EthylBenzene eine Industrie, die alle möglich machen kann

8/19/2019 EthylBenzene eine Industrie, die alle möglich machen kann

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CATALYTIC ALKYLATION of

BENZENE with ETHYLENEb b b The reaction between ethylene and benzene vapors a t pressures up to 200 pounds persquare inch gage, temperatures of P3O-27O0 C. and space velocities of about 11-50 cc. (gas, 0 C.and 760 mm.) per hour per cc. o f catalyst have been investigated in a flowing system under theinfluence of eleven different catalysts.

Sodium chloride-alum inum chloride-pumice and phosphoric acid-kieselguhr were the on lycatalysts giving detectable reactions. Mono- and diethylbenzenes were identified in the liquidproducts. The former catalysts under some condit ions conver ted as much as 9 5 per cent of theethylene t o ethylbenzenes.

A series of runs was made t o determine the ef fect of time, pressure, and space ve lo ci ty on thereaction when the sodium chloride-aluminum chloride-pumice was used. The catalyst was found tohave a very short life, the ethylene conversion decreased from 93 to 75 per cent over a period necessaryfor the conversion of 0 to 1.16 gram mole of ethylene to ethylbenzenes.

At atmospheric pressure there was n odetectable conversion, while at 200 pounds gage pressure as much as 9 5 per cent of the ethylenewas converted to ethylbenzenes.

The effect of space velocit y on the conversion was negl igib le over the range of about 11 to 5 0 CC.

Pressure had a surprising influence on the reaction.

per hour per CC. of catalyst.W. A. Pardee'B. F. D o d g e

YALE UNIVERSITY, NEW HAVEN, CONN.

ITH th e development of th e uses of styrene over thepast few years in th e manufactu re of resins and syn-thetic rubber, processes by which it might be synthe-Wized have been of interes t. When dehydrogenated,

monoethylbenzene produces styrene b y t he reaction:

heat

catalysteHsCzHs CeHaCH=CHz3

Hz(1)

It is believed th at t he most im port ant processes in operationat this time for the manufacture of styrene involve mono-ethylbenzene as the starting material. The large producersof ethylbenzene use an agitated liquid phase for contactingbenzene with ethylene in the presence of a metal halide cata-lyst, such as aluminum chloride. Recently a process for theproduction of ethylbenzene from ethyl alcohol and benzenehas been publicized. Apparently, however, this process isnot yet producing commercial quantit ies of ethylbenzene.

The present investigation is concerned with the reaction ofethylene with benzene in th e vapor phase, utilizing an appara-tus in which the mixed vapors of ethylene and benzene passthrough a catalyst bed where the reaction takes place.Since only one investigator, Komarewsky ( I ) , has reported

results on thi s vapor-phase flowing system, the data on th e ef-fect of dif ferent operating variables, such as pressure, tem-perature, and catalyst, are meager. The object of thi sinvestigation was to find a suitable catalyst to promote thereaction of ethylene with benzene in th e vapor phase t o formpredominantly monoethylbenzene,

(2)

which might be dehydrogenated to form styrene a s indicatedin reaction (1). After a suitable catalyst for the reactionwas found, the next object was to s tud y the action of th is

CSHs(g) + C2H4g) t CsHaCzHa(g)

Present address, Gulf Resesroh & Development Company, Pittsburgh,Penns.

catalyst under vario us conditions of pressure, tempera ture ,and space velocity.

Previous WorkThe alkylation of benzene with olefins has been widely in-

vestigkted, but most of the work has been confined to liquid-phase batch experiments. The only work of note reported inthe literature in which a vapor-phase flow system was em-ployed is that of Komarewsky 13). A dehydrogenationcatalyst, nickel-alumina, was used in this experiment, andvapors of ethylene and benzene a t 350 C. and atmosphericpressure were passed over th is catalyst. Analysis of theliquid product led to the conclusion th at 5 per cent of t he ben-zene charged was converted to toluene. Th e remainder wasunconverted benzene and some high-boiling residue, repre-senting about 2 per cent of the benzene charge and identifiedas a mixture of naphthalene and diphenyl. Th e gas producedby the reaction consisted of hydrogen, methane, and ethane.When benzene alone was pamed over the catalyst under thesame conditions only a small fraction of it reacted, the prod-ucts being diphenyl and hydrogen. Under the same condi-tions ethylene alone was completely decomposed to form car-bon, hydrogen, methane, and ethane. According to previous

results of Ipatieff and Komarewsky IO), thylbenzene in thepresence of the nickel-alumina catalyst at 350 C. decomposedto toluene and methane.

Much work has been doneon the benzene-ethylene reactionin which a liquid phase was pres-ent. Results , of these investi-gations show that such materi-als as metal halides, inorganicacids, and acid anhydrides (forexample, PzOJ catalyze thereaction with the resulting for-mation of ethylbenzenes, from

273


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214 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 35, No. 3

Figu re 7 Flow Diag ram f o r Syn the si s Appa ra tu s Us ed in Vapo r-Ph ase Reac t i onb e t w e e n E t h y l e n e a n d B e n z e n e

the mono- t o the hexaethylbenzene. Low temperaturesfavor the formation of these ethylbenzenes, b ut good con-versions have been obtained up to 300-400 C. As would beexpected, greater conversions occur at high pressures than a tlow. (Pressures up to 50-60 atmospheres have been reportedfor the benzene-ethylene reaction.) Since all of the publishedda ta resulted from investigations carried out in a batch processwhere a constant pressure of ethylene was maintained on thereaction mixture for periods of 1 2 to 60 hours, it is meaning-

less t o give definite conversion figures without complete de-tails of the exper iments; these details are beyond the scopeof this paper. However, it may be said th at benzene con-versions to mono-, di-, and higher alkylbenzenes were as highas 100 per cent under certain conditions.

It has been generally concluded that the metal halidesare the best catalysts for the aromatic-olefin condensations.Many investigators, dating back to Balsohn in 1879 ( ),have studied t he catalytic effect of these metal halides undervarious conditions of pressure, temp erature, and ratio of re-actants. Some of these recent investigators include Ipatieffand Grosse (6, 9), Huber and Reid ( 7 ) , Milligan and Reid( 1 6 ,1 7 ) , and Amos, Dreisbach, an d Williams ( 1 ) .

Among the inorganic acids which have been tested as cata-lysts for the benzene-olefin condensations are sulfuric, o-phosphoric, and hydrofluoric. Ipatieff, Corson, and Pines

8) nd Wunderlv. Sowa. and Nieuwland L2L

The acid anhydride, phosphorus pentoxide, was used byMalishev (14 , 15) and by Truffault 23) t o effect condensa-tion.

The products resulting from the reaction of benzene withethylene in the presence of a liquid phase consist essentiallyof mono- t o hexaethylbenzenes. The catal ysts mentioned inthe above discussion seem to exhibit very little difference inselectivity in the range of conditions There they are appreci-ably active.

Thermodynamics of the React ionThe best available ther mal dat a have been used t o calculate

an equilibrium constant for th e reaction between ethylene andbenzene in the vapor phase to form monoethylbenzene

CE (8) + CzHd(g) CE CzHs(8) (2)The only data which are lacking for this calculation are thespecific heat dat a for ethylbenzene vapor. By subtra ctingthe specific heat equation of methanol vapor (19) from theequation of ethanol vapor (19) , he effect of adding a --CH2-group to a carbon chain was evaluated. Then by adding theequation for this -CH2- group to the specific heat equationof toluene (19) the following equation was obtained:

C = 10.3 + 0.072 T

(vapor) ,

reached the conciusion that sulfuric acid doesnot catalyze the benzene-ethylene reaction butdoes catalyze the reaction between benzene T a b l e I. T h e r m a l D a t a

and olefins of three or more carbon atoms.Ipatieff, Pines, and Komareivsky 11) foundthat o-phosphoric acid catalyzed the benzene-

StandardH e a t of Free

Vaporiza- Heat of Energy ofCompound Stat e tion Formation Formation Specific Hea t 1 3 )

Gas 11,975 f8) 15,840 18) C p - 6 4- 0 .015TGas 36;640 1 3 ) C p = 6 5 4- 0 . 0 5 2 2

Ethyleneethylene reaction. Hydrofluoric acid was tested Benzene Liquid Si60 (19) 11,630 (19) . . . . . .by Simons and Archer, 20, 1) and by Calcott, ~ ~ ~ $ ~ & E e n e iquid 9 i 6 -i;dy0 19) . . . . . .Tinker, and Weinmayr 5 ) , and was found t o Ethylbenzeneethyl alcohol Gas as ... . . . . 28,'460 19) . . . . . .. . . . . . . . Cp = 2 - 0 . 0 3 0 T

. . . I . . . . C p = 4 .5 + 0.0382three or more carbons, but these investigators Gas . . . . . . . . . . C p = 7 . 8 + 0.064?

K., and gram moles; the reference temperature and pressure

promote th e reaction of benzene with olefins Of Eth yl alcohol Gas .

do not mention the use of hydrofluoric acidwith benzene and ethylene.

a Units are gram calories,are 298.10 K. alid 760 mm. Hg, respectively.


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March, 1943 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y 275

This equation should represent the specific heat of ethylben-zene. Th e units for thi s equation are gram calories, degreesKelvin, and gram moles.

Table I lists the dat a from which the following equation forth e calculation of th e equilibrium constant, K,, as a functionof temperature may be derived :

logloK , = 7 + 5.475 x 1 0 7 4 T -1.11 loglo T -3.691 (3)Table I1 contains equilibrium constants, K,, calculated

from Equation 3 for Equation 2 . Calculations based on a1 I molal ratio of ethy lene to benzene, atmospheric pressure,and 327 C. indicate tha t a t equilibrium more th an 99 per centof t he ethylene should be converted to ethylbenzene.

Table I I Equi l ib r ium Constants for Resc t ion P[CsHs(g) + CZHII(Q) CeHaCsHs(g)]

Temperature

K. c. Log10 K, K P2 9 8 . 1 2 5 1 3 . 2 2 1 . 6 6 X 10 83 5 0 . 1 7 7 IO . 8 1 . 9 1 x 10 04 0 0 . 1 1 2 7 8 . 1 4 1 . 3 8 X 108580.1 227 5 . 1 8 1 . 5 1 X 10s600 .1 327 3 . 2 2 1 . 6 6 x 108

Cata IystsI n

these preparations, outlined briefly in the following para-graphs, the following materials were used unless otherwiseypecified:

Charcoal, activated, animal, 6-20 mesh, J. T. Baker ChemicalCom any.

Algax, 10-16 mesh, Carborundum Company.Phosphoric acid, 85 per cent (specific gravity 1.71), J. T. Baker

Chemical Company.Boric acid jH8B08) , Howe and French, Inc.Sulfuric acid, 96 er cent reagent.Zinc sulfate (ZngOd 6 H ~ 0 ) , echnical grade, Merck & Com-

Sodium phos hate (Na2HP04. 2H20), Baker & Adamson.Strontium chyoride (SrCla.GHaO), c. P. granular, J. T. Baker

Zinc chloride (ZnClz), c. P. granular, J. T. Baker Chemical

Ferric chloride (FeCls 6H20), c. P. granular, Eimer & Amend.Aluminum chloride (AlCla), anhydrous, Mallinckrodt Chemical

Silver sulfate (A~~SOI), . P. powder, J. T. Baker Chemical

Water, distilled.

The percentage catalytic material referred to in each caseis based on th e difference between the to tal weight of ca talys tand the weight of support (charcoal, Alfrax, etc.) used.Solutions are aqueous unless otherwise specified.

This was the regu-lar Universal Oil Products Company polymerization catalyst,Minute details for its preparation are not available, but frominformation obtained, it was concluded that a 3 : l weightmixture of phosphoric acid and kieselguhr was extruded froma '/s-inch orifice int o pellets which were baked a t 200-260 C.A catalyst prepared i n this manner was tested in th e synthesisunit and was found to give results almost identical with thoseobtained when th e U. 0. P. catalyst was used.

Phosphoric acid waspoured over charcoal, and the mixture (1 .5:1 weight ratio ofacid:charcoal) was heated a t 250-280 C. for 17 hours and atabout 370 C. for 1 hour; after this treatment the materialwas dry at room temperature and contained about 42 percent acid.

2-3, BORON HOSPHATE-PHOSPHORICCID-CHARCOAL.14.9 per cent boric acid solution was poured over a phosphoric

Eleven different catalysts were prepared and tested.

pany, Inc.

Chemical Company.Company.

Works.

Company.

Z-1, PHOSPHORIC CID-KIESELGUHR

2-2, PHOSPHORIC CID-CHARCOAL.

acid-charcoal mixture and heated with stirring to 240 C.(5 .5 hours of heating time). Th e weight ratio of boric acidsoIution to 85 per cent phosphoric acid to charcoal was3 : I : 1.6. The resulting catalyst contained approximately18 per cent catalytic material.

2-4, PHOSPHORIC CID-SULFURIC ACID-CHARCOAL.solution of phosphoric acid and concentrated sulfuric acid waspoured over charcoal 11.1 1 9.3 weight ratio). This mix-ture was heated with stirring at 200 C. for about 30 minutes.The excess liquid was separated from the solid by filtrationthrough glass wool; then the solid material was heated at213 C. for 1 .5hours. The resulting mixture contained abo ut21 per cent catalyst.

Zinc phosphate was pre-cipitated from a hot 56.5 per cent ZnzS04.6Hz0 olution byaddition of a hot 52.5 per cent solution of Na2HP0. , .12Hz0 .Th e weight ratio of sulfate to phosphate solution was 1.1 1.The precipitate was filtered from the mixture and washedseveral times with a total of about 0.5 weight ratio of water(based on pho sphate solution) followed by drying a t 110 C.for 11 hours. About 3 per cent by weight of graphite wasincorporated in the powder t o act as a binder; then themixture was made into pellets 7/52 inch in diameter and

inch long.

Z-6, STRONTIUM HLORIDE-CHARCOAL. hot 16.7 percent solution of SrCl2.6HzO was poured over charcoal (weigh tratio, 2 . 8 : l ) . This mixture was heated, with frequent mix-ing, over a hot plate until practically dr y and was the n driedfor 30 minutes at 110 C. Catalytic material contained in th emass was about 30 per cent.

Alfrax was stirred into a50 per cent ZnClz solution (1 .75:1 weight ratio ). Th e mix-ture was stirred, allowed to stand for several minutes, filteredover glass wool, and dried a t 110 C. for about 40 hours. Theresulting material contained about 14.1 per cent catalyst.

2-8, FERRIC HLORIDE~ALFRAX. he method employedin the preparation of this cat alyst was similar to th at used in2-7. Hydrogen chloride was evolved during the dryi ng oper-ation, and the result was the formation of iron oxide. For thisreason the material was dried for only 1.75 hours at 103' C.

The resulting mass contained about 10 per cent catalyst.11-9, SODIUM CHLORIDE-ALUMINUM HLORIDE-PUMICE.The method employed in the pr eparation of this cataly st wassimilar to tha t used by Blunck and Carmody (4). The sodiumchloride-aluminum chloride salt consisted of approximately a1 1 molal complex of aluminum chloride an d sodium chloride.The complex was made by fusing the salts (with a slight ex-cess of aluminum chloride to t ake care of sublimation loss inthe early stage of th e heating process) in a pressure bomb attemperatures up to 265 C. After cooling to room tempera-ture, th e bomb was opened and heated again to d rive off th eexcess aluminum chloride. Th e fused salt was th en pouredover an equal weight of dr y pumice (8-10 mesh) with thoroughmixing. The final catalyst contained abou t 50 per cent cata-lytic material. Thi s material was very hygroscopic andnecessitated storage in a g astight container until i t was placedin th e catalyst chamber.

The Z-9 catalysts listed in Table I11 were all prepared ac-cording to the above procedure.The different letters (e. g . Z-ga,Z-Sc, etc.) signify different batchesof catalyst.

Z-10, SULFURICACID-ALFRAX.Alfrax was stirred into a 77 percent solution of sulfuric acid; themixture was heated for one hour at100 C. and was then filtered overglass wool. Th e solid was heatedfor 4 hours until the temperature

8-5, ZINC PHOSPHATE ELLETS.

Z-7, ZINC CHLORIDE-ALFRAX.


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Figu re 2. D e c r ea s e in C a t a l y s t A c t i v i t y w i t h A m o u n to f Ethy l ene Conve r t ed

reached 300 C. After this treatment the catalytic content

was about 26 per cent.Z-11, SILVER SULFATE-SULFURIC ACID-ALFRAX. Themethod for the preparation of this catalyst was similar tothat employed by Stanley, Youell, and Dymock 82) and byBliss and Dodge (3). By saturating Alfrax with a solutionof silver sulfate and sulfuric acid, filtering, and drying theresidue, a material was produced which contained about 4per cent silver sulfate and abo ut 21 per cent sulfuric acid.

Apparatus and Procedure

The ethylene used in this work came from U. S. IndustrialChemical, Inc., and was at least 99 per cent pure (prepared


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March, 1943 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S TRY

by dehydration of ethanol over phosphoric acid). Th e ben-zene used was Merck's nit ration grade which had been furtherfractionally distilled.

Figure 1 is a flow diagram for the synthesis unit. Ethylenepassed from cylinder A through pressure regulating valve Wl,purifier N , trap M , flowmeter 2'1, expansion valve WZ, nd intobenzene dropper H . The ethylene-benzene mixture passedfrom vaporizer V , eaving as vapors, and entering reactor R, fromwhich the reaction product was expanded through valve Wd, topractically atmospheric pressure. The reaction mixture thenpassed into a condenser system from which emerged the gaseousproduct. This flow of gaseous product was noted on flowmeterT2 ampled continuously by gas sampler 0, and finally meas-ured by displacement of brine solution from gas receiver P .The benzene liquid was fed from tank G by gravity into dropperH , where it mixed with the ethylene and then passed through theapparatus as noted above.

The flow rates were controlled by '/r-inch, V-point, needlevalves. The ethylene was throttled throu8h valve W S , rom apressure usually 50-100 pounds per square inch higher than thereactor pressure. The flow rate was noted by reading a pres-sure differential on manometer T I , developed by passage of thegas through a short capillary tube. The benzene flow rate wasregulated by valve W8, and noted by counting drops fallingthrough sight glass and dropper H . The reactor pressure wasmaintained by throttling the reaction vapors through valve W1

The liquid product was fractionated a t atmospheric pressurethrough a l/S-inch glass vacuum, silver-jacketed column packedwith 24 inches of a/&nch stainless steel rings. The variouscuts were identified by refractive index measurements as well asby their boiling points.

The effluent gases were analyzed by means of a standard U. 5.Steel gas analysis set.

Figu re 3. E f f e c t o f Pressure onConve r s ion

Each catalyst was tested by passing through the catalyst beda mixture of benzene and eth lene vapors in molal ratio of about2:1, at temperatures of 228 to 245 C., gage pressure of 100pounds per square inch, and vapor space velocities of 25 o 40 C.(0 C. and atmospheric pressure) per hour per cc. of catalyst.Sixteen runs were made in this preliminary catalyst study, and

y

Figu re 4. E f f e c t o f S p a c e Ve l o c i t y o n C o n v er s i o n

217

only two of the catalysts were found to promote a detectable reac-tion between the ethylene and benzene (the phosphoric acid-kieselguhr and the sodium chloride-aluminum chloride-pumicecatalysts).

reliminary catalyst study, the sodium chlo-ride-aluminum chyoride-pumice catalyst was investigated in fur-ther detail. The activity of this catalyst was studied over aperiod of time, and the pressure and space velocities were variedin a series of runs. In the investigation of the effect of pressureon the reaction, gage pressures of 0, 50, 100, and 200 pounds persquare inch were employed. The effect of space velocity wasstudied over the range 11.6 to 47.2 cc. per hour per cc. of catalyst(contact times of about 20 to 5 minutes).

A summary of the runs in which reaction was noted is givenin Table 111. No data are listed for the catalyst test runswhere no reaction occurred, but it may be assumed that theoperating data and analytical procedures were similar t o thoselisted under runs 4 nd 12.

Since the yields of triethylbenzene were only estimated fromthe distillation residue, the y are not plotted as separate curvesin Figures 2, 3, and 4. However, they are contained in thetotal conversion curves in these figures. Thi s explains why

the s um of t he mono- an d di- ordinates are no t always equalto th e total ordinates.

Following the

Preliminary Catalyst Study

Phosphoric acid supported on kieselguhr was the first cata-lyst to be tested. The results indicate th at 13-15 per centof the ethylene was convertedto ethylbenzene, predominantlymonoethylbenzene with smallamounts of diethylbenzene (about1O:l weight ratio). Since pres-sure has been found t o have sucha pronounced effect on the reac-tion when the sodium chloride-aluminum chloride-pumice cata-lyst was used, this phosphoricacid-kieselguhr cata lys t would


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probably give satisfactory conversions at pressures of 300-400pounds per square inch.

Phosphoric acid in forms other t han th at mentioned above(with kieselguhr) failed to promote an y noticeable reaction.Thu s, phosphoric acid-charcoal, boron phosphate-phosphoricacid-charcoal, and phosphoric acid-sulfuric acid-charcoalfailed to cause ethylene and benzene to react a t 100 pounds persquare inch and about 240 C.

Sulfuric acid supported on Alfrax was inactive as mas alsoth e mixed catalyst , silver sulfate-sulfuric acid-Alfrax. Thu s,it stands t ha t sulfuric acid, even though it is a good catalystfor benzene alkylation by olefins of three or more carbonatoms in the liquid phase, does not promote the reactionof ethy lene and benzene e ither in the vapor phase or liquidphase.

Strontium, zinc, a nd ferric chlorides supported on activa tedcharcoal, Alfrax, and Alfrax, respectively, were found to beinactive in th e form employed. Aluminum chloride, in th eform of a fused equimolar mixture with sodium chloride sup-ported on pumice, was quite active; ethylene conversion wasabout 69 per cent under t he same conditions of test o n theother catalysts (100 pounds per square inch, 246 C., 26.6cc. per hour per cc. catalyst).

PRESSURE S A I r A R I A ~ L E . Runs were made at pressuresof 0, 50, 100, and 200 pounds per square inch gage. A 300-pound run mas attempted, but the capacity of th e benzenevaporizer was not sufficient for operation a t this pressure.

The great effect of pressure on the reaction is shown inFigure 3. Conversion ranged from 0 a t atmospheric pressureto about 90 per cent at 200 pounds per square inch gage.Since the points in this plot a re scattered, the reliability of t hedifferent analyses has been evaluated, and the points wereweighed accordingly in drawing the curve to best representthe t rue conditions.

Table IV. Catalyst A c t i v i t y

Run N o . ene Converted Lb./Sq. In. bage Mono- DI- Tri- Total'3 Ethylene Converted to '

To ta l GramMoles Ethyl- Pressure

Sa 0.131 1 00 5 4 . 4 1 5 . 5 0 6 9 . 99b 0 .383 100 44 .3 19 .6 0 63 .9

19 .7 21 .5 23 .2 64 .40 0 ,6 83 1002 9 . 0 2 2 . 2 0 52 .1d 0.901 100

31a 0,18 0 200 64 .7 26.9 1 . 6 93 .231b 0.5 21 200 44.0 25 1 1 4 . 1 8 4 . 0310 0 .851 200 39 .3 23 .4 16 .2 78 .931d 1.164 200 3G.1 23. 4 15.6 75 .1

Sod ium Ch lo r ide -Aluminum Chlo r ide-PumiceCatalyst

Under the conditions of these tests, the sodium chloride-aluminum chloride was in the liquid state; therefore, it wasnecessary to support th e material on a carrier. Pumice (8-10mesh) was used as th e carrier but was n ot satisfactory becauseof its varying properties from one lot to another. For example,two different lots of pumice were used ; one gave an active andthe other an inactive catalyst. It was concluded that thevariation in activi ty was due to t he difference in density of t hetwo lots. The more active catalyst was prepared from theless porous lot (density of abou t 0.46 gram per cc.), a nd it sgreater activity may be attributed to a greater and thickercatalytic surface on this pumice than on the more porousmaterial (density of about 0.26 gra m per cc.). Some pre-

pared carrier would probably be much better tha n the pum-ice, bu t due to lack of time, other carriers were not tes tedexcept for one test with activated alumina. I n this test theratios of materials were the same as with pumice, bu t t hiscatalyst gave only about 20 per cent conversion. It is be-lieved, however, that the only function of these differentcarriers is to support the catalyst, and that with the samearea an d thickness of catalyt ic surface the carrier materialwould have no effect on th e reaction. Tests mere made toshow that the pumice and the alumina alone had negligiblecatalytic effect on the benzene-ethylene mixture under theconditions used.

In order t o determine the effect of the catalyst on th e indi-vidual reactants, the benzene and ethylene vapors werepassed separately through the catalyst bed. The benzenevapors were unaffected, and the ethylene was decomposed

slightly, with about 2 per cent ethane and 0.5 per cent hydro-gen in the effluent gas.CATALYsr ACTIVITY. Runs 19 and 31 were made to deter-

mine the activity of t he catalyst over a period of time at 100and 200 pounds per square inch, respectively. The da taused to plot Figure 2 are listed in Table IV, and illustrate th edecrease in activity of the catalyst as a function of molesof ethylene converted.

There was a decrease in tot al conversion from 93 to 75 percent resulting from the conversion of about 0.19 to 1.16 grammoles of ethylene to ethylbenzene. Indications are tha t theformation of higher ethylated benzenes is favored with use ofthe catalyst over a period of time.

SPACEVELOCITY S .4 VARIABLE. The vapor space velocitywas varied from 47.2 to 11.6 cc. (vapor, calculated at 0 C.and atmospheric pressure) per hour per cc. of catalyst. Thedata for these runs are plotted in Figure 4. It is concludedth at the total conversion of ethylene to ethylbenzenes wasindependent of the space velocity in th e range studied. How-ever, there are indications that more of the mono- and lessof the diethylbenzenes are produced a t the higher th an atthe lower velocities.

Li te ra tu re C i t ed

Amos, J. L., Dreisbach, R . R., and Williams, J. L. (to Dow

Balsohn, &I. M., Bull . soc chim., [2] 31, 539 (1879).Bliss, R. H., and Dodge, B. F., IND. N G . CHEM., 9 19 (1937).

Blunck, F. H., and Carmody, D. R., I b i d . , 32, 328 (1940).Calcott, W. S., Tinker, J. M., and Weinmayr, V., J . Am. Chem.

Grosse, A . V., and Ipatieff, V. N., J . OTg. Chem., 1 , 559 (1937).Huber, F. C., and Reid, E. E., IND. NQ. CHEM., 18, 535 (1926)Ipatieff, V. N. Corson, B. B., and Pines, H., J . Am . Chem. SOC.,

Chemical Co.), U. S. Pat ent 2,198,595 (April 30, 1940).

Soc., 61, 1010 (1939).

58, 19 (1936).Ipatieff, 1'. N., and Grosse, A. V., I b i d . , 58, 2339 (1936).Ipatieff, V. N., and Komarewsky, V. I., I b id . , 58 922 (1936).Ipatieff, V. N., Pines, H., and Komarewsky, V. I., IND. ND.

Kolosovskf, N. A., and Meahenin, I. S. Bull. SOC. chim., 49

Komarewsky, V. I., J . A m. Chem. Soc., 59, 2715 (1937).Malishev, B. W., Ib id . , 57, 883 (1935).Malishev, B. W. to Shell Development Co.), U. S. Patent

Milligan, C. H., and Reid, E. E . , IND. ENG. CHEM,, 15, 1048

CHEM., 8, 22 (1936).

1461 (1931).

2,141,611 (Dee. 27, 1938).

(1923).

(1922).Milligan, C. H., and Reid, E. E., J . Am Chem. Soc. 44 206

Parks, G . S., Chem. Rev. 8, 25 (1936).Parks, G. S., and Huffman, H. I., Free Energy of Some

Organic Compounds , A. C. S. Monograph GO New York,Chemical Catalog Co., 1932.

Simons, J. H., and Archer, S. . A m. Chem. Soc. 60, 986 (1938).Ibid. 60, 2952 (1938).Stanley, H. M., Youell, J. E., and Dymock, J. B., J . Soc. Chem.

Truffault, R., Compt. rend., 202, 1286 (1936).Wunderly, H. L., Sowa, F. J., and Nieuwland, J. A., J . Am.

Ind . , 53, 205T (1934).

Chem. Sac. , 58, 1007 (1936).

B A S ~ D n a dissertation presented by W. A . Pardee to t he f acu lty of t heYale School of Engineeriug in partia l fulfillment of the requirements f o r t hedegree of doctor of engineering.

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EthylBenzene eine Industrie, die alle möglich machen kann