T H E J O U R N A L O F I N D L T S T R I A L AiVD E E N G I J E E R I N G C H E ; M I S T R Y
I80
Vol. 7, NO. 3
ORIGINAL PAPER THE PREPARATION OF GASOLINE AND KEROSENE FROM HEAVIER HYDROCARBONS
Company, Ltd.,l requires the passing of petroleum and steam through a retort containing scrap iron a t By BENJAMINr. BROOKS,RAYMOND F. BACON,FRED W. PADGETT AND 540' t o G j o " C. The processes proposed by Adams,2 IRVIN W. HUMPHREY Greenstreet,3 Hyndman,4 and Turner5 specify t h e Received January 21, 1915 cracking of heavy oil a t higher temperatures' (GreenThe earlier attempts t o convert heavy petroleum street and Hyndman specify a "cherry temperature") hydrocarbons of high boiling points into lighter more in t h e presence of steam alone. The claim has been volatile products were carried out in most, if not all, made t h a t t h e water is converted into CO and hydrocases with t h e object of increasing t h e yield of illumina- gen, t h e latter effecting hydrogenation of t h e olefines produced. Testelin a n d Renard6 vary this b y passing ting oil. The "cracking" of heavy hydrocarbons by heat the vapors of oil and steam over a red-hot layer of is t o be regarded as simply a n instance of t h e general clay or alumina. Vernon Boys'? passes t h e oil and rule t h a t organic compounds are decomposed by heat. steam mixture through heated tubes containing nickel It is well known t h a t t h e simpler petroleum hydrocar- rods. Lamplough8 cracks in t h e presence of steam bons are stable a t much higher temperatures t h a n and in contact with nickel in a retort maintained a t those of higher molecular weight. Every refiner a dull red heat. Moeller a n d TVoltereck9 pass oil and knows t h a t certain crudes "crack " more easily t h a n stearnthrough tubes containing coke a t 600" t o 700' C, others, which fact is t o be accounted for by t h e pres- None of t h e above processes are being operated on a ence of hydrocarbons of different constitution. In large scale in this country a t t h e present time. Another method of subjecting t h e heavy petroleum t h e case of t h e simpler hydrocarbons which have been studied, i t is known t h a t olefines are in genera1 less hydrocarbons t o t h e higher temperatures required t o stable t o heat t h a n saturated hydrocarbons of the same produce t h e desired increased yields of gasoline is molecular weight, and naphthenes are usually more heating or distilling under pressure. It is known t h a t stable t h a n paraffines. Xormal hexane and t h e more unsaturated hydrocarbons are condensed t o saturated stable methyl cyclopentane are good examples of hydrocarbons by t h e action of heat a n d pressure. t h e latter types. It was t o be expected, therefore, IpatiewlD showed t h a t ethylene, probably t h e most t h a t attempts would be made t o produce gasoline stable of t h e olefines, could he converted into a mixfrom heavier hydrocarbons by heat decomposition at t u r e of liquid hydrocarbons a t 3 2 5 ' C. and 70 atmostemperatures somewhat higher t h a n those employed spheres pressure. ,4t 3 8 0 " t o 100' C. t h e reaction for t h e production of kerosene b y cracking. -1large was sufficiently rapid to cause a fall of 5 atmospheres number of recent patents seek t o attain this end. per minute in the pressure of t h e closed apparatus. The fatal difficulty with processes of this class, opera- Englerll and his collaborators have shown t h a t amylene ting a t atmospheric pressure, is t h e large per cent of and hexylene yield saturated compounds of t h e napholefines contained in the resulting gasoline. This figure thene type by heating under pressure. I t i s therefore will vary, when t h e oil is simply subjected t o heat a t to be expected t h a t naphthenes will be found in gasoatmospheric pressure, from 2 0 to j o per cent, depend- line and kerosene made b y pressure distillation of ing on t h e temperature a t which t h e oil is cracked. heavier hydrocarbons; indeed, this has been shown b y The maximum per cent of olefines demanded by the Engler.lZ simple general equation, RCH2 - CH2 - CHzRl + In regard to the pressure distillation processes RCH3 C H 2 = CH.R1, is seldom attained owing which have been proposed, the older ones sought to t o other reactions, such as polymerization of t h e increase t h e yield of kerosene, since gasoline, in the olefines a n d t h e formation of naphthenes. Gaso- days of such early patents as those of Benton, was line made by cracking under atmospheric pressure, of very little value. I n t h e present discussion, only the heavier portion of Oklahoma crude, i. e., t h e t h e more imp0rtan.t processes are mentioned. I n part left after distilling off t h e gasoline and li-ero- 1869, Peckham13 claimed t o have obtained, by dissene, in such a way as t o condense and return tilling under 2 0 lbs. pressure, as much as Go per cent to t h e still all b u t gasoline a n d naphtha, showed illuminatiqzg oi l of specific gravity 0 . 8 r o from a Calia content of olefines of approximately 28 per cent, 1 French Patent 451,471, December, 1912; Eng. Pat. 28,460, 1911; a s indicated by the iodine number and loss t o ordinary Zng. Pat. 20,074, 20,095, September 3 , 1912; Eng. Pat. 13,675, 1908. 2 Petroleum Gazette, 1910, July, p. 2. sulfuric acid. Consequently a number of patents 3 U. S . Patent 1,110,925; English Patent 16,452, July 13, 1912 have been issued covering processes which seek t o 4 French Patent 462,484, September 11, 1913. 6 French Patent 451,162, 1912. hydrogenate t h e olefines formed. I t has been pro8 German Patent 268,176, October 12, 1913. posedl t o hydrogenate the olefines by placing a catalyst, 7 Met. Chem. Ea#., 1914, p. 180. English Patent 19,702, August 25, 1912. such as platinum or palladium, in t h e still, but this 8 Eng. Patent 16,611, July, 1913. process is not being operated for obvious reasons. 10 Ber. d. deut. chem. Ges., 44 (19111, 2978. Several proposed processes claim t h e cracking of heavy $1 Ibid., 42 (1909), 4610, 4613, 4620; 43 (1910), 388. 1% Engler. Ibid., 33 (1900), 2915; Nastjukoff, J. RILSS. Phys. Chem. Ces., hydrocarbons in the presence of steam and iron. The 36 (1904), 881; Kraemr & Spilker, Ber. d. d e u t . chem, Ges., 33 (1900). method patented by t h e New Oil Refining Process 2265.
+
1
U. S. Patent 826,089. July 17, 1906
13
Chemical A'ews, 1869, p . 183.
Mar., 1915
T H E J O U R N A L O F I i V D U S T R I A L A N D E N G I N E E R.lNG C H E M I S T R Y
fornia crude oil yielding 2 0 per cent kerosene of t h e same‘ quality when distilled in the usual manner at atmospheric pressure. Thorpe and Young’ obtained from paraffine, by heating a t a “high pressure” and subsequent fractionation, a light oil shown t o contain pentane, hexane, heptane, octane and nonane. A few patented processes.2 including t h e recent ones of Testelin and RenardI3 subject oil t o heat and pressure a n d distil t h e liquid after t h e pressure is released. Testelin and Renard seek t o avoid t h e deposition of carbon, always obtained when oil or oil vapor is passed through a heated pipe coil, as in some of t h e earlier processes. This they proposed t o do by uniformly heating t h e pipe coil, containing t h e liquid oil, t o a temperature not exceeding 4 jo’ C., by submerging t h e coil in a bath of lead a t t h e desired temperature. A sufficient pressure was maintained on the heated
FIG.I-APPARATUS EMPLOYED BY BENTON
oil t o keep i t in a liquid state. The process patented by Clark4 describes pumping t h e oil through heated pipes, collecting t h e hot oil in a receiving d r u m where distillation under pressure is permitted. The older patents of Benton5 also embodied t h e principle of subsequent distillation after release of t h e pressure b u t heated t h e pipe coils directly by a flame. As regards actual distillation under pressure, a number of early patents describe t h e manufacture of ill u m i n a t i l z g oils by t h e use of low pressures. Thus Young6 stipulated pressures of I O t o 20 pounds per square inch. Krey7 recommended two t o four atmospheres a n d claimed t o obtain a distillate of a specific gravity of 0.820 (yield not given). Bolegs recommended pressures of three t o four atmospheres and says t h a t pressures of four to six atmospheres yield more “illuminating oil ” b u t less “lubricating distillate” t h a n t h e lower pressure. Dewar and Redwood9 devised a n appar.atus for distilling petroleum under pressure, which is t h e general arrangement now employed on a larger scale by a later patentee. Dewar and Redwood, however, did not s t a t e what p r e s s w e gave t h e results desired nor did they advoChem. News, 1871, (23). 124; 1872, ( 2 6 ) , 35. Shuchoff and Gawryloff, Zeitschr. f. alzgew. Chem.. 1895, p. 231. * Renard, Eng. Patent 3,413, February 10, 1913. 4 U. S.Patent 1,119,496 Dec. 1, 1914. 6 U. S.Patent 342,564 and 342,565. 6 English Patent 3,345, December 27, 1863. German Patent 37,728 (1886). Chem. Rev., 9 (1898), 24. U. S. Patent 419,931, 1890; 426,173. 1891; English Patent 10.277, 1889; 13,016, 1890: 5,971, 1891. 1
2
181
cate their process as one suitable for manufacturing gasoline. The foregoing brief review outlines t h e “ s t a t e of t h e a r t ” prior t o t h e patent of Bacon a n d Clark.’ The latter patent specifies t h e distillation of heavy petroleum oils between pressures of IOO a n d 300 pounds. The advantages of t h e range specified, so far as increased yields of gasoline are concerned, are brought out by t h e results represented graphically in Fig. 111. T h e yields given are not t h e maximum obtainable b u t represftnt comparative results of a series of experiments obtained by distilling a given quantity of Oklahoma reduced oil a t a uwiform rate from t h e same apparatus a t t h e different pressures indicated. The effect of pressure in diminishing t h e per cent of olelines in t h e gasoline obtained is a noteworthy feature of these results. The same effect is very strikingly shown in t h e recent results of Whitaker a n d Kittman2 on t h e effect of pressure in t h e yield of illuminants in oil gas. At goo’ C., Whitaker and Rittman obtained from a given quantity of oil 1 2 2 liters of illurninants a t 0 . 7 j lb. pressure, 50 liters a t atmospheric pressure a n d I j . j liters a t 45 lbs. (absolute) pressure. They were also able t o show t h a t at temperatures of 750’ t o 8ooo C. t h e addition of hydrogen to t h e gas mixture has t h e effect of partially hydrogenating t h e olefines a n d t h a t this reaction takes place more readily as t h e pressure on t h e system is increased. Ipatiew3 has made t h e interesting observation t h a t , in t h e distillation of petroleum under pressure, a t t h e higher pressures t h e evolved gases become continually poorer in hydrogen in spite of t h e higher temperatures required t o maintain t h e higher pressures. The pressures employed b y Ipatiew were 1 2 0 t o 3 4 0 atmospheres. We have found t h e following : TABLSI-GASES
CRACKING DISTILLATIONS UNDER 100 POUNDS PRESSURE @)Paraffine I I1 I11 I I1 I11
PROM
(a)From Jennings crude
Sample No. Temoerature in still . . . . . . . . . . . . . 340’C. coz . . . , . . . . . . . . . . 1 . 2 co..,............ 1 . 2 Illurninants.. . I . . . 15.4 Hydrogen .. 0.0 Saturated hydrocarbons ......... 81.5
.......
.
415’C. 0.5 0.5 15.3 4.0 79.7
422OC. 417’C. 0.0 0.0 1.3 0.0 13.0 25.4 4.4 0.3 81.3
74.3
4 3 2 “ C . 437OC. 0.0
0.0
37.0 0.0 0.9
33.5 0.0 3.0
62.1
63.5
The analyses i n Table I(a) were made of t h e gases evolved during a cracking distillation of a reduced oil prepared by removing from Jennings crude all constituents boiling below 265’ C. Sample I was taken as soon as I O O pounds pressure h a d been reached. Sample I1 was collected after 40 per cent of t h e charge had been distilled, and Sample I11 after 7 5 per cent h a d distilled. The liberation of hydrogen from petroleum hydrocarbons a t various temperatures has been studied by Engler4 a n d his students. They obtained no hydrogen below 470’ a t atmospheric pressure from keroseme fractions boiling below 2 8 0 ’ C. The liberation of hydrogen from different hydrocarbons a t a given 1
a 4
U. S. Patent 1,101,482. Under Int. Conv., May 6 . 1912 THISJOURNAL, 6 (1914), 479. Ber. d . deut. chem. Ges., 57 (1904), 2969. Engler and HaFer, Das Eudbl, 1, 574.
s82
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEilfISTRY
temperature depends somewhat on their constitution. Thus, benzol yields appreciable quantities of hydrogen only a t temperatures above 500' C. Our work indicates t h a t ij hydrogenat+ion of t h e liquid olefines takes place during distillation under pressure. i t occurs simultaneously with their initial formation. A sample of cracked n a p h t h a , having a n iodine number of j j . 0 , was heated t o 196' C . with hydrogen for thirty hours under 3,000 lbs. pressure per square inch. The iodine number and refining loss with sulfuric acid were practically unaffected, t h e iodine number of t h e final product being j 2 9. Results closely parallel t o this were obtained by l l r . E d m u n d Rhodes, in this laboratory, working with liquid f a t t y oils. The apparatus employed n a s a steel bomb connected with a solenoid stirrer constructed as described by Stucker and Enduli.' Uebbelohde and Woronin2 showed t h a t in the presence of nickel, hydrogen was split off from a Baku crude oil a t as low a temperature as 180" C. The results of Zelinski3 with platinum as a catalyst show t h a t
FIG.11-APPARATUS EMPLOYED BY D E W A RA N D R E D W O O D
Zeidschv. f. Eleklroch., 1913, p . 530. Petroleum, Berlin, 1911, pp. 7, 9. a Be7. d. deutschen chem. Ges., 1912, pp. 45, 3678. 4 J . Russ. phys.-chem. Ges., 1910, p. 195.
1'01. 7. NO. 3
ployed t h e per cent of olefines in t h e gasoline product was 48 per cent. T H E E F F E C T O F N I C K E L in increasing the per cent of olefines, when operating a t atmospheric pressure, opens up t h e question of t h e effect of foreign substances on the polymerization of olefines and the effect thereon of different physical factors. The percentage of olefines indicated in t h e above figure does not represent t h e minimum obtainable even without t h e adciition of a "catalyst." T h e claim is made b y Burton' t h a t by placing the pressure-controlling valve beyond the condenser so as t o condense t h e volatile gasoline vapors produced b y distilling heavy petroleum oils under about 7 j Ibs. pressure, olefines are not produced, whereas, if t h e pressure-controlling valve is placed between the still and condenser, olefines are found in t h e condensate t o such a n extent as t o render the latter process of doubtful coymercial utility, The authors felt t h a t if olefines could somehow be squeezed together or polymerized b y 7: pounds pressure in a condenser containing cold water, this fact would be a n interesting contribution t o science, but the experiment noted above, in which a cracked petroleum n a p h t h a was heated for thirty hours a t 196' C. under 3,000 lbs. pressure per square inch practically without change (iodine number reduced from j j . o IO j 2 . 9 ) , seemed t o render such a reaction as Burton describes improbable. We accordingly prepared several gallons of gasoline by distilling Oklahoma reduced " oil a t approximately 80 lbs. pressure, in one case with t h e valve between t h e still a n d t h e condenser, and in another experiment with t h e still and condenser in free communication, so as t o condense t h e vapors under pressure, all other conditions remaining the same. GASOLINE Per cent refining loss b y 5 per cent conc. HzSOi. . . Per cent refining loss by 5 per cent "oleum". KEROSENE, boiling point 302-392' F. Per cent refining loss b y 5 per cent "oleum". . . . .
.
1
II
7.9
8.0
9 .O
8.0
the part of Bemar and Redwood is not such a serious
9
1
2
U. S.Patent 1,049,667. Loe. cit.
Under I n t . Conv , July 3 , 1912.
T H E JOllRiVAL O F 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
Mar., 1915
matter as i t might be. Aside from t h e above noted discovery as claimed by Burton, it is difficult t o find a n y novelty in his patent. The operating pressures specified by Burton are four t o five atmospheres. Roleg’ described distillation under four atmospheres pressure a n d in 1886 Krey2 published t h e results obtained b y distilling various crude oils, heavy oils and residues 401 Per
cent
I
0
Refin iny LOss ”
c
Pressure m Lbs.p e r S? in. 2ao 0 40 65 80 100 20 45 60 85 205 (
*
,
‘
,
*
I
*
‘
$
0
I
400
*
A N D REFINING LOSSES OF GASOLINE OBTAINEDB Y DISTILLINGOKLAHOMA REDWCED OIL UNDER PRESSURE Gasoline = Distillate below 150’C. Refining, by 1/10 volume concentrated I-IzSOa
FIG.111-YIELDS
under pressures of three t o six atmospheres. Englera confirmed t h e claims of Krey but, like Dewar and Redwood, Engler and Krey did not discover t h e remarkable effect of t h e position of t h e pressure-controlling valve, as referred t o above. It has been pointed out t h a t t h e results presented in Fig. I11 do not represent t h e maximum yields of gasoline or t h e minimum percentage of olefines obtainable in the gasoline distillates made by distilling under pressure. I t is not t h e purpose of this paper t o point out t h e optimum working conditions of the process. However, in t h e patent of Bacon, Brooks and Clark4 it has been shown t h a t t h e ratio between t h e volume of t h e oil heated a n d the area of t h e heating surface of the apparatus employed is an important factor. This relation m a y perhaps be more clearly understood if i t is stated t h a t , other conditions remaining t h e same, cracking does not occur throughout t h e mass of heated oil, b u t t h a t t h e c r a c k i n g e j e c t produced in a g i v e n q u a n t i t y , in a gioen t i m e , w i l l , w i t h i n c e r t a i n k i m i t s , be a p p r o x i m a t e l y p r o p o r t i o n a l t o t h e heated s u r f a c e iiz contact w i t h t h e oil. It is obvious t h a t distilling slowly will have approximately t h e same effect as increasing the relative area of heated surface. Another fact brought out in this process is t h a t t h e deposition of coke on vertical heatiag surfaces is very much less, one-third to one-fifth of t h e amount deposited on t h e upper side of a horizontal surface, such as a n ordinary still bottom, in a given length of time. Under higher pressures, such as zoo lbs. per square inch, oils having boiling points above 300’ are almost completely prevented from distilling a t t h e mean temperatures in t h e still, i. e., 370’ t o 420’ C. L a i r ~ g operating ,~ a t much lower pressures, attempts t o r e t u r n the heavier boiling fractions of t h e distillate 1
Chem. Rea d . Felt- u. Havz Ind., 1898, pp. 9, 24.
* German Patent 37,728 (1886). a Ber.
d . deutschen chem Ces.. 30 (1897). 2919.
’ U. S. Patent Ser. No. 764,982-Allowed
Nov. 24, 1914. Under Int. Coov., M a y 2, 1913. To issue March 9, 1915. ’ German Patent 260,858. October, 1911, C h e n . Ztg., 1913, p. 375.
183
t o t h e still b y employing a n apparatus such as is shown in Fig. IV. Although hydrocarbons of t h e type contained in gasoline are more stable t h a n t h e heavy hydrocarbons such as are contained in “reduced” oils, i t is nevertheless important t o remove t h e gasoline from t h e “sphere of reaction” as fast as formed. Thus, heating a certain volume of heavy oil under a given pressure for a given period of time a n d subsequently distilling a t atmospheric pressure does not yield nearly as much gasoline as distillation under t h e same pressure, t h u s removing t h e gasoline a n d kerosene as fast as formed. This was well shown by a n experiment in which Oklahoma “reduced” oil was heated under a pressure of 180 lbs. per square inch for two hours a n d t h e n distilled a t atmospheric pressure. There was obtained in this way only j per cent of gasoline, while another experiment under t h e same conditions, except t h a t the gasoline was distilled as fast as formed, yielded 3 0 . 4 per cent gasoline. This indicates t h a t t h e gasoline hydrocarbons ’ themselves slowly decompose in the cracking still. I n view of this fact, i t is all t h e more remarkable t h a t t h e kerosene fractions of t h e pressure distillate obtained from Oklahoma reduced oil b y distilling inder I O O lbs. pressure are optically active. OPTICAL ACTIVITY O F K E R O S E N E HYDROCARBONS M A D E BY CRACKIKG H E A V I E R HYDROCARBONS
T h e kerosene fractions of most crudes show very little, if any, optical activity. The maximum rota-
_FIG.~ ~ - A P P A R A T UPATENTED S BY LAING
tions are noticed in t h e fractions boiling from about 230’ t o 290’ C. under 1 2 t o 14 mm. pressure. A Galician oil studied by Engler yielded a fraction boiling from zooo t o 2 5 0 ’ under atmospheric pressure, which showed a rotation (zoo mm. tube) of $ 0 . 2 ’ on t h e saccharimeter scale. The fraction boiling
184
T H E J O U R N A L OF I N D U S T R I A L A N D E S G I A 7 E E K I S G C H E J i I S T R Y
from 2 0 0 ’ t o 2j0’ C., made by cracking Oklahoma reduced oil under I O O lbs. pressure, showed a rotation in a 400 mm. t u b e of $ 0 . 3 6 ’ on t h e saccharimeter scale. Other samples showed rotations of approximately t h e same degree. I n view of t h e high temperatures prevailing in the pressure still, 360°-4200 C., the fact t h a t complete racemization has not occurred indicates t h a t these optically active hydrocarbons undergo racemization with greater difficulty t h a n optically active compounds of a n y other class. T h e corresponding fraction, boiling from 200--250’ C., distilled off the original Oklahoma crude, h a d a rotation of + c . 2’ in a zoo mm. tube on t h e saccharimeter scale. Since t h e optically active kerosene hydrocarbons made b y cracking under pressure are t o be regarded as products of t h e “splitting” of heavier hydrocarbons of higher molecular weight, the fact of their being optically active is even more remarkable. Engler and Bobrzynskil showed t h a t a fraction of Galician oil still showed an optical rotation of 0 . 8 ” (saccharimeter scale) after heating a t 3 50-360’ fcr four hours. Engler has also shown t h a t optically active oils may be obtained b y t h e destructive distillation of cholesterol. Englerl and L.larcusson2 have suggested t h a t the optical activity of petroleum oils is due t o hydrocarbons of t h e naphthene type. This is confirmed b y our observations t h a t a viscous lubricating oil prepared from Jennings crude, after refining several times with “oleum” and finally clarifying with Fuller’s earth, showed an optical rotation in a 400 mm. t u b e of 4.04’ arc or 1 1 . 6 ’ on t h e saccharimeter scale. Since this oil was odorless and tasteless, optically active naphthenic acids could not have been a factor. PRODUCTS OF CRACKIKG DISTILLATIOK UNDER PRESSCRE FORMATION O F BEXZEKE,
TOLUENE
AND
XYLEXTE--
T h e formation of aromatic hydrocarbons from petroleum oils has heretofore been assumed t o be due t o complex and little understood changes such as dehydrogenation of naphthenes and t h e formation of acetylene and t h e condensation of t h e latter t o benzene and its homologues. We have found t h e above-named aromatic hydrocarbons in gasoline made b y cracking heavy Oklahoma reduced oil under a pressure of I O O lbs. per square inch. Treatment of t h e gasoline b y liquid sulfur dioxide gave 1 0 . 0 per cent of olefines a n d aromatic hydrocarbons, mhich mixture was fractionated several times and t h e fractions whose boiling points corresponded t o t h e boiling points of benzol, toluol and xylol were nitrated in t h e usual manner, water added, and t h e crude crystalline mass t h u s obtained recrystallized several times from alcohol. Tire obtained in this way ~ ~ - d i i a i t r o b e n z o lmelting , point 9 0 . o o C . , also 2 , 4 - d i ~ ~ i t u o i o l u oof l melting point 7 0 . o o C., and z , 4 , 6 - t r i n i t r o r l z e t a ~ ~ l omelting l, a t 1 8 2 . 0’ C. Since relatively little gas3 is evolved when distilling under I O O lbs. pressure and since t h e gas cvolved Engler, Das Erdal., 1, 218. Chem. Ztg., 1911, p . i 2 9 . 3 This will vary with different oils and t h e evolution of gas becomes much more rapid toward the end of a distillation when much coke is produced. 1
2
v01, 7,
NO.3
contains not more t h a n 4 . 1 per cent hydrogen, it appears highly improbable t h a t t h e aromatic hydrocarbons in question are produced, either directly or indjrectly, by a process of splitting off of hydrogen. W e beliece the evidence p o i f z t s to the s p l i t t i n g off of beiizol, toluol a i i d xylol j r o v z large so-called p e t r o l e u m h y d r o carbons, w h i c h c o n t a i n the phepzyl radical.’ I n order t o test this hypothesis further, we have made “gaso-. line” b y heating Oklahoma reduced oil with anhydrous aluminum chloride. I n this reaction very little gas is evolved from dry petroleum oils. Should. the phenyl radicals exist in t h e complex petroleum hydrocarbons, one might expect a splitting of t h e molecule just as is known t o occur n-lien toluol is treated with aluminum chloride, C Ex, CBH6 + C6Hj.CH3 ----f CBH4
