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Aug 20,1946. :c. ‘s. LYNCH ETA;v _ _ 2,405,968 ALKYLATION OF ETHYLENE MIXED ‘FEEDS Filed May 25; 1945 . ,72 3 ® I . ‘ _g_ 5-" 7'0 sums/4125a ‘\ _ v I ‘ é ' . ' ' ' REAcTon / m‘ I ' . - [5630774015 _ _ - _1,,% _ - ' r550 A; ?'h' ETHYL ENE. SCRUEBEZ h‘. ' M11522 ’ raw INLET - Patented Aug. 20, 1946 2,405,968 ‘ UNITED STATES PATENT orricelll' ‘2,405,968 ALKYLATION OF ETHYLENE lVlIXED FEEDS Charles S. Lynch, Plain?eld, and Howard G. Codet, Mountainside, N. J., assignors to Stand ard Oil Development Company, a corporation of Delaware Application May 25, 1943, Serial No. 488,344 6 Claims. (C1. 260--683.4) l 2 The presentinvention relates to improvements in the art of alkylating ethylene mixed feeds, and more particularly, it relates to a continuous op eration of catalytically alkylating ethylene with it is associated as it is fed to the systemlbefo're isoparaf?ns in which the ethylene feed stock is contacting the catalyst in the alkylation proc ess. ,In other words, in a commercial re?nery the normal C2 or ethylene fraction will be associated with neighboring hydrocarbons and hydrogen.. In mixed with other hydrocarbons and gases and in which theralkylation is accomplished in a man ner which is cheaper than has been possible here tofore. - ' >_ _ Recently it has been found that , ethylene may 10 be alkylated with isobutane to form hydrocarbons boiling within the gasoline range, of high octane ert, and if they ?ow through the systeméwith the ethylene during the reaction, they willleventually been-found in connection with these researches ' paraffin and the ole?n with aluminum chloride for other words, the C2 hydrocarbons will contain‘in addition to the desired Qle?n, methane, ethane, and hydrogen. The para?ins, of course, are in number, incIudingZB-dimethyl butane. It has ' that the catalyst prepared by contacting the iso ,. Our present invention relates to that phase-of the above indicated process which includes sep arating the ethylene from ‘the gases'with which have to be eliminated and their'processing' and 15 elimination uselessly, ' o'fjcourse, requires ; addi "an extended period of time is a brown mobile ‘ tional facilities and utilities. In brief compass, we have devised a-procefss liquid which apparently is an aluminum chloride 'for eliminating the unwanted’ hydrocarbons in hydrocarbon» complex, which is an active cata ' lyst’possessing a long life and is otherwise satis 20 the ethylene feed, in a relatively simple andex peditious manner as will more fully appear. here factory. It has furtherbeen found in connec tion with these prior researches that the alkyla In the accompanying drawing we have shown tion may be carried outat ordinary atmospheric a?oW, plan indicating a continuous process for temperatures or above. For example, the alkyla alkylating ethylene with isobutane, including the tionmay be carried out at temperatures from 25 features hereinbefore mentioned. _ v 65‘*-200_° F. with a range of 90—l25° F. preferred. Referring in detail to the drawing, we shall It has further been found that a small amount describe a preferred method of alkylating ethylene of volatile halide incorporated with the isobutane“ inafter. , " , ' _ ' V _ with isobutane in the presence of aluminum chlo feed greatly improves the quality and the yields. Thus, from 1 to 15% of, ethyl chloride or methyl 30 ride hydrocarbon complexso that a vbetter un derstanding of our invention may be had. chloride based on the isobutane or other isoparaf I_ is a reactor which, as indicated in the draw ?n greatly increases the efficiency of the process. ing, may be an elongated, cylindrical vessel packed About 5-10 volume per cent of ‘ethyl chloride with a material such as Raschig rings. Super gives the best results. Further, it has been found posed on reaction vessel I is a settler 2 carrying that pressures of from 100-1000 lbs/sq. in. give i) a pressure gauge 3 disposed in a ventline 5 carry good results with pressures ‘of the order of 200 ing a liquid level control valve l0. Disposed at '300 lbs. preferred. The researches have also re the side of the reactor I is a vessel or receptacle “vealed that ._ the fresh feed to the reaction zone should have an excess of the isopara?in, that is 20 in which is contained aluminum chloride,and ‘ to‘ say, best results are obtainable when the fresh 40 feed 'pcontains 3 mols of isopara?in to each mol of ole?n. With respect to the amount of alu “minum' chloride, it has'been found that by main taining from _3 to 100, and preferably’ about 20 weight 'per cent of aluminum chloride in the reactor" gives ‘optimum results. Under the con~ ditions stated, numerous runs ‘have demonstrated that when Working at its best, the foregoing proc through this container where it absorbs or other wise acquires aluminum chloride and then‘flows into the reactor. The ethylene feed'enters ‘the system through a line 25 and the isobutane en ters through line 28, the latter being in_a liquid 45 condition. At the start of the operation, the iso ' butane is ?rst introduced into the empty system through line '28, flows through a scrubber 30, thence is withdrawn through line 32 and pumped by pump 35 through line 36 into reactor l until the column is nearly ?lled with lique?ed isobu ess is adapted to produce an alk'ylate over 60 volume per cent of which contains Cs hydrocar bons; including 2,3-dimethyl ‘ butane. 2,3-di tane. The ethylene feed is introduced through methyl‘butane is a hydrocarbon which has a high line 25 as a gas to scrubber 30 where it is ab 'octane number but is particularly valuable be ' cause of its excellent rich mixture performance ~ in a supercharged engine. ‘ the feed stock, as will subsequently appear, passes 55 sorbed and, passes via line 32, pump 35 and line 36 into the reactor l until the isobutane is about half saturated with respect to ethylene. The eth— 2,405,968 3 ylene and isobutane pass upwardly to settler 2 and then are withdrawn through recycle line 40 and returned to the tower 30 for recycling via line 32, but now the recycle stream passes through line 38 and thence through the aluminum chlo ride receptacle 20 and thence passes into the tower 1. After the'passage of 3-4 hours, the aluminum chloride will have reacted with the hydrocarbons to form the aforementioned aluminum chloride-"i. hydrocarbon complex, which is the active catalyst for the alkylation process, and 'after"‘this“"‘in duction” period during which-thematalyst is formed, product may be withdrawn through line 12 and delivered to fractionatingand- distilling equipment (not shown) to recover the desired products. There will come atime when .the ma 4 entering feed While the other components pass up the tower and may be withdrawn through a vent pipe 50. It is obvious that this is a desirable method of operating since the removal of hydro gen, methane, ethane, and the like, at the begin ning of the‘ operation, makes it unnecessary to circulate these inert materials'through the whole system, including the fractionation and distilla tion equipment in which the product stream‘ 12 is subsequently treated. Thus, by scrubbing the fresh feed with a recycle stream saturated with respect to the‘ unwanted components of the eth ~ylene..fresh’-feed, we“ are able to reject at once :from thesystem-dnert materials, such as meth rrane,'tethane,'hydrogen, and the like, in a simple and expeditious manner. . Our process possesses particular utility in the processing of an ethylene feed stock which con terial recycled through 20 must be directed to tains a. minor quantity of ethylene, say from another container 20a which containstfreshlalu minum chloride, the latter container being sim 20 30-40%, such as is obtained, for example, in .steam cracking of hydrocarbons. However, tour =ilar-,,in. construetionill, [and .-thence passed .into process could be used<for.feed' stocks containing .the reactor has-“before. The containerl? is as low as 10% ethylene in the feed entering thoroughly “cleaned ;and recharged with. alumi through line 25' and this-lowconcentration of numzchlor-ide .-for subsequent use-inv the process. would be highly impractical in an al .Imotherwords, the preferredmethod of operat .25 ethylene kylation process where a large preponderance of .ing .thenprocess is to “provide two or'more con inert material continuously passed through the :tainers-Miand ZOaandafter one has been in .use system. The temperature of theliquidrin- the Ire vfor some time, it willbe withdrawn vfrom the cir cycle stream is from 50° to 200° F., preferably .».culating_ system, "thoroughly cleaned and’ re .charged' "with . fresh ~zaluminum chloride. .The 30 from 75° to 125° _F.,vand the/pressure is from'100 to 11000 lbs/sq. in., preferably from'200-to; 300 .other container will imeanwhile bev on stream. lbs/sq. in. _» ' . -Theuseof itwoi-or more-containers 20 maintains In operating our process, as in the previous de continuityot operation even. though itis neces velopment of this process, wemaintain-a-molec :sary tosaddlaluminum chloride periodically to ular excess of isobutaneover the ethylene, Pref the system. to maintain. the , catalyst activity as erably we maintainv 3 to 100 mols of isobutane per previously indicated. It: will. benoted thata por mol of ethylene in-the reaction zone. The re ..tionof thelrecycle. product in line.32 may- bypass cycle ratio, i. e., theratio of recycledlproductrto -.-the.container_2>0 or slim-and passydirectlyinto the fresh feedis from 1 to 30 volumesofrecycle-prod reactor 1 gthroughzline??. ‘We-maintain a con uct per volume of .fresh feed (i. e.,‘newly added sumption. .of.,aluminum<- chloride _ in - our process 40 ethyleneand isobutane, disregarding the unde varying from 0.04 to 0.08 lb. of AlCls per, gallon sired constituents in the ethylene feed). When . of-alkylate. operating at its best, verylittle catalyst isin the . Thereis .another.,.point. with. respect to the op recycle stream, less than “0.04 weight per . erationoL-the , process .and .itis this, .viz.,_that when the reactorlbecomes ?lled with catalyst, the 1.A St cent when. operatingat 110°. F. wexcess .passesdntosettler v2, iirom which .it may be- withdrawn byidraweoff ,pipe .8. ~ Actually, .hoW > - We. have described in detail the'application of . our. invention .to .they alkylation- of ethylene and isobutane. It is to be understood'that‘ thesame principle may apply to thealklation of. propylene 50 .or.butylene where the propylene or butylene feeds are mixed or'diluted with relatively large-‘quan . .Except for .the manner cry-introducing the feed titiesof other. gaseous materials. The removal stocks; , we .haveindicatedthe . development. of the .of. propane in the scrubbing stepispossiblewhen, .alkylationprocessup to thetimeof ourinven as is usuallythe case,.:the pressures»;exceed..l25 _~..tion, .whichjinvention will?nowxbe described .in detail. ...Heretofore,.inoperatingrthe process de 55 lbs/sq. in. in the system. - ‘What we claim is: ‘ .scribed,,the ethylenefeed and the isobutane feed 1. In the continuous alkylation of~olefins with arehot fed to the system inthe manner we have isopara?ins conducted in the preesnce of an alu indicated-in.thedrawing vbut. are changed di minum chloride-hydrocarbon complex formed in rectlyto the reactor, andtherefore our improve situ during the operationof the process, the im ment comprises, principally, the. interposition » of provement which comprises ?rst forcing a mixed . the scrubber 30 into the system. .The mixed feed feed containing a minor proportion of ethylene . entering thesaid scrubber-at 25contains hydro with an isopara?in through a reaction zone con gen, .methane, ethylene,.>and ‘possibly ethane, and taining the. said aluminum chloride-hydrocar contacts.- therein .the .isobutane which enters bon complex,‘ permitting the feed stock and the through;.1ine..28. .The isobutane becomes satu catalyst to'remain incontactvwith each other for rated, of,.course, with respect. tov hydrogen, meth a su?icientperiodof- time toe?ect the‘desired .ane, ethylene, and ethane. The ethylene in the conversion, withdrawing a product stream, si - course ofQthereactionis continually removed in multaneously withdrawing a recycle stream con reactor I, but thehydrogen, methane and ethane .are unchanged-and consequently the recycle ~ taining iscbutanev and small vamount of alkylate, passing the recycle stream into a scrubbing zone, .stream in‘ 40 entering scrubber 30, after the proc everrthe: system maybe. operated .1‘00hours or more~..before!it. islnecessary to withdraw spent catalyst .throughpipe- 8. , esshas been in operation for a su?icient period forcing the mixed feed containing a minor pro portion of ethylene .in countercurrent contact of time,>=is.saturated with respect to all of the with the recycle stream whereuponthe recycle >.components entering 25, except ethylene, and hence-onlythe-ethylene is dissolved out of the 75 stream becomes saturated .with. undesired/x com 2,405,968 ponents of the mixed feed containing ethylene, withdrawing the recycle stream enriched with ethylene from the scrubbing zone and returning the same with added isobutane to the reaction zone, continuing the ?ow of materials in the manner indicated, thus causing mixed ethylene feed, after the recycle stream has become sat urated with undesired components of the fresh bing zone whereby substantially only ethylene is dissolved in said recycled product, withdrawing the undesired components of said hydrocarbon stream from said scrubbing zone, conducting the recycled product containing dissolved ethylene with added isobutane to a reaction zone contain ing the said hydrocarbon-A1013 complex catalyst, permitting the ethylene and isobutane to contact feed, to contact said recycle stream whereby said each other and the catalyst at elevated tempera undesired components are rejected by the recycle 10 tures and pressures. stream in the scrubbing zone and are adapted 3. The method of claim 2 in which the tem to be withdrawn from the scrubbing zone and perature in scrubbing zone is from about 75 to thus separated from the desired ethylene dis 200° F. solved in said recycle stream. 4. The method of claim 2 in which the pres 2. In the continuous alkylation of ethylene with sure in the scrubbing zone is from 200 to 400 isobutane in a, continuous operation employing a lbs/sq. in, > hydrocarbon AlCls complex catalyst, the improve ment which comprises feeding a hydrocarbon stream containing ethylene and undesired com ponents to a scrubbing zone, feeding a recycle product stream substantially saturated with re spect to undesired components of the feed to said scrubbing zone, contacting said hydrocarbon stream with said recycled product in said scrub 5. The method of claim 2 in which the ethyl ene feed contains from 50 to 90% hydrocarbons other than ethylene. 6. The method of claim 2 in which the A1013 consumption is from 0.04 to 0.08 lbs. AlCls per gallon of alkylate produced. - CHARLES S. LYNCH. HOWARD G. CODET.