Патент USA US2406954код для вставки
Patented Sept. 3, 1946 2,406,954 UNITED STATESEPATENT orrlclaiv ALKYLATION 0F ISOPIARAFFINIC HYDRO CARBONS ‘Carl B. Linn, Riverside, Ill., assignor to Universal Oil Products Company, Chicago, 111., a corpo ration of Delaware > No Drawing. Application September 20, 1943, Serial No. 503,105 8 Claims. 1 (Cl. 260-6834) “ v , 2 , V ‘This application is a continuation-in-part of my co-pending application Serial No. 424,783, ?led December 29, 1941. the so-called primary reaction product is accom panied by many side reactions among which ‘are decomposition or cracking reactions and isomeri-< This invention relates to a process involving zation which under certain conditions can change the treatment of isoparaf?nic hydrocarbons, both gaseous and liquid, ‘to; produce therefrom branched chain parafiinic hydrocarbons of higher such as iso-octanes into‘ a mixture of isomers of lower and higher boiling hydrocarbons frequently molecular weight. In a more speci?c sense this invention is concerned with a novel process for of lower antiknock value. Accordingly, the pres ent invention deals with the modi?cation of a alkylating isoparaf?nic hydrocarbons comprising isobutane and relatively low-boiling normally liq uid is‘opara?ins with gaseous‘ or liquid ole?ns to produce normally‘liquid saturated hydrocarbons hydrogen ?uoride alkylation catalyst by the ad dition thereto of certain inorganic compounds which have substantial solubilities therein and which moderate the action of this catalyst in which may be utilized as components of gaso such‘ a way as to improve the‘yield and quality a substantial‘proportion of the primary product line suitable for use in airplane and automobile 15: of the hydrocarbon alkylation product.v engines. ‘ ‘ According to the process of the present inven tion, isopara?ins are. contacted with ole?ns in These isopara?lnic and ole?nic hydrocarbons the‘presence of a catalyst consisting of a major have been utilized in alkylation reactions in the proportion by weight of liquid hydrogen ?uoride; presence of hydrogen fluoride alone or of hydro gen ?uoride diluted with relatively small quanti 20 and a relatively minor proportion by weight of a low boiling ?uoride or oxyfluoride which is solu ties of water. The present type of catalyst is ble in said hydrogen ?uoride. The term iso a marked improvement over previous catalysts paraf?n is herein used broadly to include all containing hydrogen ?uoride in that the activity alkylatable branched chain para?ins. The reac of the catalytic material may be controlled more accurately by proper dilution with non-aqueous 25 tion of the presentprocess is effected under con trolled conditions of temperature and pressure substances which are relatively inert catalytically until the ole?ns have been substantially consumed but which have substantial solubilities in liquid and a substantially saturated hydrocarbon prod hydrogen ?uoride. ‘ uct is formed which boils within the boiling range Bro'adly,‘the invention relates to the use of a hydrogen ?uoride alkylation catalyst which con 30 of gasoline. Isobutane is the isopara?in commonly ' sub-' tains dissolved therein at least one ?uoride or jected to alkylation although higher molecular oxy?uoride having a boiling point below about weight isopara?ins may also be reacted with ole 300° C. ‘ ' " In one speci?c embodiment the present inven ?ns under similar or modi?ed conditions of oper tion comprises the alkylation of'isoparaf?nic hy 35 ations to produce branched chain para?ins of higher boiling point than the isoparaf?ns charged drocarbons with ole?nic hydrocarbons in the presence of a catalyst comprising essentially a to the process. However, as the higher molecular weight isoparafflns such as isopentane, isohexane, major proportion of hydrogen ?uoride and a_ relatively minor ‘proportion of an inorganic com pound which is soluble in said hydrogen ?uoride and which has a boiling point below 300° C., said inorganic compound being selected from the group consisting of the ?uorides and oxy?uorides of sulfur, selenium, nitrogen, phosphorus, molyb denum, titanium, tungsten, vanadium, and silicon. etc., are themselves valuable constituents of gaso 40 line, they are consequently used less commonly as charging stocks for the alkylation process than is Mono-ole?ns, and particularly those containing from 3 to about 16 carbon atoms per ‘ isobutane. ' molecule, are utilizable for alkylating isoparaf?ns “ in the presence of a mixture of hydrogen ?uoride and a diluent o1_‘__spac_ing agent as herein de scribed, although the common ole?n-containing charging stocks are often limited to hydrocarbon‘ ride with a non-aqueous diluent so that the ordi fractions containing propene and butenes and narily vigorous reaction of anhydrous hydrogen ?uoride on catalytic condensation reactions 50 certain amounts of ethylene. Normal para?ins among hydrocarbons is moderated to the extent frequently present in hydrocarbon fractions con A feature of the present invention is the dilu tion of substantially anhydrous hydrogen ?uo that reactions of alkylation occur in preference to other less desirable reactions. Alkylation is essentially a complex reaction since the simple taining propene and butenes dilute the reacting " hydrocarbons but are separable from the ‘alkyl ation products by distillation. Thus, propane and union‘ of paraffinic andole?nic molecules to give 55 normal butane may ‘beiremoved from the alkyl» 2,406,954 3 4 ation product, while an isoparaf?n such as iso butane, which is also separated from the reaction peratures and pressures. A tabulation of the principal inorganic compounds of this class and their physical properties is presented as follows: product, is recycled to further alkylation treat ment. In order to favor the alkylation reaction rather Compound than ole?n polymerization, the hydrocarbon charging stock including the isoparai?n and add; ed ole?n-containing fraction may be commingled with recycled isopara?in so that the ratio of iso paraf?n to ole?n in the total hydrocarbon mix ture charged to the alkylation zone is approxi Boiling point, DC‘ —63. 5 —99 —-30 —52 100 —34. 5 mately 5:1. In some cases this ratio may be as. 124 low as about 1:1 or as high as 10:1, or more, the —56 —63. 5 exact ratio being somewhat dependent upon the particular isopara?in and ole?n or ole?n-contain -—95 —75 —40 ing mixture charged. The amount of hydrogen ?uoride-containing catalyst employed is preferably from about 10 to about 100 parts by weight of catalyst per 100 parts by weight of hydrocarbons undergoing treatment at any one time, although in some operations other ratios of catalyst to hydrocar bons may be used. The concentrations of hydro gen ?uoride in the composite catalysts which I have found desirable are limited by the solubilities in liquid hydrogen ?uoride of the compound or compounds chosen as catalyst diluents or spacing agents. Depending uponthe reactivity of the hy drocarbon components in a given alkylation re action, hydrogen ?uoride of different concentra tions and different proportions of hydrogen ?u oride and diluents may be employed to form active 1 Under pressure. 1 65 mm. pressure. From the statements hereinabove set forth con cerning the types of inorganic compounds which may be employed as diluting or spacing materials for hydrogen ?uoride, it will be evident that a large number of catalyst composites of varying compositions may be made according to the 30 needs of different alkylationreactions. However, the di?erent diluents or spacing agents are not necessarily equivalent inv their action. While in most cases the activity of‘ the alkylat Alkylation reaction temperatures between about 0° and about 50° C. are preferred, although satis 35 ing composite employed is due principally to the hydrogen ?uoride, it is recognized that the inor factory results may be obtained at temperatures ga-m'c compounds added thereto may at times as low as about —30° and as‘high-as about +100° exert a de?nite‘ chemical in?uence upon the re-' .0‘. when reacting isopara?ins with ole?ns in the alkylating catalysts. presence of a mixture of hydrogen ?uoride and a spacing agent as herein described. As addi tional means of regulation of the upper limits of temperature, the proportions of hydrogen ?uoride and diluent may be varied to produce good re sults provided they are co-ordinated properly‘ with the reaction temperature and rate of charge of' the isopara?ln and ole?n hydrocarbons. For instance, the reaction of' isobutane with propenev may- require more severe conditions such as a somewhat higher temperature, a longer time of‘ contact, or a catalyst containing a higher pro- " portion of hydrogen ?uoride to diluent than. thatv used for catalyzing the reaction of isobutane with the more reactive isobutene. Superatmospheric pressure, generally not in excess’ of about 20 at mospheres, is employed to assist the reaction and‘ to prevent undue loss of the reactants and cat ' actions other than merely moderating the effect of the hydrogen’ ?uoride. It is also evident that the selection of any particular compound or mix ture of compounds for use with hydrogen ?uoride is determined by solubility relations, the moderat ing effect of said compound‘ on the activity of this catalyst utilizedin thev alkylation of the isoparaf ?nic hydrocarbons involved, the general operat ing conditions‘, and the matter of economy in the‘ cost of the reagents. The process of the'present invention is carried out in either batch or continuous types» of opera~ tion. In asimple'batch type process, an isoparaf ?n to- be alkylated such as isobutane, is brought to the alkylating temperature within the approxi mate range speci?ed and in the presence of the alyst‘ by vaporization and, when desirable, to necessary amount‘of catalyst mixture comprising‘ liquid-hydrogen?uoride and spacing agent, and alkylation is e?ected by the gradual introduc maintain the hydrocarbons and catalyst in sub stantially liquid state or to effect liquefaction of tion of an ole?n, or preferably of an ole?n-iso . para?in mixture, under the surface of the liquid‘ a portion of the reaction mixture. The spacing agents or diluents which are em ployed in the present invention are inorganic ?u_ oridesv and oxy?uorides which are soluble to a substantial extent in liquid hydrogen ?uoride and which boil below about 300° C. The preferred compounds are the low boiling ?uorides and oxy ?uorides of sulfur, selenium, nitrogen, phospho rus, molybdenum, titanium, tungsten, vanadium, and silicon. Of' the last named compounds the ?uorides and oxy?uorides of silicon are most catalyst which. is stirred‘ mechanically to e?ect intimate» contact between the catalyst and the reacting hydrocarbons and to delay the settling out and separation of the catalyst which is heavier than‘ the liquid hydrocarbon mixture. Alkyla tion may be allowed to progress to different stages of reaction. In the case of the alkylation of iso butane by propene or butenes, good products from the standpoint of high antiknock gasoline are produced usually by maintaining at all times in readily obtained, particularly silicon tetra?uoride. the reaction zone‘ a molar'excess of isopara?in to ole?n. The presence of such an excess‘ of iso Most‘ of these ?uorides and oxy?uorides are nor mally gaseous compounds but are soluble to a para?ins, generally at least 2 molecular propor tionsv of isopara?in per molecular proportion of useful extent in hydrogen ?uoride. A few of the compounds are liquids or solids at ordinary tem ole?n, tends'to minimize undesirable polymer ization reactions. The mixture of‘ alkylation 2,406,954 ‘5 ,6 ‘ products-and catalyst composite is removed pe uctI-isreturned to further contactwith normal riodicallyfrom the batch'type process and sep butenes anda-mixture of fresh and used cat alyst to produce a further quantity of alkylation arated into a hydrocarbon‘layer‘ and a catalyst ' layer, the latter being returned to the reaction zone “for further use while the hydrocarbon layer is fractionallydistilled to separate therefrom the gasoline fraction and‘the excess of the isoparaf» ‘ ?n originally charged to the process. rll‘he excess product. . . From 3000 c. c.‘ (approximately 1700 grams) of the isobutane-normal butene mixture treated there is obtained approximately 850 grams of water-white, normally liquid, saturated hy'dro carbons containing less than 0.001% by weight isopara?in may be’ reacted further with an‘ ole?n in a subsequent alkylation treatment in the 10 oforganically combined ?uorine and having an end-boiling point of 450° F. The resulting nor alkylation zone of the process. mally liquid hydrocarbons are equivalent to ap It is usually preferable to carry out the alkyla proximately 200% by weight of the‘ butenes tion reaction on a continuous basis by withdraw charged to the process. 90% of the liquid hy ing from the alkylation reactor a mixture ‘of excess unreacted isoparai?ns and admixed nor 15 drocarbon products boil below 300° F. and are thus in the boiling range of aviation gasoline. mal para?ins, an alkylate of gasoline boiling The aviation gasoline ‘fraction has an A. S. T. M. range, higher boiling hydrocarbons, and catalyst octane number of 93. composite, said mixture being withdrawn at sub stantially the same rate as that at which the fresh hydrocarbon charging stock and catalyst 20 are supplied to the alkylation reactor. In order to keep low the competing ole?n polymerization reaction, the molar ratio of isoparaf?ns to ole I claim as my invention: 1. An alkylation process which comprises re acting an isopara?in with an ole?n in the pres ence of a liquid hydrogen fluoride catalyst hav ing dissolved therein a minor proportion of an inorganic compound soluble in liquid ‘hydrogen ?ns in the alkylating zone is kept relatively high throughout the entire reaction. The ratio of 25 ?uoride and boiling below about 300° C., said in organic compound being selected from the group isoparaf?n to ole?n is subject to some variation consisting of the ?uorides and oxy?uorides of and is a?ected considerably by the method of sulfur, selenium, nitrogen, phosphorus, molyb introducing the ole?n-containing fraction and by denum, titanium, tungsten, vanadium, and sili the efficiency of mixing. As the process is usually _ operated, su?icient pressure is maintained upon 30 con. 2. An alkylation process which comprises re the reaction mixture to keep a substantial pro acting an isoparaf?n with an ole?n in the pres portion thereof in liquid state. The exact pres ence of a liquid hydrogen ?uoride catalyst hav sure necessary depends both upon the composi ing dissolved therein a minor proportion of sili tion of the reaction mixture and the tempera ture employed. The alkylation reactor used in 35 con tetra?uoride. 3. A process for the synthesis of saturated the process consists quite often of a coil or tower gasoline boiling range hydrocarbons which com provided with ba?les, ori?ce plates, or other mix prises reacting an isoparaf?n with an ole?n un ing'devices, or a vessel provided with a stirrer or der alkylating conditions in the presence of a other mechanical means of agitation although > catalyst comprising essentially a major propor any method may be employed that satisfactorily tion by weight of liquid hydrogen ?uoride and a e?ects intimate contact of the reacting hydrocar relatively minor proportion of an inorganic com bons and mixture of catalyst and spacing agent pound soluble in liquid hydrogen ?uoride and employed. . boiling below about 300° C., said inorganic com The following example is given to indicate re sults obtainable by the use of the present proc 45 pound being selected from the group consisting of the ?uorides and oxy?uorides of sulfur, seleni ess, although it is not intended to limit the scope um, nitrogen, phosphorus, molybdenum, titanium, of the invention in exact correspondence with the tungsten, vanadium, and silicon. example. 4. An alkylation process which comprises re A mixture of 392 grams of anhydrous liquid acting an isopara?inic hydrocarbon with an ole 50 hydrogen ?uoride and 8 grams of silicon tetra ?nic hydrocarbon at a temperature of from about ?uoride is charged to a steel autoclave of ap -30° C. to about 100° C. in the presence of a cat proximately 5000 c. c. capacity equipped with a alyst comprising essentially a major proportion pressure-sealed stirring device. The autoclave is by weight of liquid hydrogen ?uoride ‘and a rela maintained at approximately 38° C. by immer sion in a cooling bath of appropriate temperature 55 tively minor proportion by weight of an inorganic compound soluble in liquid hydrogen ?uoride and and 3000 c. c. of a liquid mixture, consisting of boiling below about 300° C., said inorganic com isobutane and normal butene in the ratio of 3 molecular proportions of isobutane and 1 molecu lar proportion of normal butene, is introduced continuously to the autoclave over a period of two hours while the reaction mixture in the auto clave is stirred mechanically. After'complet ing the addition to the autoclave of .the mixture of isobutane and normal butene, the stirring is stopped, the hydrocarbon layer is separated from the hydrogen ?uoride-containing catalyst layer, the latter being returned to further use in an other run. The hydrocarbon layer is debutan ized, washed with water and caustic soda solu tion to remove dissolved hydrogen ?uoride, dried, and distilled to separate therefrom a substantial ly saturated fraction of gasoline boiling range containing a relatively high proportion of branched chain octanes. The isobutane recov ered in the debutanization of the alkylation prod pound being selected from the group consist ing of the ?uorides and oxy?uorides of sulfur, selenium, nitrogen, phosphorus, molybdenum, titanium, tungsten, vanadium, and silicon. 5. An alkylation process which comprises re acting an isoparaflinic hydrocarbon with an ole ?nic hydrocarbon at a temperature of from about —30° C. to about 100° C. in the presence of a catalyst comprising essentially a major propor tion by weight of liquid hydrogen ?uoride and a relatively minor proportion by weight of an ' inorganic compound which is soluble in said hy drogen ?uoride and boils below about 300° C., said inorganic compound being selected from the group consisting of the ?uorides and oxy?uorides of sulfur, selenium, nitrogen, phosphorus, molyb denum, titanium, tungsten, vanadium, and sili con and the pressure in the alkylation zone be 7 2,406,954 ing sufficient to maintain the reacting .hydro carbons .and catalyst in substantially the liquid phase. 8 'alkylation zone being sufficient to maintain the reacting hydrocarbons and catalyst in substan tially the liquid phase. 6. An alkylation process which comprises con tacting a molar excess of an isopara'i?nic hydro carbon with an ole?ni-c hydrocarbon at a tem perature of from about -30° C. ‘to about 100° C. 7. An alkylation process which comprises .re-* acting isobutane with a mono-ole?n in the pres ence of a liquid hydrogen ?uoride catalyst hav in the presence .of .a catalyst comprising essen drogen ?uoride and a relatively minor propor tion by weight ‘of an inorganic compound soluble inorganic compound soluble in liquid hydrogen ?uoride and boiling below about 300° C., said in organic compound beingselected from the group consisting of the ?uorides and oxy?uorides of in liquid hydrogen ?uoride and boiling below aboutf300° C., said inorganic compound beingse num, titanium, tungsten, vanadium, and silicon. tially a major vproportion by weight of liquid hy lected from the group consisting of the ?uorides ing dissolved therein a minor proportion of ‘an sulfur, selenium, nitrogen, phosphorus, molybde 8. The process of claim 7 wherein said inor and oxy?uorides of sulfur, selenium, nitrogen, 15 ganic compound comprises silicon tetra?uoride. phosphorus, molybdenum, titanium, tungsten, vanadium, and silicon and the pressure .in the CARL B. LINN.