Патент USA US2406778код для вставки
Sept. 3, 1946.A 2,406,778 w. E. KRUsE ETAI. SLURRYING ALUMINUM CHLORIDE È‘OR HYDROCARBON CONVERSION PROCESSES Filed Deo. _15, 1941 . uw NMRQSNHÈQ.WN NSN. Nlä. wwwwhwm w .wì 72 i M c7772 2,406,778 Patented Sept. 3, 1946 UNITED STATES PATENT OFFICE 2,406,778 SLURRYING ALUMÍNUM CHLORIDE FOR. HY DROCARBON CONVERSION PROCESSES Willard E. Kruse, Chicago, Ill., Cecil W. Nyse wander, `Highland, Ind., and John A. Bolt, Chi cago, Ill., assignors to Standard Oil Company, Chicago, Ill., a corporation of Indiana Application December 15, 1941, Serial No. 422,981 2 Claims, (Cl. Zim-683.5) 1 , 2 This invention relates to improvements in alu feed stock such as light naphtha is previously minum chloride hydrocarbon conversion proc esses and it pertains more particularly to improved methods and means for introducing make-up aluminum chloride into a continuous conversion reactor. In certain continuous aluminum chloride hy drocarbon conversion processes such as cracking, pended form for an extended period of time. Slurries of make-up aluminum chloride which are formed by the use of such pretreated naphtha can be readily handled and injected into the sys polymerization, alkylation, isomerization, etc., it is essential to effect a continuous or intermit treated with aluminum chloride before it is em ployed for making up the aluminum chloride slurry, the resulting slurry will remain in sus tem. Even in the case of a pretreated slurrying 10 vehicle, however, it is desirable to avoid a pro longed time between slurry formation and actual slurry injection. ‘ ' in order to maintain catalyst> activity at the dem We have discovered that a remarkably and un sired level. An object of our invention is to pro~ usually stable aluminum chloride slurry results vide an improved method and means for supply ing make-up aluminum chloride to such a con 15 from the use as slurrying agents of liquids which have already undergone treatment in the isom tinuous reaction chamber. A further object i5 to erization reaction itself. Products directly from provide a new and improved aluminum chloride the reactor (or from the settlers following the isomerization system wherein liquids produced in tent introduction of make-up aluminum chloride reactor) are usually contaminated with complex 20 material that would be deleterious in the slurry make-up aluminum chloride. ing step; products from these points also contain Considerable trouble has been experienced with dissolved hydrogen chloride which promotes the maintenance of aluminum chloride slurries in hydrocarbon charging stocks such, for eX comp‘ex formation and which is hence objection ample, as light naphtha. Thus in a system for able in the slurrying step. However, the cooled injecting aluminum chloride into a light naphtha 25 product from which hydrogen chlorideY has been the system may serve as a vehicle for introducing isomerization reactor Where a slurry of 2 pounds of finely ground aluminum chloride per gal lon of 153° F. end point naphtha feed stock is v removed is an excellent source of slurrying liquid. Also, the heavy ends of the isomerization prod ucts, i. e., components boiling just above neo employed, at least ’75% of the aluminum chloride heXane, are also effective for producing a stable settles out of the naphtha at a rate of 20 to 30 30 slurry which is substantially free from sticky and feet per minute. Furthermore, on contacting the adhesive materials; the recycling of this heavy fresh feed the aluminum chloride almost imme isomate fraction serves the additional and imdiately becomes sticky and tends to form a paste. portant function of increasing the- neohexane It appears that the naphtha contains a small production in the isomerization system. amount of material which reacts readily with the 35 aluminum chloride to form an adhesive. A It might be supposed that since products from the isomerization system are effective slurrying thorough drying of the charging stock does not agents that light iso~parañins would likewise be avoid the tendency of the catalyst to agglom~ effective. A test with isooctane as a slurrying erate and become sticky, and it, therefore, ap agent showed that this agent was even worse pears that the trouble is caused by the nature 40 than untreated light naphtha charging stock. of the charging stock itself or by a trace of ad» The use of isooctane resulted in an adhesive mass hesive-forming materials in said charging stock. that settled and stuck to the bottom of a con An object of our invention is to avoid the forma tainer. Isooctane is thus utterly worthless as a tion of sticky or adhesivesubstances in suchcat slurrying agent. alyst slurries and to avoid the clogging of line-s, The »sludge produced in the aluminum chloride pumps, valves, injection means, etc., through pretreating step (or spent sludge from the isom which the slurry must be passed en -route to the erization reaction Zone) may be introduced into reaction chamber. av high pressure hydrogen chloride generator and A further object of our invention is to vprovide a more efñcient utilization of liquids separated 50 treated ywith a hydrolyzing agent such as sulfuric acid or water in order to supply at least a part from isomerization products in an isomerization of the necessary make-up hydrogen chloride reaction system. Other objects will become ap-4 which is required in the isomerization reaction. parent as the .detailed description of ourinven Alternatively it may be used as catalyst mate tion proceeds.V We have discovered that if the hydrocarbon 55 rial in the isomerization reactor, being intro 2,406,778 3 4 duced separately or with recycled complex and not with the make-up catalyst slurry. Our invention will be more clearly understood from the following detailed description read in which is a schematic flow diagram of an improved about 35 pounds pressure. Hydrocarbon gases may be purged from the system through line 45 and the butane from the base of the separator' may be returned through line 45, pump 4i) and line 4I back to the top of the absorber. Hydrogen leaves the top of the absorber through line 4l. The charging stock-hydrogen chloride solution system for isomerizing light naphtha. from the base of absorber 20 is forced by pump conjunction with the accompanying drawing which forms a part of this specification and . While our invention is applicable to a wide 48 4through heater 49 and lines 55 and 50a into variety of aluminum chloride-hydrogen chloride li) isomerization reactor 5I. Hydrogen from line 4l hydrocarbon conversion processes, it is particu larly applicable in the process for isomerizing a or from outside source 52 is introduced by com pressor 53 either into line 50 or directly into re light naphtha consisting essentially of parañinic actor 5I. Make-up aluminum chloride ín the hydrocarbons of the butane to hexane boiling form of a slurry is introduced into reactor 5I from range. Referring to the drawing, a virgin naph a slurry tank by means of pump 54 and line 55. tha charging lstock is introduced by pump iil Aluminum chloride or complex from other parts through heat exchanger II to fractionating of the system are introduced into the reactor tower I2 which is provided with suitable heat through line 56. ing means I3 at its base and which is operated The reactor contains a large amount of alumi under such conditions that heptanes and heav 20 num chloride catalyst material which is usually ier hydrocarbons are removed from the base in the form of an aluminum chloride hydrocarbon through line I4. An intermediate cut consisting complex. The charging stock passes upwardly essentially of C5, Ce or C5 and Cs hydrocarbons through this catalyst material in ñnely divided may be withdrawn by pump I5 (a plurality of d‘spersed phase at a space velocity of about .2 towers will be used for the fractionation in ac 25 to 4 volumes of liquid charging stock per hour tual practice, the side stream being a diagram per Volume of catalyst material. The tempera matic representation) through heater I5 and ture in the reactor is within the range of 100 to then split into two streams, the 'small stream 400° F. and is usually in the general viciniïy of passing by line I'I to pretreating tank I3 and the 250° F. The pressure in the reactor is in the large Istream pas-sing by line I 9 to hydrogen chlo 30 range of 500 to 1500 pounds per square inch and ride absorber 2B. When the make-up aluminum may be about 850 pounds per square inch. Reac chloride is slurried with recycled material. the tion products are withdrawn from the top of re valve in line I 'I may be closed and all of the actor 5I through lines 57 and 58 to warm settler 59 and thence through line EU, cooler 6I and pres sure reducing Valve 62 to cool settler 63. Gases through line 2l and cooler 22 to reflux drum 23 leave the top of the cool settler through line 64. from which' uncondensed gases may be vented and are returned by line 32 to hydrogen chloride through line 24. When an intermediate cut has absorber 20. been withdrawn, the reflux condensate may con Clear product liquids leave the cool settler sist essentially of butane (or a mixture of bu 40 through line 65 and are introduced by pump 56 tanes and pentanes) which is withdrawn from into hydrogen chloride Stripper column 61 which the base of the drum by means of pump 25. A is provided with a suitable heating means 68 at portion of this reflux condensate may be re its base. The overhead from this stripper may be turned through line 26 to serve as reflux in the passed through line 69 to line -32 for recyclingV or top of tower I 2. Reñux condensate from this 45 may be passed through cooler ‘I0 to reñux drum source may also be introduced through line 2l 'I I. Gases from the top of this drum pass by linesy to line I7, through line 23 to line I9, through line 12 and line 32 to the hydrogen chloride absorber 29 to a hydrogen absorber system, or through 20 and liquids from the base of this drum may line 30 to storage or to a point of use elsewhere be either returned by line 'I3 for use as reflux in in the refinery. the top of the stripper or may be withdrawn The hydrogen chloride absorber 2i! is prefer through line 14. The product from line 74 is ably operated under a superatmospheric pressure chieily isobutane and when it is passed to an which may range from about 50 to 350 cr more aluminum chloride alkvlation system it is un pounds per square inch but which is preferably in necessary that dissolved hydrogen chloride be re the general vicinity of 200 to 250 pounds rer charging stock may be passed to the absorber. Overhead from fractionator I2 is withdraw):` ‘-‘~ square inch. Make-up hydrogen chloride may b2 introduced through lines 3| or 33 and a gaseous stream containing hydrogen chloride is introduced at the base of this absorber through line 32. Un 55 moved therefrom. Stripper tower S'I may thus function both as a hydrogen chloride stripper and as a stabilizer tower. Liquid products from the base of tower El are passed directly by line 'I5 or through cooler 'I6 absorbed gases, chiefly hydrogen, methane, eth 60 to caustic scrubber and Wash tower TI. Caus ane, etc., leave the top of the absorber through line 34 and may be vented from the system through line 35 or introduced through line 36 to gether with additional hydrogen containing gases from line 31 into the base of absorber 33, a suit able compressor 39 being employed for this purpose. Butane from line 29 may be introduced by pump 49 and line 4I to the top of absorber 38. This absorber may be provided with suitab`e baffles or bubble plates and it may be operated at a temperature of about 100° F. and a pressure of about 900 pounds per square inch. Gaseous hy drocarbons are absorbed and introduced through line 42 and pressure reducing valve 43 into sep arating chamber 44 which may Operate under tic may be introduced through line 78 and water through line 79. The wash water may be trapped out above the caustic inlet or the water and caustic may both be removed from the base 65 of the tower through line 80. The neutralized and water washed product is withdrawn from the top of the wash tower through line BI and it may either be withdrawn Vfrom the system through line 82 or passed 70 through line 83 and heat exchanger 84 to stabi lizer or fractionating tower 85 which is provided with a suitable heating means 86 at its base.k Heavy isomate or hydrocarbon material may be withdrawn from thebase of the stabilizer through line 81 and removed from the system through 2,496,778 5 line 88. `or returned lthrough. vlinesßß and 30, tothe slurry tank. A light isomateßmay be, withdrawn as. a side stream from tower 8.5 through line 9|.. (Here again, a’plurality .of ,towers` would be used in >actual practice.) or >5Ib through lines 5,6 or IDB. ' >The lpretreating with aluminum chloride in lump form,> supported form or complex form in chamber I8 alters thewcharaoter of the charging stock in such a Way as to prevent the formation ' `Overhead :from the stabilizer is passed `through cooler 92toreflux drum’Bßfrom which gases 6 recovery drum I05„or >to one of .the reactors 5I of sticky adhesive compounds with the powdered ' aluminum chloride in slurry tank IIB. In the absence .of ,the nretreating _step the. slurry 'formed he vented through line. 8.4... >A portion .ofthe vre flux may be returned'hyypump .95 Athrough line 96Á to theztop of the .stabilizer and a, lightfrac tion consisting,V iorexar'npl , :chiefly .of butanes maybe .withdrawn from .thefsystem through line .in tank ,|.|8 rapidly plugs lines 55, 55a, etc. and the pumps, -valves, etc. >associated therewith. The pretreating step insures'the formation of a slurry »which-is. sufiiciently free from sticky .and adhesive materials so that it will not agglomerato 91.. Instead of ¿employing a .single'reactor we may employ Ía multiple reactorV system. Thus .charg ing stockv with ahsorbedhydrogen chloride :may be introduced throughlineâßb to reactor Elib and make-up .catalyst `may be .added to .this reactor through :line 5517. Alternatively, the products leaving the top of reactor'äl may be> passed by line .98..tl1rough cooler 99 .and to reactor 5Ib> and the products from the top'of reactor 5|b Amay be passed through “line |00 and line v58 to warmset and will not cause aplugging of the transfer limes, ' pumps and valves. A hydrolyzing agent such as sulfuric >.acid or wateris `introduced¿into drum |05 through line |25 and the sludge or `colsey residue is withdrawn from the .drum .through line |26. Recovered hy Y drogen chloride _is returned through ,line |21 and line >32 to absorber Z0. If water is used as a hy drolyzing ragent it should be employed in lless than stoichiometric amounts in order that the recov tler 59. ¿Catalyst from the Vbase of reactor `5|b may lbe 25 ered hydrogen chloride ¿may be substantially an~ hydrous. Larger amounts of recovered khydrogen withdrawn by pump |.0I and either withdrawn chloride may be obtained by the use of sulfuric from the system through .line |02, passed by lines acid and such use is particularly advisable where |03 and 5B .to reactor 5I or passed. through, lines |03 to line |04 to "hydrogen Vchloride recovery sludge cokermeans `are available Vfor recovering drum |65. Catalyst‘may.be'withdrawn from the 30 base of reactor. 5| by pump |05 and either with_ drawn from the system through line |01, passed to reactor EIb .through line `I08'or passed to the hydrogen chloride recovery drum through lines |09 and |114.L `Material from lines ,|02 or |01 or. 35 both may be .employed to pretreat naphtha in the sulfuric acid. tank I8. ~ settieu catalyst _material from settler 59 may be passed through lines .III and |08 to reactor ' The hydrogen chloride _recovered from chamber |05 mayA notbe _suiiicient to supply all of the re quired >make-up `hydrogen chloride andV addi tional hydrogen chloride may, therefore, have to be added through line .3L „ The additional `hy drogen chloride may be generated in a high pressure generator |21 luy-adding a hydrogen sup plying agent through line |28 and a chlorine` sup plying agent through line |29. The by-oroduct 40 vfrom .this generator mayy be >withdrawn through line |30 and the produced hydrogen chloride may actor 5|. Precipitated catalyst material from be introduced directly through line 33 into the cool settler B3 may be pumped as a slurry by base of the absorber 20 without the necessity of pump ||3 through lines ||4 and 90 to the slurry employing pumps or purifying means. The hy tank but is preferably pumped through lines I I5 and |08 to reactor 5|b or through lines III;` and 45 drogen supplying agent may be hydrogen itself, a gas containing hydrogen (e. g., from line 35), 56 to reactor 5|. a hydrocarbon or sulfuric acid.` The chlorine chamber 5|b or through lines || 2 and 56 to re Our invention is primarily connected with the supplying of make-up aluminum chloride to the isomerization system hereinabove described. supplying agent may be chlorine gas, sodium chloride, hydrochloric acid, etc. Thus chlorine may be introduced through line |29 and burned Powdered aluminum chloride from source ||1 is 50 with an excess of hydrogen or hydrogen contain introduced into slurry tank ||8 by means of any ing gas introduced through line |28 or reacted suitable hopper, screw feeder, or other feeding with a hydrocarbon introduced through line |28. means. Slurry tank ||8 may be provided with a Sodium chloride or aqueous hydrochloric acid suitable mixer or high speed stirrer driven by motor I 20. The oil for making up the slurry may 55 may be introduced through line |29 and sulfuric acid may be introduced through line |28. be obtained from pretreating tank I8 through line While the pretreating of a portion of the feed |2| or from various parts of the system through stock with aluminum chloride makes it possible line 90. to produce a pumpable slurry in tank ||8 we In prereating tank I8 the aluminum chloride is preferably in lump form or is deposited on a 60 have found that a superior type of slurry is pro duced by employing liquids recycled from the suitable support such as Kieselguhr or is in the system through line 8.0. Such liquid may be form of a hydrocarbon complex. Thus lump alu withdrawn from the product stream between minum chloride may be introduced from source cooler 'I6 and wash tower '|'| and passed to tank |22 and may be retained in the pretreating cham ber by screen support |23. Light naphtha from 65 |20 through lines |3I, 89 and 90. 'I'he product at this point is substantially anhydrous and is line |'| enters pretreating chamber IIB below free from catalyst material and hydrogen chlo screen |23 and passes upwardly through the bed ride. The "pretreatment” of the charging stock of lump aluminum chloride, leaving the top of for the preparation of a slurry Vehicle is in this the pretreating chamber through line I2 I. A vis cous brownish red complex may be formed by the 70 instance effected in the isomerization reactor it self. contacting of charging stock in this pretreating Another liquid Which produces a highly desir chamber and since this oil complex is heavier able type of slurry is that obtained from the base than charging stock it settles to the base of the of stabilizer or fractionator column B5 from lines pretreating chamber and may be withdrawn therefrom through line |24 to hydrogen chloride 75 81 and 89. This liquid may consist' chieñy of 2,406,778 7 8 methyl pentanes and unisomerized normal hex;` ane. By using this liquid as a slurrying agent for make-up aluminum chloride we not only ob tain a highly satisfactory slurry but We 'also ob unabsorbed gases from the top of the absorption zone, making up an aluminum chloride slurry of iinely divided «solid aluminum chloride particles in a portion of the stream after hydrogen chlo ride has been stripped therefrom and introducing tain increased yields of neohexane, i. e.; We ob tain isomerization products of higher octane said aluminum chloride slurryV into said isom number and hence of greater value as aviation fuel blending stocks. While We have described specific examples of our invention in considerable detail it should be ll() understood thatour invention is not limited to these particular examples nor to the speciñc con material contained therein. Y 2. The method of >isomerizing a parañinic hy drocarbon charging stock boiling Within the bu tane to hexane boiling range Which method com ditions'recited therein since other examples and other operating conditions will be apparent to those skilled in the art from the above detailed description. erization zone for maintaining the activity of the liquid aluminum chloride-hydrocarbon complex prises adding hydrogen chloride to said charging stock, and introducing the charging stock With added hydrogen chloride at a low level into a con ‘ tinuous . isomerization zone containing a large ` `We claim: amount of liquid aluminum chloride-hydrocar bon complex catalyst material, eñecting isomeri l. The method of isomerizing a paraiiìnic hy drocarbon charging stock boiling within the bu tane to hexane boiling range which method com prises absorbing hydrogen chloride in said charg zation of said charging stock in said isomeriza tion zone, withdrawing a product stream contain-ing catalyst material and hydrogen chloride from the upper part of said isomerization zone to a set tling Zone, removing catalyst material from said stream in said settling zone, introducing said ing stock in an absorption zone to form a hy drogen chloride solution, heating said solution toY isomerization temperature and introducing the heated solution at a low level in a continuous 25 stream from said settling zone to a stripping zone, isomerization zone containing a large amount of stripping hydrogen chloride from said stream in said stripping zone, treating the stripped stream with caustic to effect neutralization thereof, frac liquid aluminum chloride-hydrocarbon complex catalyst material, effecting isomerization of said charging stock in said isomerization Zone, With drawing an isomerization product stream con taining dissolved catalyst material and hydrogen tionating the neutralized product stream to obtain - a plurality of fractions including a'heavy frac tion, making up an aluminum chloride slurry of finely divided aluminum chloride particles in a portion of said heavy fraction and introducing said aluminum chloride slurry into said continu chloride from the top of the isomerization zone to a settling zone, removing catalyst material from said stream in said settling zone, intro ducing the stream Whichstill contains hydrogen chloride from said settling zone to a stripping Zone, stripping hydrogen chloride from said «stream in said stripping zone', returning hydrogen chloride containing gases from the top of the stripping zone tothe absorption zone, venting ` ous isomerization zone for Amaintaining the activ ity of the liquid aluminum chloride-hydrocarbon complex catalyst material contained therein.> WILLARD E.V KRUSE. 40 " CECIL W. NYSEWANDER. ' JOHN A. BOLT.