US2347955A

US2347955A - Catalyst and method for preparing the same

Info

Publication number: US2347955A
Application number: US337656A
Authority: US
Inventors: Korpi Karl
Original assignee: Union Oil Company of California
Current assignee: Union Oil Company of California
Priority date: 1940-05-28
Filing date: 1940-05-28
Publication date: 1944-05-02
Anticipated expiration: 1961-05-02

Description

' drocarbons.

Patented May 2, 1944 CATALYST'AND METHOD FOR PREPARING THE Sm Karl Korpi, Redondo Beach, Calif., assignor to Union Oil Company of California, Los Angeles,

Calif" a corporation of California No Drawing. Application May 28, 1940, Serial No. 337,656

11 Claims.

carbon content thereof. The invention relates particularly to catalysts for converting naphthene hydrocarbons into aromatic hydrocarbons and also to the conversion of olefin hydrocarbons to parafiinic, naphthenic and aromatic hy- The invention also relates 'to a method for preparing such catalysts. This application is a continuation, in part, of my-copending application Serial No. 321,983 filed March 2, 1940. a

It is known to produce aromatic hydrocarbon solvents by solvent extraction of straight run gasoline particularly those obtained from California or asphalt base crude oils which are rela-,

tively free from olefin hydrocarbons. Past attempt to produce aromatic solvents from gasolines obtained by thermal pyrolysis and/or .polymerization of hydrocarbons have not been successful principally for the reasons that (1) the available cracked gasolines have not been particularly rich in aromatic hydrocarbons and (2) these cracked gasolines have contained large amounts of olefinic materials. The first objection has been eliminated to a large extent with theadvent of catalytic cracking which will make available pressure distillates containing as much as 50% by volume of aromatic hydrocarbons. The aromatic content of these pressure distillates is about three times as high as that of straight run gasolines obtained from Western crudes and some pressure distillates produced by simple thermal means. Thus, cracked gasolines produced by catalytically cracking oils are a particularly rich source of aromatics from which aromatic solvents may be produced.-

However, the recovery of the aromatic hydrocarbons from cracked gasoline has been somewhat uneconomical principally due to the presence of olefin hydrocarbons in the cracked gasoline. The solvent extraction of the cracked gasooline for recovery of the aromatics, as for example, with liquid sulfur dioxide, has resulted in the simultaneous extraction of both the olefin and aromatic hydrocarbons. In order to reduce the olefin content of the aromatic extract to what may be considered a satisfactory value, a

rigorous and wasteful sulfuric acid treatment has It is an object of my invention to reduce the olefin hydrocarbon content of pressure distillates or other hydrocarbon mixtures whichare rich in aromatic hydrocarbons to produce aromatic solvents which are relatively free from olefin hydrocarbons. complish the recovery of relatively pure aromatic hydrocarbons without resorting to expensive and wasteful treating procedures.

I have discovered that olefins may be separated from aromatic hydrocarbons by subjecting the aromatic fraction containing the olefins to eatalytic treatment at elevated temperatures. Such catalytic treatment results in converting the olefins into non-olefinic vmaterials such as naphthenic, aromatic and paraflinic hydrocarbons so that in the production of aromatic solvents, the non-aromatic materials may be separated from the aromatic hydrocarbons by simple extraction with selective solvents such as liquid sulfur dioxide.

The reactions involved in the thermal catalytic treatment are numerous depending upon the character of the stock undergoing treatment and on the conditions of operation. When treating stocks containing olefins, 'it is believed that a major reaction is in the cyclization of the olefins into cyclo-p'araflin hydrocarbons or naphthenes. Another major reaction taking place resides in the formation of parafiin hydrocarbons from the olefins. Another major reaction of great importance is in the formation of aromatic hydrocarbons from either or both the cyclo-parafin hydrocarbons present in the original stock or produced from the olefin hydrocarbons. In one case, I subjected to the catalytic treatment a hydrocarbon fraction composedof about olefins and 20% paraifins and obtained a resulting indicates that all of the naphthenes were converted into aromatic hydrocarbons without substantially changing the parafflns present.

It is another object of my invention to convert olefin hydrocarbons into paramn, naphthene and aromatic hydrocarbons by subjecting hydrocar- It is another object to acbon fractions containing substantial amounts of olefins to thermal catalytic treatment.

It is thus another object of my invention to. subject naphthene hydrocarbon fractions to eatalytic thermal treatment to transform the naphthene hydrocarbons into aromatic hydrocarbons.

It is a further object of my invention to provide catalysts particularly adapted for carrying out these conversions.

I have further discovered that the process of sulfur content of stocks containing sulfur, In one particular instance, the sulfur content of the feed was reduced from 0.67 to 0.13% with simultaneous olefin reduction in two passages of the stock through the reactor.

phosphoric acid is partially or totally neutralized by means ofa caustic alkali, (potassium, lithium deoleflnation' results in materially reducingthe and sodium hydroxides). Such a catalyst may be prepared by first adsorbing the phosphoric acid on the carrier particularly on activated carbon and drying the mixture when necessary by' readily as straight phosphoric acid, thus enabling The choice of catalysts in my process for the catalytic treatment of hydrocarbons to transform .oleflns or naphthenes is extremely important. I have found orthophosphoric acid and other forms of phosphoric acid such as tetra, meta and pyro phosphoric. acid to be good catalysts. It is preferable to employ a carrier for the catalyst. Carri'ers which maybe used include charcoal, car

borundum, coke and like carbonaceous materials,

alumina, clay and the like. Neutral carriers as preformed phosphates and other mineral acidsalts of metals may be used.

I have found the activated carbons such as wood charcoal, petroleum and metallurgical coke,

' that the resulting catalyst has .only a moderate soft and hard coals and other carbonaceous materials, bone charcoal, sugar'and starch charcoals and the like to be superior to the other carriers. I have found activated carbons prepared from nut shells, such as cocoanut, walnut and the like to be particularly effective carriers for the catalyst. An activated carbon of this type is one commercially prepared by the Carbide and Carbon Chemicals Corporation and sold as "Columbia Activated Carbon. This activated carbon is prepared from cocoanut shells by steam oxidation at high temperatures. I have-found a catalyst adsorbed on this type carrier to be about 5 to 50 times as effective as the same catalyst adsorbed on ordinary unactivated wood charcoal. The catalytic material is preferably prepared by adsorbing orthophosphoric acid or other phosphoric acids on the carrier particles of suitable. size and porosity and heating the mixture to dryness at a temperature of 800-400 F. 'Ihe amount of catalyst' which is adsorbed on the carnearly 90% in a single pass of the olefinic stock I rier may vary within wide limits depending upon the character of the catalyst and the carrier. with the phosphoric acid catalysts, I have found it desirable to adsorbas much as 50 to 150 ml. of

the. acid of 75-85% HJPO4 concentration on-250 ml. of the granular carrier. I have found that by saturating the carrier with catalyst and then drying the saturated carrier that the catalytic life of the catalyst is greatly increased over that obtained by adsorbing smaller quantities of the catalyst. For convenience in preparing the catalyst, the strength of the catalyst employed should not preferably be less than substantially 50% H'sPO4. However, phosphoric acid of as low as 5' or.10% strength may be used.

Using theabove catalyst in treating pressuredistillates containing about 20% olefins, I have obtained a reduction of 50-80% in olefin content per pass of the pressure distillate vapors over the catalyst while maintaining a temperature of 750- 800=F. and atmospheric pressure in the reactor containing'the catalyst. A catalyst .which I have found to be supexicr the catalyst to be used for a considerably longer period of time. Another advantage resides in the fact that this catalyst is less corrosive to the reactor and accessory equipment than the straight phosphoric acid would be.

The above procedure of first adsorbing the catalyst 0n the carrier, drying, adding the caustic soda and again drying is very important to obtain a catalyst adapted to produce superior catalytic effect. I have found that when the phosphoric acid is first partially or totally neutralized before being adsorbed on the carrier and dried effect in the catalytic process.

Using this catalystfor treating pressure distillate vapors containing 20% oleiins, I have ob tained a reduction of -90% in olefin content in a single pass of the material over thecatalyst while maintaining a temperature of '750-800 l". and atmospheric pressure in the reactor. Further reduction in olefin content may be obtained bydecreasing the rate of introduction of hy- ,drocarbon to the reactor or by recycling the product of the first p age-through the reactor. In producing the p ially neutralized catalyst, I have discovered that the best results are obtained'when the phosphoric acid is neutralized with less than one equivalent of the caustic alkali per mol of the acid. I have found the preferred neutralization to be within the range of Va to equivalents per mol of acid. For example, I have obtained olefin reduction to the extent of through a phosphoric acid catalyst which had been neutralized with V5 to equivalents of caustic alkali per mol of the acid. Using straight phosphoric acid catalyst, the reduction in olefin content was about 60% per pass through the catalyst and using phosphoric acid catalyst which had been partially neutralized with equivalents of the alkali per mol of the acid, the reduction in olefin content of the stock was about 77% per pass. Using phosphoric acid catalyst which had been partially neutralized'with one, one and one-half and two equivalents of the caustic alkali per mol of the acid, the catalysts were efiec-.

tive in reducing the olefin contents of stock by approximately 72%, 70%, and 58 respectively.

A completely neutralized phosphoric acid catalyst was effective to reduce the olefin content of the stock by only 30%. In the above, the parhydrocarbons and preferably to provide a'c'atalyst to straight phosphoric acid is one which he 78 composed of phosphoric acid adsorbed on soone composed of silica contained on activated carbon or silicic acid adsorbed on the activated carbon. Such a catalyst may be prepared by first adsorbing an aqueous sodium silicate solution on the granules of activated carbon and then treatingthese granules containing the adsorbed sodium silicate solution with hydrochloric acid in order to precipitate silicic acid on the granules. Other acids such as sulfuric, acetic, phosphoric, nitric, carbonic, etc., which are stronger than silicic acid and which therefore liberate free silicic acid from silicates may be used in the place of the hydrochloric acid. The granules are then thoroughly washed with water in order to remove any free hydrochloric acid and sodium chloride that may have been formed. The thus treated granules are then dried at a temperature of about 300 F. in order to remove water. This drying causes part of the silicic acid to be converted intosilica, the remaining silicic acid being converted into silica during the course of a few minutes of catalytic operation at the more elevated temperatures of about 800 F. The catalyst thereafter may be said to consist of silica contained on the activated carbon carrier.

Using this catalyst for treating pressure distillate vapors containing 44% olefins, for example, I have obtained a reduction of 8090% in olefin content in a single pass of the material over the catalyst while maintaining a temperature of about 750-800 F. and atmospheric pressure'in the reactor.

In preparing the catalyst, the sodium silicate solution which is generally purchased as a thick syrup is preferably first diluted to a thin consistency with 2 to 4 parts of water. Then a sufficient amount of the solution is adsorbed on the activated carbon carrier as to incorporate about 20 to 30% of the undiluted sodium solution. The granules are then treated with hydrochloric acid preferably 3N-HCl which is accomplished 'by soaking the granules in about two volumes of the acid for several days. The excess acid is then drained from the granules which are then washed thoroughly with water and dried.

It is thus another object of my invention to provide a catalyst composed of silicic acid or silica adsorbed on activated carbon. It is another object of the invention to prepare this catalyst by adsorbing sodium silicate solution on activated carbon and then treating the activated carbon carrier with hydrochloric acid to convert the sodium silicate to silicic acid and then heating the thus treated silicic acid on the carrier to convert part or all of the silicic acid to silica.

I have found that the presence of moisture during the reaction aids materially in prolonging the catalytic activity of the catalyst used in the process of treating hydrocarbons particularly when using catalyst of the phosphoric acid type. I have observed that the presence of moisture in the reactor has prolonged the lifeof the catathat the temperature of operation is higher than lyst more than 40 hours without materially dehours operation. The moisture may be introduced into the catalytic zone by merely injecting water into a preheater through which the vaporized charging stock is passing on its way into the catalytic reactor. The heat in the vapors and in the preheater vaporizes the water which then passes through the reactor in the form of steam which may be removed from the treated.

vapors by condensation. The high temperature employed in the reactor causes a part of the phosphoric acid to be volatilized and removed together with the treated hydrocarbons and steam. This will be recovered with the condensed water which may be recycled to the reactor.

While the above are the preferred catalysts, other catalysts which may be used to transform olefin or naphthenes in hydrocarbonmixtures comprise zinc, cadmium and other metal phosphates, hydroxides or alkali and alkaline earth metals such as sodium, potassium, lithium and calciumhydroxides, metal halides such aszinc, aluminum and iron chloride and bromides, metal sulfates such as sodium, potassium and zinc sulfate and oxides of metals and non-metals such as aluminum and boric oxides. The catalysts are preferably used with activated carbon carriers. In general, any catalyst which has heretofore been employed for the purpose of polymerizing gaseous hydrocarbons may be used as a catalyst in the ,process of deolefination of hydrocarbons forming the subject matter of my invention.

The temperature at which the catalytic reaction is carried out depends primarily upon the nature of the transformation desired which in turn depends upon the nature of the stock. For example, when converting naphthene hydro- 4 carbons into aromatic hydrocarbons, I have found when converting olefin hydrocarbons to naphthenes or paraflins. Naphthehe hydrocarbons may be converted into aromatic hydrocarbons by operating the catalytic process at a temperature preferably between 850 F. and 1000 F. although lower yields of aromatics per pass may be obtained at temperatures as low as 750 F. Temperatures above 1000" F. may be used particularly when the stock does not contai hydrocarbons that will cause undesirable side reactions such as the cracking of paraflins to produce olefins. Olefin hydrocarbons are converted to naphthenes and parafiins at temperatures preferably between 700 F. and 850 F., using the catalytic process of my invention although temperatures as low as 600 F. may be used with correspondingly lower yields of transformed materials. The olefin hydrocarbons may also be converted directly to predominantly aromatic hydrocarbons with some paraffin and naphthene formations by operating the catalytic process at temperatures above. 850 F. The paraffin hydrocarbons may be converted to olefins by carrying out the catalytic reaction at temperatures above 900 F.

Thus, when treating hydrocarbon mixtures by the catalytic process of my invention, I may select and control temperatures suited to the stock to be treated and to the product des red. For example, when treating a hydrocarbon mixture consisting predominantly of naphthenes and paraflins, I may catalytically treat this stock at temperatures between 850 and 900 F. to convert all of the naphthenes into aromatics without appreciably altering the paraflins. When treating a mixture of hydrocarbons consisting predominantly of olefins and naphthenes, I may select a temperature for the reaction of about tion. The products issuing from the reactor may be transformation.

' The condensed products 750 to convert the oleflns into naphthenes and paraflins without substantially changing the naphthenes into aromatics but by operating at temperatures between 850-90 0 F., I may convert both the oleflns and naphthenes into predominantly aromatics with some paraffin formation. Some naphthenes may be unchanged depending upon the rate of flow of material through the reactor. When treating a mixture of hydrocarbons consisting predominantly of oleflns and paraiiins, I may catalytically treat at about 750 F. and obtain transformation of oleiins into naphthenes and parafiins without aiiecting the paraflins present in the charge. However, by increasing the temperature of reaction to 850-900 F., the oleflns may be transdrocarbons. This may be accomplished by exformed directly into aromatics but theparaflins again will be substantially unchanged.

Pressure influences the reaction in that it reduces the time of the reaction and increases the catalytic activity of the catalyst to reduce the olefin content in the charging stock passing through the. reactor. The process, however, may be carried out successfully at atmospheric pressure. I have obtained successful deolefination oi hydrocarbons by employing pressures from atmospheric to 200 lbs. per square inch. Pressures from sub-atmospheric to as high as 5000 lbs. per square inch may be used. In the process of converting naphthenes to aromatics,

superatmospheric pressure is not essential, in. fact, in some cases, is detrimental since it reduces the yield of aromatics. However, by increasing the temperature of the reaction, the

detrimental eiiect of pressure may be overcome.

In general, the process of transforming oletins and naphthenes is carried out by simply commercial operations,=it may be desirable to provide a plurality of these reactors so that they maybe operated alternately in order to provide for the removal and regeneration of the cata lyst. If desired, the reactor may be provided with conveyors for containing the catalyst which may be moved through the reactor and outof the zone of reaction where the used catalyst may be reactivated or replaced with fresh catalyst before beingintroduced into the reactor. The

free of oleflns and which is superior to the origivariations of means and method for nrovidins the catalyst in the reaction zone and for regeneration are obvious to thou skilled in the art and form no particular part of my inven-i recycled throughthe reactor in cases where the passage of the stock through the reactor does not produce sumcient deolennation orde'sired Also, the rate of passage of.the- 1 stock through the reactor, in other words, the

reactingtime, may be varied to give suiiicient time-for the feed in the reactor in order to obtain the desired 1 reaction. By providing sumcient time in the reactor,-the feed stock maybe [transformed adequately ina single passage through the reactor.

tracting the treated mixture with a solvent that selectively dissolves the aromatic hydrocarbons -in the mixture and rejects as a fraction insoluble in the solvent the ncn-aromatic-hydrocarbons such as the paraflln, naphthenic and other non-aromatic hydrocarbons. By allowing the mixture of treated material and solvent to stratify into two layers, the phase of solvent and aromatic fractions may be removed from the other phase of non-aromatic hydrocarbons and may then be distilled to recover the solvent. Solvents adapted to extract the aromatics from the non-aromatic hydrocarbons are liquid sulfur dioxide, phenol, dichlorethyl ether, furfural and the like. I

The extraction of the treated hydrocarbons also extracts any residual oleflns along with the aromatics. If desired, the extract containing the oleilns may be retreated by the catalytic method to reduce further the olefins contained in the extract. The thus treated product may be re-extracted to remove non-aromatic hydrocarbons which may have been produced by the retreatment. This procedure of catalytic treatment and extraction may be repeated as many times as is necessary to produce an extract that is substantially free from olefins.

If desired. the originalstoclr containing a mixture of hydrocarbons may be first extracted to separate and concentrate the olefins and aromatics present in the mixture and the extract may then be treated by the catalytic process to convert the olefins into non-oleflnic materials. This, of course, will reduce the amount of stock to be passed through the catalyst reactor. If desired, the product obtained from the reaction may be treated with sulfuric acid to remove any traces of unconverted oleflns.

While I have described above a particularly desirable use of my invention as applied to the purification of aromatic hydrocarbons to remove imdesirable olefins, the process may be applied for the production of olefin-free, gum stable motor fuels of high anti-knock which may be used either per se or as a blend for other gasolines. For example, I may subject a pressure distillate composed chiefly of aromatics, paraflins and oleflns to the above treatment and produce a motor fuel composed of aromatics, paraiiins and naphthenes which. is substantially be produced from normally liquid oleflns containing little or no aromatic hydrocarbons or non -oleflnic material. This may be accomplished by subjecting the oleflns to the catalytic ing-may be produced. The normally'liquid oleflns tobe processed maybe produced by poly- Y merlzation' oi normally gaseous oleflns.

1 It is thus another object of my invention to convert oleflns into naphthenes to produce desirable motor fuels.

or the a... may as stated above, the,catalytic, treatment of 'then treated to recover pureraromatic hy- 1s oleiins converts these hydrocarbons into naphthenes which are at least partially converted into aromatic hydrocarbons. This is particularly true when using a catalyst of phosphoric acid which has been partially neutralized on the carrier with caustic soda. Instead of treating olefins to produce aromatic hydrocarbons, I may treat naphthene hydrocarbons by the above described catalytic method to produce aromatic hydrocarbons which may be extracted if desired to produce aromatic solvents.

I have also discovered that a motor fuel of suitable boiling range containing naphthene hydrocarbons may be catalytically treated as above to produce a motor fuel of improved anti-knock value. In this treatment, the naphthene hydrocarbons are converted into aromatic hydrocarbons which are of higher knock rating than the corresponding naphthenes. The presence of olefins in the charging stock is not essential as long as the gasoline contains naphthene hydrocarbons. For example, I may catalytically treat a gasoline fraction having an anti-knock value of about 65- and containing about 30% naphthene hydrocarbons and produce a motor fuel having an anti-knock value of about 75. This process may be operated on straight naphthenes, i. e. containing little or materially no other hydrocarbons or the treatment may be carried out on a mixture of naphthenes and aromatic or parafinic or other hydrocarbons. 'When treating a straight naphthene fraction, for example, one containing cyclohexane, methyl cyclopentane, cycloheptane and substituted cyclo paraflins and having, for example, an anti-knock value of about 65,- I may convert by the above catalytic treatment this fraction into one having a blending anti-knock value of about 100 and'above which may be blended with gasolines of lower anti-knock values.

As stated above, the transformation of olefins to naphthenes and paraffins takes place at lower temperatures than the transformation of naphthenes to aromatics. I have discovered that olefins may be converted to aromatics by carrying the process in several stages of operation in which the temperature in each stage is controlled such that the'olefins are first converted into naphthenes and paraflins in the first stage and the thus produced naphthenes are converted in the second stage into aromatics. Thus, by employing temperatures of 700-850 F. in the first naphthenes and parafilns containing little orno olefins and it is desired to obtain the maximum production of aromatics from this stock, the first stage may be operated at higher temperature, i. e., above 900 F. This high temperature first stage operation will convert the naphthenes into aromatics and will convert the paramns into olefins. The products of the first stage may then be passed through a second stage maintained at a lower temperature, i. e. 850 F.-

900 F. in order to obtain transformation of the hlumbia activated carbon.

olefins formed in the first reaction zone into aromatics. By recycling a part of the products from the second stage, a product may eventually be produced consisting of any desired aromatic content. The above twostage operation whereinthe first stage is operated at a higher temperature, i. e. above 900 F., then the second stage may be used to treat stocks that are predominately paraffins to produce aromatics. This may be' accomplished first by converting parafiins to olefins in the first stage and converting the olefins to aromatics in the second stage and re cycling a part of these products to obtain a product of any desired aromatic content.

In the aforementioned two-stage operation, the charging stock may be either normally liquid or normally gaseous olefins and/or paraffins to produce the normally liquid aromatics, parafiins, naphthenes and olefins.

The two-stage catalytic process which is included within the scope of my invention is particularly suited for the reforming of low antiknock gasolines to produce high anti-knock gasolines. Thus, I may subject gasoline containing appreciable quantities of naphthenes and low knock rating parafiins to the catalytic treatment in the first stage operated at a relatively high temperature, i. e. above 900 F., to transform paraflin hydrocarbons into olefins and naphthenes into aromatics. The products of the first reaction stage may then be passed through a catalytic zone maintained at a lower temperature, i. e.

,850-900 F. to transform the olefins into aromatics.

Other objects, ieaturesand advantages of my invention will become apparent to those skilled in the art from the following specific examples:

EXAMPLE 1 A cracked gasoline was topped to produce a bottoms fraction having a boiling range of 200-450 F. and containing about 29.2% by weight of olefins. These bottoms were vaporized and the vapors were passed through a reactor consisting of an elongated stainless steel tube about 4 feet long and about one inch in diameter which contained about 230 ml. of catalyst composed of phosphoric acid adsorbed on Co- The topped gasoline was passed through the reactor at a rate of about 125 ml. perhour. The temperature was maintained inthe reactor at about 800 F. Atmospheric pressure was maintained throughout the operation. Water at a rate of 30 ml. per hour was pumped into the vaporized stream of charging stock passing to the reactor.- The hydro. carbon vapors and steam passing through the reactor were condensed and the water was removed from the hydrocarbons. The condensate of hydrocarbons was again topped to remove fractions having a boiling point below 200 The catalyst was prepared by saturating carbon particles capable of passing through a screen of 6 mesh and being held on a 14 mesh screen, with phosphoric acid and allowing the excess acid to drain from the carrier which was then dried at 400 F. About 230 ml. of the thus prepared catalyst was used to effect the reaction.

Tests on hourly samples of the recovered products of reaction boiling between 200-450 F. showed a consistent olefin content of about 13% which was maintained-for at least 7 hours. The product of reaction containing 13% olefins was recycled through the reactor containing the same with the aromatics.

catalyst while maintaining the same operating conditions. The treated product from the res actor was again topped to 200 F. initial boilin point. A test on the bottoms showed a redu'ca reduction of about 50% of olefins per cycle of charging stock.

Exmu: 2

A hydrocarbon fraction having a boiling range of 170-400 F. and composed of 60% by volume of aromatic hydrocarbons consisting chiefly of benzene, toluene and xylene, 14% by volume of olefins and 26% by volume of parafiins and other non-aromatic and non-olefinic hydrocarbons was treated with catalyst at 800 F. as in Example 1. After the first cycle of operation, the product of reaction showed an olefin content of 5.6%. This was reduced to 8.2% by recycling the once treated product through the reactor containing the catalyst under the same conditions of operation.

The liquid products of the reaction were then mixed with 2 volumes of liquid sulfur dioxide at a temperature of about --18 F. and the mixture was allowed to stratify into two layers. consisting'of an upper layer of non-aromatic hydrocarbons dissolved in a small amount of the sulfur dioxide and a lower layer consisting of the aromatic hydrocarbons dissolved in the bulk of the liquid sulfur dioxide. The lower layer was withdrawn and the liquid sulfur dioxide was distilled to produce'a fraction of aromatic hydrocarbons and representing about 65% by volume of the material undergoing extraction. The extracted aromatics contained the small amount of unconverted olefins which were present in the treated stock and whichwere extracted along Exam 3 A pressure distillate was topped to produce a hydrocarbon fractionhaving a boiling range of IDS-410 F. and composed of 20% olefins. 15%

aromatics, 48% naphthenes and 17% paraflins, This fraction was then passed through the reactor'containing 230 mi. of catalyst at a'tempera'ture of about 800 1". and atmospheric pressure and at a rate of 60 ml. per hour and was continued for five hours. The'catalyst was prepared by adsorbing 25 of. 75% H.1PQ4 on 230 ml. of

Columbia activated carbon of 8-14 mesh and stirring until dry without added heat. ''''.en 25 ml. of 20% aqueous sodium hydroxide '.as added to the carbon containing the phosphoric acid '5 and the mixture was stirred well while drying with the application of gentle heat. The amount of caustic soda added to the carbon containing 10 The total product recovered at the end of five hours of operation from the reactor which represented 93% of the feed charged to the rereactor consisted of a hydrocarbon fraction having a boiling range of 170-429 F. and consisted of 2% olefins, 37% naphthenes, 26% aromatics and about 35% parafins which was obtained in a single pass through the reactor. Very little gas was produced during the treatment and this consisted of 58.4%l1ydrogen, 1.4% olefins, 35.6%

paramns and 4.6% of material solublein caustic .soda.

The above treatment was retreated using the same feed stock, temperatures, pressure and catalysts in which the phosphoric acid adsorbed on the carbon was partially neutralized by various equivalents of causticsoda per mol of the phosphoric acid. The following table contains a summary of the catalyst used and the composition of the resulting product together with the gravity. and Engler distillation of the final product. Included also are tests on the feedstock whichwas subjected to the treatment.

The product obtained by the treatment of the stock with phosphoric acid neutralized with onehalf equivalent of caustic soda per mol of acid suiting product which represented about 94% of the once treated feed stock showed an aromatic content of a paraflln content of 33% and an olefin content of 2% indicating that all 5 of the naphthenes were converted into aromatics.

The polymer gasoline having a boiling range of -390" F. and composed of approximately 80% olefins and 20% was treated in 50 accordance with Example 3 using the phosphoric acid catalyst which had been neutralized with one-half equivalent of caustic soda per mol of acid. The treated product representing 92% by volume of the feed stock and obtainedin a '65 single'pass through the reactor consisted of 5% olefins, 15% aromatics, 12% naphthenes and 68% paramns.

' Table 1 com andant-dam smtb museum Cataiystusad-NaOH volume n par amp v n.1 I

o NPh; ltfi". mm, tbsnslm m mm 1 10.0 4 40.0 2.0 40.0 :11 14 10.4 00.1 01.1 41.0v us no 0% g 2.4. no no an 41.4 100 a0 s00 :10 4a 2.0 10.0 01.0 04.0 41.0 m :11 as m- 4a a as no. no vsu 41.0 171 an an s11,- 410 4.5 21.0 40.4 140 41.0 11: a :00 .011 4a a: 10.0 41.4 11.0 41.1- 111 :10 an s11 41: a s: a: s; at a a '11.: 11.0 40.0 .2110 40.: us :40 3 1;: g

10.0 iao 4s.0 11.0 a. 100 an as 4'10 ExAmPLr:

. the reactor consisted of 80% aromatics and 20% parafilns. The gravity and Engler distillation of the extract feed stock and the final product are given below:

Table 2 Gravity Engler distillation, F. "A.I. Initial 50% 90% 95% Max.

Gasoline extract feed... 41 213 247 282 335 352 382 Finalproduct. 37 164 233 271 319 343 396 EXAMPLE 6 A pressure distillate was topped to produce a hydrocarbon fraction having a boiling range of 200-400 F. and was composed of 44% olefins, 10% aromatics, 20% naphthenes and 26% paraflins. This fraction was then passed through a reactor consisting of an elongated stainless steel tube about four feet long .and about on inch in diameter which contained 230 ml. of catalyst at a temperature of about 750-800 F. and atmospheric pressure and at a rate of 60 ml. per hour. The catalyst was prepared by adsorbing 75 ml. of an aqueous solution of 20 ml. of sodium silicate solution diluted with 55 ml. of water on 230 ml. of Columbia activated carbon. The sodium silicate solution was the Philadelphia Quartz Companys E Brand sodium silicate solution of 40 Baum and having an alkali-silica ratio of 1 to 3.22. The approximate composition of this sodium silicate solution is 29% S102, 9% NazO and 62% H20. Then the activated carbon containing the sodium silicate solution was allowed to soak in 500 ml. of 3N-HC1 for about two, days with occasional stirring. The excess hydrochloric acid was then drained from the granules of the carbon and these were washed thoroughly with water to remove free sodium chloride and hydrochloric acid before use, leaving a surface of silicic acid on the carbon granules. The granules are then dried at 300 F. The drying and the use of the catalyst at more elevatedtemperatures causes the sllicic acid to gradually change to silica so that the major catalytic operation is with silica on the activated carbon ExAmLI: '7

A straight run gasoline having a boiling range of 19(i-380 F. and composed of 14% aromatics, 42% naphthenes, 43% parafllns and 1% oleflns and having an octane number of 60 .was passed through a reactor containing about 4 liters of the catalyst described in Example 6 at a temparafiins and-4% olefins and had an octane number of 75.

The foregoing description is not to be taken as limiting my invention but merely as illustrative of one mode of carrying it out as many variations may be made thereon as will be recognized by those skilled in the art which are within the scope of the following claims.

I claim: I

1. A catalyst comprising the product of a mixture of a carrier and an acid containing a phosphate radical, said catalyst being prepared by adsorbing phosphoric acid 'on said'carrier followed by neutralizing said phosphoric acid on said carrier with approximately one-sixth to twothirds equivalents of a caustic alkali per' mol of said acid. e

2. A catalyst comprising the product of a mixture of carbon and an acid containing a phosphate radical, said catalyst being prepared by adsorbing phosphoric acid on said carbon followed by neutralizing said phosphoric acid on said carbon with approximately one-sixth to twothirds equivalents of a caustic alkali per mol of said acid.

13. A catalyst comprising the product of a mix- I ture of activated carbon and an acid containing a phosphate radical, said catalyst being prepared by adsorbing phosphoric acid on said activated carbon followed by neutralizing said phosphoric acid on said activated carbon with approximately one-sixth to two-thirds equivalents of a caustic alkali per mol of said acid.

4'. A catalyst according to claim 1 in which thebarrier is alumina.

5. A method of preparing a catalyst which comprises adsorbing phosphoric acid on a carrier and subsequently neutralizing said phosphoric acid on said carrier with approximately one-sixth to two-thirds equivalents of a caustic alkali per mol of said acid.

6. A method of preparing a catalyst which comprises adsorbing phosphoric acid on carbon and subsequently neutralizing said phosphoric acid on said carbon with approximately onesxith to two-thirds equivalents of acaustic alkali 9. A method of preparing a catalyst which come prises adsorbing phosphoric acid on a carrier, drying the mixture and subsequently neutralizing said phosphoric acid on said carrier with approximately one-sixth to two-thirds equivalents of a caustic alkali per mol of said acid.

10. A method of preparing a catalyst which comprises adsorbing phosphoric acid on carbon,

naphthenes, 40%

drying the mixture and subsequently neutralizing said phosphoric acid onsaid carbon with approximately one-sixth to two-thirds equivalents of a caustic alkali per mol of said acid.

11. A method of preparing a catalyst which comprises adsorbing phosphoric acid on activated carbon, drying the mixture and subsequently neutralizing said phosphoric acid on said activated carbon with approximately one-sixthto two-thirds equivalents of a caustic alkali per mol of said acid.

' KARL KORPI.