US2461540A - Process for the isomerization of a low-boiling saturated hydrocarbon - Google Patents

Description

Feb. 15, 1949.

A TTORNE Y.

Patented Feb. 15, 1949 PROCESS vFOR, THE ISOMERIZATION OF A LOW-BOILING SATURATED HYDROCAR- BGN Frederick E. Frey, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporaton'of Delaware Application October 5, 1942, Serial-No. 460,867

15 Claims. l

This invention relates to a catalytic process for reconstructing saturated hydrocarbons. More particularly it relates to the use of a catalyst which comprises a major proportion of concentrated hydroiiuoric acid and a minor proportion oi boronuoride. This application is a continuation-in-part of my copending application, Serial No. 426,627, led January 13, 1942, now U. S. Patent 2,403,649, issued July 9, 1946, which in turn is a continuation-in-part of my copending application Serial No. 323,443, filed March l1, 1940, noW U. S. Patent 2,317,901, issued April 27, 1943.

The aforementioned copending application discloses that, in the presence of substantial proportions of hydroiiuoric acid and under suitable conditions of time and temperature, saturated hydrocarbons are reconstructed to hydrocarbons of different carbon-skeleton arrangement and different boiling point Paraiiinic hydrocarbons, for example, undergo conversion to isomers and to hydrocarbons of both lower and higher molecular weights and correspondingly lower and higher boiling temperatures. I have found a marked improvement in the eiciency and utility of concentrated hydrorluoric acid as a catalyst for reconstructing hydrocarbons is brought about by including with it a minor `proportion of boron fluoride.

An object of this invention is to improve concentrated hydrofluoric acid as a catalyst for reconstructing hydrocarbons.

Another object of this invention is to provide an improved catalytic process for isomerizing normal butane to isobutane.

Another object of this invention is to produce isobutane, isopentane, and isohexanes from normal pentane.

. Another object of this invention is to produce isobutane and sohexanes from isopentane.

A further object of my invention is to effect a catalytic conversion of hydrocarbons.

Another object is to obtain conversion of a drastic type, with fracture of the carbon skeleton with consumption of only low and economical amounts of BFa as well as HF.

Other objects and advantages of this invention will be apparent from the accompanying disclosure and description and the accompanying drawing.

The present invention, broadly, comprises treating saturated hydrocarbons with concentrated, preferably anhydrous, hydrouoric acid which contains, or which has had added to it, 'a minor proportion of boron fluoride to produce hy- 'drocarbons of higher and/or lower molecular Weights than the original hydrocarbons, together with some isomers. By saturated hydrocarbons I intend to include paraiins and cycloparans, and by various modifications of my invention I can convert normal parafiins to isoparafns, particularly those having morev and/or fewer carbon atoms per molecule and, for cycloparaflins, I can change the number of carbon atoms Ain the ring, as in convertingv methylcyclopentane to cyclohexane and dimethylcyclopentane to methylcyclohexane. In one specific embodiment myv invention comprises treating normal pentane with substantial amounts of liquid concentrated hydrofluoric acid, preferably essentially anhydrous hydrofluoric acid, to which has'been added a minor proportion of boron fluoride to produce isobutane, isopentane vand higher-boiling branched-chain hydrocarbons.

As disclosed and discussed in my above mentioned copending application Serial No. 426,627, several different types of chemical reactions may be involved in the process for reconstruction of hydrocarbons. The predominating reaction types, as deduced from a consideration of reactants, products, operatingconditions, and vtheoretical aspects relating to the invention, may be exemplified as follows, as applied to saturated hydrocarbons:

(l) 2 07H10 CtHu CsHis (Hcptanes) (Hexanes) (Octanes) (2) (u) n-heptane branched heptanes (b) n-butane isobutane f (3) 2C1H1 CeHiz 2C4H1u (Heptanes) (Cyclohexane) (Butanes) (4) CuHu CHaCaHs (Cyclohexane) (Methyleyelopentane) The iirst two reactions, namely, reconstruction to produce both higherand lower-boiling parafiins, and isomerization, respectively, predominate under relatively mild conditions. The yield of cyclics, exemplied in the third equation by cyclohexane, is increased `by increasing the temperature and/or the time of reaction. Several other types of reactions undoubtedly occur in the reconstruction process; however, the above-mentioned types appear to account for most of the effects which are produced. The general term reconstruction is used herein to denote the production of one or more of the above mentioned effects and/or of other inherent advantageous effects which resultfrom the practice of my invention.

Although the catalyst used in my process contains the same two ingredients as a catalyst previously proposed by Ipatieff and Pinesfor use as an isomerizing catalyst (U. S. 2,283,142 and 2,3l8,226), the twor-catalystsare by' no'means equivalent in composition, physical characteris- 3 or activity. The cataiyst of Ipatiei and Iiies comprises a major proportion of boron fluoxnocliiied by a minor proportion of hydrofiuoric acid; it is used in a nickel lined reactor to increase .its ac* v, active temperature range for isom riaation of butano is 302`to 39a F. (i550 to 20 C l. On the other hand my catalyst comprises a major proportion of hydroiiuoric acid modied or activated by a minor proportion of boron fluoride; no nickel or other catalytic agentzis required, and the reactions may be conducted at room temperature or at .temperatures only slightly above room temperature. Mycatalyst, in its preferred form, is a homogeneous liquid solution of boron fluoride, or ,a hydroiluoric acidboron fluoride complex, in a large Vexcess of liquid hydroiiuoric acid Whereas the catalyst of lpatiei and Pines appears to bea heterogeneous mixture comprising. boron fluoride gas, .a boron uoridehydrofluoric acid complex, which. maybe at .least partly liciuid under the prescribed operating con- Citions, Aand metallic nickel which is a solid. Essentiallyno .free .or uncoinbined hydroiluoric acid is present the catalyst of Ipatie and Pines.

. An ;understanding of .sorne..aspects oi the invention .maybe .aided ,by referring to the accompangying .drawing which is .a schematic flow. diagramof .one arrangement of apparatus for .practicingA `one modication of the invention. For the. sake (of. concrete illustration, the description of the flow diagram will belimited .to the reconstruction of normal pentane. The invention is, however, applicable to many other hydrocarbons and .should be limited Yonly as specied in the appended claims.

Normal pentane may ,be introduced through iniet .1.0 to-reactor il; .concentrated hydroiiuoric acid maybe introduced through inlet i2, a mirir proportion ofboron liuoride, through in let..,|,.3, The .liquid catalyst phase and the hydrc carbon reactant phase are brought into Iintimate contachiorexample by emulsiiication, to effect reaction. rllhe proportion of boron fluoride may bein the' reuse oiabcut al tc about 30 per sent by Weight of the hydrouoric acid; yusually it should be less than about l per cent. A proportion in the range A ci about l .to 5 per cent is usually preferred .because suche composition is a very active reconstructing catalyst at `or slightly above Iroom temperature, yet the proportion of added boron -fluoride -is sufficiently lov.T that excessive costsfor replacing and regenerating the catalyst are not incurred. in general the proportion oboron luoride may be correlated with the reaction temperature, the maximum proportion being somewhat higher with decrease in temperature. 'In many instances it is desirable to add'small amounts ofboron fluorideat-various times v.throughout the course of the reaction, as at a plurality of points along the length of a longvreaction zone through which a stream of reactants is continuously passed. The relative proportions of A catalyst and hydrocarbon are, withina wide range, not critical; goed results ,are obtained using a hydrocarbon to catalyst ratio `by Weight 'in the range of about 0.1 to 3 or more, preferabl y it should be in the range ,ci -about 055' to 1:5, and in any event it is desirable to operate under conditions of temperature', pressure, and concentration such that appreciable Aamounts of 4a liguid hydrouoric acid phase is .present inv .the Areaction zone. At very low or veryhigh ratios, separation of the reaction prod uctsgfrpm' the catalyst is diih'cult.

The reaction `tern-perature for reconstructing normal pentane may be in the range of about 0 to 409 F. and preferably the process is carried out in the range of about 12S-250 F. At low temperatures the reaction rate is slow, Whereas at high temperatures Lrate of spending of the catalyst or product degradation is excessive. In

general the optimum reaction temperature is dependent upon the hydrocarbon material being treated. For reconstructing normal butane, lo and/'or normal hexane, the temperature should be about 50 to Y100" F. higher than for normal pentane.

The reaction time may vary from about 1 minute te tvro hours or more. The optimum 1,5 time varies, in general, inversely with the rection temperature. For temperatures within the above-mentioned preferred ranges the optimum time is ordinarily in the range of about 5 to 6 0 minutes. At very short times the con- 29 Version is incomplete, thus putting an unnecessarily heavy load on separating and recycling equipment, Whereas at very long times, the undesirable secondary reactions occur and. the life of the catalyst in terms of quantity of products per unit quantity of catalyst is short. Generally the tiineand temperature should be correlated to give about 7G .to 96 per cent conversion per pass for reconstructingf normal pentane; about 60 to 80 per cent per pass for reconstructing ischen- 30 tane; ,about .50 to 7 0 per cent per pass for iso merizing normal butano; and 5G to 90 per cent per pass forV reconstructing hexanes and/or heptanes. Y

As the catalyst and the reactant hydrocarbons are only slightly soluble in one another, especially at relatively low temperature, it is desirable to provide a means Aof agitation in reactor li. The means for agitation may consist of stirrers, jet inlets, or bailles, or the reactor may be in the form of a tube'of such dimensions that the flow of reaction mixture through it is turbulent. Rapidrecirculation in a closed cycle, with continuous introduction of charge and withdrawal of eiiiuents, may also be practiced.

Ifhe reaction mixture passes from reactor ll through conduit ie to separator I5 wherein by gravitational o1' centrifugal means and/or cooling it is separated into two liquid phases. The lighter or hydrocarbon phase, which contains a small proportionv of dissolved hydrouoric acid, may be passed lthrough conduit i6 to fractionator 4.1.' From fractionator H a mixture of hydrofluoric acid and low-boiling hydrocarbon material is distilled overhead and is recycled through conduit 'i8 to separator i5 and/or through conduit 43 to reactor ll. If any boron iiuoride is present in the hydrocarbon phase passed through conduit lgfgit is ,obvious that boron fluoride Will also be present in the overhead fraction passed so through conduit I8, since it is lower-boiling than hydrogen fluoride. Hydrocarbon material, free from dissolved hydrouoric acid, is passed from the bottom of fractionator il through conduit IB to deisobutanizer 253, Wherefroni isobutane is distilled overhead and is Withdrawn through outlet 2L The remaining hydrocarbon material is passed from the bottom of deisobutanizer 2t) through conduit 22 to deisopentanizer 23, wherefrom isopentane is distilled overhead and is Withdra-Wn'through outlet 2Q. At least a part of this material may be passed, if desired, back to reactor l I from conduit 2d through conduits lll and y21. `-lydrocarbon'material from the bottom of deisopentanizer -23 is passed through conduit 25 to vdepentanizer 26; wherefrom normal pentane is CFI distilled overhead and is recycled through conduit 21 to reactor I I. Isohexanes and other normally liquid hydrocarbons are passed from the bottom of depentanizer 26 through conduit 28 to rerun column 28, wherefrom a major fraction suitable for blending in motor fuel is distilled overhead and is withdrawn through outlet 3Q. This fraction may be subjected to further fractionation and puriiication, if desired. A minor fraction of relatively high-boiling material is withdrawn through outlet 3l. A fraction of intermediate boiling range may, ify desired, be removed through conduit 42 and passed to conduit 21 and reactor I I.

Most of the heavier or catalyst phase from separator I5 is recycled through conduit 32 to reactor I I. Preferably, for purification or regeneration, part of it is passed through conduit 33 to purication equipment, illustrated by iractionay tor 34. From fractionator 34 substantially pure hydrofluoric acid is distilled overhead and is recycled through conduit 32 -to reactor II. Any free boron fluoride which is present in the catalyst passed through conduit 33 to frac-tionator 34 will, of course, also be present in the overhead fraction removed through conduit 32. High boiling materialA may be withdrawn through outlet 35;- preferably however, it is passed through con duit 3B to heater 31. Heater 3l heats the material to a temperature in the range of about 100 to 600 F., usually more preferably in the range of about 350 to 500 F., whereupon fluoroorganic materials are decomposed, liberating HF. Some boron fluoride is also liberated. The heated and decomposed material then passes through conpending application Serial No. 769,980, filed August 21, 1947.

It will be appreciated that the drawing is only diagrammatic, and that suitable specic equipment for the practice of any modification ofrmy invention may be readily designated and designed by one skilled in the art. Although the description of the drawing has been limited primarily to a description and discussion of the reconstruction of normal pentane, the same principles which are involved may be readily applied to a reconstruction oi other specic saturated hydrocarbons or hydrocarbon fractions, such as fractions secured from natural or straight-run gasolines, particularly the recycle of fractions of higher and/or lower boiling points, or ranges, than the hydrocarbon material in the net charge.

A few of the many aspects of my invention are illustrated by the following examples, which are illustrative but not necessarily limitative of the invention.

Example I A series of test runs for reconstructing hydrocarbons were made in .a closed 18 liter steel reactor having a motor driven stirrer. The procedure was to charge predetermined quantities of anhydrous hydrofluoric acid, boron fluoride and hydrocarbon material to the reactor, to adjust the reaction temperature by means of a heated water or oil bath surrounding the reactor, to stir the mixture for a suitable reaction time, to withdraw the reaction mixture, to separate the hydro vcarbon products from the catalyst, and to deter- 35 mine the composition and properties of the prodduit 38 to flash chamber 39, wherefrom hydroucts. The following data were obtained:

Test no l 2 3 4 5 6 Hydrocarbon Charge. n-pentane n-pcntane n-pentane iso-pentanc n-butane n-butane BFH, weight per cent of HF 2. 7 .9 S. 5 8 2. 8 Temperature, F 77-90 10G-115 73-165 122-126 13S-144 ll-174 Time, min 34 19 10 225 48 45 Composition 0I product, weight per cont: i

propane 0 0 2A 1 1.1 0 0 lsobutane.. 24. 3 31.0 36. l 34. 2 4. 8 10. 8 n-butane l. 2 3. 2 9. 9 6. 7 95. 2 8S. 7 isopentane. 19. l 20. 4 20. 9 20. 5 n-pentaue.. 29. 8 15. 5 5. 8 3. 7 0 0. 5 hexanes and heavier 25. 6 29. 9 25. 2 33. 8

Total Conversion, Weight per cent 70. 2 84. 5 94. 2 70. 5 4. 8 11.3

Composition of hexanes and heavier, volume per cen z 12 25 5 38 31 25 18 11 l0 14 ll Pentane free aviation fraction (336 F. cut

point):

Yield, volume per cent hexanes and heavier i 97. 6 '95. 2 97. 3 97. 9 Gravity, A. P. I 78.0 Y72. 2 76. 6 77. 9 Octane No., A. S.

Clear 71. 8 71.8 68.0 73. 8 1 ce. TEL 85. 8 85.8 87. 7

iluoric acid and boron iiuoride are withdrawn overhead, and recycled through conduit 32 to reactor il, and a high-boiling residue or sludge is withdrawn through outlet 60. Hydrogen fluoride may be introduced to conduit 36 and/or chamber 39 during the decomposition of the high boiling catalyst complex and polymer to increase the amount of BFa released in molecular form. This procedure for catalyst regeneration is f moreA It is evident from this data that my invention is broadly applicable to the conversion of paraffin hydrocarbons to isomers and/cr to hydrocarbons of higher and/or lower molecular weights. Recycling of undesired products may be employed to increase the ultimate yields of desired products.

Example II In another test run, normal hexane and con.-

thoroughly described, and is claimed, iny my co- T5 centrated hydrofluoric acid. to which has been '7 added-52 weight per cent'heren'ueride were shaken together in a closed steel pressure vessel forll minutes. The temperaturewas maintained at 180 F. by an electric heater. The resulting hydrocarbon material was found to have the following composition:

The total conversion in this run was 58.5 per cent 'of the original normal hexane. It is evident that the principal reaction occurring in this test run was isomerization of normal hexane to isohexanesl including neohexane and diisopropyl. It is further evident from this test run that my invention, in one oi its modifications, may be applied to the production of high yields of neohexane and diisopropyl :from less highly-branched hexanes. Such a modication comprises reconstructing normal hexane and/or methylpentanes in the presence of concentrated hydroliuoric acid containing a minor proportion of boron fluoride, separating neohexane and/or diiso-propyl from the'- resulting reconstructed hydrocarbon material and recycling other hexanes and heavier hydrocarbons to the reconstructing step.

Example III In anothertest run, normal hexane wasreconstructed under conditions similar to those of Example` II except that the temperature was 'i 260 F. andthe time was 35 minutes. The resulting hydrocarbon material was found to have the following composition:

Hydrocarbon: Weight per cent Propane 13.8 Isobutane 27.6 n Butane 9.0 Isopentane 18.3. n P entane 4.5 Ischexanes 14.5 n Hexane 3.9 Heavier 8.6

The total conversion in this run was 96.1 per cent of the original Vnormal hexane. The conditions for this run Vwere'more drastic' than will usually be desired, since it is not usually desirable to produce such large proportions of propane. It is evident from this run however that at a some.-

what lower temperature and/or a shorterreactionV tier-,1s of my inveniionniay be practised Witheet departing from the spiritof'the disclosure andV discussion or from the scopeof the claims.

I claim:

i. A process for converting normal pentane to other parai'ln hydrocarbons including at least one isomeric pentane, which comprises subjectinga substantially saturated hydrocarbon material comprising normal pentane to the action of a catalyst consisting essentially of liquid concentrated hydroiiuoric acid and boron fluoride in an amount between about 1 and about per-cent by weight of said hydrofluoric acid at a reaction temperature between about and 25,0? F. vunder f a pressure suiiicient to maintain said hydrofluorlc acid in liquid ,phase for a time suicient to eect a conversion of at least 50 per cent of said normal pentane to other parafln hydrocarbons including at least one isomeric pentane.

2. A process for converting normal butano to other paraffin hydrocarbons including isobutane; which comprises subjecting a substantiallysaturated hydrocarbon material comprising normal butano to the action ofv a catalyst consisting essen-y tially of liquid concentrated hydrouoric acidandboron fluoride in an amount between about 1 and about 5 per cent by weight of said hydroiiuorc acid at a reaction temperature between about lo() and 256 F. under a pressure sufficient to maintain saidhydrofluoric acid in liquid phase for a time suflicient to effect a conversion of at least 5) per-cent of said normal butane to other` parain hydrocarbons including isobutane.

3. A process for the production of neohexa-ne from a hydrocarbon other than neohexane and containing from rive to six Vcarbon atoms per molecule, which comprises passing such a paraiin hydrocarbon to a conversion zone as the sole net hydrocarbon charge, charging also to said conversion zone parailin hydrocarbons of lower molecular weight having at least four carbon atoms per moleculeY and recovered from effluents of said conversion, charging further to said conversion zone parain hydrocarbons of higher molecular weight and recovered from eiiluents of said conversion, contacting said para'in hydrocarbons in said conversion zone at a conversion temperature with liquid hydroiiuoric acid to which has been added not more than about ten per cent by weight of boron fluoride to effect a conversion of a large part of said net hydrocarbon charge to some other hydrocarbons including neohexane, recovering from efluents of said conversion zone neohexane so produced, recovering also parafdns of lower molecular' weight and having at least four carbon atoms per molecule .and returning same to said conversion zone, and recovering further low boiling parains of higher molecular weight and returning same to said conversion Zone.

4. A process for converting normal pentane into isobutane, isopentane and isohexanes, which comprises subjecting liquid normal pentane at a conversion temperature to the catalytic action of ay liquid catalyst consisting essentially oi' concentrated hydrogen iluoride and boron triiiuoride in an amount between about 1 and about 5 per cent by Weight of said hydrogen fluoride and under a pressure suiiicient Vto maintain said catalyst and said hydrocarbon as liquids fora time su'icient to effect a substantial conversion of normal pentane to isobutane, isopentane and isohexanes, and subsequently recovering from eiuents of said conversion a fraction comprising at least oneof said isoparailins so produced.v

y5.4% process -for isomerizing .normal pentime- 9 to produce isopentane, which comprises subjecting normal pentane to isomerization under isomerization conditions and in the presence of a liquid catalyst consisting essentially of concentrated hydroiluoric acid and boron triiluoride in an amount between about 1 and about per cent by weight of said hydroluoric acid and under a pressure suflicient to maintain said catalyst and said hydrocarbon as liquids to form isopentane, and recovering from eiiiuents of said isomerization isopentane so produced.

6. A process for the conversion of a normal paratlin having from four to six carbon atoms per molecule to an isoparain having the same number of carbon atoms per molecule and an isoparafiin having a different number of carbon atoms per molecule, said different number of carbon atoms per molecule ranging from four to six, which comprises subjecting said normal paraffin with intimate mixing to the -action of a liquid conversion catalyst consisting essentially of liquid hydrofluoric acid and boron triuorde in an amount between about 1 and 5 per cent by weight of said hydrofluoric acid under conditions such that said catalyst and said normal pararn are maintained as liquids and conversion of said normal paran to said isoparaiin is the principal reaction, and recovering from the reaction mixture isoparaflinS-so produced.

'7. A process of isomerizing a normal paraffin 3.

having at least 4 carbon atoms per molecule, which comprises subjecting said normal paraffin to the catalytic action of 0.1 to 3 times its Weight of liquid concentrated hydrouoric acid as the eiective catalyst, together with boron fluoride in tion by reactions comprising isomerization and disproportionation, said saturated hydrocarbon fraction containing at least one saturated hydrocarbon of at least 4 carbon atoms per molecule, which comprises subjecting said saturated hydrocarbon fraction to the catalytic action of 0.1 to 3 times its weight of intimately admixed liquidY concentrated hydroiluoric acid, together with boron trifiuoride in an amount in the range of about 0.1 to about per cent by weight of the hydrofiuoric acid, as the effective catalyst at a conversion temperature and under a pressure sufcient to maintain said hydroiiuoric acid and said hydrocarbon in liquid phase for a time suflicient to effect a substantial conversion of saturated hydrocarbons contained in said hydrocarbon fraction into other saturated hydrocarbons including at least one isomer of a saturated hydrocarbon so converted, and subsequently recovering from effluents of said isomerization a hydrocarbon fraction comprising an isomer of said saturated hydrocarbon so produced.

9. A process for converting saturated hydrocarbons contained in a saturated hydrocarbon fraction by reactions comprising isomerization and disproportionation, said saturated hydrocarbon fraction containing at least one saturated hydrocarbon of at least 4 carbon atoms per molecule, which comprises subjecting said saturated hydrocarbon fraction to the catalytic action of 0.1 to 3 times its weight of intimately admixed liquid con- Y i l0 v centrated hydroiluoric acid together with boron trifluoride in an amount in the range of about 0.1 to about 10 per cent by Weight of the hydrofluoric acid as the sole catalytic material at a conversion temperature and under a pressure suilcient to maintain said hydrofluoric acid and said hydrocarbon in liquid phase for-a time between about 1 minute and about 2 hours and sufficient to effect a substantial conversion or" saturated hydrocarbons contained in said hydrocarbon fraction into other saturated hydrocarbons including at least one isomerof a saturated hydrocarbon so converted, and subsequently recovering from eiuents of said isomerization a hydrocarbon, fraction comprising an isomer of said saturated hydrocarbon so produced. 10. A process for converting a parafiin hydrocarbon contained in a saturated hydrocarbon material into an isomeric hydrocarbon, which comprises subjectinga liquid saturated hydrocarbon material containing at least one low-boiling par afn hydrocarbon of at least 4 carbon atoms per molecule to a conversion ytemperatur-e in the presence of about 0.1 to3 times its weight of intimately admixedliquid concentrated hydrouoric acid together with boron uoride'in an amount in the range of about 0.1 to about 10 per cent by weight of the hydroiluoric acid as the essentialcatalyst under a pressure suilcient to maint-ain said hydrofluoric acid and said hydrocarbon in liquid phase for a time suicient to convert said paramn hydrocarbon into an isomeric hydrocarbon.

11. A process for converting a pentane into isobutane, an isomeric pentane, and isohexanes, which comprises subjecting a liquid 'pentane at a conversion temperature to the catalytic'action of liquid hydrogen fluoride together with betweenv about 0.1 and 5 per cent its weight of boron trlfiuoride as the essential catalyst under a pressuresuilicient to maintain said hydrouoric acid and said hydrocarbon in liquid phase for a time sufficient to effect a substantial conversion of said` pentane to isobutane, an isomeric pentanaand isohexanes, and subsequentlyV recovering from effluents of said conversion a fraction comprising at least one of said isoparafns so produced.

12. A process for eecting disproportionation and isomerization of a low-boiling paraffin hydrocarbon having at least 5 carbon atomsv per molecule, which comprises subjecting a liquid saturated hydrocarbon material comprising such a paraiiin hydrocarbonat a reaction temperature not greater than about 250 F'. to the catalytic action of about 0.1 to 3 times its weight of intimately :admixed liquid hydrouoric acid together with boron fluoride in an amount between about 0.1 and Ey per cent by weight of the hydroiiuoric acid as the essential catalytic material under a pressure sufficient to maint-ain said hydroiiuoric acid and said hydrocarbon in liquid phase for a time suilicient to effect isomerization and a substantial disproportionation of said paraiin hydrocan bon, forming parain hydrocarbons having fewer and more carbon atoms per molecule, and subsequently recovering from effluents of said reaction a fraction comprising at least one of said parailln hydrocarbons so produced.'

13. A, process for the isomerization of a lowboiling saturated hydrocarbon having from four to six carbon atoms per molecule to produce an isomeric saturated hydrocarbon having the same number or carbon atoms per molecule while contained in a saturated hydrocarbon fraction, which comprises subjecting said saturated hydrocarbon fraction with intimate admixing'to the .action qf a liquidwnversion catalyst @Qnsyislting essentially of concentrated vliquid khydrouori acid .and @Oren triuoride in' an amount between about Iaiidi per cent by weight of said hydro'luoric acid, thehydrocarbon to catalyst ratio by Weight'being in vtherange of aboutl to vabout 3, at a conversion temprature between about and` about 4005FMunder a pressure suffi# cientto maintain said catalyst and'said hydrocarbon as liquids and for a time between about 1 minute and about 2 hours andsuicient to eiect as'ubs'tantial amount Yof hydrocarbon conversion as evidenced by a Substantial extent of. change in the carbon skeleton of said saturated hydrocarbon having from four to six carbon atomsk per molecule, and subsequently recovering from effluents of said isomerization a hydrocarbon fraction comprising an isomer of said saturated hydrocarbon so produced.

14. A process for isomerizing a low-boiling oycloparafn hydrocarbon having at least six carbon atoms per molecule to produce a cycloparain having the same number of carbon atoms per molecule and a diierent number of carbon atoms lin the nucleus while contained in asaturated hydrocarbon fraction, which comprises `subjecting said V.saturated hydrocarbon fraction -to isomerizaticn under isomerization conditions in the presence of 0.1120 3 times its weight of intimatelyadmixedliquid concentrated hydrouoric acid together with boron triuoricle in an amount between about 0.1 and per cent by weight of the hydrogen fluoride as the essential isomerization catalyst under a .pressure sufficient to maintain said hydrouoric acidand said hydrocarbon in liquid phase for a time between `about 1 minute yand about 2 hours and sucient to eiect a substantial extent of con-V Version of said cyoloparain hydrocarbon to a cycloparain hydrocarbon isomeric therewith, and recovering from eiuents of said isomerization Aa hydrocarbon fraction comprising an isomeijic cycloparain hydrocarbony so produced.

15. A process` for isomerizingv a low-boiling 12 cysloreran hydrocarbon having ,at easter ACfrffion atoms per ,molecule .t9 Dradt acre aan navman@ Sr-i e beiwofL atoms Per 1119112,.0.1.1.1r.arida@affermineitherA Qi carton ma @relocation hydro@ therewith, andrew/@ring tram. arriva,-.. mztol 51 hyparb?. lt ,09.1.3221 .g an isomeric cycloparain hydrocarbonhsdproduced.

c FBEDElCE-EREY- REFERENCES CIT-En The forearms references are of recentie the leof this patent:

UNITED STATESxP-.Trl

Germany May 23, 1931

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