Патент USA US2405874код для вставки
Äu., §39 l E. F. BULLARD ETAL' ALKYLATION OF AROMATIC HYDROCARBONS ‘ Filed Nov. 2, 1942 g . 0') - , ë - invenîors'. Edwin F. Bullard g John Anderson - . I Sumner H. McAllìs'fzr bg *heir* AHorneg//ß i . ',. fg, , 2,4%,874 Patented Aug. 13, 1946 UNITE A STATES r vorricle > " 2,405,874f ' i ALKYLATION oF Artor/nrrl'e` HYDRocARBoNs l e . ' > _ Edwin F. Bullard, Oakland, John Anderson; Berkeley, and Sumner H. McAllister, Lafayette,` Calif., assignors to Shell~ Development Com pany, San Francisco, Calif., a corporation of Delaware Application November 2, 1942, Serial No. 464,286 l 11 Claims. (Cl. 26d-671)- î l hydrocarbon to be alkylated before they are used -This invention relates to the reaction of aro matic hydrocarbons with alkylating agents and particularly to the production of motor fuels and motor fuel components by alkyl-ation of such in the process. hydrocarbons. It deals with an improved method Ul for carrying out such alkylations whereby prod ucts having superior characteristics may be ob _ _ ` . Alkylating agents Whichpmay be used in the process include oleñns, particularly suitable frac tions of petroleum crackingvproducts containing ethylene, prop_ylena» isobutylene, normal butyl enes, the amylenesor mixtures of one o1' >more such olefms.„'¿,1nstead of the oleñns, polymers thereof'ma’yg-be- used, „Not only may ethers, al An important object of the invention is to pro vide a more efñcient and economical method of 10 cohols and esters corresponding to the foregoing oleñns beemployed, but also ctherethers, alco alkylating aromatic hydrocarbons in the vapor hols and esters, such as dimethyl, methyl-ethyl, phase. Another object is to improve vapor phase tained. , methyl-isopropyl, di-normal propyl, ethyl-iso propyl and like ethers, methyl and higher pri methods of reacting benzene and the like in the presence of solid acid alkylation catalysts. A further object is to increase the yield of desirable mary alcohols, may be used. Either inorganic or organic esters such as halides, ksulfates, phos phates, borates, formates, acetates and the like may be employed as alkylating agents. The al alkylation products by reacting aromatic hydro carbons with oleiins. Still another object is to produce aromatic alkylation products having kylating agent-.may be used in a pure or sub superior properties, particularly as regards their motor fuel characteristics. Other objects and 20 stantiallypure former as', mixtures of one or kmore ,alkylating agents with or without other advantages of the process of the invention will materials which do?not interfere with the desired be apparent from the following description. Various methods of alkylating benzene and As >catalyâtsfor the process, acids are used. higher aromatic hydrocarbons have been pro posed from time to time, but they have not been 25 Most preferably the chosen acid catalyst is em ployed with a suitable carrier so that it may con successful because of their inefficient conversion veniently be used in solid form as packing for of the starting materials »and/or their poor qual reaction.v ity of products. It has now been found that these disadvantages of prior alkylation methods may be overcome by the use of an improved re action system employing, preferably, more ad , » . tower or tube type reactors. Acids of phosphorus are particularly suitable for this purpose, par 30 ticularlymixtures of ortho or meta phosphoric acid or pyrophosphoric` acid with kieselg‘uhr or other suitable clays or earths such as areV de vantageous reaction conditions. scribed in U..S. Patent 1,993,513. However, other catalysts such as sulfuric acid, hydrogen fluoride The new process may be applied to the alkyla tion of a wide variety of aromatic hydrocarbons, although when used for the production of motor fuels or motor fuel components volatility consid erations make it more advantageous to use lower . 35 or the like adsorbed on porous supports. or as a coating or ñlm on non-porous packing material or the like may also be used in the process. It boiling aromatic hydrocarbons, particularly ben is also feasible to 'employ liquid acid alkylation zene and toluene. Where such considerations are of lesser importance, higher boiling com catalysts inthe process. pounds may be employed. ThusJ ethyl benzene, vapor phase with a substantial excess of aromatic the xylenes, propyl or isopropyl benzene, mes itylene,-the butyl benzenes, the cymenes, and ' The alkylation is preferably carried out -in the hydrocarbons‘based on the alkylating agent used. It has already been Suggested that in alkylating homologues, naphthalene and its corresponding benzene 1an excess be used to suppress formation substitution products, and the like -may be used. 45 of higher alkylation products. Such excess ben The source of the aromatic starting material is zene is not suñìcient for most efficient reaction -not important. The coal tar industry provides la and it has been found desirable to use at least convenient source of benzene, toluene, etc., but three,l and more preferably ñve to ten or more, petroleum fractions containing these compounds, mols `of the aromatic -hydrocarbons being al particularly the highly aromatic fractions obtain 50 kylated per mol Yof oleñn or equivalent alkylating able by catalytic reforming or hydroforming, are agentV in the process of the invention. In this also useful. Such fractions may advantageously way not onlylare undesirable side reactions such be subjected to extraction with suitable solvents, as the formation >of poly-alkylated products sub for example, as described in U. S. Patent 2,114,524, stantially eliminated, but. also high conversions to increase the concentration of the aromatic 3 of the alkylating agent to valuable products are obtained. The reaction is most advantageously carried out under superatmospheric pressure; preferably known but it has been found desirable to submit at least one-tenth, and preferably at least one fourth, of such aromatic hydrocarbon to treat ment with sulfuric acid under the previously de pressures of 200 toA 400 pounds per square inch are used. The temperature and time of contact which will be most desirable will depend upon the scribedïconditions before returning it to the al kylation unit. The treatment may be effected along with or separately from the treatment of the initial feed. particular catalyst used and the alkylating agent chosen. For the alkylation of benzene with ole The attached drawing shows, diagrammatical iins such as propylene in the presence of phos 10 ly, an assemblage of apparatus particularly phoric acid, a temperature of about 200° C. to adapted for producing cumene by reaction of 400° C., preferably about 250° C, to 300° C., and benzene -with propylene according to the inven a hydrocarbon feed rate of about 0.1 to 0.8 gallon tion. In the drawing only the more important per hour per pound of catalyst are most advan pieces of equipment are indicated for the most tageous. This combination of reaction conditions part, since the location of auxiliary equipment gives results which are markedly superior with such as pumps, valves, storage tanks, pressure-, respect to yields, conversions and efficiency of op temperature- and flow-regulating and measuring eration to those obtained by other methods. ~ devices, heat exchangers, and the like will be evi It has previously been considered that alkyla dent to those skilled in the art. In the arrange tion of aromatic hydrocarbons accomplished a ment of the drawing, benzene from a source not suiñcient purification -of the reactants and prod shown,y is fed by line I to a mixer 2 in which it ucts so that no other treatment was" necessary. is contacted with sulfuric acid introduced via However, to obtain» the -best results according to line 3. The resulting mixture passes by line 4 to the- present invention, it is desirable to treat the settler 5 from which acid is taken olf by line 6 feed stocks used, especially the aromatic hydro and returned to mixer 2 by lines l and 3. A carbon, for removal of undesirable components, part of the acid maybe continuously or inter particularly sulfur-containingoompounds such as mittently withdrawn from the system by line 8. thiophen'e, since otherwise these compounds un The partially treated benzene is conducted by line dergosimultaneous reaction and appear in the product, materially reducing its quali-ty especially for motor fuel use. Such treatment not only im proves the quality of the product and-simplifies its further processing, but also improves the ef fective life ofthe catalyst in the process. ï »For the ¿treatment of benzene, for example, it is-‘preferredto use sulfuric acid of about 90% to 100% concentration' at a temperature of about 10° Cl‘to. 60° C.,»-preferably about 98% concentration at about20°~C.’ A ratio of acid to benzene above 1 tolO by volume is’desirable 'and ratios- of about 0.16:1 to 025:1 are preferred. The acid and ben zene may be intimately contacted by agitation in a mixer or other vessel, countercurrent now in a 9, together with fresh acid introduced by line I0, 30 to mixer II where a’ further intimate mixing is effected. The resulting emulsion is taken by line I2 to settler I3 in which the acid and hydrocar bon phases are again separated.> The separated acid is taken off byline I4 and a part returned 35 to the second reaction stage by line I5 while the remainder is conducted to line 3 by line I6 to furnish the partially spent acid for the first re action stage. The thus-treated hydrocarbon is fed by line I'I to mixer I8 which is supplied, con 40 tinuously or intermittently,` with a caustic from line I9. The caustic-benzene mixture is fed via .line 20 to settler 2l from which caustic is with drawn by line 22. The withdrawn caustic is re turned to mixer I8 for further use by lines 23 and 45 I'I, a part being withdrawn as necessary by line tower which may or may not contain >packing to promote-'intimate mix-ing, or. in any other suit able manner. A contact time of acid with. ben zenegof at least 3Yminutes, and more preferably/i to -6 minutes or longer, is desirable. 'Contact in a plurality ofreactionstages is advantageous in reducingfthe amount of acid required for treat 50 been caustic-treated in theY same manner as the acid-treated benzene introduced via lines 26 and bon is Washed with a base such asl aqueous caus duced via lines 26 and 29 and thus be caustic ment of a givenv volume of aromatic hydrocarbon. After thev acid treatment the aromatic hydrocar 24. The treated benzene is taken off by line 25 and mixed with propylene or propylene-contain ing hydrocarbon which may advantageously have 2l. Alternatively, the propylene may be intro treated along with the benzene. In either case the mixture of propylene and treated benzene is 55 conducted by line 29 to reactors«30 which are Merely treating the feed stocks before alkyla shown as a bank of tubes through which the re tion is not suíîicient to obtain the best results in action mixture flows in parallel. The reactors the present process. It has been found neces contain Ygranules of phosphoric acid or other suit sary to return to the sulfuric acid treating stage able acid catalyst not shown and are heated by at least _a part of the excess unreacted aromatic 60 steam or other means also not shown. They are hydrocarbon recovered from the product. - Since preferably constructed to withstand pressures of this aromatic hydrocarbon has been previously the order of 1000 pounds per square inch. As subjected to the sulfuric acid treatment as well previously indicated, however, other forms of re as to the alkylating conditions, it would be thought that it would'be ideal material for re 65 actors may be used and the reaction mixture may flow through> two or more reactors in series in cycling directly to the alkylation and that fur tie soda before being used in the alkylation step of the invention. ther treatment could not possibly be of advan tage. It was surprising therefore' to discover that by’ feeding a part of this stream to the sulfuric acid treating unit instead of to the alkylation re action, materially improved results, especially with respect to product quality, were obtained. The exact nature of allthe changes in the recycle stead of through all reactors in parallel as shown. Line 40 is provided -for introducingl steam or other activating or controlling agent as may be required to maintain the activity of the catalyst. l It may also be used to introduce fresh-catalyst or cata lyst-regenerating agents.v ¿ 1 f " The reacted -hydrocarbon mixture, comprising cumene and ,unreacted' ¿benzene and ‘_propylene benzene or other aromatic hydrocarbon which and any inert materials introduced-„with the feed are >responsible for ¿the improvedY results‘ïisV not 75 or otherwise, is withdrawn from the reactors by 2,495,374. 5 6 line 3| and conducted to depropanizer column 32 Example IVk in which the lower boiling components are sep The ¿effect of sulfuric acid treatment of the `benzene feed on the quality of the reaction prod ucts was shown by the following comparative runs made with coal tar >benzene which was reacted with propylene in the presence of solid phosphoric acid catalyst using a reaction temperature of 200° arated and taken off overhead by line r3.3.l _The remaining cumene and benzene are taken'oiï as bottoms by line 34 and fed to debenzeni'zer col umn 35 from which the unreacted _benzene is re moved by line 36 and returned to the reaction by . line 31 after withdrawal of a part of line 38 for C. to 250° C. and a pressure of 250 pounds per square inch. The benzene in one case was used treatment with sulfuric acid in mixersl 2 and Il along with the fresh benzene feed. The cumene 10 directly and in the other case was treated with 25 poundsv of 98% sulfuric acid per barrel at about produced is recovered by line 39. The following examples further illustrate the 20° C.. The molar ratio of benzene to oleñn in advantages ofthe process, although no limitation each .case was 5:1 and the feed rate was 1800 to 2000 grams,n of ,hydrocarbon per liter of catalyst on the invention is to be inferred therefrom as the same principles may be applied to the reaction of 15 per hour. ' the same or other aromatic hydrocarbons with other alkylating agents. acid Untreated Sulfuric treated benzene benzene ' Example I To show the advantages of a high ratio of ben 20 zene to alkylating agent, a series of test runs were made with a solid phosphoric acid catalyst, using Sulfur in the benzene (wt. per cent)_____ ' Oleiîns in the benzene (wt. per cent) _ __; 0. 47 0. 76 0.06 0. 09 Sulfur in the cumene (wt. per cent) _ _ _ __ 0. 51 0.05 a reaction temperature of 200° C. to 250° C. and a pressure of 250 pounds per square inch. The hy drocarbon feed rate was 2000 grams per hour per liter of catalyst for each of the different benzene The'propylene conversions and cumene yields for different periods of catalyst use were as follows: propylene mixtures used. The following results .30 . Mol ratio benzene to oleiin Cumene in Propylene the product converted p Per cent Per cent 86 90 93 n 74 5-6 ___________ __ 47 The effect of pressure on the reaction was de termined in a series of tests using a solid phos phoric acid catalyst and a feed containing 5 mols ' 86 3-4.„ » 88 90 87. 5 88 S8 89 87 ‘88 89 « The products were tested as 5% and 10% blends in 100 O. N. aviation gasoline with a ñnal tetra 40 ethyl lead content of 4.0 cc. per gallon. VEaxrmple AII of benzene per mol of propylene. treated benzene coläsersmn product c‘ìläìerëlgn product ' (Wt. %) _ ' a (Wt- %) 1-2 _______ __ 35 Using sulfuric acid benzene caétttsìf“ ‘Prowler Ci‘àuëâlâe Prowler@ @ditte sampling 65 90 94 Using untreated Gallons of cu~ mene produced per pound of were obtained: Rating in 3-C engine test Y Product from untreated Feed rate ärssugî lágrâìmsof bumper y T0931- Sq àà) ' 'I 45 P TOPY1 @ne h.1`- Der non 111 Clâiëääsft the feed ggg. Pagar Cinthe _ ture sion - “mene 5 Crude 10% blend____. Iso-octane+l.l DTOdllCt 50 ° C'. Per cent 2,0 0 r2 esta 8.2 20o-250 200-250 a92s1 as90ss 4, 000 8.2 s2 90 20o-250 blend ____ ._ Is -octane 0.7 Product from sulfuric ` acid-treated benzene co. teaming. ?’ f ' tristi. °° ° a Is - tan 1.1 . fle d cc. of Iso-octane-l-Lö cc. of lead lead tetraethyl. tetractliyl.` Copper dich gum (mg./100 ml.) Per cent 2,030 4,000 2,000 . % n space) Per cem) benzene 55 Product untreated from treated benzene benzene 5‘7 blend ________________________ __ Example HI 103]o blend _______________________ ,_ . 5 1 10 2 Effect of temperature was determined in com parative tests using a feed rate of 2000 grams of 60 Considering the small amount of cumene in these blends, the effect of the sulfuric acid treatment of hydrocarbon per hour per liter of catalyst space, the benzene is seen to be remarkable. a benzene to propylene mol ratio of 5 to 1, and a pressure of 250 pounds per square ` inch. The propylene concentration in the feed was 8%--8.2% . Temperature Cumene in ‘ the product Per cent Example V 65 Benzene was alkylated with isobutylene using the same apparatus as that employed in the pre ceding example. A catalyst temperature of 250° Propylene converted yPer cent l75°-200° C __________________________ __ 90 60 70 200°-250° C __________________________ ._ 90 90 The catalyst life under these conditions was of the order of 80 gallons of cumene per pound of cata C. Was used. The isobutylene conversion was '70% when using a 4.9 to 1 ratio of benzene to oleñn, and '76%, using a 6.2 to 1 ratio. With beta butylene in place of isobutylene, the conversion was 69% when using a .4.9 to 1 ben zene to oleñn ratio. In all cases the product con tained about 85% butyl benzene and was practi lyst. At higher temperatures the life decreases. 75 cally free from oleñn polymers. „ 7 _ aetaevfi We claim as our invention: arating unreacted benzene from the reaction products and contacting the separated Vbenzene - 1. A process of producing cumene which com prises treating benzene with sulfuric acid of at least 90% concentration at about 10° C, to 60° C. >with concentrated sulfuric acid for a time suf ñci'ent'to substantially reduce the thiophene con for a time sufficient to reduce the thiophene con tent thereof, and returning the sulfuric acid tent thereof, admixing the treated benzene with treated benzene to reaction with further isopro propylene in the ratio of 3 to 10 mols of benzene pylating agent. per mol of oleñn and contacting the mixture un ’7. A process of producing an alkyl benzene der a pressure of between 250 and 600 pounds with a solid phosphoric acid catalyst at a tem 10 which comprises reacting a substantial molar ex cess of benzene with an alkylating agent under perature of 200° C. to 300° C. using a space Veloc a pressure of at least 250 pounds per square inch ity of 0.1 to 0.6 gallon of hydrocarbon per pound in the presence of Ia solid acid alkylating catalyst, of catalyst per hour, fractionating the resulting separating unreacted benzene from the reaction products to separate unreacted benzene, and re products and contacting the separated benzene turning at least 4a part of `the thus-recovered with concentrated sulfuric acid for a time suf benzene to said sulfuric acid treatment for fur ñcient to substantially reduce the thiophene con ther reactîon in the process. tent thereof, and returning the sulfuric acid 2. A process of producing cumene which com treated benzene to reaction with further alkylat prises passing a mixture of benzene and propylene ing agent. in a molar ratio of at least 4 to 1 over a solid 20 8. A process of producing an alkyl benzene which comprises contacting benzene with concen trated sulfuric acid for a time suflicient to sub phosphoric acid catalyst at a temperature of 200° C. to 300° C. and a pressure of at least 250 pounds per square inch, separating at least a part of the stantially reduce the thiophene content thereof, unreacted benzene from the products, contacting and reacting a molar excess of the resulting ben at least a part of said separated benzene with 25 zene 'With an alkylating agent in the presence of sulfuric acid of at least 90% concentration, and a solid acid alkylation catalyst under a pressure returning the acid-treated benzene for further re 0f '250 to 600 pounds. Y action in the presence of said phosphoric acid 9. A process of alkylating an aromatic hydro catalyst. carbon which comprises treating said hydrocar 3. A process of producing cumene which' com with at least one-tenth of its Volume of con prises treating benzene with sulfuric acid of at 80 bon centrated sulfuric acid for a time sufficient to least 90% concentration for a time suflicient to materially reduce the thiophene content thereof, reduce the thiophene content thereof, reacting ¿and reacting a molar excess of the resulting aro the acid-treated benzene with propylene in the matic hydrocarbon with an alkylating agent un presence of a solid phosphoric acid catalyst under 35 der a pressure of at least 250 pounds per square a pressure of at least 250 pounds using aV molar inch in the presence of a solid acid alkylation cat ratio of benzene to propylene of at least 4 to 1 and alyst under alkylation conditions. a temperature between 200° C. and 300° C., and recovering the resulting cumene. y 10. A process of alkylating an aromatic hydro carbon which comprises treating said hydrocar 4.0 boniwith sulfuric acid of at least 90% concentra prises contacting benzene with between one-tenth tion at 10° C. to 60° C. for a time of at least 5 and one-fourth of its volume of sulfuric acid of minutes sufiicient to materially reduce the thio 95% to 100% concentration for a period of 5 to 10 L1. A process of producing cumene which com phene content thereof, reacting a molar excess of the resulting aromatic hydrocarbon with an al kylating agent in the presence of a solid acid al minutes at about 10o C. to 30° C. sufficient to ma terially reduce the thiophene content thereof, neutralizing the acid-treated benzene, and con kylation catalyst under alkylation conditions, sep arating unalkylated aromatic hydrocarbon from tacting a mixture of said benzene Vand an iso propyl-ating agent containing at least three times the stoichiometric amount of benzene to isopro pylating agent with a solid acid alkylation cat the reaction products, and returning at least a part thereof to said sulfuric acid treatment. 50 alyst under alkylation conditions. 5. A process of producing cumene which com 11. A process of alkylating an aromatic hydro carbon which comprises reacting a molar excess of said hydrocarbon with an alkylating agent un der a pressure of at least 250 pounds per square inch in the presence of a solid acid alkylation prises contacting benzene with concentrated sul furie acid for a time suñîcient to substantially reduce the thiophene content thereof, and react 55 catalyst under alkylation conditions, separating ing a molar excess of the resulting benzene with unalkylated aromatic hydrocarbon from the re an isopropylating agent in the presence of a solid action products and contacting at least a part acid alkylation catalyst under a pressure of 250 thereof _ with sulfuric acid for a time sufficient to’600 pounds. ’ ` to materially reduce the thiophene content there 6. A processof producing cumene which com 60 ofgand returning the thus-treated hydrocarbon prises reacting a substantial molar excess of ben to the alkylation reaction. zene with an isopropylating agent under a pres EDWIN F. BULLARD. sure of at least 250 pounds per square inch in the JOHN ANDERSON. presence of a. solid acid alkylating catalyst, sep ‘ SUMNER H. MCALLISTER.