Патент USA US2411483код для вставки
Patented Nov. 19, 1-946 -' ' 2,411,4s3 ’ UNITED, ‘STATES PATENT OFFICE 2,411,483 CORROSION’ INHIBITION IN CATALYTIC HYDROCARBON CONVERSION Aaron Wachter, Berkeley, and Richard S‘. Treseder, San Francisco, Calif., assignors to Shell Development Company, San Francisco, _ Caiif., a corporation of Delaware . _ -No Drawing. Application August 28, 1943, - Serial No. 500,458 ' , (Cl. 260—.666) 15 Claims. 1 ' 2 . This invention relates to the execution of cata the product obtained in the preparation of the lytic reactions with the aid of Friedel-Crafts type catalyst or added subsequent to the preparation catalysts and relates more particularly to the of thecatalyst. ~ ' catalytic conversion of hydrocarbons with the The organo-metal hahde complex catalysts, for aid of catalysts comprising an organo-metal 5 examplethose comprising an aluminum halide halide complex. . ' ‘ hydrocarbon complex, are utilized with advantage vIn the execution of catalytic conversions on a as catalysts in the execution of catalytic hydro practical scale with the aid of Fridel-Crafts type carbon conversion processes, such as, for example, catalysts it is often desirable, and sometimes im those involving isomerization, alkylation, reform perative,'that the catalysts employed be of the ing, cracking, and polymerization reactions. type‘comprising the metal halide in the form of Other processes in which they can be applied an organic complex, because of physical and comprise the re?ning or treatment‘of hydrocar chemical characteristics peculiar to these ‘com bons comprising, for example, normally gaseous pounds. Catalysts comprising such an organe hydrocarbons, normally liquid hydrocarbons in metal halide complex generally consist of a liquid 15 the motor fuel boiling range, recycle stocks, or sludge obtained by mixing a metalhalide with an organic compound under suitable conditions, resulting in the interaction of the .halide with the organic compound and/or decomposition lubricating oils, etc. ‘ A di?iculty encountered in the utilization of the organo-aluminum halide complex catalysts, often seriously detracting from the advantages products thereof. I The metal ‘halide constituent 20 otherwise inherent in their use on‘a practical of the organic complex may comprise a halide such as the chloride, bromide or?uorlde of such scale, is their corrosive nature. They are par ticularly corrosive to steel and iron- or ferrous metal-containing materials of which the appa ratus in which the processes are conducted must metals as, for example, A], B, Ga, In, Te, Be, Mg, B, Cd, Cu, Co, Zr. Of these metal halides the halides of- aluminum, particularly aluminum 25 generally be manufactured. Such corrosive chloride and aluminum bromide, are preferred. effect, it must be pointed out, not only results in Suitable organic compounds with which the metal rapid deterioration of costly apparatus, but in a halides are combined vunder conditions resulting , rapid decline in the useful life of the organo in the obtaining of the desired organo-metal metal halide complex catalyst, thereby’further halide complex comprise, for example, aromatic 30 increasing the cost of. the operation. Though it hydrocarbons, such as benzene and toluene; hy is not intended to limit the invention by any drocarbon fractions such as kerosene extracts; theories advanced herein to set forth more clearly cyclic ole?ns such as cyclohexene, cyclopentene the nature of the invention, it is believed that and alkyl :derivatives' thereof; parailinic and such increased rate in the decrease of the catalyst olef'inic hydrocarbons of straight or branched 35 life is often due, at least in part, to the rapid chain structure; phenols; organic acids, ethers, increase of iron in the catalyst as a result of the etc. In the preparation of the complex catalysts latter’s corrosive effect upon the ferrous metal the organic‘compound and metal halide are sub containing surfaces in contact therewith. The jected to an elevated temperature, for example, ‘effect of a relatively high concerrtration of» iron not substantially in excess of about 150° 0., gen 40 on the life of these catalysts is illustratedq'by the erally in the presence of an added hydrogenv following example. a ‘ halide, for a su?icient length of time to result in ' the formation of a liquid, or sludge, consisting ' Example I A dimethylcyclopentane-containing fraction of essentially of an organo-metal halide complex. straight run gasoline having a boiling range of It is to be pointed out, however, that the present 45 from 85° C. to 98‘? C. was treated with acatalyst _invention is in no wise limited by the method . consisting of an AlCla-toluene complex under the of production of the organo-metal halide cata lysts. . f ‘ , following conditions: ' Temperature: 80° C. The catalyst is generally employed in the pres ence of an added hydrogen halide promoter, such 50 Contact time: 17 minutes as, for example, hydrogen chloride, hydrogen bromide, hydrogen ?uoride, alkyl halides or ma ' ‘ ' ' Catalyst to hydrocarbon ratio=1:3 terials capable of producing any of these halide promoters under the conditions of the execution Hydrogen chloride in the amount of‘ 0.1% by weight was added to the charge. The operation was discontinued when the catalyst activity had of-the reaction. ‘The complex may, furthermore, comprise suspended metal halides remaining in dropped to 50% of the equilibrium conversion of dimethylcyclopentane to methylcyclohexane. Though ability of the compound to dissolve in Under these conditions 106 gallons of the hydro cal operating conditions with a separate portion the orango-imetal halide complex is not essen tial to the attainment of the corrosion inhibiting e?ect, those capable of solution in the catalyst sludge are nevertheless somewhat preferred. of the same catalyst in which iron in an amount Suitable compounds of the inhibitor metals com carbon charge were treated per pound of AlCla in the catalyst. In a, second operation a separate portion of the same feed. was treated under identi- - of 6% by weight of the catalyst had been dis solved. ,The amount 'of hydrocarbon charge prise their halide salts, such as the chlorides, . treated per pound of AlCls in the catalyst in the - bromides and ?uorides; their oxides; salts of or ganic acids, and oxygen-containing mineral second operation amounted to only '18 gallons. Certain metals, for example nickel, and alloys acids; etc. when adding the metal inhibitor in ' the form of its halide salt it is not necessary that the halide correspond to that of the metal halide constituent of theorgano-metal halide sludge. For example, when utilizing a hydrocarbon-alu containing materials. The cost of these mate-~ rials, however, generally prohibits their use in 15 minum chloride complex catalyst the inhibitor metal can be added in the'form of the chloride, practical installations, and even though attacked bromide, ?uoride, a salt comprising more than to a lesser degree by the complexes than ferrous one type of halide atom, or it may be added as a metals they are nevertheless seriously corroded mixture of any two or more of such halide salts. over prolonged periods of contact with these cat alysts. Resort to expedients such as the coating 20 Compounds of the inhibitor metals, the addition of which has, proven to be particularly effective of the metal surfaces in contact with the cat in suppressing‘ the corrosive activity of the or alyst is generally found to be impractical and are availablewhich are not so readily corroded by the complex catalyst as the ferrous metal costly. Many of the available coating -materlals, gano-metal halide complex catalysts, comprise necessary repairs. in combined form, a su?lcient amount of the - compounds containing the metals of group IV in such as, for example, plastics, are often found to deteriorate and crack after relatively short 25 their tetravalent ‘form and those of group V in the trivalent form,v for example SbCla, AszOa, ASCls, time of use, thereby entailing additional costs, as TiCh. Whenv the inhibitor metal is thus added well as a serious loss of time required to'e?ect compound containing it is added to the catalyst It has nowbean found that the serious di?i culties heretofore encountered in the utilization 30 to provide a concentration of the inhibitor metal therein within the above-‘defined range. The of organo-metal halide complex‘catalysts can be presence of SbCla in the complex catalysts in con substantially completely obviated by maintaining centrations of from about 0.02% to about 14%, . in the catalyst small amounts of a corrosion in and preferably from about 0.1% to about 6%, hibitor selected from the metals of groups IV and ' V of the periodic table. By the term "metals” 35 have been found highly satisfactory. Although it is generally su?icient to effect the as used throughout the speci?cation and ap addition of but one of the ‘inhibitor metals to the pended claims it is intended to include the ele-. complex, more than one of these metals may be ments arsenic and antimony. added to obtain a catalyst devoid of any substan The inhibitor metal, or The organo-metal halide complex catalysts comprising at least one of these metals are sur 40 tial corrosive effect. compound comprising it, may also be employed‘ prisingly devoid of any substantial corrosive ac tion upon most metal surfaces, and particularly in the form of an admixture or even chemical combination with organic compounds.v Thus, in hibitor metal-containing sludge recovered‘from more efficient in their corrosion inhibiting effect 45 one operation wherein the inhibitor metalwas employed ascorrosion inhibitor and/or catalyst than others, their comparative e?iciency in this component, may be added to the charge of ‘the regard being, to some extent, determined by‘ the same or an entirely separate process. For ex particular operating conditions used, the com» ample, an SbClz-containing sludge, obtained in positionv of the particular catalyst employed, and the composition of the metal surface in contact 50 the isomerization of para?inic hydrocarbons, in the alkylation of isopara?ins with olefins, or simi with the catalyst. The presence of arsenic in upon ferrous metal-containing surfaces, in con , tact therewith. Some of the inhibitor metals are ‘even as small an amount as 0.05% by weight of the catalyst is suflicient to substantially suppress corrosion of steel in contact therewith. Anti mony effects substantial suppression of corrosion of a steel surface in contact with the catalyst when present in an amount below about 0.1% by lar operations, with the aid of metal halide-con taining catalysts may be' introduced into the‘ charge to a naphthene 'isomerization process to attain the desired corrosion inhibition. 55. The following example is given to illustrate the absence to a surprising degree of any substantial corrosive action upon metal surfaces by theor weight of the catalyst.- It is therefore apparent gano-aluminum halide complex catalysts con that the exact amount of the particular inhibitor required to obtain substantially complete inhibi 60 taining a metal of groups IV and V of the periodic table; it is to be understood,v however, that the tion of ‘corrosion will vary somewhat with the . values given are illustrative rather than limiting. particular metal used. The concentration. of the inhibitor metal in the organo-metal halide com-v Example II . plex catalyst is generally maintained in the range of from about 0.01% to about 7%, and preferably In a series of tests, polished metal surfaces of from about 0.05% to about 3%, by weight of the low carbon steel and 5% nickel steel were brought catalyst. Lesser or greater concentrations may into intimate contact with ‘AlCh-hydrocarbon however be used within the scope of the inven complex catalysts at temperatures and for time tion. ‘ ‘ Of the metals of groups IV and V suitable as 70 intervals indicated in the table below. The liquid ' catalyst was agitated by bubbling dry HCl through corrosion inhibitors, antimony, arsenic and tita nium are preferred. The inhibitor metals need not necessarily be introduced into the catalyst chloride, identi?ed in the'following table by the in the uncombined or metallic form but may be letter "A”; an AlCla-toluene complex, prepared ’ it. The catalysts used were: an AlCla-toluenev complex prepared with chemically pure aluminum employed in the form of a‘ suitable compound. 75 with an AlCh of a technical grade of purity, iden-' 2,411,488 5 . I ti?ed in the table by the letter “B”; and an AlCla hydrocarbon complex prepared by the interaction 6 during the course of operation. It is to be pointed out that it is essential to the attainment of sub stantial or complete suppression of corrosion that the presence of the inhibitor in the catalyst, pref of chemically pure aluminum chloride and a smokeless kerosene extract, identi?ed in the table by the letter “C." In a series of separate tests erably within the prescribed ‘concentration, be maintained throughout the operation during ' similar metal surfaces were contacted under sub stantially identical conditions with separate por ' which the catalyst is used. subjection of the tions of the same catalysts to which the indicated metal surface to the catalyst containing the in metals of groups IV and V in the amount and hibitor or treatment of the metal surface with ' form given in the table below were added. Sepa 10 the inhibitor metal in the form of a suitable com pound, such as, for example, antimony trichlo rate runs were also made ‘wherein similar metal surfaces were subjected under substantially iden ride, does not render such a ‘surfaceimmune to subsequent corrosion by the catalyst in the ab tical conditions to contact with separate portions of the indicated catalyst to which'Fe and PC]: sence of one of the inhibitor metals. This is'il-_ were added in the amounts shown. The corrosion 15 lustrated by the following examples. rates ‘of the metal surfaces were carefully deter Example III mined and are given‘ in the following table for _ Three polished specimens of low carbon steel were immersed for 15 minutes in acatalyst con - each of theindividual tests in mils per year. Corrosion rate . | Catalyst C Inhibitor per cent of Temp., cat. by wt. ‘' C. t t ‘2 n 80 tllgls‘f' 20 sisting of an AlCla-toluene complex containing 0.4% SbCls by weight of the catalyst. The speci- . mens were then contacted for a period of 24 mils per year Low 7 5% carbon Ni steel steel hours with a portion of the identical catalyst to 425 1 P-196 A..- Nona... .......... -- so’ 0-20 a, 530 1.660 P-20l A.-. 0.2% SbCls ........ .. 80 0-24 7 6 80 24-89 ’ of 80% C. and agitated by bubbling dry hydrogen , chloride gas through it. The rate of corrosion in 8 ll 80 0-21 6 .13 80 21-88 9 18 P-l99 A.-. 4% S110]; .......... ., 80 80 0-23 23-41 6 a 5 s r-zzs B... None .............. .. so 0-25 5,600 P-233 B... 1% T1014 .......... -- so 0-24 35 were immersed for 1 hour in an AlCla-toluene 80 80 24-89 0-24 25 11 complex to which 0.3% of AszOa had been added. 80 24-87 4 P-m5 A.-- 0.4% SbOl; ........ -- . - P-247 B... 0.1% A520: ________ ._ . ' P-251 B... 0.3% A820] ........ _. P-259 , which no SbCls had been added. The catalyst in both instances was maintained at a temperature 80 0-137v 100 0-24 24 .... _. P-237 B... 1% A501: .......... .. 80 0-24 1 .... .. so 24-136 3 .... .. 80 0—23 0.3% AS201 ........ _. 100 0—24 2 .... .. 0.3% AS101 ________ ._ 100 0-24 2 .... -. P-260 C... Example IV The specimens were then immersed for 24 hours 0. 6 0.3% AS203 ........ -- , 30 Three polished specimens of low carbon steel _-. P-198 0... None ............ .."._ mils per year was found to average 2160. 2, 140 .... .. P-262 A..- 1'7 Fe 288 FcrOz).-.- 80 0-24 2, 250 .... - P-263 A..- 1 0 Fe ?lings) .... _. 80 0-24 1,500 P-ZM B..- 1% P01; .......... _. 80 0-24 2,630 ...... .... .. in a separate portion of the identical complex catalyst containing no AS203. The catalyst in both instances was maintained at 80° C. and asi tated by bubbling dry hydrogen chloride through it. The average rate of corrosion in mils per year 40 was found to be 1870. I Often, depending upon the particular material. being treated. with the organo-metal halide com plex ‘catalyst containing a metal inhibitor, a cer- ' amount of the inhibitor will be removed from As shown by the foregoing example, corrosion 45 tain the catalyst body in the reaction zone by en trainment and/or solution in the reaction prod with an organo-metal halide, complex is obviated uct. This will be the case in processes wherein of ferrous metal-containing surfaces in contact substantially completely and considerable saving, hydrocarbons constitute the material undergoing ' as represented by increase in the life of equipment, is realized by the inclusion of only relatively small 60 ‘treatment. The inhibitor metals, though added in metallic or other form, are generally converted amounts of a metal of group IV or V in the cata tothe halides in the presence of the catalyst, par lyst. It is, furthermore, seen from the above ex- . ticularly when a hydrogen halide promoter is ample that the ability to effect the suppression of present. These halides are soluble to a certain the corrosive effect of the catalyst is not possessed degree in hydrocarbons and will be extracted by the purely non-metal phosphorus, or by small 65 from the catalyst in the reaction zone as the amounts of iron. That the ability to effect the process ‘proceeds. The inhibitor metal is, there suppression of corrosion by sludge-type catalysts fore preferably initially added to the catalyst in is not possessed by all metals was further indi sufficient amount to assure a corrosion inhibiting cated in tests wherein small amounts of nickel and concentration therein and additional amounts copper were added to catalysts of this type with 60 added continuously or intermittently to the feed out the attainment of any decrease in corrosive entering the reaction zone during the course of nes and resulting deterimental consequences. .‘ execution of the process to assure the main'te- L The inhibitor metalin uncombined or combined nance at all‘ times of a corrosion inhibiting con form may be introduced into the catalyst in any centration of the metal'in the catalyst. A par suitable manner. It may be introduced into the 05 ticularly advantageous method of operation com catalyst in the form of solid pieces; a powder; as prises the addition of the inhibitor to but a por a slurry or a suspension in a suitable liquid me tion of the hydrocarbon charge and thereafter dium, such as, for example, a suspension in a hy combining the inhibitor-containing portion of the drocarbon or a hydrocarbonfraction; as a solu feed with the rest of the hydrocarbon feed enter tion in a suitable solvent, for example, an acid, 70 ing the reaction zone. Such method of operation ' such as a hydrogen halide; etc. The inhibitor wherein but a portion of the charge passes metal may be introduced into the catalyst before through a suitable inhibitor-adding zone greatly contact therewith of the material to be treated; facilitates maintenance of the inhibiting amount or it may be introduced in part or in its‘ entirety i of the inhibitor within the reaction zone. It fur into the charge or directly into the reaction zone 76 'ther enables separate heating of the main por ' ‘ ~ "2,411,488 8 . tion of the charge to a temperature sumciently high to maintain the desired reaction conditions Hydrogen’ chloride in the amount of 0.1% by and the lesser portion to a temperature most favorable to solution of the desired quantity of 1 was terminated when the activity of the catalyst inhibitor therein. , weight was added to the feed. The operation had declined to a point where the conversion of dimethylcyclopentane to methylcyclohexane had dropped to 50% of equilibrium conversion. Un der these conditions 36 gallons of hydrocarbon ‘ Since only relatively low concentrations of the inhibitor metals are generally required to obtain the inhibition of corrosion, the concentration of ‘the metal in the reaction product will generally be so small that its removal therefrom will not be required. Separation of the inhibitor metal or a compound containing it from the reaction prod uct may, however, be effected by any suitable feed was treated pei'\pound of AlCls in the cata lyst. The operation was repeated with separate portions of the same catalyst and feed under identical conditions with the exception that 0.8% by weight of AszOa was added to the catalyst. The amount of hydrocarbon feed treated per pound of AlCla in the catalyst was increased to means comprising, for example, one or more of such steps as water-washing, washing with alkae 15 42 gallons. line solutions suchas aqueous sodiumhydroxide, Example ' VI distillation, fractionation, scrubbing, solvent ex traction, treatment with solid adsorptive mate .A portion of the same feedutilized in the op-' rials, etc. In the processing of hydrocarbons with eration of Example V was treated under the con-, ' the organo-metal halide complex catalysts in the 20 ditions set forth in. Example V with an AlCla presence of one of the metal inhibitors, for ex ample arsenic, antimony or compounds thereof, it has been found that the-inhibitor or compounds containing it, such as the halides, can readily be removed from the reaction product by the addi 25 tion thereto of small amounts of water which cause the inhibitor to settle out as a hydrolysis toluene complex catalyst of different origin. 47 gallons of the hydrocarbon feed were treated per pound of A1013 in the catalyst. Treatment of a separate portion of the same feed under identical conditions as the foregoing operation but with the exception that 1.6% by weight of A5203 was ' added to the catalyst resulted in an increase in product. The inhibitor thus separated may be the amount of’ hydrocarbon feed treated to 51 returned to the catalyst in the reaction zone, gallons. - preferably after undergoing a dehydration treat 80 ment and optionally its conversion to a more suit able form, such as tube metallic form or a. halide Salt. ‘ . \l j . I A particular advantage in the utilization of an Example VII A dirnethylcyclopentane-containingv hydrocar bon fraction having a boiling range of from 85° . C. to 95° C. was treated in continuous operation inhibitor metal, such as antimony or its com 35 at a temperature of from 80° C. to 100° C. with an ‘ pounds, for example, antimony trichloride, reAlCla-hydrocarbon complex obtained by the in sides in the ability to separate any antimony tri chloride in they reaction product by simple frac a teraction of A1013 and a kerosene extract to con vert the dimethylcyclopentane content of the feed The maximum amount bons the antimony trichloride may be separated 40 .of feed treated per pound of catalyst, in repeated as a separate Ifraction containing the antimony operations, amounted to 110 gallons. The op tionation; Thus, in the treatment of‘hydrocar ' to methylcyclopentane. trichloride above its melting point. The thus re erations were repeated with substantially iden ticalfeed, catalyst and operating conditions with the reaction 'zone without the need for further the exception that SbCla in the amount of 0.2% treatment of the recovered inhibitor prior to re 45 by weight of the catalyst was initially added to covered antimony trichloride may be returned to cycling it. > the catalyst sludge and additional SbCla was continuously added to the hydrocarbon feed to sion inhibitor must be the absence of any sub maintain a concentration of 0.01% of SbCl: in stantial adverse effect upon the activity of the the hydrocarbon feed entering the reactlon'zone. catalyst. In this respect the metals‘ of groups IV 50 Under these conditions-the treatment of 150 to and V possess the advantage of having no harm 200 gallons of feed per pound of catalyst as ful effect upon either the activity or the useful determined by substantially identical conversions life of the organo-metal halide complex catalysts. of dimethylcyclopentane to 'methylcyclohexane Certain of the metal inhibitors, particularly ar were obtained. senic, antimony and titanium and compounds 55 The invention therefore provides a highly e?i An essential characteristic of a suitablelcorro containing them, particularly the halides, often are found to exert not only a promoting effect cient method for the elimination of the severe di?iculties heretofore encountered in the use of metal halide catalysts as a result of the corrosive depending upon the particular composition of the catalyst and operating conditions used, but also. action of these catalysts upon metal surfaces in to increase the useful life of the catalyst. The 60. contact therewith, thereby enabling the attain highly advantageous effect upon catalytic activity and useful catalyst life _by inclusion of these cor rosion inhibitor metals in the organo-aluminum halide complex catalysts-is shown in the following examples. ' ' Example V A ‘naphthenic straight‘ run dimethylcyclopen tane-containing fraction boiling in the range of _85° C. to 98° C. was treated with a catalyst con ment not only of a substantial increase in the life of the equipment and the useful life of the cata lyst but the substantial savings and reduction in cost of operation occurring therefrom. ' We claim as our invention: _ 1. In the execution ‘ of ‘ catalytic reactions wherein reactants are contacted with a catalyst , consisting of a preformed organo-metal halide“ complex catalyst in a reaction zone comprising sisting of an AlCla-toluene complex under the 70 a metal-containing surface in direct contact with said catalyst, the method of ‘inhibiting corrosion following conditions: ‘ ' . of said metal-containing surface and increasing Temperature: 80° C. ~ the useful life of said catalyst which comprises Contact time: 17 minutes ' maintaining in said catalyst a corrosion inhibit Catalyst to hydrocarbon ratio= 1:3 75 ing amount of a member of the group consisting 2,411,483 ' 10 of antimony. and antimony halides 'in which all containing surface and increasing the useful life halide atoms are the same.v ‘ of said catalyst which comprises maintaining in 2. ‘In a catalytic hydrocarbon conversion proc-, said catalyst from about 0.05%to about 3% by ess wherein hydrocarbons are converted in the ' weight of an antimony ‘trihalide in which all presence of a catalyst consisting of a preformed 5 three halide atoms are the same. organo-aluminum halide complex in a reaction 9. In a catalytic hydrocarbon conversion proc- ~ zone comprising a metal-containing surface "in ess wherein hydrocarbons are converted in the direct contact with said catalyst, the method of presence of a catalyst consisting of a preformed inhibiting corrosion of said metal surface and aluminum chloride-hydrocarbon complex in a , increasing the useful life of said catalyst which‘ 10 reaction zone comprising a metal-containing sur comprises maintaining in said catalyst acorro face in direct contact withsaid catalyst, the sion inhibiting amount of antimon . 3. In , the execution - of _ catalytic method of inhibiting corrosion of said metal sur face and increasing the useful life of said catalyst reactions vwherein reactants are contacted with a catalyst which comprises maintaining in said catalyst , consisting of a preformed metal halide-hydro 15 from about 0.1% to about 6% by weight of anti ‘ carbon complex in a reaction zone comprising a mony trichloride. metal-containing surface in direct contact with ‘ 10. A non-corrosive‘ aluminum halide-hydro carbon complex catalyst consisting of a pre said catalyst, the method of inhibiting corrosion > of said metal-containing surface and increasing formed aluminum halide-hydrocarbon complex the useful life. of said catalyst which comprises 20 containing a corrosion inhibiting amount of anti maintaining in said catalyst a corrosion inhibit ing amount of an antimony trihalide in which all three halide atoms are the same. mony trihalide" in which all three halide atoms are the same. ' , ‘ 11. A non-corrosive aluminum chloride-hydro carbon complex catalyst consisting of a pre formed aluminum chloride-hydrocarbon complex containing a corrosion inhibiting amount of 4. In a catalytic hydrocarbon conversion proc ess wherein hydrocarbons are converted in the presence of a catalyst consisting of a ‘preformed organo-metal halide complexin a reaction zone comprising a metal-containing surface in direct contact with said catalyst, the method of inhibit SbCls. . 12. A non-corrosive aluminum chloride-hydro carbon complex catalyst consisting of a pre ing corrosion of said metal surface and increas 30 formed aluminum chloride-hydrocarbon complex ing the useful life of said catalyst which com containing from about 0.1% to ‘about 6% by prises maintaining in said catalyst a corrosion weight of SbCla. ' inhibiting amount of an antimony trihalide in 13. In a catalytic hydrocarbon conversion proc which all three halide atoms are the same. ess wherein hydrocarbons are contacted under 5. In a catalytic hydrocarbon conversion proc 35 conversion conditions with a catalystconsisting ess wherein hydrocarbons are converted ‘in, the of a preformed organo-metal halide complex ‘presence of a catalyst consisting of a preformed in a reaction zone comprising a metal-containing aluminum.halide-hydrocarbon complex in a re surface in direct contact with said catalyst, the action zone comprising a metal-containing sur method of inhibiting corrosion of said metal sur face in direct ‘contact with said catalyst, the 40 face and increasing the useful life of said catalyst method of inhibiting corrosion of said metal - containing surface “and increasing the useful life of said catalyst which comprises maintaining in said catalyst a corrosion inhibiting amount of antimony trichloride._ 6.‘ In the execution .of catalytic reactions‘ which comprises adding antimony to said hydro v carbons prior to contact with said catalyst in controlled amounts to maintain a concentration of from about 0.01% to about’! % by weight of 45 said metal in said catalyst. wherein reactants are contacted with a catalyst consisting of a preformed aluminum chloride hydrocarbon complex in a reaction zone com-> . v 14. In a catalytic hydrocarbon conversion proc ess wherein hydrocarbons are contacted under conversion conditions with a catalyst consisting of a preformed organo-metal halide complex in prising a metal-containing surface in direct con 50 a reaction zone comprising a metal-containing tact with said catalyst, the method of inhibiting surface in direct contact with said catalyst, the corrosion of said metal-containing surface and method of inhibiting corrosion of said metal increasing the useful life of said catalyst which surface and increasing the useful life of said . ‘ comprises maintaining-in said catalyst from about catalyst which vcomprises adding to said hydro 0.1% to about 6% by weight of antimony tri-' 55 carbons a_ member of the group consisting of an chloride. timony and antimony halides in ‘which all halide 7. In a catalytic hydrocarbon conversion proc atoms are the same prior to contact with said ess' wherein hydrocarbons are converted in they _ catalyst. ' presence of a catalyst consisting of a preformed aluminum halide-hydrocarbon complex in a re action zone ‘comprising a metal-containing‘sur face‘in direct contact with said catalyst, the .method of inhibiting corrosion of said metal- , 15. In a catalytic hydrocarbon conversion proc- . ess wherein hydrocarbons are contacted under conversion conditions with a catalyst consisting of a preformed organo-metal halide complex in a reaction zone comprising a metal-containing sur containing surface and increasing theuseful life face in direct contact with said catalyst, the of said catalyst which comprises maintaining in 65 method of inhibiting corrosion of said metal said catalyst from about 0.01% to about 7% by 1 surface and increasing the useful life of said weight of antimony. ' . 8. In a catalytic hydrocarbon conversion proc ess wherein hydrocarbons are converted in the presence of a catalyst consisting of a preformed aluminum chloride-hydrocarbon ‘complex in a.v 70 reaction zone comprising'a metal-containing sur face in direct contact with said catalyst, the ' method of inhibiting corrosion of said metal catalyst which comprises continuously adding SbCh to said hydrocarbons prior to contact with said catalyst in controlled amounts to maintain a concentration of from about 0.1% to about 6% SbCls in said catalyst. AARON WACHTER. RICHARD S. 'I'RESEDER.