US2397085A - Manufacture of motor fuel - Google Patents

Description

March 26,4 1946.

E. R. BOEDEKER ET AL MANUFACTURE OF 4MOTOR FUEL Filed June 18, 1945 Patented Mor. ze, 194e l 2,397,085

UNITED STATES -PA'rENT oFFicE MANUFACTUBE F MOTOR FUEL Edward R. Baedeker and Alex G. ObladfDallas, Tex., alsignors, by mesne assignments, to Sooony-Vaouum Oil Company, Incorporated. New York, N. Y., a corporation of New York Appui-.ation Jone'is, 1945, semi No. 600,042 1o claims. (ci. acoessai This invention relates to the production of gasprocesses for the production of high octane gasooline hydrocarbons of high anti-knock value from line, an important and necessary step is the treatisoparaiiins and olenns. The invention relates ment of the product hydrocarbons for the removal particularly to an improved process for the protherefrom of small amounts of nuorine comduction of high octane gasoline in which a hyd pounds, such as organic uorides and hydrogen droiiuoric acid allnrlation process, involving the uoride, which remain in the product hydrocarstep of deiluorinating the alkylate product hydrobons after the usual settling and fractionating carbons by means of a solid defluorinating agent, treatments for the removal of hydroiluoric acid is combined with an isomerization process for the and excess reactants. This deiiuorination of conversion of terminalv bond oleiins to non-terl0 the alkylat'e product hydrocarbons is ordinarily minal bond oleiins. carried out by passing the hydrocarbon product It is well known that motor fuel of high octane stream in contact, under proper conditions, with quality may be obtained by the alkylation of low a solid, porous, adsorbent material known to be boiling isoparafllns. such as isobutane, with low catalytically active for hydrohalogenation and boiiing olonne, guoh as the buteneg, to produce i5 dehydrohalogenation reactions, suchas dehydratsoturated hydrocarbons within the gasoline boiled bauxite, Activated Alumina, alumina gel. or the ing range. In commercial practice the feed stocks llke- When utilized fOr this PurpOSe. these meteordinarily employed for the production of alkylate rials gradually become inactive for the eillcient gasoline comprise butane-buteno mixtures whioh removal of the iluorides, and it is necessary that contain all the butane and butene isomers, viz., they be either discarded and replaced by fresh normal butane, isobutane. isobutylene, butene-1 materials', or reactivated. However, reactivation and butene-2, these isomers being presentinvary- 0f the Spent Catalyst iS Costly, and lt has been ing, though significant. quantities. Such feed found to be more economical to utilize bauxite stocks are commonly employed for the reason until its activity becomes too low and then disthat they are readily available ln large quanti- 08rd it rather than t0 utilize the mere eneetive, ties, and because they produce alkylate hydrobut more costly. Synthetic materials, Such as Accarbons having highly desirable octane ratings tivated Alumina. and volatility characteristics, We have found that these contact materials, It has recently been discovered, es disclose after they have been llSed 8.8 deuolilltln and claimed in a copending application of Joe E. esenlfare highly eiiicent catalysts for the isom- Penick and Urban H. Wagner, Serial No. 532.794, erzatlon of vterminal bond oleiins to non-terminal med April 25, 1944, that, the yioms and ootone bond olefins. And we have found that when such numbers of the product hydrocarbons obtained materlals are used 8S isomerzatien etalyste. bythe hydi-ofiuoi-io ooid olkyiation of buianmbusuch use tends to assist their reactivation, so that tene mixmres may bemarkedly increased by dethey may be more readily and less expensively creasing the proportion of butene1 in the food reactivated as defiuorination agents, since the mixture prior to olkyiotion, As proposed in that isomer-ization reaction produces a deposit of carapplication, a particularly suitable method of acben 0n the Contact material Which iS redlly 0X!- complishing' this decrease in the proportion of dized in the. regeneration treatment. This oxidabutene-l, especially from the viewpoint of eco- 40 tien reeetin. being highly cxothermlc, facilinomical utilization of the olefin components of tetes the attainment 0f the relatively 111811 temthe feed stock, is to subject the feed stock to Pereture'S required for the removal of theadsorbed lsome,7129.171011t 30 as to convert the butened een.. llOlideS from the ol'ltael'. bed in the regenel'tln tained therein to butene-2. l treatment.

It is the primary object oi the present inven- 5 In ecel'dance With the Present invention. I tion to provide an improved method for the manprocess for the manufacture of hish octane zasufacture of high octane motor fuel in which the oline hydrocarbons iS Proposed. which includes advantageous step of isomerizing the terminal Vau volkylation step. a deuorination step and an bond oieiins contained in commonly utilized allsomerization Step. in which process the contact kylation charge stocks is combined with a hydro- 0 materiels are Used, in one stage, for the denuiluoric acid alkylation process in a novel and ecoorination of alkylate product hydrocarbons. and. nomiogi manner, in another stage, for the isomerization of termi- Other and further objects of our invention will nal bond olens contained in alkylation charge appear from the following description thereof. stocks, after which they are regenerated for fur- In conventional hydroiluoric acid alkylation '55. ther use in the process. In this way, the cost of continually replacing the deuorination contact materiaifromtimetomeasheretoforerequired,isavoidedandtwosteps,viz.,

and are accomplishedbytheuseofasinglecontaetmaterial.

In ce with the preferred manner of carrying out our process, separate contact beds ar'e provlded,andtlxesteps'ofdeiluorinatingthe alkylate product hydr and isomeriaing the charge stock comprising terminal bond oleilns are effected simultaneously in the differenthedathebedsbeingaltematedwith respect to the diilerent steps at regulated intervals in the course of the process. Since a step in our prom is the reactivation ofthebedaftettheisomerlzationstep of the has been completed, we prefetto utilizethreesuchbedainorderthattheisomanddtingstepsmaybeeilected concurrently with the regeneration step.

The regeneration step of our process requires that the contact bed. after completion or the isomerlmtin Step. be purged of all volatile hydrocarbon material and then subiected to a treatmentwithahotoxidizinggasmixtureatatemperature of from about 900 F. to yabout 1100 F. for several hours to remove, by combustion. the car material deposited on the contact agent,particularlyintheeourseoftheisomeriza tion cycle. The contact bed is then cooleddown to derluorlnation temperature for use in the next proces cycle.

The operating conditions required for carry ing out the deilnorination step of our process are already well hown. Thus, the alkylate product hydrocarbons may be edectively deucrinated by cong them with materials, such as alumina fgel or dehydrated bauxite, preferably the former.

at a variety of ilow rates, at temperatures rang- Aingfromaslow as50F.toashighas700F. The operation may be eiected in either the liquid or vapor state, suitably high pressures being em- Plyed. where liquid phase operation is used, to

tiallysuppress vaporizationof the hydrocarbons. f

The istion step of the process may be conducted over a reLaidvely wide range of space velocities at temperatures of from about 300 F. to about '100 F. in the liquid or vapor phase, suitalnlcr high pressure being employed, where the tion is effected in the liquid phase, to

When the process is in operation, one of the contactors will be on stream for the isomerization of the alkylation feed stock containing terminal bond olens, another will be operating as a deuorinating zone for the alkylate hydrocarbon products. while the third will be undergoing regeneration for further use as a deuorination zone.

Assuming contacter A to be on stream for isomerlzation, a feed stock comprising terminal bond oleilns enters the process system by way of line l provided with a control valve 2, and is directed, by operation of control valves 3 and 4, in lines i and 5 to vthe contactor A. Suitable conditions for the operation of contacter A when isomerizingra butane-butene mixture, having a total butenes content of 46 weight per cent and 18 weight per cent of butene-l, are the use of space velocities of from about 5 to about 25 liquid volumes of butane-butene feed per volume of alumina gel contact material per hour, at temperatures ranging from about 500 F. to about 700 F. Under these conditions the butene-l content of the feed stock mixture will be substantially com' pletely isomerized, i. e., to an equilibrium mixture ofbutene-l and butene-Z.

At the same time, contactor B will be on stream for deiluorination of high octane alkylate hydrotive for the deuorination of the hydrocarbon maintain the hydrocarbons liquid at the particu- Y lar temperature emplvyed.

The principle of our invention is applicable to any ric acid aikylation process where it is desirable to isomerize terminal bond olens, such as butene-l, pantala-1, 3 methyl butene-I or the like, contained in the alkyiatlon feed stock to the lding non-terminal bond oleilns. IIii'he specific conditions to be employed for the deiinorination and isomerization steps. such as the temperatures` and the space velocities will, of course, vary depending upon the particular contact material employed and the ilow requirements of the alkylation prom to which the invention is applied. Y

Inorderthatourhrventionmaybehetter understood.' reference is made to attached drawillgwhillh c -14 l u H- ce2 i' musiratesasllitable formofapparatus forcarryingout the process of our-invention.

Inthedrawingthereareshownthreecontactors,A.B,andC,bedsof contact material such as Activated Alumina, dehydrated bauxite or alumina gel, preferably the latter.

stream in contactor B.

During the period that contactors A and B are on stream for isomerization and deuorination as an air-flue gas mixture, followed by a second steam purge to remove any oxygen containing gases, the contact bed thus being reconditioned for further use in the deuorination treatment.

During the. period that the contactors A, B,

and C are subjected successively and alternately to the deuorination, isomerization and regeneration treatment, as described above, the material flow in the remainder of the system is as follows:

From co'ntactcr A, `isomerized feed stock is withdrawn in line i4, whence itis directed, by the operation of control valve l5, in lines I4 and I6 to a. cooler il, wherein it is suitably cooled prior to use in the alkylation step of the process. The feed stock is withdrawn from the cooler in line I8 which discharges it into line i9, whence it enters alkylation zone 20. In line I9 the isomerized feed is joined by supplemental isobutane feed being admitted to the process in this line through valve 2|, and recycle isobutane entering this line from line 22.

Hydrouoric acid catalyst in the liquid state enters the process system from line 25 through valve 26 and is carried to alkylation zone 20 by way of lines 25 and 21.. The alkylation zone 20 may comprise any suitable form of valkylation vessel, capable of effecting the required intimate contacting of the catalyst with the reactant maasoman terial. for example a conventional reaction loop, or a Stratco contactor. suitable means being provided for maintaining the proper alkylating conditions of temperature, the pressure being sulficient to maintain the reaction mixture in the liquid state.

From the allwlator, the reaction mixture `is withdrawn in line 28. whence it is discharged into separator 30, wherein it is stratified to form an upper hydrocarbon layer and a lower acid cata` lyst layer. From the separator, the lower acid catalyst layer is withdrawn in line 3| andvreturned, by way of lines 3i and 21, to the alkylation zone. The used acid catalyst may be withdrawn from the process for regeneration as desired through line 32, by operation of valve 33.

The upperhydrocarbon layer formed in separator n is withdrawn therefrom in line 35 whence it enters at the top of hydroiluoric acid stripping tower I6. From the stripping tower the main portion of the hydroiluoric acid content of the hydrocarbon charge is stripped of! and withdrawn overhead in line 31 together with a small amount of light end fractions of the charge. This overhead hydrofluoric acid stream is returned to the separator I0, by way of lines 31 and 2B.

The stripped hydrocarbon product mixture is withdrawn from the bottom of tower 3l in line 38 wherein it is directed to debutanizing fractionator 40. Fromlthe debutanizer -unreacted isobutane is removed overhead in line 4 I and sent to condenser 42, wherein it is condensed before being returned to alkylation zone 2n by way of lines 22 and Il. Normal butane isWithdrawn from tower 4I by way of line 43 and removed from the process system. although it may be isomerized and returned to the alkylation zone, if desired.

'I'he debutanized alkylate products are withdrawn from tower 40 in line 45 and sent to accumulator 46, from which they are withdrawn in line 41 ,and conducted to preheater 6, wherein they are heated to deiluorination temperature. The heated product stream is lwithdrawn from preheater 6 in line I2 and directed, as already described above, by` way of lines i2 and i3 to contactor B. -It will be understood that preheater-'may be replaced by a cooler, or'it may simply be omitted as in instances where the temperature employed in the deiluorination contactor is relatively close to the temperature of the alkylate products eluent from the accumulator 46. The detluorinated product stream is withdrawn from contactor B in line 48 and is directed, by operation of control valve 49, to line 50, wherein it is conducted to fractionating tower 5f. In tower 5IA the alkylate products are separated into desired alkylate product of high, octane boiling range and heavy alkylate. The heavy alkylate fraction is withdrawn from the bottom of the tower in line 52, while the desired high octane alkylate product is withdrawn overhead in line 53.

We have found that anoperating cycle of about 30 hours for the isomeriztion and deiluorination treatments may be employed before regeneration of the alumina gel contact bed is necessary. Since it is generally desirable that the isomerization process be carried out at a higher temperature level than is employed in the deiluorination operation, the ilow of hydrocarbons through the deiluorination contactor should be discontinued a sufficient period of time before the contactor is .number of such beds.

to be utilized for isomerization to permit the contact bed to be brought up to the proper temperature level. The detluorination operation is. therefore, started in the contactor containing freshly regenerated contact material before the isomerization stage of the process is changed over f to anew contactor. It is generally advisable to allow from two to five hours, depending upon they size of the contact bed andthe heat transferprovisions made, for the heating of .the contact bed to the isomerization temperature level.

For the sake of simplicity and clarity, in the foregoing description of our invention and in the drawingvarious details have been omitted, including, for example, now lines for the conduction of the regeneration gases to and from the diiferent contactors. as well as, conventional heaters, pumps, valves, flow control means, etc., the use of which is wellunderstood by those familiar with the art. v

From the foregoing description of our invention it will be appreciated that several noteworthy advantages are obtainable by its use. Thus, provision is made for the economical regeneration of the contact material utilized for the deiluorination of the alkylate vhydrocarbon products thereby avoiding the expense of frequent replacement of this material, as heretofore required. Further, by our process it is economically feasible to utilize the more costly, but more eillcient synthetic contact materials, such as alumina gel, \for the detluorination treatment rather than the less active contact agents, sincethe contact materials are regenerated by our process rather than discarded upon deactivation. Also, the activity -of the contact catalyst for the isomerization treatment of the olefin charge stock is enhanced by its prior use as a deiiuorination agent in accordance with our process. Finally, improve- While in describing our invention-we have indic'ated that we prefer to use three contact beds.

it will be apparent to those skilled in the artA Ithat the manner of operating our process may be modified to permit use of a greater or lesser contactbed is required for operation of our process where an adequate reserve of isomerized feed stock is maintained, so that operation of the alkylation process may be carried on while the contact bed is in use for defiuorinating the product hydrocarbons, and where means are provided for temporarily storing untreated alkylate products, while the contact bed is on stream for the isomerization of the olefin feed stock.

Other modifications of our invention, not spe- I cically described herein, may be made by those skilled in the art without departing from the spirit and scope of our invention, and therefore only such limitations should be imposed as are indicated in the appended claims.

l. A process of producing high octane motor fuel from isoparailins and a charge stock containing terminal bond oleiins which comprises the steps of: (1) passing said charge stock'over a contact bed comprising a solid, porous, metal oxide material known to be catalytically active for hydrohalogenation and dehydrohalogenation reactions, said bed having been treated in a manner hereinafter defined, under oleiln isomerizing conditions, to isomerize said terminal bond oleilns, (2) subjecting the contact bed from step 1 For example, only one to an oxidation-regeneration treatment by means of hot oxidizing gases to condition it for further use in the process, (3) alkylating the isomerized charge stock obtained in step 1 with said isoparalns in the presence of hydrouoric acid catalyst to produce a mixture comprising high octane' al. kylate hydrocarbons, (4) separating the main portion of said acid catalyst from said alkylate product hydrocarbons, passing the product hydrocarbons from step 4 over the regenerated contact bed from step 2. under deuorinating conditions, to remove therefrom substantially al1 residual hydrofiuoric acid not removed in step 4 and substantially all other fluoride compounds formed in step 3. (6) utilizingthe contact bed from step 5 as the contact bed in step 1 of the process, and (7) fractionating the deiiuorinated product hydrocarbons from step 5 to separate the, desired high octane motor fuel therefrom,

2. A process for the production of high octane motor fuel from isoparaiiins and a charge stock containing terminal bond olens which comprises the steps of (1) passing said charge stock over a contact bed comprising active alumina gel catalyst treated in a manner hereinafter dened, under olen isomerizing conditions, to isomerize said terminal bond oleiins, (2) subjecting thecontact bed from step 1 to an oxidation-regeneration treatment by means of hot oxidizing gases to condition it for further use in the process, (3) allwlating the isomerized charge stock obtained in step 1 with said isoparaiiins in the presence of hydrofiuoric acid catalyst to produce a mixture comprising high octanevalkylate hydrocarbons, (4) separating the main portion of said acid. catalyst from said alkylate product hydrocarbons,

(5) passing the product hydrocarbons from step 4 over the regenerated contact bed from step 2, under defiuorinating conditions, to remove therefrom substantially al1 residual hydrofluorie acid not removed instep 4 and substantially all other iiuoride compounds formed in step 3, (6) utilizing the contact bed from step 5 as the contact bed in step 1 of the process, and (7) fractionating the defiuorinated product hydrocarbons from step 5 e to separate the desired high octane motor fuel therefrom.

3. The method of conducting a continuous process for the manufacture of high octane motor fuel in a reaction system comprising an alkyl- 50 ation zone and a defluorination-isomerization zone, saidv defluorination-isomerization zone cor`n. prising a series of solid alumina gel contact beds which process' comprises: (1) reacting isobutane with an olen feed stock rich in butene-2 and obtained in a manner hereinafter dened in the presence of hydrofluoric acid catalyst in said alkylation zone, (2) withdrawing a product mixture comprising high octane alkylate hydrocarbons from said alkylation zone, (3) separating said mixture into an acid .phase and a hydrocarbon products phase, (4) treating said hydrocarbon products phase to remove fiuorine containing substances therefrom by Passing said phase through one. ofthe aforementioned alumina gelcontact beds, (5) treating an olefin feed stock,

rich in butene-l, to isomerization, by passing said stock through another of said alumina gel contact beds which has been previously utilized as the contact bed in step 4 of the process whereby the butene-i content of said olen feed stock is converted to butene-Z, (6) using the isomerized feed Y stock from step 5 as the butene-2 rich feed stock in step 1 of the process, (7) alternately and sucbeds in said deuox'inatlon-mme-to deiiuorlnate said alkylate product hydrocarbons and to isomerlze said olefin feed stock, and (3) fractionating the ted alkylate product hydrocarbonsfromstepdtoobtalnthedadred 'high octane motor fuel.

4. A proeSS 101' u i rn. em uf high mm motor fuel from isobutane and a butane-butene fraction containing signiiicant amounts of bu- 10 tene-1 which compris: (1) posing said butanobutene fraction over a bed of active alumina gel catalyst treated in a manner h dened,

under oleiin isomerizlng conditionstoconvertthe butene-l-in said fracidon to an isomer thereof,-` (2) reacting the isomerlzed butano-humane fracnon from step 1 with sind isobutane, under any1- ating conditions, in the presence of hy acid catalyst to produce a mixture comprising high octane alkylate hydrocarbons, (3) separatgoingthemain portion oftheacld catalyst from the ailcylate hydrocarbons obtained in step 2, (4) contacting said alkylate hydrocarbonswith abedofaluminagelcatalymunderdeiiuorinating conditions, to remove therefromk mbstantiaily all residual hydroiinoric acid not removed in step 3 and substantially all other fluoride compounds formed in step 2, (5) utilizing the bedofalumina gel romstep4asthecatalystbed instep1, (6) utilizingthebedofaluminagelfrom steplasthecatalystbedinstepdafteranintermediate oxidation-regeneration treatment and (7) fractionating the deiuorinatcd alkylate hydrocarhons from step 4 to Separate the desired high octane 'motor fuel therefrom 5. In a process for the production of alkylate motor fuel hydrocarbons from iso and a.

charge stock containing terminal bond olens comprising subjecting the charge stock to oleiin isomerization conditions over an oieinisomeriza- 0 tion catalyst, alkylating Said isilmel'ized cham stock with said isoparailins in the prence od hydroiluoric acid catalyst, separating the main portion oi' said acid catalyst from the alkylate product mixture derived from said alkylation step,

subjecting said product mixtin-e to deiiuorlnatim treatment hy contacting said mixture with a solid adsorbent material to remove minor quant/Itis of hydroiluoric acid and also organic fluorld therefrom, the improvement which compris utilizing the contact material from the deiiuorlnaidon treatment of the process as the effective catalyst for the isomerlzation of said charge stock. 6. In a process for themanufacture of octane gasoline from isoparailins and a charge stock containing 101enns comprising subjecting said charge stock to isomerzatlon to convert said 1oleilns to 2olens, alkylatng said isomerlzed charge stock with said isoparamns in the presence of hydroiiuoric acid catalyst, separating the main portion of said catalyst from the alkylate prod# uct mixture, subjecting said product mixture to a deilnorlnation treatment by contacting said mixturewthabedofsolidadsorbentoontact material tosuhstantially completely remove hy- 5 droiiuoride and organic flnorides therefrom, the

improvement comprising providing a pluralltyof Vseparate adsorbent contact beds, effecting the Vdeiluorlnationstepoftheproeessinoneofsaid beds, effecting the isomerimticn step ofthe proe- 'essbypassmgmecnarge-stkmpe incontactwithanotherofsaidbedswhlchhas previously been used for the deiiuorinaion step, regenerating another of said beds for further use inthedeiiuorinationstepofthepromandincessively utilizing each of the alumina gel contact 15 termittently switching the isomto a deiluorination treatment by contacting said mixture 4with a bed of solid adsorbent contact materia! to substantially completely remove hydrogen fluoride and organic uorides therefrom.l the improvement comprising providing a plurality of separate adsorbent contact beds comprising alumina.- gel. eiecting the deuorlnation step of the process in one o! said beds. eiecting the isomerization step of the process by passing the charge stock to be isomerized in contact with another of said beds which has previously been used for the defiuorination step, regenerating another of said beds for furtheruse in the deiluorination step of the process, and intermittently switching the deiiuorination, isomerization and regeneration steps of the process, successively, from one of said contact beds to the other. v

8. The process of claim 5 wherein said contact lmaterial is dehydrated bauxite.

9. The process of claim 5 wherein said contact material is Activated Alumina. Y

10. The process of claim 5 wherein said contact material is alumina gel. i l

EDWARD R. Bonham. ALEX G. 01mm.

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