US2333625A - Conversion of hydrocarbon oils - Google Patents

Description

Nov. 9, 1943.

CONVERSION OF HYDROCARBON OILS I, Filed Feb. 10, 1941 REFORMING STOCK (GASOLINE, NAPHTHA OR THE LIKE) F INELY DIVIDED souo CATALYST v THERMAL 9 REFORMING NAPHTHENIC OIL FROM MIXING THERMAL CONVERSION RODUCTS PARTIALLY COOLED IN TRANSIT TO CATALYTIC CONVERSION STEP CATALYTIC Ia OOLING CONVERSION (HYDROGEN- TRANSFER REACTION) RECYCLE 6F THI MATERIAL As COOLING MEDIUM Is OPTION AND IT MAY ALSO BE USED WHEN DESIRED AS CATALYST CARRIER I2 I SEPARATION "J I4 RESIDUEI GASES INTERMEDIATE LIQUID CONVERSION PRODUCTS GASOLINE 7 (HIGH OCTANE NO.) LOW BROMINE N0.

INVENTOR CHARLES H. ANGELL ATTORNEY Patented Nov. 9, 1943 UNITED STATES PATENT OFFICE 2,333,625 p 1 CONVERSION or nYDnooAnBoN OILS Charles H. Angeli, Chicago, 111., assignor to Universal Oil Products Company, Chicago, 111., a corporation of Delaware 13 Claims.

The invention relates to an improved process for the production of high yields of substantially saturated hydrocarbons boiling within the range of gasoline and of high antiknock value from (C1. rac -o) In the thermal reforming step of the process any of the well known formsnof apparatus.commonly employed for this type of operation may be utilizedwithin the scope of the invention and gasoline or gasoline fractions of inferior anti- 5 the'same applies'to the low temperature cataknock value,'naphtha and the like. lytic cracking or hydrogen transfer reaction. it The process ofthe invention comprises an is the usual practice in thermal reforming operinterdependent combination of thermal and catations to, quickly heat the charging oil to a high alytic conversion steps which cooperate to pro cracking temperature in altubular heating coil duce a gasoline of high antiknock value and of 1 and then maintain it ator near the maximum substantially saturated nature, suitable, for extemperature attained fora predeterminedtime ample, as aviation gasoline, from light hydroin a soaking zone which may comprise a relacarbon oil distillates, such as gasoline or gasotively ild y ea d cont of t coil in line fractions of inferior antiknock value, naphthe same. or separate furnace structure or an entha and the like. t 15 larged well insulated or mildly heated reaction The thermal conversion step of the process-is chamber, or both, wherein the desired time facpredominantly a thermal cracking operation of tor is obtained, the heating a s ak ng n s the type now well known in the art as reformnormally being operated at a relatively high ing, whereby gasoline or gasoline fractions of superatmospheric pressure. The coil'or coil and relatively poor antiknock value :or light distil- 0 ch mber are de g e o. give-the required time Of lates, such as naphtha, are converted into high r n d r the t ratur a d p ss yields of gasoline of materially improved 'anticonditions employed. and upon discharge of the knock value. x 4. resulting hot conversion products from thesoak- One of the characteristics ofthe gasoline noring'section theynare normally cooled in one or mally produced in thermal reforming operations a combination of several well known manners to is its highly olefinic or unsaturated nature which atemperature at which deleterious further con- -at least partiallyaccounts forits good antiknock Version is prevented. This temperature norvalue but prevents it from meeting the acid-heat mally of the Order Of 170 theretest requirements for aviation gasoline. .The abouts. hydrogenation of thermally reformed gasoline In the p e d embodiment of the invention by conventional methods to saturate its olefinic the aforementioned conventional practice may components and bring it within the acid-heat be followed in the thermalreforming step, extest requirements for aviation gasoline results cept: that cooling of the reformed products is in considerable depreciation of its antiknock regulated to reduce them only to a temperature value and is a. rathernexpensive roced r d atwhich the subsequent low temperature catato the cost of producing-hydrogen and the cost yt cra king. or hy transfer a nc of reduced nickel and similar catalystswhich be adva t us y t ds t p ra are usually employedto promote hydrogenation. may be withinthe range above specified, but I have found that the highly olefinic 'or un-- preferably is of a somewhat higher order,.-for exsaturated nature of gasoline produced"by'-ther' 4.0 a p e, p to or thereabouts- 1 mal reforming can be materiallydecreased-with- The pa t y Cooled p s the thermal out excessively decreasing its antiknock value by m n p t n a n th p se nv subjecting it to a type of reaction'which' is tion, intimately contacted in areaction zone sue known as-the low temperature catalytic crackceedingthe thermal reforming step with a cataing or hydrogen transfer reaction and in the lytic material capable of promoting the. hydroprocess herein provided I employ this type of gen transfer reaction, in the presence of a hydroreaction'as the second conversion step of the gen donor, such as naphthenic oil derived from process to which th roducts of the thermal Within the system or from an external sources reforming step are supplied. The'catalyticmaterial employed may be any of No novelty is claimed herein for either of the he We l nown C c g ata y s pa of conversion steps per se, but inventionis believed promoting the desired low te p a cracking to reside in the cooperative and interdependent 1' y n transfer reaction I Specifically manner in which these ,two steps are herein n empla e the use of catalysts comprisin sili combined t achieve th d r d lt ab ve and one or more of-the metal oxides selected from mentioned. I '55 the group which consists of alumina, zirconia same are now known by those familiar with the art, the invention is not concerned with and-.1

claims no novelty for the particular catalyst comtion or its specific methoditofnprcparationzd The catalyst may be employed as.one.or,a pl u.

rality of fixed beds of SOIid',JEIEIDJIIEIZVQaKfiGIESNJE, through which the hydrocarbons to be converted. a

are passed at a. temperature suitable for conducting the desired reaction or they may be dispersed= in finely divided solid form in the stream of-.the-.-

fluid hydrocarbons undergoing treatment, in

which Ilattericase-"theyo arespmfembzlyzin the 01m ofa nriei pcwderrcapahl'e oirresmainingrrlispersed in said streamm. Wmrremplnyedrasma; ipowder, the required: quantityiz'ofi icataziytic'z materia'lvis preierabiyldnjectedmas auslunryrxirrdispersiomrin As ta speciakieatime ofnthei tnventronpwhich; is advantageousam.-ordinarily.employiedi powdered mixednwitlraaltiora portiomzofcthe cooling oil! 101' with allilon' a portiom ofath'a hydrogenirdormr emiployed, 'Ethe latter. :alsorsecving: air-.noulin'gi.oil'; and the resulting slums;armdispersionwitcatzenlystapar:

"ticl'es in the oil isainiirecte'd hmthmrequinedmuamtimes: into the flowing streamvcfoconversioxr prod,- ucts- -passingcfrom thethermai cracking: steptito the i low temperatumcatflyttci cracking or hydro:- gen transfen xstep; whereby: tthecsinjected soil'r is caused to'semiapluraslttytofitmrcttonas 40 The accompanyingzdrawingiis essentialiy a flow diagram-"illustrating! the: processspnnrvidsdlby the "invention:-

Mtenrinigwtd. the drmwiugwthezhydmcanboir .oil

charging stockztotbeacomrerted twhichumaycome prise' such materialcas zgasodhreiorogasolineuirac- "ti'ons ofE-fnieri'oiwantiknoclcMflwe;znaphthmon the like; :is supplie'd from storagezorelsewhene, as ideisired, through line I to thermal reformingetreatmam; iini zoned! wherein it-iiswzsubjcctedxtol well r know m corrdi'tions 'of hig'hr crackingxizemperature,

'substantiainsuperatmosphericepressure"and:Ttimie regulated etc: :prcd'uce therefrom; ihigh: yields: of gasoline: ofv materialiy improved antiknoohvalue.

This typeio -bperat1o'r1,-2 nowmenerally known was refoiimfnmr: =2 distrnguishcddlrbmr rt-lreztherma'l cracking: tor 'zhi-viehilfiihfififl zpmuoei-iqod anti knock gasohnetirr that iitilcmnlqysrzflnnraliy his-h:- er temperamuness'nndi :pmessntesc and: 'rlonger conversion timeza'ndi iefiectsna mltemkimpmvemeflt imzzthei antikmd: zvaluazor. 'iihe'gasoiinm dracttons -01: the charging. nilnwithoutmxccsstrely alterin theieboilingrwnge: witlsronttheexcesstves production: of:fixed::gasescandiafractionsiboiling:aboye themngemf-rgasmmcd'.

The .tlrermairreformingistopsiwill ordinarilybe QC'CDIIIPFEhBdEiiHIEHvfElOHSQtBd hoatinguwfl .disposed; within; a iumacerwith iptowsiomiorxm-ilder heating or of the; coil ithmugh which theeil-':i s last pas'sed asacompareid withithe pm- :7

ceding: 1 portion; x ofwth'e: moth: with. the) Object of quickly-heating: the whargingtoil tota relatively high crackingrtemperaturerandithemmaintaining it rim-ca eprgedetermineda-timm "8.12m a substantially uniform temperature relatively-close to thezmaxiv mum previously attained. In this type of apparatus the portion of the coil through which the oil last passes and wherein it is maintained at a substantially constant temperature is known as a soaking section. Alternatively, the length of the soaking section of the coil may be decreased and augmented or entirely replaced by a welleinsulateda-or mildlu h ated: enlar ed ve s or ,readtionychamber to whiblntheml'iigher heated products from the coil are supplied and wherein their thermal conversion is continued for a sufficient time to accomplish the desired results.

The-productscof the thermal refOrming step are rdirected. thercirom through line 3 to the catalytic conversion step 4 wherein the hydrogen transteraactionris.conducted. Instead of cooling these products, as is done in conventional practice; to a temperature at which no substantial further cracking thereof will occur and thereafter separating the same into selected light amt heavy; *fractions; they; -are; .inv :ther. improved Dmcessw. provided f4 byr. the 2 invention, cooled: only to a :temperaturerat'i which desired subsequent. Ecatalytic; conuersioncireacti'on cflna be advantageously gconduhted' and supplied, without separation: thereof :and; :in. commingled state "with r the cooling oil) employed'to reduce their temperaturetonthe desired? dfigreeittm the catalytic conversion-step. i Asimplied in:thenforegoinmstatement, cooling 1 oic the .thrmally :reomied -pn0.ducts sin. I transit fromrthe-xthermalfireforming to thecatalytijc won.- versionwzoneiis iaccomplishedxafi least part; by connningli-ngvia -s1iitable-- icoiolmgp oils-therewith. Ordinarily, since the hydrogen.transferrreaction isnusuallyconducted at,- 'a --substantiallyilower pressure-than :th'aiz' employedrin: the r therma'larefomning step; apart of the coolingr-is rpr-eferably accomplished:rbymeducing-thel ressure-imposed upon: the stream. TQIT reformed 'apnoducts as. they now they thermal reforming =2Z0ne= to th'e caizailytiofl'comverslonwzorre: may be ac'com;- plished in a conventional manner byiproividingza pressure-deducing walye'of 'suitable iwell known -formr not illustratedi i ,liiie"3 andu'tol reduce numphig costsrthe:wolin-gioili lsi-preferably added tofbhc stream' 0f utefoi'med'products afterxpassage offihbilfizttefi through-the pressure reclucing valve, althoughit mayg- -wheh desiredgibe supplied, all or irr part, to dine 3 on lthe up-streamfside 'cf th'e pressure "reducingvalve ''or directly .170 the valve. As previously: mentioned; 1 the type, of ieatalytic conilersion I reaction herein' contemplated is believeditoin-volve-thediberation ofthydrogen-from ra, rportionlofsthe'reactantsapresent; by dehydroger ationi-on crac ng: hcrep wandnthe chemical ddition i 2 .21 3- iibem edr 'hydi0gen7'= to clefinic asoline fr ions, fiq m f' n f i fi fi fi m'al reformingst p-'1 wp heriic oil; is Qne of-fthe-best sources .ofi-h-ydrogen {or reaction and provision is made r-torucomminglingi the "desired-- quantity of iaphthenic. oil from anexternal source a d or from'within the system-with the thermally "reformed products 'asthe pass; from the thermal yreiforming to the catalytic conversion step. The naphtherrim oil'is -iintr dultedr in the case =-here illustrated; into'lined via -iines 5', 6- and-z-l. or, alternatively; through mixing {zone-8, 'as-- will be later described, and,.-iwhen so: supplied to the oSy iem-gwi-ll. serve as all or. a portion; of. thecoolingrzoil l-forreducing- -thetemperatureof, the thermally re-formed-. products to the desired degree.

In casethe .quantitypr naphthnic nil required for conducting the hydrogen transfer reaction is not sufficient to effect the desired cooling of the reformed products, a sufficient additional quantity thereof 'to accomplish the de-' sired cooling may be employed or th naphthenic oil may be supplemented by another cooling oil from within or external tothe system. When, on the other hand, the quantityrof naphthenic oil required for the hydrogen transfer reaction is in excess of that which would be required at normal temperature to cool the reformed. products, it may be preheated sufficiently prior to commingling the same with the reformed products to limit cooling of the latter to the desired degree. As a feature of the invention, when the catalyst employed for promoting the hydrogen transfer reaction is in the form of powdered or finely divided solid material which flows with the oil undergoing treatment through the catalytic conversion zone, it is preferably commingled with the reformed products as a'dispersion in a portion or all of the cooling oil employed, whereby the latter also acts as a carrier for th catalytic material. Thus, in one embodiment of the invention the naphthenic oil functions as hydrogen donor, cooling oil and carrier for the catalyst. When employed as a catalyst carrier, all or a regulated portion of thenaphthenic oil may be supplied through line to mixing zone 8, wherein finely divided solid catalyst particles supplied to this zone through line 9 are dispersed in the oil, and the dispersion directed therefrom through lines to and 1 into line 3.

The catalytic conversion zone 4, wherein the hydrogen transfer reaction is conducted, may, within the scope of the invention, comprise an insulated or mildly heated coil or reaction vessel wherethrough the catalyst is passed as a dispersion of finely divided solid particles in the stream of fluid hydrocarbon reactants undergoing treatment in this zone or, alternatively, one or a plurality of reaction vessels containing one or more fixed beds of granular catalyst may be employed. In the latter case, provision is preferably made for periodically reactivating the catalyst in situ. This may be accomplished in a conventional manner by employing a plurality of reactors which "are each alternately employed as a zone in which the hydrogen transfer reaction is conducted and a zone'in which the previously used catalyst is reactivated. Ordinarily, I

reactivation will comprise burning deleterious, heavy, hydrocarbonaceous conversion products deposited on the catalyst particles therefrom by passing a stream of hot oxygen-containing gases throughthe fouled catalyst bed'or beds.

Each of the types of catalytic conversion systems mentioned, as well'as'the provisions mentioned for periodically reactivating catalyst when fixed beds thereof are employed, are now familiar to those conversant with the art. A detailed illustration thereof is therefore unnecessary for an understanding of the invention by those familiar with the art to which the invention is addressed. This also applies to the thermal reforming step and to the conventional methods and means which may be employed for-separating the intermediate and final products of the process into the desired fractions.

The products of the catalytic conversion step are supplied from zone 4 through line I l to separation in zone l2, which may comprise conventional separating and fractionating equipment. Normally gaseous products of the process, exclusive of some of the relatively heavy gases which may be left dissolved in the gasoline product to impart the desired vapor pressureithereto, are removed from' the separating step through line I3 to storage orv elsewhere, as desired. The gasoline product of the desired vapor pressure and end-boiling point is directed from the separating step through line M to storage or to any desired further treatment. This material will be a substantially saturated gasoline of materially improved antiknock' value, as compared with the asoline or gasoline fractions supplied to the reformingstep, and will ordinarily meet the requirements for' aviation gasoline. The higher boiling components of the products supplied to the separating step are, in the particular case here illustrated, separated into relatively light and relatively heavy fractions, the latter comprisingthe residual product of the process and the former comprising the. intermediate liquid conversion products. It is, of course, also within the scope of the invention to separate the intermediate liquid products into any desired number of selected fractions, although the drawing illustrates separation of only one stream of this material fromthe lighter and heavier products of the process. g

Residual liquidisremoved fromthe separating step, in the case here illustrated, through line l5 and, in casethe catalyst employed for promoting the hydrogen transfer reaction is in the form of finely divided vsolid material dispersed in the oil, it will be removed with the conversion products from the catalytic conversion step and largely concentrated'in the residual liquid removed from the separating step through line [5. In such instances, suitable well known means. not ilustrated, such as settling chambers, filters or the like, may be provided for recovering catalyst in substantially dry state'from the liquid residue, whereafter the recovered catalyst may be reactivated for further use within'the system, discarded or employed for other purposes or returned, in part, to the catalytic conversion step without reactivation by burning. In the latter instance, the recycled catalyst is preferably washedsubstantially free of readily soluble deleterious deposits before it is returned to the catalytic conversion step.

Intermediate liquid products of the process are removed from the separating step through. line l6 and may be supplied therefrom to storageor to cracking treatment in another system or elsewhere, as desired. The invention also contemplates the use of regulated quantities of the total or selected fractions of the intermediate'liguidconversion products as cooling oil for the thermally reformed products and, when desired, as a catalyst carrier. In. some instances, selected fractions of the intermediate liquid conversion products will be sufficiently. naphthenic in cha acter that. they may also be employed as a hydrogen donor in the catalytic conversion step of the system. When employed for any or all of these purposes, intermediate liquid conversion products may be directed from line I6 through line I! to cooling zone l8, wherein their temperature is reduced to the desired degree topermit their eflicient' use as cooling oil for the thermally reformed products, and wherefrom the cooled oil is directed through line l9 and may thence be introduced through line 1 into line '3 to commingle therein with thereformed products from zone 2. When used as a carrier for the catalyst, the cooled intermediateliquid conversion prod ucts may be directed through line I!) to mixing zone 8, wherein the catalyst supplied to this zone catalyst: reinpldyedl A; Miwbontinent naphthal'thavinglraniroctane number of: approximately 33:9.sadtem1i'riedaby the CI 1 F2 motor] nrethod innd la iboiiingirange :of approximately' isli to'i4 I F$ comprises theeharg ingroil whichiissupplie'd io theithermahireform ingeoirllof thesystemi Aftemperatureoizapproxi I metel bem'f F.' andralsuperatmcspherie pressure oi ebont 800 peundsiipez squam'ririchais employed at the outletrofrthe irerorminglzone "and rthectin'ie i-n'- the-'soaking secticn eorrespondgcto:alicold oil feed rate of approximately gallcmsperrhour per eubieioot -of soa-kmgspacer The "products 0! 'th'e :thermab reforming astep are icomm'ingle'd with=straight-runrgasoline in the proportion oirappreximatel 'l'volume otkero'sene toe volumes oimapntha ensrging'stocknno are cooled to a vtemperamre oi approximately 7715" F! The-kerosene =iunctidnsas cooliiigoil} hydrm gen donor and carrier io'r the rcatalyst employed. The catalyst is'a fine :po'wder consisting essen approximately lo mols of silicato 1 or alumina;

An "aver-ag'e' temperature o1 approximately 725? F; is maintained 1 in *stheeata'lytic' 1 conversion or hyd'rogem- 'transrer- -step wherein the partially cooled thermal conversion'prod'ucts-and kerosene 'are'reactediri thepres'en'ce of the catalystht a superatmospherie' pressure or approximately 100 pounds persquare-inch)" Tlie -=space velo city in thhm'a'tatlytiif 'conversion z'one, expressed as the ratio 'or reactibn space in this zone (iii cubid feet) per cnbi'c' fo'otof reactantston aeool liquid-basis) pressed through this zone perhour-is approxi mate'lyl; p I

' The productsof the catalytic reaction or hydrogen'tr'ansfer'stepare-separated to recover a 400 fiend-"point gasoline which amounts to approximately .87 "volume per cent of the naphtha charged. to the thermalreforming stem-and has anhctanenumbr ofaproximately'llfi as determined byth'e Ci'FfiR'f'motorVmethod and a bromine number '01 approximately 1. Iclaim as myfinventio'n: v

1 A" process for the conversion of anhydroca'rbon distillaltesuch as gasoline, naphtha and the like in't'o'highyields of substantially paraffin'ic gasoline of improvedfantiknoelt value, which comprises thermally reforming said distillate, cooling the resulting products to apre'determined lower cracking temperature and contacting the same, in'the presence of an added substantially naphthenic .oil, with 'a-cracking'catalyst under conditions suchas to effect partial dehydrogenation of the naphthenic' oil. and the transfer of hydrogen thus. produced to the reformed gasoline, and recovering. substantially, saturatedv .gasoline from the resulting .pro'ducts.

' 2. 'Theprocess defined in claim 1 "wherein said cooling of the reformed products isfaccomplished,

- at least in part, bycommingling said naphthenic oil,- at a 'lowertemperature', therewith:

. 3.) Theirproeess \definfidlinfclaliml'l lwher'einisaid tl'lemna'lui'efflrmingg ofi the idistillalte ris: accom; -plished at: a. v substantial asunenatmospherici press sure i and: said: coolingmfisthe reformed products is accomplished, inlpart; ibyl substantially reducing the. pressure thereon (as they pass from the ther mal reforming astep s. to the catalytic conversion step and ,':in part, by jcommingling :therewith rsaid naphthenic oil at aalower temperatures 4. x The process defined in claimi whereintsaid catalyst isliin: thewfdrm sofsxflnely divided solid particles dispersed in soil and wherein 'said :conl; ing. of the reformed produets-lisiaccomplishedhat least in" part; by'i commingling rregulatd quanti; ties'of said dispersionitherewithn,

5. The processdefined intclaimfl whereinisaid catalyst is 'in theform? 1of; Lfinely *divided 'so1id particles dispersedin atileastia pcrtionioftfsaid naphthenic' roil; and wherein :saidccooling-rottdahe reformed productseis: accomplished-F.atldeast v in pant; i by commingling 'tregulated quantities. oi said fdis'persion I therewith.

6. The hydrocarbon 1011 conversion.'-. process which? comprises heating 'a distillate comprising gasoline fractions '=of inferior rantikno'clr 1 value to a highiithermal crackingitemperanire atnza substantialv :superatmcspherie ressure' to' con:- vert the same into high yields of bleflnscontain ing 'gasoline iof improved antiknock :value; cool ing "the resulting hot ireformedrxproductsnto-ra predetermined lower temperature within :the Ecat+ alytic cracking range? contacting the. cooled products, in thepresencetohan added hydrogen donor, with a 'catalyst of. the smears-alumina "type under conditions such as to convertolennic fcom ponents '01 the :refermed-vgasoline into tsubs'tam tially saturated gasoline fractionsyflandlirecov= ering from the resulting productsra substan tially saturated '2' gasoline. iproductiioi: materially improved "antihnock I value as compared with :uie gasoline fractions of i said distillate;

7. The hydrocarbon:- oil conversion". process which comprises heating :ai distillate compris in'g gasoline fractions or inferior: 'antiknocle'vaiue to a highithemralicrackingtemperatureaha sub stantia'r superatmosphe'rie: :pressure 'Jto: c-eonvert the same into ihigh yields "of roleil-n-tcentainin'g gasoline of improved-antikrimlr'walue', materially reducing the pressure' on the' resulting reformed product's and commingling therewith regulated quantities ofa-naphthenie wail of lower tempera ture'ywherebyito reduce-the 'temperature ofsaid reformed products to Z a= "predetermined value within 'the 'catal-yti'c cracking range-contacting the commingled "oilsf iin a 1 catalytic conversion zone with "a catalyst and "under conditions capable i of promoting-the r transfer 0f hydrogen from said naphthenic oi-i tdol'fifiic components of the reformed "gasoline; efi'ecting said "hydrogen transfer 'atsaid reducedtemperature and pressure and recovering from the resulting prod ucts a substa'ntialli saturated 'gasolirjie product of good antik'nock'value. p

8."The process defined "in claim? 'wherein said catalyst is disposed "within the catalytic con version zone 'to' which"said"commingled "oils are supplied.

9. The process definedln'claim' '7 wherein said [catalyst is in the form of porous solid 'parti'cles disposed in at least one fixed'bed in said catalytic conversion zone.

V 10. The-process defined "incl-aim 7 wherein said catalyst 'is in the form of finely divided solid particles dispersed "in; oilfand wherein said dispersion is' "added-*to the stream "o1" reformed products supplied to said catalytic conversion zone.

11. The process of hydrocarbon oil conversion which comprises heating a distillate comprising gasoline fractions of unsatisfactory antiknock value to a high thermal cracking temperature at a substantial superatmospheric pressure and maintaining it in the thermal cracking zone for a sufiicient time to convert the same into substantial yields of olefin-containing gasoline of materially improved antiknock value, thereafter cooling resulting hot reformed products to a predetermined lower temperature within the catalytic cracking range, commingling therewith a naphthenic oil and passing the cooled commingled materials at substantially reduced pressure through another reaction zone in intimate contact therein with a catalyst of the silica-alumina type, under conditions such as to convert olefinic components of said thermally reformed gasoline into substantially saturated gasoline fractions by the transfer thereto of hydrogen from said naphthenic oil, and recovering from the resulting products a substantially saturated gasoline of improved antiknock value.

12. A process for improving hydrocarbon distillate containing gasoline fractions of low antiknock value, which comprises thermally reforming the distillate, thereby forming olefinc gasoline, commingling a relatively cool naphthenic oil with the heated products of the reforming step and cooling said products to a lower temperature suitable for catalytic conversionof olefins to paraflins, subjecting the resultant mixture at said lower temperature to catalytic conversion under conditions such as to effect the transfer of hydrogen from said naphthenic oil to the olefinic gasoline, thereby effecting substantial saturation of the olefim'c gasoline, and recoving the substantially saturated gasoline thus produced.

13. The process as defined in claim 12 further characterized in that finely divided catalyst for the catalytic conversion step is dispersed in the naphthenic oil which is commingled with the heated products of the thermal reforming step.

CHARLES H. ANGELL.

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