Патент USA US2408725код для вставки
ou: s, 1946. J. QBAILIE `E1' AL TOLUENE rnocnss Filed Aug.,"r. 1942 ' y .2,408,724y 2,408,724 Patented Oct. 8, 1946 ” UNITED- sTATEs ¿PATENT OFFICE f Y f ' i e L2,408,724.L7''A 1 y ‘ 7 l f TOLUENE PROCESSrl James C. Baìlieand Rodney V. Shankland, VChi cago.' Ill., assignors »to Standard OÍlCom'pany, Chicago, Ill., a corporation of ,Indiana> ‘ ' . „ vApplication August 7, 1942„se1f`ialjNq.. 4535929 _ ‘ "zV claims._ (c1. l.stof-ccs)l 2 ' , As a result .the amount of> toluene which can be produced in a has .beenw possible*> heretofore. ‘_ This invention relates to a process of making toluene from petroleum hydrocarbons and more given installation using our improved toluene di speciñcally tothe catalytic treatment of a se rective catalyst can be two to four times the lected fraction of petroleum naptha at conver sion temperatures and in the presence of hy-v 5, amount obtainable in the same time with cat-' ~ alysts heretofore employed. drogen, employing for the purpose a catalyst which lwe have discovered to be unusually eiiec tive for producing toluene. ' - i >Our process is illustrated by a drawingwhich accompanies the speciñcation and whichmshows diagrammatically an apparatus for carryingout ' It has been -known heretofore that catalytic ' treatment of petroleum hydrocarbonsunder cer-v tain conditions will produce aromatic hydrocar bons from hydroaromatics and parafiins. The aromatic hydrocarbons thusproduced range all the way lfrom benzene thru the Xylenes, higher alkylated benzenes, napthalene and'other con ’densed ring aromatic compounds. Because of the extraordinary demandfor toluene in the manu-V facture of explosives, it has become urgently Yirri'j- the process.v , " v ~ Referring to the ‘ drawing, the apparatus'shown representsy a prefractionator l, a catalytic re ~ actor__2„ andfafterÓ i'ractionators 3 and `4. Heat ers 5 and 6 maysuitablybepipe heaters in which coils’of’tubing'are placed,v within a ‘furnace set ‘ ting ‘and the material heated is forced thru the j The stock employed for our pi‘oces's isV .prefer-_ ' coils. ' - . , . y ' v ably a close-cut straight-run naptha fraction portant to produce the maximum amount vof from 'crude petroleum, but we mayv also employ toluene instead of other less Vdesirable aromatic 20 cracked napthas and"v particularly cracked Íhydrocarbons such `as' benzene and Xylene._ The processes employed- hereto-fore for convertingi'pe troleum napthas to aromatics have failed to yield morethan about-¿'10 to 15% of toluene based on the petroleum hydrocarbon treated when processing Mid-Continent light napthas using Yconverti-f napthas of low unsaturati'on from thermal lor catalytic cracking.y YTher napthas preferred for our process are those containinga high concen-A , ` tration’of cycloparafûnic hydrocarbons and more particularly >`hy'ç‘iro‘arornatic . hydrocarbons. .ln tional commercial operating" conditions. «Fur order to obtain the best yields of toluene wev pre came deactivated rather rapidly especially `with respect to their toluene-producing ability. vAsa vproducing result of their capacity relative averaged instability lthruout thethetoluene-` life of , those catalysts was even considerably less than range embracing 4the ‘boiling point> _of toluene, e. _232° >ET.;4 A fraction .having initial and iinal thermore, the catalysts prevrviouslyv employed `be these figures would indicate. In contrasttojthe priorA processes, ourv process has`v produced> u, 19-20%>of toluene from a selected naptha frac tion which is a toluene yield 25% greater than fer to employ a naptha fraction having aboiling ~ boiling points within 25°F. of the boilingupoint of toluene is very desirable and it is undesirable to _employ` a _naptha fractionhavinginitial and final boiling points more thanA about 50° F. away from vthe boiling >point of toluene. Aj light naptha fraction having an vinitial boiling point of about 180° F. and a final boiling point of about 280° F‘. ` is characteristic of the widest hydrocarbon frac has been producible by other processes. ' tion, which it ’isy desirable -to subject to catalytic ï One object of our invention isto provide a toluene process and catalyst for converting per 4.0 treatment by our process. vSince poor fractiona troleum napthas into toluene with a higher de- " ‘ ‘gree of conversion than processes known hereto fore. Another object iswto provide a catalyst with rgreater stability, particularly stability toward the high temperatures employed in catalyst regen’- v eration, *therebyy producing a higher level ofÍ toluene conversion over the life of the catalyst. Another object of our invention `is to provide a vprocess of converting a selectedy petroleum naptha into aromatic hydrocarbonswhich pro duces substantially no other hydrocarbons boil _ingíin the region of the toluene boiling point.> Y As a result *ofA such clean-cut conversion, substan tially pure toluene is obtainable by fractionation without the use. of selective solvents or chemical reagents.A A still further object of our invention ' tion will often produce la considerable variation in the initial' and ñnal boiling points, it is some what preferable v.to control the/boilingy ran'geof the naptha by the 10%_and9`0% points, ASTM. A naptha having a 10% point of1 200° F, or’ above and a 90%, point of: 250° F. or below is verysatîsj factory. 1 . Referring to the 'drawingpetroleum naptha‘or y_gasoline is charged to the process by line , I0 and vaporized in coil Il of' furnace 5. >The vap'ors'are conducted by transfer line l2 toy fractionator l where heavy naptha is discarded as a residue by line I3, while light. hydrocarbons undesirable for our process are withdrawn by vapor line lill. The desired naptha fraction is trapped out of the column by line ‘t5 leading to stripper iE wherein further fractionation takes place-andvundesir is to provide a catalytic process for making tolu >ably light hydrocarbons are» returned to the main ene in which the toluenefproducing activity of column by vaporili-ne l1. The desired fraction, the catalyst is suñiciently high to enable the `proc yfor example a fractionvboiling from about 200 60 ess to be operated atmuch higher capacitiesl than 3 2,408,724 to 260° F. is`withdrawn by line I 8 and forced thru heater 6 where it is heated in coil I9 to the de sired conversion temperature or somewhat above. The hot hydrocarbons are conducted by transfer line 2l] to reactor 2. Hydrogen may be charged to the process by line 2 I, and hydrogen-contain ing gas may be recycled by line 22 and coil 23 'I'he amount of hydrogen is suitably about 1 `to 5l mols per mol of hydrocarbon treated and, in gen 4, heated to reaction temperature or above by heat ing coil 23 located in furnace 6, as vpreviously described. The amount of gas recycled in this way depends on the net gas production, the hydrogen- concentration of the gas and other factors. Excess gas may be withdrawn by valved ï outlet a4. This recycle gas may be enriched with respect» to hydrogen content by including an ab sorber (not shown) in the recycle system to re eral, about 3 mols of hydrogen is a satisfactory -10 move low boiling hydrocarbons and thus raise amount. This corresponds roughly to `2500 cubic the hydrogen concentration in the recycle gas. feet per barrel of naptha. The hydrogen may The crude toluene fraction is conducted by line be introduced directly into the naptha fraction 29 to fractionator `4 -which is preferably an eni and simultaneously heated with the naptha in cient fractionating tower with a large number coil I9, or it may be separately heated and in 15 of plates. In this tower the, toluene is with troduced into the oil or v.directlyinto the re drawn as a side stream by trapout line 35 lead~ actor 2. . . ` ing to stripper 36, the vapors being returned to Reactor 2 is charged 'with the catalyst in the main tower »by line 3l, while the toluene is granular or pelleted form. The hydrocarbons Withdrawn from the ysystem by line 38. On pass downward thru the catalyst bed and the con verted `products may be withdrawn by linev 24. Other methods of contacting the naptha with the catalyst may rbe employed without departing from our invention. For example, the catalyst may be supplied in the >form of a powder and main tained suspended in thereaction vessel. In this case, deactivated catalyst maybe withdrawn as 20 account of the presence of a small amount of para?linic hydrocarbons boiling near the toluene boiling point, it is not practicable to recover all ' the toluene from the products by fractional dis tillation. Therefore, in practice the amount of 25 substantially pure, nitration grade toluene re~ covered from the c-rude toluene fraction is about '7D-80 percent. ySome additional toluene and a ñuid from time-to-time or continuously regen close-boiling parañînic hydrocarbons are. present erated and returned-to the system. \ in fractions boiling just above vand just below Reactor 2 .is preferably operated under pres 30 the toluene boiling'. point. Ay heavier fraction is sures of the order of 50 to 500 p. s. i., anda withdrawn as a condensate from fractionator 4 temperature preferably vin the -range of 900 to by line 39 and recycled by line 40 to the con 1050“ F. Somewhat lower or _ higher temper atures may be employed, e. g. temperatures as version step. Hydrocarbons «boiling `below toluene are with low as 850° li'.y may be employed with low -space 35 drawnas a vapor stream by line 4I and further velocities and temperatures >as high as 1100o F. fractionated in fractionator 42. Substantially may be maintained with ,high space velocities. all the toluene carried away with the light prod The space velocity» employed is usually within the range .of about 0.1 to5 volumes of naptha ucts is collected as a condensate in the base of fractionator 42 whenceV it is conducted by line per hour per gross volume of catalyst, a space 40 `43 back to the conversion step of the process. velocity of 0.5 to 2 being most commonly em Benzene and other light hydrocarbons are with ployed. The volume of naptha referred to in drawn by line> 44 to condenser `45 and receiver indicating the space velocity is the liquid volume 46, whence they are discharged by line 47. Par of the naptha charged at standard temperature afñns may be recovered from this fraction by conditions, while the volume of catalyst referred 45 «further fractionation and/or chemical treatment to is the gross volume occupied by the catalyst, or the benzene fraction may be employed in the not the net volume of the catalyst ywhen cor manufacture of high knock >rating motor fuels, rected for voids. It should be understood that aviation gasoline, etc., for example by blending the amountfof toluene produced can be generally with the naptha fractions eliminated in tower increased by operating at. lower space velocities 50 `I thru lines I3 and I4. The tower 46 is vented and/or higher` temperatures, but that in general byline 48. vgas losses are increased at the same time. vWhen using our toluene directive catalysts it is pos sible to effect conversion at reasonable space - In recycling the fractions bordering on toluene, i. e. the stocks recycled thru lines 39 and 43„we obtain, in effect, a catalytic puriñcation of this velocities, for example, 1 to 2 V. H. V. producing 55 intermediate material from which it has here high >yields of-toluene with only moderate gas tofore been diñicult to recover the toluene. The losses. , , - "l toluene contained therein passes thru the cat The reaction products from 2.pass, by line 24, alytic reactor 2, substantially unchanged, while thru cooler 25 and thence» by line 2S to gas non-aromatic hydrocarbons boiling near the boil separator 21, thence to fractionator 3 wherein 60 ing point of toluene are converted into additional a heavy aromatic fraction is separated and with toluene and/or other products of diiîerent boiling .drawn by line 28. This heavy fraction, sub points by the action of the catalyst. Some alkyl stantially free of toluene,4 may be‘employed in ation of recycled benzene also appears to take the manufacture of motor fuels, aviation gaso lplace in reactor 2, thereby forming additional line, etc., for example by blendingl with the 65 toluene. » _naptha fractions eliminated in fractionator I by After the conversion operation has proceeded lines I 3 and I4. It may also be used> as a solvent for a period of time, usually about six hours, in paints, varnishes, etc. A lighter fraction con-A the activity of the catalyst is diminished by an taining substantially al1 of the toluene produced accumulation of carbonaceous deposits which is withdrawn as a side stream by line 29. A 70 must be removed. This is accomplished by pass crude light fraction substantially free of toluene ing an oxygen-containing regeneration gas thru ‘is withdrawn- by vapor line 30. Fixed gases in the catalyst.> The stream of naptha entering cluding hydrogen are withdrawn from separator reactor 2 is interrupted or diverted and air or 21 by line 3l and recycled by blower 32 and line -other oxygen-containing gas is introduced by line 22 back to the reactor, preferably after being 75 v49 under carefully controlled conditions to pre' y asesoria. 5 vent overheating the catalyst.. Spent-regener Other vslealt` acids may »be -used such as citric, ation gas »is lwithdrawn »by line .-50., _The 'heat evolved lduring regeneration 'may bei dissipated in various-ways, for example, by cooling coils. not shown. ' l > , , y .» 6 tration-¿cfabout 1 te 6 percent is satisfactory, ehloroacetic.. etc., » , Y The amalgamation may be vaccomplished. >,by addingapmercury salt or mercurio oxide :to the acid solution before adding the aluminum. Rapid solution of the metal takes place with‘the forma ' . The'tolueneçfraction withdrawn by line 38 will ordinarily contain upwards of 95% toluene and tion of ~asol which _in the case of Aformic acidis more iluid .than that. obtained with acetic acid. Thesol be coagulated by adding an electro lyte such aszammonium ycarbonateand in the case of more highly concentrated sols, coagulation-may occurspontaneously when standing ¿or on 'heating Whatever. This desirable result has not been pos- n The coagulatedrsolîis then dried slowly in a cur siblewith catalysts employed heretofore because rent .of warm, dry air and the dried alumina is of the relatively larger amount of non-aromatic 15 ignited, for example by heating to a temperature hydrocarbons occurring in the products, having of .about-1100?J F. .and Aholding at that temperature boiling points close to the |boiling point of toluene about twenty-four to forty-.eight hours. Organic land inseparable therefrom by fractionation. The acids adsorbed on the alumina producea certain use of our new catalysts has made it possible for us to produce nitration grade toluene directly 20 amount of >carbonization on heating, and carbon so .producedis `burned away by air during> _the from the catalytic conversion process with no de » ignition" Ístep, care being taken to lcontroltl'ie :rate crease in toluene yield but with even greater yield of burning to avoid overheating the alumina and than obtainable by the previous processes. The impairing its 'catalytic activity. Where formic toluene fraction may be submitted to additional acid is usedin preparingthe sol, carbonization is »purification'by extraction with a-selective solvent, minimized.. by extractive distillation using a solvent such as As indi‘catedhereinabove, themolybdenum-pro phenol, nitromethane, etc., or by a chemical treat moter may be Aadded to the alumina during prep ment when desired to prepare the toluene for. some aration or after ignition and we have iound .that special purpose. ' v The catalysts lwhich ’we-employ rand which We 30 when the promoter is added after ignition the resulting catalyst is. more khighly directive for the term “toluene directive catalysts” are comprised formation of toluene `.than when the promoter is of aluminum oxide of high purity promotedwith added before ignition, for example while the alu molybdenum. . They may' 4‘be prepared conven mina is inthe sol form. Thusin comparing two iently by dissolving metallic aluminum under con ditions to produce an alumina sol, after which the 35 catalysts, one in which the molybdena is added to the valumina sol, and the »other in which the >sol is converted to alumina gel. In forming the `molybdena- is added to `the ignited alumina, we dry gel from the sol vit is desirable fto kcoagulate find tha-t whereas thearomatization lcharacteris >thesol to a firm, solid, vibrant jelly which is dried tics are Ysubstantially the same, each catalyst pro and ignited as will be described hereinafter. The ducing >apprexi-mately the same amount of aro lalumina is promoted'with molybdenum whichmay matics, -the distribution -of aromatics is quite dif be applied either before or after the formation ferent, the alumina promoted »after ignition giv ofthe gel, the latter method. producing .a more ing a higher yield of toluene. The explanation of it is feasible to operate with toluene concentra tion above 98%. We may control the fractiona tion in tower 4 to .produce nitration grade toluene directly fromithe process without the necessity of any solvent Vextraction or chemical treatment toluene-directive catalyst. . . Another method'of preparing our'specially pure aluminum oxide catalyst is by precipitation `of aluminum hydroxide from aluminum salts .of high purity followed by extensive `washing-1 untilthe »this «phenomenon is not understood. traneous metals therefrom completely’apparently >miolybdena to purealuminum oxide ignited at 800 to 1100° F., thek ammonium molybdate solution The >amount Vof promoter employed is usually about 5 to l0 percent of molybdenum oxide `'based on the weight of the catalyst and We may use somewhat greater amounts., for example 15 to 20 Wash water shows no qualitative testfor vextrane percent'. A convenient way of applying the pro 'ous'metals, particularly metals of the iron group and the alkali metals. On account of thegel'att 50 moteris by means of the ammonium molybdate salt which is’easily water-soluble and may be Vnous nature of aluminum hydroxide it has here .added in solution. Thus when applying the tofore been substantially impossible to wash ex because of their colloidal -adsorptive retention. We have found that if the aluminum hydroxide y A paste obtained on precipitation is solidly frozen ’ and thereafter thawed, the gelatinous character is largely destroyed and Washing is greatly facili- ~ tated. After complete removal 'of extraneous metals thealumina obtained in this way is dried land ignited, and the molybdenum promoter is can be applied directly to the alumina, which is then dried ' and reignited. After 'preparing the catalyst as hereinabove described, we preferto grind it to approximately 30 to 100 mesh and vpellet >the resulting powder in -a >suitable pelleting machine. An organic binder such as rosin, -stearine pitch, -etc.,'may be em ployed for this purpose,_kthe binder being removed Subsequently by heating and ignitine. For the purpose just described, aluminum hy After operating our process for a period of droxide may be precipitated ’from _aluminum chlo for example one, to twenty hours, the Íride, aluminum nitrate, aluminum sulfate, or .6.5 hours, activity of the catalyst becomes impaired by an added. ` I other soluble aluminum salt, by the addition of ammonia to the salt solution. ., «accumulation of carbonaceous deposits. ~ 'hours is a convenient..time of operation. The catalyst may be prepared from metallic aluminum by the method described in U. S..P-atent 2,274,634. The general procedure involved re quires amalgamation of the aluminum metal, for Six It isy ïthen necessary to interrupt the conversion oper -ation and regenerate the catalyst by contacting Y 7.0 example aluminum in theforrn of .foil or granules is amalgamated andconverted into an alumina sol in the presence of diluteacid. A Weak organic acid such as acetic .or formic acid at a ‘concen-- 75 it with air or other oxygen-containing gas, as .mentioned hereinabove. The use of regenera ytion `gas containing a relatively small amount of oxygen, e. g._1 to 5 percent, facilitates the opera» tion.;:Qontrol-.of,regeneration is improved »by 2,408,724 7 8 retaining the catalyst in small diameter tubes of naptha treated. The following results were obtained as an average of three successive six surrounded by a cooling medium." After regen eration _the catalyst is ready forfurther con hour reaction periods with the same catalyst, regenerating the catalyst between runs, and as tacting of hydrocarbon vapors and it may be re used and regenerated an indeñnite number of times. An outstanding characteristic of our cat an average of two reaction periods at about dou ble the space velocity. Data obtained with a commercial catalyst are included for comparison. alysts made from pure alumina is their high thermal stability. Thus we have found that the catalytic activity actually increases in use for a period of time before it reaches a constant ac Alumina gel 10 catalyst tivity level where it remains 'for a long period of time. Aver~ The following data show the results obtained in the production of toluene by our process: A Mid-Continent straight-run light naptha having a boiling range of 196 to 258° F., and A. S. T. M. distillation shown in the table, was treated with a catalyst prepared in the following way: Amalgamated aluminum was dissolved in acetic acid beginning with about 1 per cent con 20 centration and later adding additional acid to bring :the concentration to 2% as the aluminum` Aver- Commercial catalyst Aver Aver age of age of age of age of 3 runs 2 runs 7 runs 2 runs Temperature, ° F ______________ __ Space velocity _________________ _ _ Yields, output basis: 985 Vol. per cent liquid product__ ' Wt. per cent dry gas ______ _ _ 970 978 l. 00 v . 2.01 » 0. 94 978 l. 9 56. 0 6:1_6 73. 3 83. 7 39. 1 32', l 23. 1 13. 5 0, 32 45. 3 0.14 48. 0 0. 18 52. 6 0.1 55. 4 In liquid product ___________ _, L1 cui 204-255° F __________ ._ 34 97. 8 25. 2 79. 8 21. 3 59. 4 15. 5 35. 0 Yield based on naptha feed__ 19. 0 16. 0 1.5. 6 l2. 9 Wt. per cent carbon ____ Gravity of liquid product_ ____ __ Toluene, vol. per cent: dissolved. The resulting alumina sol containing about 6% of A1203 congealed to a solid jelly on The commercial catalyst was an Activated Alu standing. 'I‘he jelly was dried and ignited for 25 mina containing about 9% of molybdenum ox twenty-four hours at 1100° F. It was then treat ide. It will be vseenfrom the data that at a ed with ammonium molybdate solution, dried space velocity of about 1 our improved catalyst and further ignited at 1000° F., 9 percent molyb shows an increase in toluene production from denum oxide being impregnated in the catalyst 15.6 to 19% which is approximately‘22%. At the in this way 30 higher space velocity of approximately 2, the in crease was from 12.9 to 16%, exactly'24% in Inspection of Mid-Continent light 'naptha feed crease. ' stock 'Still more striking is the toluene concentration Gravity A. P. I ________________________ __ 61.0 in the fraction 204 to 255° F. This figure gives A. S. T. M. distillation, °F.: r 35 an indication of the completeness of the con Initial _______________________ _-_ ____ __ 196 10% 208 version of'parafiln's and napthenes to toluene. At approximately unit Vspace velocity the toluene 20% ________________________________ 211 purity'in this fraction increased from 59.4 to 30% ______________________________ __ 213 97.8%, almost double, while at the higher space 40% _______ __, _____________________ __ 4216 40 velocity of approximately 2, the increasek was - ______________________________ __ 50% ___ _ __.. 219 60% ___ __________ _-_ _______________ __ 70% 80% ` 227 ____________________________ ____ 231 90% = _ - 239 End point _______________________ __ _____ __ 258 Analysis: Aromatics, v01. per cent- l Benzene' __________________ __ 0.3 Toluene __________________ __ 2.2 Xylenes more than double. Another catalyst was prepared from amal gamated aluminum in the same Way as that’l'ust described except that the alumina sol was coag 222 __________________ __ 0.7 ulated by the addition of ammonium carbonate and ammonium molybdate, sufficient ammonium molybdate solution being added to the sol to pro vide a catalyst containing about 9% of molyb denum oxide, M003. The catalyst was then dried 50 and ignited. This catalyst, ywhich may be termed a “co-gelled catalyst,” wasA employed with the same naptha under the same conditions as just Total ______________________ __ described and gave the following results at two different space velocities: 3.2 Napthenes, vol. per cent 55 Initial, 205° F _____________ __12.9 205-228° 22S-255° 255-270" Total F _______________ __ 13.1 F _______________ __ 12.7 F _______________ __ 2.2 ________ __ ____________ __ 40.9 Parafûns, vol. per cent Initial, 205° ,F _____________ __ 22.3 205-228° F _______________ __ 11.8 two ô-hr. runs runs Temperature ________________________ _ _ 972 975 Space velocity ______________________ _. Yields, output basis: ' 1. 0 1. 99 Vol. per cent liquid product-.. _.. 60. 5 68. 4 Wt. per cent dry gas ____________ _. Wt. per cent carbon.; ___________ __ Gravity of liquid product API ______ _ _ 35. 1 0. 13 48. 9 28. 3 0. 1 52. 2 28. 5 87. 9 17. 2 22. 0 68. 0 15.1 In liquid product _______________ _. In cut 204-255° F ________________ __ Yield based on naptha feed _____ __ F _______________ __ ' 4.3 Total ____________ ___ _______ __ Average oi two 6-hr. Toluene, vol. per cent: 22S-255° F ____________ _____ 16.1’ Z55-270° 60 Average of 54.5 It will be observed from these data that the catalyst in which the molybdenum oxide pro 100.0 70 moter is co-gelled with the alumina is consider ably less effective in producing toluene’than the The naptha referred to was passed in a stream catalyst in which' substantially the same alumina Residue (not examined) _______________ __ 1.4 -thru the catalyst under a pressure of 200 p. s. i. gage for a period of six hours, employing '2500 cubic feet of hydrogen per barrel (42 gallons) was promoted with molybdenum oxide, applied subsequent to ignition of the alumina. The total aromatics produced by the two catalysts were 2,408,724 9. 10 Having» thus described >our invention what.' _we found to be substantially the same. Apparently the toluene-directive raction ofthe catalyst isk considerably influenced by the method of adding claim is: . 1. The process of making toluene in high con centration from petroleum naptha which com the' promoter element, the toluene `production prises contacting said naptha at a lconversion being improved by `adding thepromoter to the temperature Within the range of about 850 to alumina after> ignition. An examination ci the 1100" F. with a catalyst substantially free of alkali data just presented shows .17.2% average yield 'of metals consisting essentially of aluminavgelpro toluene from the co-gelled catalyst and 19% from moted-withßabout 5 .to 10 per cent of molybdenum the'catalyst promoted after ignition, an increase oxide, the boiling range of >said naptha lying 10 of 10.5% in this case, operating under the same within about 50° F. of the boiling point of toluene, conditions with the same. spacevelocity.H Space supplying t'o the reaction zone about 1 4to 5 mols Velocity is the volume lof'liquidnaptha per hour of hydrogen per mol of naptha treated and re-, charged per gross volume of catalyst. Thus if covering toluene from the reaction 4products,‘sa.id two barrels of naptha are charged' per hour thru alumina gel having been prepared by dissolving 15 one barrel of catalyst, the space velocity is 2. f I_n order to determine the chemical changes occurring in the catalytic process, we made an~ amalgamated metallic aluminum in a weak acid » thereby forming an alumina sol, gellingsaid sol, drying and igniting the resulting alumina gel, and valyses- of the products obtained from two runs applying the molybdenum promoter to the gel made with the best commercial catalyst avail» ableand two runs made with' the impregnated 20 subsequent to igniting by impregnating said gel With a solution of ar soluble compound of molyb alumina gel catalyst from amalgamated alumi denum and re-igniting the catalyst. ; num. Products obtainedv from runs made _at two 2. The process of‘claim 1 wherein the catalyst different space velocities, approximately 1 and employed has a-n alkali metal content less than approximately 2, were tested. The conditions were 980° F., 200 p. s. i., and 6-'-hour reaction 25 0.1,per cent by weight. 3. The` process of producing .toluene in high Vperiods with about 2500 cubic feet of hydrogen _concentration from petroleum which comprises per barrel. The results are shown 1n the follow ing table: , contactingfa naptha boiling-'within .the range of f 196 Ito 258° F. at .au temperature of about 850 to 30 1100° F., with an alumina gel catalyst substan Naptha.. Aluginma Coiâärlier y (feed) catalysty Space velocity,~Vn/h'r./Vc_>__«..-. -. _______ __ vYields based‘on feed: 2.01 , 1.00*v 1.90 ' . Carbon ____ ._Wt. per cent.. ........ _, 0. 14 Dry~gas ....... ._--_~___.do~.'__; 25.5 C415.; ` _per cent Cs’S „__ ‘ Toluene .... ......._.-.do_.-r , per cent-. v255-300° F.: l 4.4 _ Napthenes andvparaiîûns l _ percent.. i _ `6.5 - Higher aromatics_-._do____ napthenes-l-para- liins.___.-_»..v__.:per cent.. 3:3 0.5 to5 volumes per hour per volume of catalyst in. .the'reaction zone, introducing 'into `said reac tion» zone about 1 to 5 mols of hydrogen per mol 4.1 W A .n 2.9 of rnaptha-1treatedv and Vrecovering toluene from the reaction products, said alumina gel having ` A. 0.5 ’ l A ` from' the class consisting- of acetic and Íormic acids, »startingthe solution in an acid or about 11% concentration `and=subsequently increasing _ 1.2 2.6 lic aluminum in a dilute organic acid selected I _ 0 been preparedÍ by dissolving amalgamated metal . A10.7 11.0 11a-9 ` 1.4 , l, 13.0 15.8 ` 23.2 ,_ 0.2 „ v 0.4 12.7 11.6 ~, 3.1 , 28.2- 22.41 2.2 y16.0 19.0 0.»7 Higher 10.2 f Above 300° F.: 2 2.3 . ~ . 53.7 Xylenesnegi.;li..;.;do..i. ,_ 3.1 „ A y 4.7 35.2 I ` Napthe‘nes ‘and paralnns Y 6.3 4.4 feeding said naptha at -a space velocity of about ' per sente. ` 3.0 7.3 _ 204-255212: ~ ' >9.7 11.8 6.5 action zone in the range of about 50 to 500 p. s.’i~.f, . 0. 16 20.9 0.?.l `Napthenes and‘paraülns ' 094 . . 0.10 10.'8 ~ Benzene...V.... ..`.-..do'._'-. , „ _. 0. 19 33.1 ._.d0_.__ ________ __ 1Z0-204° F tially free of alkali metalsfand impregnated with about .5,.t'ol20 -per .-cent of molybdenum oxide, maintaining the pressure' Within'the catalytic'r‘e'l catalyst 1.5 y the'concentration until an alumina sol containing 1.6 Vfrom’ about‘l .to 10 percent A1203 is'fobtain'ed; de hydrating- said sol tor alumina‘gel of «low moist-ure content, and heating said alumina gel in an at . 1 255-270° F. in case of feed. 2 Above 270° F. in case of feed. Norm-_Percentage is by volume except Where indicated. n Y50 mosphere oi'controlled oxygen content to remove adsorbed organic acid. 4. The process of making .toluene in high :con As indicated hereinabove, we prefer to lprepare centration from petroleum which comprises con our toluene directive catalyst from metallic alu tacting, _in a reaction zone, a petroleum naptha minum, ñrst forming an alumina sol, then a gel. boiling in the range of 196 to 258° F. with a cata Metallic aluminum of high .purity should be used 55 lyst consisting essentially of alumina gel pro for lthis purpose. All reagents should be substan- -moted with about 5 to 10 per cent of molybdenum tially free of other metals except the desired pro oxide, .the said catalyst being substantially free moter and We have found that the alkali metals of alkali metals, maintaining said reaction zone in .particular are objectionable. . The catalyst at a temperature of about 900 -to '1050° F. and m-ade from aluminum metal is .substantially free a pressure of about 50 .to 500 pounds per square of sodium, containing not more than about .01 inch, introducing into said reaction zone about percent of this element. »We prefer that the 1 Ito 5 mols of hydrogen per mol of naptha hydro alkali metal content of our .catalyst be not more carbon treated, charging said naptha .to the re than 0.1 percent. ' If the alumina is prepared by precipitation 65 from an aluminum salt, it is important to employ an aluminum salt, for example aluminum nitrate, ï which is substantially free of alkali metal salts. This objective may be attained'readily when sub 70 limed aluminum chloride is employed for prepar ing .the catalyst. The use of distilled Water and glass, wood or ceramic> mixing vessels in making up the catalyst is importanti-,o prevent contami nation. . action zone at a space velocity of about 0.1 to 5 volumes of liquid naptha per hour per gross vol ume of catalyst in .the reactionyzone, and recov ering toluene from the reaction products, said valumina. gel catalyst having been prepared by dissolving amalgamated metallic aluminum in a weak acid thereby forming an alumina sol, co-p a'gulating said sol to a ñrm, vibrant gel, drying ' and igniting Ithe resulting gel, and impregnating said gel with a solution of a soluble compound of 2,408,724 ll l2 molybdenum which on ignition Will be converted to molybdenum oxide. the reaction zone, and recovering toluenefrom the reaction products byV direct distillation, said 1 5. The process of makingY toluene jfrom .pe troleum in high concentration sufûciently ‘free alumina gel catalystA having been prepared by dissolving amalgamated metallic aluminum ín a weak acid to form an alumina sol, then jgelling the sol by adding a solution of’ electrolyte, drying from contaminating non-aromatic hydrocarbons of similar boiling points to permit the recovery of substantially pure to-luene b-y directdistillation of the, products which comprises contacting, in and igniting the resulting gel, and impregnating said gel with a solution of a soluble compound of molybdenum which on ignition will be con a reaction zone, at a temperature of about 900 to ,1050° F. a naptha boilingwithin the range 10 verted to molybdenum oxide._ ; ` of.l80 .to 280° F. With a Catalyst consisting-es 7. The process of making toluene of high' con sentially of alumina .gel promoted with. about 5 centration from petroleum which comprises con to. 10 per cent of molybdenum oxide` and sub tacting a petroleum naptha boiling Within. the stantiallyfree of alkali metals at a ypressure of range of 180° to 280° F. with a porous solid about50to 500 vpounds per square inchand in catalyst consisting essentially of alumina gel pre the presence of aboutl to„5 mols of added hy pared by dissolving amalgamated aluminum drogen per mol yof, naptharhydrocarbon treated, metal in a weak acid, gelling the resulting sol, charging said naptha to the, catalytic reaction drying and igniting the resulting gel and pro zone at a space velocity of about 0.14 to 5.«volmoting it with about 5 to 10 per cent of molyb urnes of liquid naptha per hour vpergross volume 20 denum oxide by impregnating it With a solution of _catalyst in the.k reaction zone, and recovering of a molybdenum compound which on ignition toluene from . the reaction products >by direct will be converted to molybdenum oxide, then ig distillation, saidv alumina gel having --been pre niting said impregnated gel, maintaining a space velocity Within the range of about 0.5 to 5 vol pared by dissolving amalgamated metallicalu minum in a Weak acid thereby forming `an alu umes of naptha per hour yper gross voluime of minasol, gelling said sol, drying and igniting theresulting gel, and impregnating saidgel with asolution of a soluble compound of molybdenum which on _ignition will ,be> converted >to »molyb denumoxide. The, >process, of, makingtoluene . _. from4 .. . .pe troleum in lhigliconcentration suilîcientlyfree from contaminating non-aromatic hydrocarbons Totsirnilar boiling points topermitthe recovery lof substantiallyv pure, toluene by _direct distille., tionof the products which comprises ~contacting, catalyst in the reaction zone, maintaining the reaction temperature at about 900 to 1050° F. and a pressure of about 50 to 500 pounds per square inch, supplying to the reaction zone about 30 l to 5 mols of hydrogen per mol of naptha treated, fractionating 'the reaction products into a substantially pure toluene fraction,y a heavy substantially toluene-free Xylene fraction, a light substantially toluene-free benzene fraction, kand 35 at least one intermediate boiling fraction con taining toluene and non-aromatic hydrocarbons boiling close to toluene, recycling said interme in»4 a> reaction „_ zone,` lat `atemperature v.of .about 900¿ to _1050€ F. a naptha lboiling.,within the range of 1,80 to 280° F. with a catalyst consistingessen tially of alumina Vgel promoted With about 5to 10_,per cent of molybdenum oXideandsubstan tially, freeßf alkalif metals at a pressure .of about V50u30> 5_00 pounds per squareV inch and. inthe presence ofabout >_1,to _5 mols lof _added hydrogen pêlëmol of n_aptha hydrocarbon treated,.charging Sßfíd, naptha _tothe catalytic reaction zone ,ata spacel‘velocity of. about 0.1>> to 5 volumesof liquid - _naptha per _hour per grossvolumeof catalyst in diate boiling fraction to said catalytic conversion step, thereby converting said non-aromatic hy 40 drocarbons into aromatic hydrocarbons and prod ucts having boiling points less close to the boil ing point of toluene than the boiling point of said non-aromatic hydrocarbons in said intermediate fraction and subsequently separating said last mentioned products from toluene in» said frac tionation step. ` ‘ ` ~ JAMES C. BAILIE. RODN'EY V. SHANKLAND.