CZECHOSLOVAKIA DUBBSCRACKINQ UNITWITH CONTINUOUS COKINQ, BRATISLAVA,
Motor Fuel from Oil Cracking "roduction by the Catalytic Water Gas Reaction
T
HE process of producing hydrocarbon o i 1s f r o m coal is in commercial use, via carbonization either a t low and high temperatures, hydrogenation, and the water gas reaction. Four plants are now in operation in Germany with a capacity of 150,000 metric tons per year of gasoline from the water gas reaction ( I S ) . The R a d i s c h e Anilin- und Sodafabrik of Ludwigshafen, Germany, in 1913 disclosed conversion of mixtures of carbon monoxide and hydrogen into saturated and unsaturated gaseous and liquid hydrocarbons, alcohols, aldehydes, ketones, acids, water, and carbon by catalytic treatment a t e l e v a t ed temperatures and pressure (3). It was stated that when mixtures of two or more parts of carbon monoxide and one of hydrogen were subjected to 100-120 atmospheres
GUSTAV EGLOFF, EDWIN F. NELSON, AND J.
c. MORRELL
Universal Oil Products Company, Chicago, 111. -~
~
~~~~
~~
~
High yields of gasoline of satisfactory antiknock value may be produced in the catalytic conversion of water gas into hydrocarbon oil by recovering a light, relatively high-antiknock gasoline, reforming the naphtha, and cracking the bottoms from the distillation operation. The final gasoline product is obtained by blending the low-boiling products of the topping and cracking operations together with a high-antiknock gasoline obtained by catalytically polymerizing the olefinic gases obtained by cracking. Aviation gasoline may be produced by blending, for example, low-boiling, straight-run, and polymer gasolines. 555
and 300-400" C. (572-752' F.) over a catalyst impregnated with alkali and oxides of cobalt, osmium, or zinc, the above products were formed. Mixtures of carbon monoxide and h y d r o g e n can be prepared in many ways; the 1 to 1 mixture known as water gas is readily p r e p a r e d by the action of steam upon coke a t temperatures around 1000° C. (1832" F.) according to the reaction
C
+ HzO +CO + H)
(1)
In the presence of a nickel catalyst, methane and steam produce a mixture of water gas and hydrogen as follows:
Hence, a 1 to 3 mixture of carbon monoxide and hydrogen can be derived from coal gas, natural gas, and gases from
INDUSTRlAL AND ENGINEERIYG CHEMISTRY
556
cracking oil. Carbon dioxide, through reduction, is also a ready source of carbon monoxide. The reducing agent may be coke, hydrogen, or methane, which react as follows: COa c 4 2 c o (3) COP Hz +CO HzO (4) 3coz CH4 +4CO 2H20 (5)
+ + +
+
+
Reactions 1 to 5, together with the reaction 6, CHd +C 2H2
+
*
(6)
whereby hydrogen is produced by the pyrolysis of methane, permit the mixture of carbon monoxide and hydrogen in any desired proportion. According to the Badische Anilin- und Sodafabrik, the catalytic hydrogenation of carbon monoxide proceeds at 300" to 420" C. (572" to 788" F.) and up to 120 atmospheres pressure in the presence of various elements and their oxidesfor example, cerium, chromium, cobalt, manganese, molybdenum, osmium, palladium, titanium, and zinc. Basic materials such as alkali were found to improve the catalyst, and the substitution of carbon dioxide for carbon monoxide was found to decrease the yield of liquid hydrocarbons. The greatest advance in the conversion of carbon monoxide into liquid hydrocarbons was made by Fischer and Tropsch (8) who in 1923 investigated the oxygenated compounds produced in the hydrogenation of carbon monoxide. They found that water gas passed over iron impregnated with potassium carbonate a t 150 atmospheres pressure and 400" to 450" C. (752" to 842" F.) formed an aqueous mixture of aliphatic alcohols, aldehydes, ketones, acids, and esters. Practically no hydrocarbons were formed and the mixture was given the name Synthol (synthetisches OZ). Later investigations of Fischer and Tropsch (9)demonstrated that the yield of Synthol increased with increase of carbon monoxide over hydrogen (Table I) and increasing strength of alkali with metallic iron used as catalyst (Table 11). It was also discovered that the siae of the aliphatic molecule synthesized depended upon the strength of the alkali used (10). An outstanding dficulty in Synthol production was the presence of such sulfur compounds as carbon disulfide, carbon oxysulfide, and hydrogen sulfide in the water gas and other gases used (9). They were found to poison the catalyst unless substantially removed.
TABLE I. INFLUENCE OF GABMIXTURE COMPOSITION Ratio. CO to HZ
0
P:2 1:l 2:1 Estimated volume
-Temp.-O C.
a.
F.
Yield of Syntholu Pressure per Cu. M. of Atm. Entering Gas Mixture
cc.
410 770 122 410 770 72 410 770 85 of water-free product.
17 26 32
Catalyst Compn. (In Order of Increas- -Temp.ing Alkalinity) O C.
+ LiOH Fe + KOH Fe + RbOH
Fe Fe -
~
4- NaOH
420 420 420 420
F. 788 788 788 788
of hydrogen does not produce any hydrocarbons but almost exclusively compounds containing oxygen, the Badische Anilin- und Sodafabrik had already put into practice the highpressure synthesis of methyl alcohol because we, as has already been mentioned, aimed to produce motor fuels out of carbon monoxide. For this purpose even ethyl alcohol is not well suited; still worse is methyl alcohol with its small calorific value, since it is composed of 50 per cent oxygen by weight." The Fischer and Tropsch synthesis of hydrocarbons is known as the benzine synthesis or Kogasin process (named from kohle gas benzine). The process utilizes a mixture of hydrogen and carbon monoxide in the proportion 2 to 1, with cobalt, iron, or nickel as catalyst (6) without alkali a t a temperature of 200" C. (392" F.) and under atmospheric pressure, In the presence of strong alkali the polymerization continues until solid paraffin rather than liquids is produced
+ +
(16).
The theoretical yield of liquid hydrocarbons or Kogasin ('7) is 185 grams per cubic meter of gas containing 29.5 per cent carbon monoxide and 60 per cent hydrogen. Latest reports show a yield of 151 grams or 81.6 per cent conversion into hydrocarbons with such a mixture by two stage operation at 190" and 184" C. (374" and 363"F.), respectively, using a cobalt-copper-tkorium-kieeelguhr catalyst. Water gas, containing 42 per cent carbon monoxide and 48 per cent hydrogen, gave a yield of 160 cc. of oil per cubic meter of water gas, csing a nickel-manganese-aluminum oxide catalyst (1). On the basis of 40 pounds of coke required to produce 1COO cubic feet of water gas (Z),this is equivalent to 56 U. S. gallons of liquid hydrocarbons per short ton of coke. Kogasin is principally a straight or slightly branchedchain mixture of saturated and unsaturated hydrocarbons having the following fractions (11): gasoline, 30" to 220" C. (86" to428"F.); Dieseloil, 220" to 350" C. (428" to 662" F.); and wax separated from the Diesel oil fraction. The gasoline fraction is water-white and sulfur-free. Fatty acids are present in small quantities ( I d ) . Olefins are present to over 50 per cent (14). Since there is little branching of the hydrocarbon molecules, it has an octane number below 50 (5). The nature of the hydrocarbons in Kogasin depends upon the catalyst and water gas mixture used, cobalt producing more unsaturated oils than nickel (4). The following table shows the olefin content of Kogasin from various sources: -Val. % Olefins in,Synthetic Benzine from:Water gas Mixed gas Cracked gas (C0:Hz = 1:l) (CO:Hz = 1:2) (C0:Hz = I S ) 5 35 16
Ni
co Yield of 8 nthol per c u . of Entering Gas Mixture
h.
Pressure Atm. 141-124 141-121 140-130 140-133
The following statement (IO) of Fischer is of interest, since it gives the point of view of B fuel technologist with a fine insight into the future: "About a year after Tropsch and 1had discovered that high-pressure hydrogenation with a surplus
Catalyst
TABLE 11. INFLUENCE OF ALKALI WITH IRON AS CATALYST cc. 0.8 10 '
40 48
~~~~
The next step in the hydrogenation of carbon monoxide into hydrocarbons was the reversal of the conditions requisite for the synthesis of the oxygenated compounds. Fischer and Tropsch in 1926 reported the conditions necessary for the formation solely of saturated and unsaturated hydrocarbons by hydrogenation of carbon monoxide a t atmospheric pressure.
VOL. 29, NO. 5
55
12
35
With sufficient hydrogen and nickel catalyst, the reaction is essentially (1): nCO (2n 1) Hz +CnHzn+z nHzO heat
+
+
+
+
No lubricating oil fraction is present in Kogasin, although lubricating oils are obtainable from Kogasin by condensation reactions (11). The gasoline derivable from the hydrocarbon oil produced by the catalytic treatment of water gas has a low octane rating and therefore requires reforming to yield a product suitable for modern motors. By fractionating a very light gasoline from the Kogasin oil, subjecting the naphtha and bottoms to selective cracking conditions, and polymerizing the olefins present in the gas, a yield of over 84 per cent of 66 octane number gasoline was obtained in tests conducted by the Universal Oil Products Company research laboratories.
IEDUSTRIAL AND ENGINEERING CHEMISTRY
MAY, 1937
TABLE IV. SEMI-COMMERCIAL-SCALE FRACTIONATION OF KOGASIN OIL
TABLE 111. PROPERTIES OF KOGASIN OIL Gravity 'A. P. I. Sp. gr. a't 60' F. (15.6' C.)
63.0
Sulfur ya Octank NO. (c. F. R. motor method)
557
0.01
Properties of Products Gasoline Bottoms Gravity OA. P I. 69.6 49.3 1oD-Cc. Engler Distillation SP. gr. dt 60' F. (15.6' C.) 0,7036 0,7826 Sulfur, o% 0.014 0.010 O F. (" C.) F. ( 0 C.) Color Saybolt 19 ... % . . . 0 .2 Bottdms, settlings and water Initial b. p. 113 (45) 60% over 368 (187) ... Saybolt Universal'viscosity a i 100' F. (37.8' C.) 36 59' over 148 (64) 420 (216) Octane No. (C.F. R. motor method) 40 487 10 170 (77) 657 205 (96) F. (" C.) 215 (102) Flash (Cleveland open cup) 702 (372) 245 (118) 225 (107) Fire (Cleveland open cup)d F. ( " C.) 286 (141) yo over 97.5 Flash (Penfky-Martens), F. (" C.) 160 (71) 323 __ (162) % bottoms 1.0 Cold test, F. (" C.) 45 (7) % loss 1.5 100-cc. Engler distn., O F. ( " C.): Initial b. p. 107 42) 378 (192) 5 o over 139 431 (222) 155 68) 446 (230) YIELDS AKD QUALITYOF LIGHTGASOLINE FRACTIONS T.4BLE 176 (SO) 466 241) 199 (93) Yields, Volume Per Cent of Kogasin Oil 484 503 t.251) (262) 40 o 50 Gasoline 20.0 33.8 43.5 56.3 523 (273) -__ Bottoms 79.8 66.0 56.2 43.5 272 (133) 553 (289) Recovery 99.8 99.8 99.7 99.8 299 (148) 592 (311) Loss 0.2 0.2 0.3 0.2 327 (164) 633 (334) 359 (182) 688 (364) Properties of Light Gasolines 396 (202) 747 (397) Gravity, "A, P. I. 84.1 79.3 75.8 72.4 Yo over 98.0 98.5 Sp. gr. at 60' F. (15.6' C.) 0.6563 0.6713 0.6826 0.6940 1.0 1.5 Qotane No. (C.F. R. motor method) 73 66 58 49 1.0 0.0 100-cc. Engler distn., Initial b. p. 110 97 (36) 5 over 126 (52) 126 TABLEVI. PROPERTIES O F LIGHT GASOLINE-4ND NAPHTHA 140 (60) 138 160 (71) 150 7-70 Based on Gasoline-Based on Kogasin Oil-178 (81) 160 30% Light gasoline 42.5 Light gasoline 29.1 197 (92) 175 40% 57.1 Naphtha Naphtha 39.0 214 (101) 190 50% Recovery 0.3 99.6 Loss 235 (113) 200 Total 68.4 Loss 0.4 220 232 80% Properties of Products Light Gasoline Naphtha 252 90% Gravity 'A. P. I. 79.8 61.7 268 Sp. gr. Lt 60' F. (15.6' C.) 0.6697 0.7324 point 299 Sulfur, % 0.01 0.02 96.5 98.0 98.0 98.0 68 Octane No, (C. F. R. motor method) 4 1.0 1.5 1.0 1.5 2.5 0.5 1.0 0.5 100-cc. Engler distn., ' F. (" C . ) : 219 (104 Initial b. p. 96 (36) Properties of Bottoms 255 (1241 117 (47) over 267 (131) 126 (52) 58.0 55.9 Gravity 'A. P. I. 54.2 52.0 282 293 (145) (139) 135 (57) 0.7711 Sp. gr. &; 6OOF. (15.6' C.) 0.7467 0.7551 0.7620 144 (62) 100-cc. Engler distn. O F. (" C.): 303 (151) 40 152 (67) Initial b. p. 210 (99) 260 (127) 312 (156) 372 189) 316 (158) 50 1 s (72) 242 (117) 274 (134 334 (168) 389 1198) 171 (77) 328 (184) soy 258 (126) 298 1481 346 (174) 397 (203) 193 (83) 182 (89) 344 (173) 70d 284 140) 324 [162) 361 (183) 416 (213) 362 (1%) 80% 50 368 f187) 400 (204) 428 (220) 484 (251) 388 (198) 208 (98) End 90% point %9' 604 318 650 343) e 4 (357) 241 (116) 523 (273) Encf point 705 !374] 700 (371) 728 1387) 740 (393) 98.0 98.0 98.5 98.0 98.0 98.5 9% over 1.0 2.0 Yo bottoms 1.5 1.0 2.0 2.0 1.0 0.0 0.5 0.0 7 0 loss 0.0 0.0 0.7275
20
I;:;{
... ... ... ...
so
j69)
"I
v.
...
%
82
;;i
7 %
%%
&Zi
m o
The so-called Kogasin oil had a boiling range of 113" to 702" F. (45-372" C.). This oil contained 68.4 per cent of gasoline with an octane value of 40 and a boiling range of 107" to 396" F. (42" to 202" C.). As determined by a 100-cc. Engler distillation, the Kogasjri oil used in the selective cracking tests had the properties listed in Table 111. The Kogasin oil was fractionated in a semi-commercialsize pipe still into motor fuel and bottoms The yields were 68.4 per cent motor fuel and 31.4 per cent bottoms. The two fractions had the properties shown in Table IV. The motor fuel, of 396" F. (202" C.) end point, present in the Kogasin oil has an octane number (C. F. R. motor method) of 40 which is too low for modern motors because of its high knocking properties under combustion conditions; hence it must be subjected to reforming or cracking conditions in order to raise the octane rating. However, a fraction of approximately 70 octane number gasoline may be distilled from the oil which requires no reforming or cracking and then blended with the cracked naphtha fraction to produce a highoctane motor fuel. A study was made of gasoline fractions in the Kogasin oil to determine their octane ratings. This was carried out in a 10-inch Hempel glass bead column with the yields and quality of the light gasoline fractions present as shown in Table V. The gasoline produced by the semi-
TABLEVII. REFORMING OF NAPHTHA Charging Stock
Yield of reformed gasaline, vpl. yo of Kogasin oil Gas, cu. ft./barrel of Kogasin oil Analysis of product (reformed gasoline) : Gravity, "A. P. I. Sp. gr. a t 60' F. (15.6" C.) Sulfur, % Reid vapor pressure lb./sq. in. Octane No. (C. F. R. motor method) 100-cc. Engler distn., F. (: o C.) : Initial b. p. Over
-Naphtha--
29.0 325
26.8 338
63.7 0.7249 0.02 10.0 57
64.4 0.7223 0.2 10.6 62
98.0 1.0 1.0
. 98.0 1.2 0.8
lig
.-
90%
E3 point EEoms 0
loss
.
commercial-scale pipe still was refractionated into a 68-octane fraction and a naphtha bottom. The properties of the light gasoline and naphtha are shown in Table VI.
558
INDUSTRIAL AND ENGINEERING CHEMISTRY
The naphtha fraction of the gasoline was reformed a t 1020" F. (549' C.) and 750 pounds per square inch pressure. The naphtha had an octane number of 40 which was raised to 57 and 62, depending upon the time factor used. The results of the reforming test are shown in Table VII. The analysis of the gas produced from the cracking operation is shown in Table VIII.
VOL. 29, NO. 5
The bottoms from the semi-commercial-scale distillation of Kogasin oil were subjected to selective cracking by means of a two-coil operation. The conditions were 935' F. (502" C.) and 500 pounds per square inch in thelight oil coil, and 969" F. (521" C.) and 300 pounds per squaqe inch in the heavy oil coil. The results of the selective cracking of the bottoms are shown in Table IX.
UNIVERSAL OIL PRODUCTS CATALYTIC POLYMERIZATION UNITWITH
A
CAPACITY OF 4,250,000 CUBIC FEETPER DAY
MAY, 1937
INDUSTRIAL AND ENGINEERING CHEMISTRY TABLEVIII. ANALYSISOF GAS
Density (air = 1.00) Compn., % by vol.: Hydrogen Nitrogen Carbon monoxide Carbon dioxide Oxygen Methane Ethylene Ethane Propene Propane Isobutene n-Butene n-Butane Pentanes and heavier Total
1.180 Total olefins Total propylene and higher olefins Pentanes and heavier (as liquid) : Ga1./1000 cu. f t . L./cu. m. 7 by voi. of charging stock
3.7 2.3 0.3 0.0 0.2 10.5 4.2 28.7 16.7 19.1 0.4 4.4 7.2 2.3 100.0
25.7 21.5 0.83 0.11
1.71
0.67
%
Heating b y value vol. of(calcs.) K O asin B. oil t. u./ cu. Et.
1890
CRACKING OF BOTTOMS TABLEIX. SELECTIVE Yield, vol. % of charging stock: Gasoline Residuum Gas and loss Gas, cu. ft./barrel of charging stock Yield, vol. Yo of Kogasin oil: Gasoline Residuum Gas. cu. ft./barrel of Kogasin oil Analysis of product (craoked gasoline): Gravity ‘A. P. I. Sp. gr. d t 60° F. (15.6O C.) Sulfur, % Reid va or pressure, lb./sq. in. Octane (C.F. R. motor method) 100-cc.Engler distn., F. ( ” C.): Initial b. p.
72.0 10.6 17.4 710 22.6 3.3 224
I
68.5 0.7075 0.02 12.5 60
80.
1% 20% 50% 90%
92 (33) 112 (44) 124 (51) 140 ( 6 0 ) 210 (99) 354 (179) 414 (212) 422 (2171 97.0 1.0 2.0
Over
E3 point
P loss Efoms 4
15.4 0.9632 41 5.9 250 (121) 310 (154) 130 (54) 55 (13) 376 (191) 12.0
._ Compn. of cracked gas, % by vol.: Carbon dioxide Oxygen Ethylene Propene and butenes
0.0 0.0 9.3 25.2
Light gasoline Polymer fraction Total ProDerties of ComDonents
% by vol.
% b y wt. 22.0 19.2 5.4 5.6 27.4 24.8 Light Polymer Gasoline Fraction Blend 80.3 83.2 69.3 0.6681 0.6591 0.7047 30 ... Negative
... ...
73 100-cc. A . S: T. M. distn., Initial b. p.
F. (” C.):
...
87 102 108 115 122 30 128 40 136 E% 143 151 162 179 90 199 221 97.0 1.0 2.0 a The polymer gasoline has a blending value of
... ... 81
101 (38)
The olefins present in the gases produced from the reforming and cracking of naphtha and bottoms from Kogasin oil can be readily converted into high-octane gasoline by catalytic polymerization a t 450’ F. (232” C.) and 200 pounds per square inch. This treatment will produce a gasoline with an octane rating of 81 and high blending value, as determined by the F. R.motor method. The yield of gasoline based upon the naphtha and bottoms is increased 8.5 and 8.1 per cent, respectively, by adding the polymer gasoline to the cracked gasolines. The results obtained based upon reforming the naphtha, selectively cracking the bottoms, and polymerizing the cracked gases, are as follows:
c.
Charging Stock Yield % of charging stock: Cricked gasoline Polymerized gasoline Total Yield of Kogasin oil: Cric%ed gasoline Polymerized gasoiine Total Octane No. of blends
Naphtha
Bottoms
68.7
72.0
8.5 -
__ 8.1
77.2
80.1
26.8 3.3 30.1 66
2.5
22.6
25.1 64
A summary of the percentage yields of gasoline derived from the Kogasin oil as light gasoline from reformed naphtha, cracked from bottoms and polymer, is as follows: Yield of products from Kogasin oil, 70by vol.: Light gasoline Reformed gasoline from naphtha Cracked gasoline from bottoms Polymer gasoline Total gasoline Octane No. of blends of all gasolines
29.1 26.8 22.6 5.8
84.3 66
The octane value of the gasoline produced was of a satisfactory quality from the viewpoint of the immediate purpose for which it was intended. The octane number of the gasoline could be increased readily by more drastic cracking, which would a t the same time increase the gas yield and hence the amount of high-octane polymer gasoline.
Aviation Gasoline In connection with the production of an aviation gasoline, the simple procedure was followed by blending the low-boiling straight-run gasoline with the polymer gasoline in the proportions given. The data on the aviation gasoline are shown in Table X.
Refining Cracked Gasoline from Kogasin
TABLEX. DATAox AVIATION GASOLIKE Composition of blend, based on original Kogasin oil:
559
0 0
776
92 (33) 105 (41) 113 (45) 172 (78) 122 (50) 190 (88) 131 (55) 141 (61) 150 (86) 214 (101) 162 (72) 175 (79) 223 (106) 190 (88) 236 (113) 213 (101) 267 (131) 239 (115) 299 (148) 291 (144) 326 (163) 97.0 98.0 1.0 1.0 2.0 1.0 94 in this gasoline.
The cracked gasoline from Kogasin may be treated to a 25-30+ Saybolt color and gum of less than 5 mg. per 100 cc. with satisfactory color and gum stability by the use of one pound of sulfuric acid per barrel, followed by neutralization and fire and steam distillation, or by liquid- or vapor-phase clay treatments. The polymer gasoline requires no treatment.
Literature Cited (1) Aicher, Myddleton, and Walker, J. SOC.Chem. I n d . , 54, 313T, 320T (1935). (2) Am. Gas Assoc., “Combustion,” 3rd ed., 1932. (3) Badische Anilin- und Sodafabrik, German Patent 293,787 (1913). (4) Fischer, Brennstof-Chem., 16, 1-11 (1935). (5) Fischer, Oel Kohle Erdoel Teer, 11, 120 (1935). (6) Fischer and Koch, Brennstpf-Chem., 13, 428-34 (1932). (7) Fischer and Pichler, I b i d , 17, 24-9 (1936). (8) Fischer and Tropsch, Ihid., 4, 276 (1923). (9) Ibid., 5, 201, 217 (1924). (10) Fischer and Tropsch, Proc. Intern. C o n f . B i t u m i n o u s Coal, Nov. 15-18, 1926, 238, 239, 243. (11) Koch and Ibing, Brennstgf-Chem., 16, 185-90, 261-8 (1936). (12) Koch, Pichler, and Kolbell, Ibid., 16, 382-7 (1935). (13) Oil Gas J.,35, Nos. 31 and 32 (1936). (14) Tropsch and Koch, Brennstsf-Chew., 10, 337-46 (1929). RECEIVED December 21, 1936. Presented before the Division of Petroleum Chemistry at the 92nd Meeting of the American Chemical Society, Pittsburgh, Pa., September 7 to 11, 1936.
