US2662103A - Production of paraffins - Google Patents

Description

Dec. 8, 1953 M. P. MA'ruszAK PRODUCTION oF PARAFFINs Filed Dec. 18, 1945 2 Sheets-Sheet l Dec. 8, 1953 A M. P. MATuszAK 2,662,103

PRoDUcTIoN 0F PARAFFINS Filed Dec. 18, 1945 2 sheets-sheet 2 v f lsoBUTANE coNDENsER LAYER Di lLI F' 4| cooLER Lx y v 43 -"j\ HF LAYER T" 4o INVENToR.

FIG 2 ME MATuszAK BY MMM (WMU ATTORNEYS Patented Dec. 8, 1953 A PaoDUc'rroN or PARAFFINS Maryan PMatuszak, Bartlesville, Okla., assigner to Phillips Petroleum Company, a corporation of Delaware Applicationpecember 1s, 1945, serial No. 635,764`

This invention relates to the production of paraflins from isopentane and more particularly to the production. of isobutane and parains heavier than isopentane from isopentane.` .Still more particularly, it relates to production of iso-v butane and paraflins heavier than isopentane from isopentane by a process involving .simultaneous disproportionation and alkylation of isopentane with a low-boiling aliphatic olefin having at least 3 carbon atoms per molecule and with a catalyst consisting of liquid substantially anhydrous hydrofluoric acid either alone or promoted with up to per cent of boron uoride based on the total Weight of catalyst.

This application is a continuation in part of my co-pending application, Serial No. 467,872, filed December 4, 1942, now Patent 2,399,368 issued April 30, 1946.

The principal object of this invention is to increase the total yield of higher-boiling and normally liquid or gasoline-range parains produced from a given weight of an oleflnic reactant in hydrouoric acid-catalyzed conversion of isopentane to heavier parafns.

Another object is to produce high yields of isobutane and isohexanes from isopentane and an olefin in the presence of liquid substantially anhydrous hydrofluoric acid allrylation catalyst.

Another object is ,to provide a process of the foregoing type wherein isoparains heavier than visopentane and having high octane rating are produced in greater overall yield fromA given quantities of isopentane and aliphatic olefin.

Numerous other objects of the present invenv tion Will be apparent to those skilled in the art from a consideration of this specication taken in conjunction With the accompanying drawing wherein Fig. 1 portrays diagrammatically one arrangement of equipment which may very advantagev ously be employed in carrying out the present invention, and Y Fig/2 portrays a modification' ofthe reaction .l vessel wherein the reaction is' carried out in a combined reaction-fractional distillation column. I have now found that by the employment of suitable proportions of reactants and of suitable reaction conditions which are fully detailed here- 4 claims. (Cl. 26o-683.4)

under certain yconditions a surprisingly large proportion of the isopentane is converted to isobutane and isohexanes concurrently With primary alkylation of a minor proportion of the isopentane, so that yields of hexanes and higherboiling gasoline hydrocarbons of at least 400 and even as high as 500 or more per cent by Weight of the olefln'charged are obtained.

The isobutane produced by the disproportionation may be used as feed stock for other processes, as fora process in which it itself is alkylated. I

' have found that in the interest of an increased yield of higher-boiling or gasoline hydrocarbons (C6 and heavier) from the disproportionationalkylation, it is preferable to remove the isobutane from the reaction mixture as soon as possible after its formation, 'and that it is preferable not to recycle the isobutane to this particular process. On the contrary, better yields of higher octane hydrocarbons are obtained if the isobutane is'alkylated With an olefin in a separate zone.

ASubstantially immediate removal of the isobutane as soon as it is formed may be accomplished in any suitable manner. For example charging and Withdrawal rates and residence time in a continuous process may be so adjusted that the reaction mixture is promptly Withdrawn from the reaction zone and passed to suitable steps for the rapid removal of isobutane. It is desirable to avoid alkylation of isobutane in the disproportionation-reaction Zone. Removal of isobutane from the reaction Zone is additionally desirable because it facilitates the desired reaction, namely, disproportionation In many cases it will be found desirable to effect substantially immediate removal of isobutane from the seat or center of reaction by conducting the reaction in a fractional..distillation column.

The molar ratio of isopentane to olen charged to the reaction zone should be at least 5:-1 and preferably is` at least 7:1.` It may range as high as 10:1 or even higher, up to 20:1. This ratio has reference to the external feed, i. e., to the total isopentane and olefin introduced to the reaction zone. This is to be distinguished from the internal molar ratio, i. e., the molar ratio of isoparaiiin to olefin in the reaction zone itself. As

Will be obvious to those skilled in the art, because of very rapid consumption of olen, the internal molar ratio of isoparaflin toolefin may be exceedingly high, for example as high as :1 or even 1000: l. In the case of continuous operation, the 'external molar ratio .of isopentane to olen may be determined from the relative amounts of isopentane and clen charged at any instant. In batch type operation, where the oleiin is usually added over an extended period of time t the reaction zone containing the isopentane and the hydrouoric acid catalyst, the molar ratio reerred to above is that of the total isopentane charged to the total olein charge.

The amount of 'hydrofluoric acid employed Yas catalyst may vary within Wide limits. Ordinarily it will be such that the volume of hydrofluoric acid is at least equal to that of the hydrocarbons present in the reaction zone. Usually thehydrofluoric acid will be present in such amount that it will form a separate acid phase, thereby requiring provision of suitable means for agitat ing and securing intimate contact between the hydrocarbon phase and the catalyst phase. :The volume ratio of hydrofluoric acid to hydrocarbons may range from 1:10 up to 2:1.

. The reaction temperature may range from 40 to 3Go" F. Temperatures below 40 F. are disadvantageous and are lseldom employed. The preferred temperature range is from lilOto Y20.0 F. Employment of temperatures Within this range gives considerably higher'yields-andis preferred.

The pressure in the reaction zone .should be sufficient to maintain the hydrocarbons and the hydrofluoric acid in liquid'ph'ase.

Ordinarily I employ a catalyst consisting of substantially anhydrous hydrofluoric acid. This catalyst should preferably not contain 7more than a few per cent o'f Water., vsay not over A5 per cent. If the hydrocarbons available contain entrained or dissolved Water to any substantial extent, appropriate measures should be .taken to kremove such water prior rto charging the hydrocarbons to the reaction yzone, .so that the hydrocarbons ,charged are essentially anhydrous. This prevents the accumulation of water .in the hydroluoric acid which has ,a very great alnity .for Water. Accumulation of Water in the catalystfis undesirable because tit destroys its activity rand :requires that .an objectionably ,large proportion 'of the catalyst be continuously rejected from vthe system since .hydrofluoric acid andwaterlforman azeotrope which cannot be -resolved economically 1in vany way'novv known to the art.

In some cases, it maybe desirable toemploy a vcatalyst consisting of substantially anhydrous hydrofluoric acid promoted witha knnlnor proportion of boron uoride. For example, the 'amount of boron fluoride employed may irange from va trace up to but not exceeding 10 Weight per cent of the total catalyst. tion of hydrouoric acid and causes the reaction to proceed .somewhat more expeditiously. However, the expense connected with theuse of boron iiuoride and Vrecovery thereof .may make .its :employment unwarranted.

As the olefin I may use any Ylow-boiling aliphatic olen having at least 3 caxbonatoms 'per molecule. Thus .l may use rany of the C3 to :Cs oleiins including propylene, any of .the butylenes and any of the amylenes. Mixtures of any'two or more of the C3 Vto VCs oleiins maybe used.

The 'reaction time .may vary within quite Wide limits depending upon the conditions underwhich the reaction is carried out. Normally .the reac- .tion time will not be less than 5 minutes nor greater than 1 hour. The hydrocarbons `should be held in the reaction zone long enough to :accomplish substantially complete consumption Yof the oleiin and formation'of the desired .products to the desired extent. It is believed that theol'en Boron fiuoride promotes the acis consumed substantially entirely by allrylation of a minor proportion of the isopentane. The reaction is characterized by the formation of isobutane from isopentane in an amount ecual to at least 150 and occasionally as high as 250 Weight per cent of the olefin charged. It is further characterized by the formation of Ce and higher parainsfrom isopentane tothe extent of at least 400 vand occasionally as high as 5Go or more weight per cent of the olen. The yield of Apentane-free liquid hydrocarbons produced by theprocess 'of the present invention is at least 130 weight per cent and often as high as 200 or even ..230 `Weight per cent of the theoretical alkylationyield. In most cases at least 30 volume per centofthe Ca and higher paranins produced by Ithe process arer hexanes (isohexanes) which are very valuable. In addition my process yields substantial percentages of each of higher branched chain paraiiins, namely, heptanes, octanes, nonanes and .decanos and heavier.

The major reaction occurring in the process Aof Vthepresent.inventionis disproportionation of the isopentane to isobutane and lto heavier than isopentane.

Aisoparaffins A 'minor reaction `is lthe alkylation of a portion of the isopentane With the olefin employed. The olefin acts to alkylate a minorproportion only of the isopentane. The disproportionation of the isopentane takes place .very expeditiously intheprcsence cf the reactants rnotesth'e disprcportionation of the remainder of the isopen'tane .'to' a 'very pronounced degree.

The process of my inventionmay `very advantageously be `carried out in a combination reaction-fractional distillati-on column to which the 'isopentane and `the olefin in the `proper external imolarratiofmay be charged continuously. Liquid substantially anhydrous hydrofluoric acid may be injected continuously at a point or several 'points of the column. This hydrouoric acid may serve as the reux for the column. The bottom 4of the vcolumn is reboiled in the usual way. The yolefin may be introduced with the isopentane or .at another point in the column. It may be introduced at Aa multiplicity of points along the column. Since the olefin is substantially immediately consumed by reaction none goes out in the overhead vapors. The overhead from the column 'is an azeotrope of isobutane and hydrogen uoride. This mode of operation is especially advantageous because the isobutane formed by 'disproportionation is immediately removed from the zone of reaction by fractional distillation. The overhead vapors of isobutane and hydrof1uorio-acid may be condensed and the resulting liquid condensate .subjected to layer formation. The isobutane layer is withdrawn from the system and may be 'passed to a separate alkylation step wherein 'it is alkylated with an olen. The acid layer is recycled to one or more points of the column as a source of hydroiiuoric acid for the reaction and as a redux for the column. The column `may be operated under any suitable low super-atmospheric pressure which is sufficient tn hold the temperatures in the column at the de- Isired level. The zone of the bulk of the reaction should be between 40 and 300 F. and preferably between and 200 F. The top temperature 'of vthe column will be the boiling point of the isobutanehydrouoric `acid azeotrope under the column pressure; The bottom temperature should be at least suiciently high to insure substantially complete removal of isopentane from the withdrawn kettle product so that the isopentane charged to the column is not allowed to escape therefrom but is held therein until it is converted to higher and lower isoparafns.

Where the reaction is conducted in a fractional distillation column in the manner just described, the amount of hydrcfluoric acid present must be suicient to form a separate liquid acid phase in the major reaction zone in the column. Although at times it may be desirable to provide special means for attaining intimate contact between the acid phase and the hydrocarbon phase wherever they are present in the column, ordinarily the bubble trays or column packing will provide the necessary intimacy of contact. However, if desired, additional provision may be made for obtaining such Contact. The selection of suitable means for accomplishing this result will be obvious to those skilled in the art.

The bottoms product from the reactor-,fractionator is treated in any suitable manner to recover the valuable products contained therein, namely, the parains boiling above isopentane. If an acid phase is present, this bottoms product is passed to the usual settler where the hydrocarbon is drawn oil separately from the acid phase, which is recycled to the column.

In Fig. l of the drawings, isopentane charge'L via line I to reactor 2. Olein enters the system via line 3; hydrcuoric acid enters by line if it is desired to use a small amount oi boron fluoride as a promoter, it may be fed in via line 5, The olen maybe admixed with the hydroiluoric acid prior toV entry into 2; but preferably it may be fed in separately asv via line l or it may be fed in admi'xture with the iscpentane as Via line Reactor 2 is provided with the usual means for maintaining the desired ternperature therein and for obtaining the desired degree of contact between the acid phase and the hydrocarbon phase. The reactionk eiiluent is passed via line 5I to settler 8 from which the hydrocarbon layer is fed via line 52 to deisobutaniaing column 3. rEhe acid layer is withdrawn via line 53 and recycled via line 5d to reactor 2. Ordinarily a suitable portion or" the acid layer is continuously rerun as in unit Iii prior to recycling. The portion to be rerun is passed via line 55 to rerun unit Il) (which is of known type) and the rerun HF is returned Via line 56 to line i and reactor 2.

The overhead fraction from deisobutanicing column may be passed directly via lines 5l, 5S and 52 to a separate alkylation unit I i wherein it is alkylated with an olefin using hydrofluoricacid as the catalyst. Ordinarily this overhead fraction will contain substantial proportions of hydroi'luoric acid. Removal of such hydrofiuoric acid is not necessary prior toalkylation in unit I i. If desired, however, the overhead from column 9 may be fed to unit I2 and/or unit i3 for rem-oval of hydroiiuoric acid and light gases such aspropane and lighter, respectively. Hydroiiuorie acid separated in unit i2 may be recycled via line It. The thus puried isobutane be fed toralkylation unit II. tageous to do so, there may be occasions when it will be desired to recycle the isobutane derived from the overhead. of column 9 to the reactor 2. rhis may ber done by means or" lines I5 or it.

The isobutane overhead traction from column- While it is distinctly disadvan-v Y 6 wherein hydrofuoric acid may be removed in known manner. The thus puried isobutane may be-fed to alkylation unit I I by means oi lines 6d, 6I and 62. The separated HF is discharged from unit I2 via line 64 whence it be discharged from the system via line 65 and/or recycled to reactor 2 Via line ld. Alternatively the isobutane leaving unit I2 via line Gti may be fed via line t3 `into separation unit I3 wherein light gases namely propane and lighter are separated in known manner. The light gases are discharged from unit I3 and the system via line 5E. The so puried isobutane leaves unit I3 via line d'1 and is fed Vthereby and by line 62 to alkylation unit i l.

If desired the isobutane overhead fraction from ycolumn 9 may be passed via lines 53, 6I to unit I3 for the separation of light gases only, the resulting isobutane free from such gases as propane and lighter thence being passed via lines 6'! and'62 as before.

Extraneous HF is fed to alkylation unit I I ria line 68 and olefin is fed thereto via line The bottoms product from column 9 is fed via line 10 to deisopentanizing column I? which removes overhead the unreacted isopentane. This isopentane is withdrawn via line 'Ei and may be recycled to unit 2 via line I t. -If desired a portion of the overhead from column l? may be discharged from the system via line i2. The bottoms product from column il consists of paranns heavier than isopentane and contains not only the alkylateformed in unit 2 but also the Ce and heavier paraiiins formed by disproportionation of isopentane therein. This product may be treated in any suitable manner to recover its componente, for example, it may be passed via lines 73, 'M and I5 to fractionation system it for separation into several high octane fractions as ind"- 'cated YIi desired, a portion or all of the C@ and heavier bottoms fraction withdrawn trom column I1 via line 'E3 may be withdrawn from the system via line In many cases it may desirable to pass the bottoms product from line 'F3 -through lines 'I4 and 'il to a column E@ wherein the isohexanes are separated overhead via line "i8 from. the heavier material which is withdrawn as bottoms product via line '19. This bottoms product may conveniently be fed from line 'i9 through line 'I5 to the fractionation system. it for further resolution into the desired fractions thereof.;

If desired, the isohexanes fraction separated as overhead in column 2li may be fed via line 'it to an alkylation unit 2l wherein it is alkylated with olefin introduced via line 8-5 using introduced via line 8l' as the catalyst.

The alkylate-containing hydrocarbon miXtiu-e formed in units II and ZI may if desired be fed via lines 22 and 23 respectively to the common fractionation system I9.

Fractionation system i3 is of a type well known to the art and may conveniently comprise a series of fractional distillation columns. If the isohexanes were. not previously removed by the use of column 2Q they are separated in system i9 as a fraction withdrawn via line 82.. The isoheptanes may similarly be withdrawn as a separate fraction via line S3. The octanes and heavier may be withdrawn via line 84.

In Fig. 2 of the drawings, there is portrayed equipment for carrying out the reaction o the present .invention in a fractional distillation column 30. Column 3S is equipped with the usual bubble trays as indicated by the dotted linesand with the usual reboiler 3 I. The isopentane either L cy itself or in adinixture with the olen is introduced at an intermediate point in the column, usually around the midpoint, by means .of lin-e 32. Optionally the olen may be separately introduced at one or a plurality7 of points which may be below the point of isopentane entry as Yshown in the drawing, or which might in certain `cases be above the point of isopentane entry. For this purpose line 33 and associated injection lines may be provided. The hydrofluoric acid in liquid form .s

is introduced via line 34. The overhead vapors consisting essentially of isobutane and hydrofluoric acid are removed Via line 35, cooled in condenser 33 to liqueiy there, and the resulting liquid condensate subjected to layer separation in settler 37. The isobutane layer is Withdrawn from settler 3? by line The Aacid layer `is drawn oi by line 3S and is recycled via line 39A for admixture with incoming fresh hydrouoric acid in line 3s. The reboiled bottoms product, consisting essentially of parafns boiling valcove isopentane, is fed via line le to settler lll when aseparate acid phase is present. The hydrocarbon layer is Withdrawn via line i2 and fed to a recovery system which may be similar to that shown in Fig. l or any .other fractionation system. The acid layer is withdrawn by line 43 and recycled via lines 39 and 33A to line 34 and to column 3'3. If the bottoms product in line 40 vdoes not contain a separate phase of hydrofluoric acid, it may be passed directly via line it to the recovery system. It is often desirable to cool the Ibottoms product flowing in line @il in order to get a better separation in settler IH. For this purpose cooler may be provided.

While it is generally preferred to re-introduce the hydroiiuoric acid flowing in line 39 to the top of column Si? by means of lines 33A and 34, I may, as is indicated by Fig. 2 of the drawings, introduce a portion ci this recycle at other points in column 9. For this purpose line 55 Aand associated inlet lines Lli, t3, l-El, 5e and 59A may be employed.

The following examples are illustrative of some of the many aspects of the invention but are not necessarily limitative.

Examples l' to VI Data for several batch-type runs Afor the conversion of isopentane in the presence of hydrofluoric acid, using various olenns, are presented together, for the sake of brevity and conciseness, in the following tabulation.

In the run with propylene, Example I, the amount of isobutane formed was not determined, but it was probably approximately molecularly equivalent to the yhexanes (isohexanes), which constituted over S per cent of the liquid product. This run was made at an insuiciently high temperature for optimum results, but it is clear that a high extent of disproportionation occurred in spite of this fact.

Among other things, it may be noted from these data that the yield of depentanized liquid product was much higher than that to be expected from ordinary alkylation, being as high as over twice the theoretical alkylation yield computed on the basis of one molecule of olein reacting with one molecule of isopentane. Yields even higher than those shown are obtained at relatively higher temperatures, such as temperatures in the preferred range of 100 to 200 F. With respect to the two runs made with isobutylene, the yield was highest in the run that was made at the relatively higher temperature. In all these runs', more .than one .molecule of isopentane reacted per molecule -of olefin to 'give higher-boiling parafiins; indeed, in the higher-*temperature run with isobutylene over :five molecules of isopentane reacted per molecule of olefin. Since oleiins, because of their relatively greater readiness to react chemically, are in general more valuable than the corresponding parains, a major advantage of the disproportionation- -alkylation here exemplified is obvious.

Disproportio-nation-alkylation of isopentane Example I II i III 'IV V VI Olefm 03H6 -CiHa i-C4H3 1-C4Hs 2-C4Hrs 05H10 Temperatllr0,` F- (i5-79 i -(i4-86: 38-61 66400 I 68-102 -73`100 Reaction time, min 35-70 l0-30 l 10-30 i l0-30 10-30 l 9-31 Isopentane/olefin A (mol.) .(feed) v. 7, 25 8. 75 7. 62 8. 31 '7..5 E 10. 2 Hydrocarbons/HF ol, 7.6 l1 1 'l l 'Iso'bu'tane Iormcd, f

Weightperceut ci olen 261 200 '155 187'` 165 Peutaue-frec liquid 2 product:

Yield- Weight percent of olen 406 535 443 '405 l 445 437 Weight peri cent of theoretii cal Aallrylation yield 136 234 194 177 195 216 Composition, vol. percent:

Eemnes." 30. 7 45. 2 42. 3 37. 7 41.4 49. 5 Heptaues 8. 8 10.2 9. 0 5.1 6, 7 7.5 Octanes 41.7 5.8 11.6 6.4 7.7- 3.4 Igonanes l 2%7). 3 g 37. 0 32. 2 21. 9 ..ccaues .5f 15.4 Heavier 3.4 2. o 4. 3 138 12- 0 2. 3

Total 100.0 100. 0i '100.01 100.0 100. 0 100.0

Aviation-'gasoline I fraction: f

Cut point, F.. 338 .289` 289 284' 293. 295 Yield,

ceut 81.4 76. 2 80. 7 S4. 3 78.0 Reid vap pressure, lb 3. 2 4. 65 4.60 4. 45 4. l0 5.15 Gravity, APL 71. 2 75. 6 '75. 2 74. 6 73. 7 76. 4 ASTM distillation, F.-

First drop.. 138 143 143 142 145 140 10% evap 173 153 155 155 161 150 50% evap 213 175 177 183 191 166 evap 274 264 273 271 268 284 End point.. 344 334 328 321 336 332 ASTM octane 0 cc. TEL. 75. 0 75. 0 76. 2 74. 6 79. 2 72. 2 l cc. TEL-. 86. 3 88.7 90.1 87. 7A 89. 3 86. 3 Total products, weight percent of olefin .f 796 643 500 632 602 In the above tabulation two figures are given for temperature. lThe first figure is the ternperature at the start of the reaction, and the second figure is the temperature at the end of the reaction which is exothermic. Likewise, two numbers are given for reaction time. These iigures give the shortest and the longest times that the olen was inthe reaction zone. These were batch-type runs in which the olefin was added lgradually over an extended period of time.

asesinosw 9 tion unit such as unit H in Fig. 1, preferably in the presence of hydrofluoric acid as catalyst.

This procedure is much more 'advantageous than Y recycling the isobutane together with unreacted isopentane back to the first unit 2, for the overall yield of gasoline-range liquid parafns for the two-stage operation is considerably larger than for the one-stage operation.` Furthermore, the liquid Yproduct from the alkylation of isobutane is considerably higher in octane rating than the liquid product from the disproportionationalkylation of iscpentane with ther same oleiin; for example, the aviation-gasoline'.allrylate from hy-V droiluoric acid alkylation of isobutane with isobutylene has an octane number of about 95--96, which is 20 units higherthanigtheyalues; given; in the foregoing tabulation for the aviation-range fraction of the product from they conversionof isopentane. Hence, because of the present de-k mand for high-octane aviation gasoline, the two@l stage operation yielding two gasolineLrange prod`Y ucts is relatively more advantageous than the onestage operation having combined recycling of isobutane and unreacted isopentane. However, this .one-stage opera-tion is not outside the broadest scope of this invention.

The isohexanes produced by the disproportionation may be similarly advantageously separated from the product, as by fractional distillation and may be used as such for blending in motor fuels or may be alkylated with an olefin as in unit 2l of Fig. 1, preferably in the presence of hydror'luoric acid to give paraiins of different volatility.

It should be observed that the reactions promoted in accordance with this invention do not comprise secondary reactions such as for ex ample that of cracking subsequent to ordinary alkylation. In such cracking-alkylation, the reactant isoparain is alkylated with an oleiin as in ordinary alkylation and the resulting alkylate is allowed to crack into smaller compounds. Obviously, such cracking-alkylation results in little or no improvement in the over-all yield of parafrlns heavier than the original parain, whereas by the present invention the over-all yield of such heavier parafns is markedly increased, and to a surprisingly and quite unexpectedly high degree in the light of past knowledge. Briefly, instead of promoting reactions following alkylation, the present process promotes reactions preceding or accompanying alkylation.

In accordance with this invention, certain desirable reactions are selectively promoted that ordinarily occur to only relatively minor extents in alkylations of parans with olefins in the presence of liquid acid-type alkylation catalyst. Because the invention may be practised otherwise than as speciiically described or illustrated, and because many modifications and variations within the spirit and scope of it will be obvious to those skilled in the art of hydrocarbon conversion, the invention should not be unduly restricted by the foregoing specification and examples.

I claim:

l. An improved process for converting isopentane to higher-boiling isoparaflins boiling in the gasoline range, which comprises charging isopentane and a low-boiling aliphatic olefin having at least three carbon atoms per molecule, in a molar ratio of isopentane charged to olefin charged of at least 7:1, to an intermediate portion of combined reaction-fractional distillation zone, introducing a liquid hydrouoric acid alkylation catalyst to the upper portion of said zone as yal liquid reflux for said distillation, maintaining in an intermediate reaction portion of said theextentv of at least Weight per cent of the i theoretical alkylation yield, at least 30 volume per cent of said Cs and higher paramns being isohexane; removing as an overhead distillate iromsaid zone a mixture comprisingr hydrogen iiuorideand isobutane and lighter hydrocarbons, cooling and condensing said mixture and separat- .ing a liquid hydrocarbon material from liquid hydroiluoric acidjreturning at least a portionof said liquid hydrofiuoric acid to said zone as said reflux, separately alkylating isobutane'contained in said liquid hydrocarbon material to produce normally liquid isoparaiiins boiling in the gason line range, passing a resulting crude alkylate to a separating means, removing from the aforesaid reaction-fractional distillation Zone as a'highM boiling product a liquid hydrocarbon material free from hydrogen fluoride and comprising C6- andehigher hydrocarbons produced in said zone, passing the last said liquid hydrocarbon material to the aforesaid separating means, and removing from said separating means as a product of the process an isoparafiinic hydrocarbon material comprising isoparafns boiling in the gasoline range produced from isopcntane in said zone, and produced from said isobutane alkylation.

2. An improved process for converting isopentane to higher-boiling isoparaiiins boiling in the gasoline range, which comprises charging isopentane and a low-boiling aliphatic olefin having at least three carbon atoms per molecule, in a molar ratio of isopentane charged to olefin charged of at least 7 :1, to an intermediate portion of combined reaction-fractional distillation zone, introducing a liquid hydroiiuoric acid alkylation catalyst to the upper portion of said zone as a liquid reflux for said distillation, maintaining in an intermediate reaction portion of said zone a reaction temperature, a ratio of liquid hydroiluoric acid catalyst to liquid hydrocarbons from 1:10 to 2:1, and a reaction time between 5 and 6D min utes and sufficient to effect complete reaction of charged olefin and formation of isobutane to the extent of at least 151) weight per cent of said olefin and of Cs and higher isoparaflins to the extent of at least 400 weight per cent of said olefin and to the extent of at least 130 weight per cent of the theoretical alkylaticn yield, at least 3c volume per cent of said Ce and higher paraiiins being isohexane, removing as an overhead distillate from said zone a mixture comprising hydrogen fluoride and isobutane and lighter hydrocarbons, cooling and condensing said mixture and sepa rating a liquid hydrocarbon material from liquid hydrouoric acid, returning at least a portion of said liquid hydrofluoric acid to said zone as said reflux, removing from the aforesaid reactionfractional distillation Zone as a high-boiling product a liquid hydrocarbon material free from hydrogen fluoride and comprising Cs-and-higher hydrocarbons produced in said zone, passing the last said liquid hydrocarbon material to separating means, and removing from said separating ll means as a product of the processy anv isopara'f.-v nic hydrocarbon material comprising iso-parait?V ns boiling in the gasoline range produced from isopentane in said zone.

3. Anv alkylation process which comprises reacting isobutane with an olen under alkylating conditions, separately alkylating isopentane with propylene in the presence of hydrogen fluoride at a temperature of from about 75 F. to about 150 F. While maintaining a molar ratio of isopentane to propylene of about 7.2511, whereby to produce a substantial amount of isobutane concurrently with the alkylated isopentane, and supplying the isobutane thus produced to the rst-mentioned alkylating step.

4. An alkylation process which comprises reacting isobutane with an olefinl under alkylating SRIES conditions, separately batchwise alkylating isoof isopentane to propylene of about '7.25 :21, Whereby to produce a substantial amount of i'sobutane concurrently with the alkylated isopent'ane, and supplying the isobutane thus produced t'o the first-mentioned alk-ylating step.

MARYAN P. MATUSZAK.

References cited in the nie of this .patent UNITED STATES PATENTS Number` Name Datei 2,227,559 `Stevens et al Jan. 7, 1941v 2,255,610 Bradley Sept. 9, 19'4-1 2,267,730 Grosse et al. i Dec. 30, 1941 2,311,531 Fulton Feb. 16, 1943 2,322,800 Frey 1 June 29, 1943 2,365,426 Molique Dec. 19, 1944 2,399,368 Matuszak Apr. 30, 1946 2,405,993 Burk Aug. 20, 1946 2,436,483 Newman .7 7 Feb. 24, 1948

Claims (1)

1. AN IMPROVED PROCESS FOR CONVERTING ISOPENTANE TO HIGHER-BOILING ISOPARAFFINS BOILING IN THE GASOLINE RANGE, WHICH COMPRISES CHARGING ISOPENTANE AND A LOW-BOILING ALIPHATIC OLEFIN HAVING AT LEAST THREE CARBON ATOMS PER MOLECULE, IN A MOLAR RATIO OF ISOPENTANE CHANGED TO OLEFIN CHARGED OF AT LEAST 7:1, TO AN INTERMEDIATE PORTION OF COMBINED REACTION-FRACTIONAL DISTILLATION ZONE, INTRODUCING A LIQUID HYDROFLUORIC ACID ALKYLATION CATALYST TO THE UPPER PORTION OF SAID ZONE AS A LIQUID REFLUX FOR SAID DISTILLATION, MAINTAINING IN AN INTERMEDIATE REACTION PORTION OF SAID ZONE A REACTION TEMPERATURE BETWEEN 100 AND 200* F., A RATIO OF LIQUID HYDROFLUORIC ACID CATALYST TO LIQUID HYDROCARBONS FROM 1:10 TO 2:1, AND A REACTION TIME BETWEEN 5 AND 60 MINUTES AND SUFFICIENT TO EFFECT COMPLETE REACTION OF CHARGED OLEFIN AND FORMATION OF ISOBUTANE TO THE EXTENT OF AT LEAST 150 WEIGHT PER CENT OF SAID OLEFIN AND OF C6 AND HIGHER ISOPARAFFINS TO THE EXTENT OF AT LEAST 400 WEIGHT PER CENT OF SAID OLEFIN AND TO THE EXTENT OF AT LEAST 130 WEIGHT PER CENT OF THE THEORETICAL ALKYLATION YIELD, AT LEAST 30 VOLUME PER CENT OF SAID C6 AND HIGHER PARAFFINS BEING ISOHEXANE, REMOVING AS AN OVERHEAD DISTILLATE FROM SAID ZONE A MIXTURE COMPRISING HYDROGEN FLUORIDE AND ISOBUTANE AND LIGHTER HYDROCARBONS, COOLING AND CONDENSING SAID MIXTURE AND SEPARATING A LIQUID HYDROCARBON MATERIAL FROM LIQUID HYDROFLUORIC ACID, RETURNING AT LEAST A PORTION OF SAID LIQUID HYDROFLUORIC ACID TO SAID ZONE AS SAID REFLUX, SEPARATELY ALKYLATING ISOBUTANE CONTAINED IN SAID LIQUID HYDROCARBON MATERIAL TO PRODUCE NORMALLY LIQUID ISOPARAFFINS BOILING IN THE GASOLINE RANGE, PASSING A RESULTING CRUDE ALKYLATE TO A SEPARATING MEANS, REMOVING FROM THE AFORESAID REACTION-FRACTIONAL DISTILLATION ZONE AS A HIGHBOILING PRODUCT A LIQUID HYDROCARBON MATERIAL FREE FROM HYROGEN FLUORIDE AND COMPRISING C6AND-HIGHER HYDROCARBONS PRODUCED IN SAID ZONE, PASSING THE LAST SAID LIQUID HYDROCARBON MATERIAL TO THE AFORESAID SEPARATING MEANS, AND REMOVING FROM SAID SEAPRATING MEANS AS A PRODUCT OF THE PROCESS AN ISOPARAFFINS HYDROCARBON MATERIAL COMPRISING ISOPARAFFINS BOILING IN THE GASOLINE RANGE PRODUCED FROM ISOPENTANE IN SAID ZONE, AND PRODUCED FROM SAID ISOBUTANE ALKYLATION.

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