process of the present invention.

The hydrocarbon material employed was a benzene soluble petroleum vacuum still residuum (Initial Boiling Point 6l0F., 15% overhead 962F.) having the following composition Weight Sulfur 3. l3 Nitrogen L45 Carbon 353g Hydrogen 1043 oxygen 0.8

The proportions listed here result from :1 series of independent chemical analyses and, therefore, the sum of the weight percents is slightly in excess of IOU.

A soluble, i.e., homogeneous, oxidation catalyst was prepared by combining 0.74 weight percent molybdenum powder with tertiary butyl hydroperoxide in the presence of tertiary butyl alcohol and a mixture of C to C glycols containing from 4 to 6 hydroxyl group per molecule wherein at least one of the hydroxyl groups was primary. The weight ratio of tertiary butyl hydroperoxide to tertiary butyl alcohol to glycols was about 2.l:4:1. This combination was heated to about 60C. with constant stirring and maintained at this temperature for about 1.5 to 2 hours until all the molybdenum has dissolved.

Tertiary butyl hydroperoxide was used as the oxidant to oxidize the sulfur impurities in the hydrocarbon material. Benzene was used as a solvent in the oxidation reaction and amounted to 50% by weight of the oxidation reaction mixture.

The oxidation reaction mixture was formed by combining the hydrocarbon material, benzene, catalyst and tertiary butyl hydroperoxide with constant stirring to insure uniformity. This mixture contained 3.6 moles of tertiary butyl hydroperoxide per mole of sulfur and 187 ppm. of molybdenum.

200 grams of this reaction mixture was placed in a glass reaction flask equipped with heating means, stirrer and a water-cooled condenser. The flask was heated to about 75-8lC. which caused the reaction mixture to reflux. This temperature was maintained for 16 hours to effect sulfur oxidation. After this period of time, the product in the flask was stripped free of esssentially all benzene,.tertiary butyl alcohol (from tertiary butyl hydroperoxide decomposition) and lighter components.

The remaining hydrocarbon product was cooled and placed in a glass vessel which itself was in a salt bath. This material was heated to a temperature within the range from 750F. to 800F. and maintained at this temperature for 4 hours. Throughout this period of time, hydrogen gas at atmospheric pressure was sent through the glass vessel. At the end of 4 hours, the liquid product was sampled and analyzed for sulfur content. It was determined that the above processing had removed about 50% of the sulfur which was originally contained in the vacuum residuum.

The second portion of the product from the oxidation reaction was placed in a 300 cc. autoclave along with an amount of tetralin so asto form a mixture of 50% by weight of hydrocarbon product and 50% by weight of tetralin. This mixture was heated to a temperature ranging from 750F. to 820F. at a pressure ranging from 420 psig. t'520 psig. for 4% hours. During this periodof time, hydrogen was sent through the autoclave. At the end of this period of time, a liquid sample was removed from the autoclave and analyzed for sulfur content. It was determined that the aboveprocessing had removed 74% of the sulfur which was originally contained in the vacuum residuum. Reduced cracking was observed when the oxidation product was treated in the presence of tetralin. In addition, coke formation (based on amount of benzene insoluble material in the final liquid product) in the sample processed using tetralin was on the order of fold less than the coke formation in the first portion of the oxidized product.

EXAMPLES III AND IV A vacuum still residuum (having a composition similar to that of Examples I and II) was treated under oxidation conditions and stripped following a procedure similar to that of Examples I and II. The oxidation product material was separated into two portions.

One portion of the oxidized product (76 grams), containing 3.2% sulfur, was placed in a closed autoclave. A temperature of 750F. was maintained within the autoclave and hydrogen was used to maintain a pressure of 700 psig. After 4 hours, the mixture in the autoclave was cooled and the pressure reduced to atmospheric conditions by the release of hydrogen and other gaseous products. A sample of the liquid product remaining in the autoclave was tested for sulfur content. It was determined that the above oxidation temperature treatment had removed 48% of the sulfur originally contained in the vacuum still residuum.

A second portion of the oxidized residuum (27.5 grams) was combined with 41 grams of tetralin and the mixture placed in a closed autoclave. A temperature ranging from 750F. to 780F. was maintained within the autoclave and hydrogen was used to maintain a pressure ranging from 850 psig. to 935 psig. After 3 hours, the mixture was cooled and the pressure was reduced to atmospheric conditions by the release of hydrogen and other gaseous products. A sample of the liquid material remaining in the autoclave was analyzed for sulfur content. It was determined that the above oxidation-temperature treatment had removed of the sulfur from the vacuum still residuum. The product yield losses due to cracking and coke formation of the oxidized residuum processed in the presence of tetralin were reduced relative to the losses of the oxidized residuum processed without a separate hydrogen donor material.

While in the foregoing disclosure certain examples have been set forth which illustrate details specifying modes of applying this invention, it should be understood that such details may be varied considerably by one skilled in the art without departing from the spirit of this invention.

1 claim:

1. In a desulfurization process for producing a hydrocarbon material of reduced sulfur content wherein at least a portion of the sulfur in a sulfur-containing hydrocarbon material at least a major portion of which boils above about 550F., is preferentially oxidized by contacting said sulfur-containing hydrocarbon material with active oxygen in the form of an oxidant selected from the group consisting of organic peroxides, organic hydroperoxides, organic peracids, hydrogen peroxide and mixtures thereof, the improvement which comprises heating said oxidized sulfur-containing hydrocarbon material with at least one hydrocarbon hydrogen donor component capable of transferring hydrogen to said oxidized material under conditions such that hydrogen is transferred from at least a portion of said component to form hydrogen sulfide without the addition of a catalyst, said heating occurs at a temperature in the range from about 500F. to about 1350F. and such that for each parts of said oxidized sulfurcontaining hydrocarbon material from about 5 parts to about 2000 parts of hydrocarbon hydrogen donor component are present, and thereafter recovering from said tent.

2. The process of claim 1 wherein said hydrocarbon hydrogen donor component is selected from the group 3. The process of claim 2 wherein said hydrocarbon hydrogen donor component is selected from the group consisting of indane, C to C tetralins, decalin, di-, tetra-, and octa-hydroanthracene, C and C acenaphthenes, tetrahydroacenaphthene, partially hydrogenated anthracene, partially hydrogenated phenanthrene, partially hydrogenated pyrene and mixtures hew? 4. The process of claim 3 wherein said heating occurs such that for each 100 parts of said oxidized sulfurcontaining hydrocarbon material from about 100 parts to about 1000 parts by weight of said hydrocarbon hydrogen donor component is used, said heating occurring at a temperature in the range from about 650F. to about 1000F. at a pressure in the range from about atmospheric pressure to about 2000 psig. and including a heating time in the range from about 10 minutes to about 8 hours.

5. The process of claim 4 wherein said component is selected from the group consisting of C to C tetralins and mixtures thereof.

6. A desulfurization process for producing a hydrocarbon material of reduced sulfur content which comprises l. oxidizing at least a portion of the sulfur contained in a hydrocarbon material at least a major portion of which boils above about 550F. with active oxygen in the form of an oxidant selected from the group consisting of organic peroxides, organic hydroperoxides, organic peracids, hydrogen peroxide and mixtures thereof;

2. heating said oxidized sulfur-containing hydrocarbon material with at least one component capable of transferring hydrogen under conditions such that hydrogen is transferred from at least a portion of said component to form hydrogen sulfide without the addition of a catalyst, said heating occurs at a temperature in the range from about 500F. to about 1350F. and such that for each 100 parts of said oxidized sulfur-containing hydrocarbon material from about 5 parts to about 2000 parts by weight of said hydrocarbon hydrogen donor component are present; and

3. thereafter recovering from step 2 a hydrocarbon mat r al hay ta s u sd su fu o t 7. The process of claim 6 wherein from about 0.5 atoms to about 10 atoms of said active oxygen are included per atom of sulfur present to oxidize at least a portion of the sulfur contained in said hydrocarbon material.

8. The process of claim 7 wherein said oxidant is selected from the group consisting of organic peroxides,

organic hydroperoxides, organic peracids and mixtures thereof containing from 1 to about 30 carbon atoms per active oxygen atom and said oxidation occurs in the presence of a catalyst comprising a metal in an amount effective to promote the oxidation of sulfur, said metal being selected from the group consisting of Group IV-B metals, Group V-B metals, Group Vl-B metals and mixtures thereof.

9. The process of claim 8 wherein said component is selected from the group consisting of mixed napthenicaromatic condensed ring compounds having up to about 40 carbon atoms per molecule, aromatic compounds containing from about 13 to about 26 carbon atoms per mole and having at least one alkyl substituent having from about 7 to about 20 carbon atoms, cyclo-paraffins containing from about 3 to about 15 carbon atoms per molecule, alkyl derivatives of said cycloparaffins containing at least one alkyl group having from 1 to about 15 carbon atoms and mixtures thereof.

10. The process of claim 8 wherein said metal is selected from the group consisting of titanium, zirconium, vanadium, tantalum, chromium, molybdenum, tungsten and mixtures thereof and is present in an amount from about 5 ppm. to about 10% by weight of said sulfur-containing hydrocarbon material.

11. The process of claim 10 wherein said component is selected from the group consisting of indane, C to C tetralins, decalin, di-, tetra-, and octahydroanthracenes, C and C acenaphthenes, tetrahydroacenaphthene, partially hydrogenated anthracene, partially hydrogenated phenanthrene, partially hydrogenated pyrene and mixtures thereof.

12. The process of claim 11 wherein said metal is molybdenum.

13. The method of claim 12 wherein said component is selected from the group consisting ofC to C tetralins and mixtures thereof.

14. The process of claim 12 wherein said catalyst is prepared by a method which comprises interacting molybdenum metal with a compound selected from the group consisting of organic hydroperoxide, organic peroxide, hydrogen peroxide and mixtures thereof in the presence of at least one saturated alcohol having from one to four carbon atoms per molecule at conditions such that at least a portion of said molybdenum is solubilized.

15. The process of claim 14 wherein said heating occurs such that for each parts of oxidized sulfurcontaining hydrocarbon material from about 50 parts to about 1000 parts by weight of said hydrocarbon hydrogen donor component is used, said heating occurs at a temperature in the range from about 650F. to about 1000F. at a pressure in the range from about atmospheric pressure to about 2000 psig and for a time within the range from about 10 minutes to 8 hours, and said interacting occurs at a temperature in the range from about 25C. to about 100C.

16. The process of claim 14 wherein said catalyst is prepared by a method which comprises interacting molybdenum metal with tertiary butyl hydroperoxide in the presence of tertiary butyl alcohol and at least one monoor poly-hydroxy alcohol having from 1 to about 16 carbon atoms per molecule and having at least one primary hydroxy group, said monoor poly-hydroxy alcohol being present in an amount sufficient to enhance molybdenum solubility.

Claims

1. IN A DESULFURIZATION PROCESS FOR PRODUCING A HYDROCARBON MATERIAL OF REDUCED SULFUR CONTENT WHEREIN AT LEAST A PORTION OF THE SULFUR IN A SULFUR-CONTAINING HYDROCARON MATERIAL AT LEAST A MAJOR PORTION OF WHICH BOILS ABOVE ABOUT 550*F, IS PREFERENTIALLY OXIDIZED BY CONTACTING SAID SULFUR-CONTAINING HYDROCARBON MATERIAL WITH ACTIVE OXYGEN IN THE FORM OF AN OXIDANT SELECTED FROM THE GROUP CONSISTING OF ORGANIC PEROXIDES, ORGANIC HYDROPEROXIDES, ORGANIC PERACIDS, HYDROGEN PEROXIDE AND MIXTURES THEREOF, THE IMPROVEMENT WHICH COMPRISES HEATING SAID OXIDIZED SULFUR-CONTAINIG HYDROCARBON MATERIAL WITH AT LEAST ONE HYDROCARBON HYDROGEN DONOR COMPONENT CAPABLE OF TRANSFERRING HYDROGEN TO SAID OXIDIZED MATERIAL UNDER CONDITIONS SUCH THAT HYDROGEN IS TRANSFERRED FROM AT LEAST A PORTION OF SAID COMPONENT TO FORM HYDROGEN SULFIDE WITHOUT THE ADDITION OF A CATALYST, SAID HEATING OCCURS AT A TEMPERATURE IN THE RANGE FROM ABOUT 500*F. TO ABOUT 1350*F. AND SUCH THAT FOR EACH 100 PARTS OF SAID OXIDIZED SULFUR-CONTAINING HYDROCARBON MATERIAL FROM ABOUT 5 PARTS TO ABOUT 2000 PARTS OF HYDROCARBON HYDROGEN DONOR COMPONENT ARE PRESENT, AND THEREAFTER RECOVERING FROM SAID HEATING A HYDROCARBON MATERIAL OF REDUCED SULFUR CONTENT.

2. The process of claim 1 wherein said hydrocarbon hydrogen donor component is selected from the group consisting of mixed naphthenic-aromatic condensed ring compounds having up to about 40 carbon atoms per molecule, aromatic compounds containing from about 13 to about 26 carbon atoms per mole and having at least one alkyl substituent having from about 7 to about 20 carbon atoms, cyclo-paraffins containing from about 3 to about 15 carbon atoms per molecule, alkyl derivatives of said cyclo-paraffins containing at least one alkyl group having from 1 to about 15 carbon atoms and mixtures thereof.

2. heating said oxidized sulfur-containing hydrocarbon material with at least one component capable of transferring hydrogen under conditions such that hydrogen is transferred from at least a portion of said component to form hydrogen sulfide without the addition of a catalyst, said heating occurs at a temperature in the range from about 500*F. to about 1350*F. and such that for each 100 parts of said oxidized sulfur-containing hydrocarbon material from about 5 parts to about 2000 parts by weight of said hydrocarbon hydrogen donor component are present; and

3. thereafter recovering from step 2 a hydrocarbon material having reduced sulfur content.

3. The process of claim 2 wherein said hydrocarbon hydrogen donor component is selected from the group consisting of indane, C10 to C12 tetralins, decalin, di-, tetra-, and octa-hydroanthracene, C12 and C13 acenaphthenes, tetrahydroacenaphthene, partially hydrogenated anthracene, partially hydrogenated phenanthrene, partially hydrogenated pyrene and mixtures thereof.

4. The process of claim 3 wherein said heating occurs such that for each 100 parts of said oxidized sulfur-containing hydrocarbon material from about 100 parts to about 1000 parts by weight of said hydrocarbon hydrogen donor component is used, said heating occurring at a temperature in the range from about 650*F. to about 1000*F. at a pressure in the range from about atmospheric pressure to about 2000 psig. and including a heating time in the range from about 10 minutes to about 8 hours.

5. The process of claim 4 wherein said component is selected from the group consisting of C10 to C12 tetralins and mixtures thereof.

6. A desulfurization process for producing a hydrocarbon material of reduced sulfur content which comprises

7. The process of claim 6 wherein from about 0.5 atoms to about 10 atoms of said active oxygen are included per atom of sulfur present to oxidize at least a portion of the sulfur contained in said hydrocarbon material.

8. The process of claim 7 wherein said oxidant is selected from the group consisting of organic peroxides, organic hydroperoxides, organic peracids and mixtures thereof containing from 1 to about 30 carbon atoms per active oxygen atom and said oxidation occurs in the presence of a catalyst comprising a metal in an amount effective to promote the oxidation of sulfur, said metal being selected from the group consisting of Group IV-B metals, Group V-B metals, Group VI-B metals and mixtures thereof.

9. The process of claim 8 wherein said component is selected from the group consisting of mixed napthenic-aromatic condensed ring compounds having up to about 40 carbon atoms per molecule, aromatic compounds containing from about 13 to about 26 carbon atoms per mole and hAving at least one alkyl substituent having from about 7 to about 20 carbon atoms, cyclo-paraffins containing from about 3 to about 15 carbon atoms per molecule, alkyl derivatives of said cyclo-paraffins containing at least one alkyl group having from 1 to about 15 carbon atoms and mixtures thereof.

11. The process of claim 10 wherein said component is selected from the group consisting of indane, C10 to C12 tetralins, decalin, di-, tetra-, and octa-hydroanthracenes, C12 and C13 acenaphthenes, tetrahydroacenaphthene, partially hydrogenated anthracene, partially hydrogenated phenanthrene, partially hydrogenated pyrene and mixtures thereof.

12. The process of claim 11 wherein said metal is molybdenum.

13. The method of claim 12 wherein said component is selected from the group consisting of C10 to C12 tetralins and mixtures thereof.

15. The process of claim 14 wherein said heating occurs such that for each 100 parts of oxidized sulfur-containing hydrocarbon material from about 50 parts to about 1000 parts by weight of said hydrocarbon hydrogen donor component is used, said heating occurs at a temperature in the range from about 650*F. to about 1000*F. at a pressure in the range from about atmospheric pressure to about 2000 psig and for a time within the range from about 10 minutes to 8 hours, and said interacting occurs at a temperature in the range from about 25*C. to about 100*C.

16. The process of claim 14 wherein said catalyst is prepared by a method which comprises interacting molybdenum metal with tertiary butyl hydroperoxide in the presence of tertiary butyl alcohol and at least one mono- or poly-hydroxy alcohol having from 1 to about 16 carbon atoms per molecule and having at least one primary hydroxy group, said mono- or poly-hydroxy alcohol being present in an amount sufficient to enhance molybdenum solubility.