SEPTEMBEH, 1935
INDUSTRIAL AND ENGINEERIXG CHEMISTRY
(3) Egloff, Schaad, and Lowry, J . Phys. Chem., 34, 1617-1740 (1930); 35, 1825-1903 (1931). (4) Ipatieff, J . Russ. Phys.-Chem. Soc., 38, 64-75 (1906); Ber., 44 2978-87 (1911); 46, 1748-55 (1913). ( 5 ) Nash, Stanley, and Bowen, J . I n s t . Petroleum Tech., 16, 830-55 (1930).
1077
( 6 ) Pease, J . Am. Chern. Soc., 53, 613-19 (1931). (7) Stanley, J . SOC.Chem. Ind., 49, 349-54T (1930). (8) Waterman and Tulleners, J . Inst. Petroleum Tech., 17, 506-10 (1931). RECEIVED May 24, 1935.
Polymerization, a New Source of Gasoline
FIGURE 1.
EA
KEW cata-
lytic process has been developed for the production of g a s o l i n e f r o m the olefins in cracked gas and a plant is in commercial operation which is capable of processing 3 million cubic feet of gas per day. The c o m m e r c i a l plant has operated continuously for 23 days, producing 313,090 gallons of 81-octane g a s o l i n e f r o m the olefins in 58,054,000 cubic feet of gas whose propylenebutylene content was 27.4 per cent. The y e a r l y p r o d u c t i o n of cracked gas in this country as a by-product of the cracking process is 300 billion cubic feet, of which 50 billion cubic feet, are olefins. The latter has a po-
POLYMERIZIKG I ~ P P A R A T U SOF THE U N I V E R S 4 L O I L PRODUCTS
V. S. IP.ITIEFF, B. B. CORSON, AND
GUSTAV EGLOFF
Universal Oil Products Company, Riverside, Ill. 0
A catalytic process has been developed for the conversion of gaseous olefins into gasoline. The catalyst is rugged and active and can be regenerated. Cracked gases containing 17.6, 37.5, 43.1, and 69.7 per cent of propylene and butylenes gave gasoline yields of 3.3, 6.0, 6.8, and 10.9 gallons, respectively, per thousand cubic feet of gas processed. A commercial polymerization plant is in operation which is producing gasoline at the rate of more than 5 gallons per 1000 cubic feet of cracked gas.
COMPANY
tential production of a billion gallons of polymer gasoline of 81 octane number. The total gasoline p r o d u c t i o n i n t h i s country in 1934 (straight-run and cracked) was 17.785 billion g a l l o n s of a b o u t , 65 octane number. Mild operating conditions of 230' C. (446' F.) and 200 pounds per square inch pressure have been found satisfactory in this p o l y m e r i z a t i o n process. The catalyst is a hard, gray-towhite, granular solid, n-hioh is noncorrosive. It is not poisoned by carbon monoxide, hydrogen sulfide, mercaptans, or o t h e r constituents or refinery gases. The catalyst gradually loses its activity with continued use but can be readily regenerated t o its o r i g i n a l activity with a time
1078
INDUSTRIAL AND ENGINEERING CHEMISTRY
VOL. 27, NO. 9
FIGURE 2. FLOWCHARTOF GAS-POLYMERIZING PROCESS
at 204' and 232' C. (399.Zo and 449.6' F.) and pressures of 100 and 200 pounds per square inch. The spent gas issued from the top of the stabilizer column, and liquid p o l y m e r w a s continuously drawn off from the bottom of the column. The analytical values used i n c a l c u l a t i n g t h e olefin polymerization were obtained by absorption of propyleneb u t y l e n e s by 87 per cent sulfuric acid and ethylene by b r o m i n e . The theoretical yield of liquid polymer (Figure 3) was estimated on the basis of the gravity of t h e liquid product and the average molecular weight of the FIGURE3. THEORETICAL LIQUID YIELD 4. DISTILLATION OF LIQUIDPOLYMER olefins contained in the gas, (SPECIFICGRAVITY,0.722) FROM OLEFIKIC FIGURE FROM STABILIZER GAS GAS as calculated from Podbielniak distillation data. The efficiency of over 90 per cent. Regeneration consists in removing high-polymer hydrocarbons or carbonaceous material from the catalyst by air oxidation. Regeneration has been accomplished without removing the catalyst from the polymerization towers. Figures I and 2 show the construction employed in the commercial unit in which preheated gas is passed through insulated catalyst towers. The polymer product is cooled and then passed to a stabilizer to produce the vapor-pressure gasoline desired. The following data were obtained in a pilot plant capable of processing about 400 cubic feet of gas per day. The unit consisted essentially of four vertical electrically heated towers in series, charged with catalyst, and a stabilizer., The cracked gases to be processed in the small pilot plant were received in cylinders a t pressures of 100 to 1000 pounds per square inch. High-olefin gases, such as "stabilizer reflux," were emptied into a charger equipped with a Jerguson gage glass, from which the liquid was forced into the polymerizing unit by means of nitrogen a t constant pressure. Lowolefin gases, such as pressure-still "receiver gas," were pumped into a steam-heated, high-pressure gas holder which PERCENT O V E R ( v o L J was connected t o the polymerizing unit by a steam-heated OF LIQUIDPOLYMER FIGURE5 . DISTILLATION FROM ST.4BILIZER REFLUX line. The gas being processed was passed over the catalyst
SEPTEMBER, 1935
IXDUSTRIM. ASD ENGINEERING CHEMISTRY
complete analysis of the gas was determined by a combination of fractional distillation and absorption methods. The gas was separated into fractions corresponding to one, two, three, four, and five carbons by low-temperature distillation, and each fraction was subsequently analyzed for olefin content by absorption. The two methods of gas analysis-absorption and distillation-absorption-checked each other within 2 to 5 per cent.
Gases Used for Gasoline Polymerization Units RECEIVER Gas. The gas derived from the so-called liquid-vapor phase cracking of a mixture of Rlidcontinent and West Texas topped crude oil was separated in a receiver from the gasoline which had been condensed under 75 pounds per square inch pressure. The cracking conditions which produced the gas were 500" C. ((932"F.) and 200 pounds pressure. STABILIZER REFLUX. The stabilizer reflux was derived from the cracked gasoline which was subjected to a stabilizing tower action in which the vapor pressure of the gasoline was reduced to 10 pounds Reid vapor pressure. The stabilizing tower was operated a t a top temperature of 55" C. (131" F.) and a pressure of 180 pounds. The temperature control on the top of the tower was maintained by pumping back reflux liquid. The stabilizer reflux, which is a liquid under the conditions of the stabilizer tower, is a gas a t atmospheric pressure. STABILIZER Gas. The stabilizer gas used during these experiments was produced from the vapor-phase cracking of gas oil subjected to 550" C. (1022" F.) and atmospheric pressure. The gasoline from this operation was subjected to stabilizer action a t 200 pounds pressure and a top temperature of about 60" C. (140" F.). The dissolved gas evolved from the stabilizing action on the cracked gasoline was subjected to polymerizing conditions. Vapor-phase stabilizer reflux was obtained from the same stabilizer tower from which the stabilizer gas was obtained.
Polymerization of Pressure-Still Receiver Gas (from Liquid-Vapor Phase Cracking) This gas was obtained in the cracking of a mixture of Midcontinent and West Texas topped crude; the separation of the gas from the gasoline was made a t 75 pounds per square inch pressure. The average olefin content of the gas was 17.1 per cent of propylene-butylenes and 7.2 per cent of ethylene. The polymerization of this receiver gas was studied a t temperatures of 204" and 232" C. and pressures of 100 and 200 pounds per square inch a t a number of feed rates. Increase in temperature from 201" to 232" C. (with equal contact times) increased the extent of polymerization about 15 per cent. The olefin polymerization a t a given temperature and contact time was the same a t 100 and 200 pounds. The polymerization of propylene-butylenes ranged from 64 to 95 per cent and that of ethylene from 13 to 31 per cent. -4typical percentage analysis of the gas is as follows: Hydrogen Methane Ethylene Ethane
4.3
22 2 6 0 17 3
Propylene Propane Butylenes Butane
11.2 26 8 4 0 5 6
Pentane Carbon monoxide nitrogen Hydrogen sulfide
+
0 2 1.6 0.8
The decrease in gas rolume caused by passing through the polymerization unit averaged 17.5 per cent. About 60 per cent of the hydrogen sulfide appeared in the polynier product as liquid sulfur compounds, 90 per cent of which were mercaptans. The boiling range of the polymer was raised by increasing the reaction temperature and also by increasing contact time. For example, the A. S.T. AI. 100-cc. distillation temperature a t the 90 per cent point mas 11"to 22" C. (19.8" to 39.6" F.)
1079
higher for polymers produced a t 232" C. than for polymers made a t 204" C. Run data in Table I show the operating conditions, the olefin content of the gas, the extent of polymerization, and the liquid yields obtained by passing the cracked gas through the catalyst bed only once. TABLEI. RUN DAT.4 ON RECEIVER GAS Operating conditions: Hours on test 120 120 Gage pressure, lh./sq. in. 200 200 Temp., C. 204 232 Inlet gaa rate, cu. ft./hr./lb. of catalysta 2.1 1.3 Olefin content of gas: Propylene and butylenes, % 17.3 18.6 Ethylene, % 7.2 6.6 .Olefin polymerization: Propylene and butylenes, % 64 79 Ethylene, 13 1ti Ga1./1000 cu. f t . of gas: Liquid polymer 2 9 3.8 Gasolineb 2.7 3.5 a Apparent density of catalyst 0.9. 6 Initial boiling point, 134' F . ' ( 5 i o C.): end point, 401' E. (205'
120
200 232
0.6
16.8 7.0 95
31 4.0 3.7
C.).
______-
Distillation and other characteristics of the crude and of the steam-distilled polymer are presented in Table 11. TABLE11. PROPERTIES
OF
POLYMER
FROM
RECEI.VER
Crude Polymer a t 60' sp,i$; ' A.a t P.60'I. F. Gr..
F. (15.6' C.)
61.2 0.734
0.732 30 22
... ...
Savbolt Color 'stabiiit),a G u m (copper dish), mg./100 cc. Sulfur. '7, Inductlo; period, min. Induction period 0.025% wood dist. inhibitor Octane No. (C. F. R. motor method) Octane blending value (25% i n fuel .%-3;bC. F. R. motor method) Reid vapor pressure a t 100' F. (38' C.), lb.
...
5 0 4 40 2i5 82
0.4
...
+
(:AS
SteamDistd. Po 1y m e r 61 8
...
82
...
120 5 0
8.5
100-Cc. A. S. T. h.1. Distillation
F. Initial h . p . Per cent distilled orer: 5 10 20 30 40 50 60 70
c. 52
167 189 216 232 245 260
i5 87 102 111 118 127 136 149 166 198 249
277 301 331 388 481
80 90
O
125
E n d point a Equivalent t o 2 hours of noon June sunlight b Octane number of fuel A-3, 44.
F. 134
= c.
180 194
82 90 100 107 114 120 127 138 151 169 205
2 12 225 237
248 261 280
303 337 401
57
Polymerization of Stabilizer Reflux (from LiquidVapor Phase Cracking) Cracked distillate is stabilized by fractionation under pressure to the desired vapor pressure, and stabilizer reflux is the liquid condensate which is recirculated to the stabilizing tower. It is a gas a t atmospheric temperature and pressure. The stabilizer reflux, whose polymerization is described below, contained 37.5 per cent of propylene and butylenes and a trace of ethylene. The following gas analytical data (in per cent) are complete except for hydrogen sulfide, which was scrubbed out by caustic solution before distilling through the Podbielniak column : Hydrogen Methane Ethylene Ethane
0 1 0 1 0 6 3 2
Propylene Propane Ieohutylene n-Butylenes
16.6 16 8
10 2 10 2
Ieohutane n-Butane Pentane Nitrogen
+
20 5 20 0 12 0 5
1080
INDUSTRIAL AND ENGINEERING CHEMISTRY
This gas was processed a t 204' C. and 100 pounds pressure with three feed rates. In a number of the runs the gas was analyzed as it came out of each of the four catalyst towers and it was noted that 75 per cent of the total polymerization took place in the first two catalyst towers and only 25 per cent in the last two toxers. Run data on the polymerization of stabilizer reflux on a once-through basis are given in Table 111.
TABLE 111. RUN DATAON STABILIZER REFLUX Operating conditions: Hours on test 72 72 72 100 100 Gage pressure, lb./sq. in. Temp C 204 loo 204 204 Inlet ;as rite, cu. ft./hr./lb. of catalyst 4.9 3.4 2.1 Olefin content of gas: (Propylene and butylenes), % 37.5 37.5 37.5 Olefin polymerisation: (Propylene and butylenes), % 72 81 89 Ga1./1000 cu. it. of gas: 6.0 6.9 7.2 Liquid polymer G d...~~. i nea 5.4 6.2 6.5 . a. a Initial boiling point, 150' F. (66' C . ) : end point, 389O F. (198' C.) ~
Distillation and other characteristics of the crude and of the steam-distilled polymer are presented in Table IV.
VOL. 27, A-0. 9
ene-butylenes ranged from 78 to 96 per cent and that of ethylene from 7 to 35 per cent. The temperatures 204'and 232' C. were practically equivalent for the polymerization of propylene and butylenes except a t the shortest contact times. I n the case of ethylene, the higher temperature gave 5 to 10 per cent more polymerization a t short contact times, but the two temperatures were equivalent in polymerizing effectiveness a t the longer contact times. L-nder the experimental conditions studied, the ethylene polymerization contributed 1 to 10 per cent of the total yield of liquid polymer. The decrease in gas volume caused by passing through the polymerization unit averaged 39 per cent; that is, for every hundred cubic feet of inlet gas there were 61 cubic feet of exit gas. This gas shrinkage varied from 33 to 45 per cent under the operating conditions. The feed rate, within the range studied, had very little effect upon the boiling point of the liquid polymer except for the end points. Contrary to the behavior of pressure still receiver gas, the higher operating temperature produced a lower boiling product, the 50 per cent point of polymer made a t 232' C. (449.6' F.) being about 14' C. (25.2' F.) lower than the 50 per cent point of polymer made a t 204' C. (399.2' F.). Typical run data are presented in Table V to show operating conditions, olefin content of the gas, extent of olefin polymerization, and the liquid yield on a once-through basis.
OF POLYMER FROM STABILIZER REFLUX TABLEIV. PROPERTIES
Gr. O I P I. at 60' F. Sp.'gr.-a't ti00 F. Color Saybolt Colorlstability Gum (co per dish), mg./100 cc. Sulfur Induciion period min. Induction period'+ 0.025% wood dist. inhibitor Octane No. (C. F. R. motor method) Octane blending value (25% in fuel A-3; C. F. R. motor method) Reid vapor pressure at 100' F., lb.
SteamDistd. Polymer 62.8 0.728 30 21 4 0.16 40 275 82
Crude Polymer 64.6 0.722
+
...
... ...
8
0.18
... ...
81
...
12 1 5.0
11.0
100-Cc. A. S. T . M. Distillation Initial b. P. Per cent distilled over: 5 10 20 30 40 50 60
70 80 90 End point
F.
C.
F.
C.
103
39
150
66
153 171 194 207 217 229 248 283 328 404 459
67 79 90 97 103 109 120 139 164 207 237
177 192 203 211 218 225 239 258 285 326 389
81 89 95 99 103 107 115 126 141 163 198
~~~~
TABLE V. RUNDATAON STABILIZER GAS
0.6 3.4 16.0 17.8
Propylene Propane Isobutylene ??-Butylenes
29,O 22.2 2.9 2.0
Butadiene Butane Pentane Nitrogen Hydrogen sulfide
+
3.3 2.0 0.2 0.4 0,2
The gas was processed a t 100 pounds per square inch gage pressure and a t temperatures of 204" and232' C. Depending upon the operating conditions, the polymerization of propyl1
Tropsch and Mattox,
IND.
ENQ.CHmar.. Anal. Ed., 6, 104 (1934).
72 100 232 0.3 42.7 21.2 96 32
8 4 7.0 C.).
Distillation and other characteristics of the crude and of the steam-distilled polymer are presented in Table VI. The distillation characteristics of the crude liquid polymer are further illustrated by the following Podbielniak distillation data (Figure 4) :
Polymerization of Stabilizer Gas (from VaporPhase Cracking)
Hydrogen Methane Ethylene Ethane
~
Operating conditions: Hours on test 120 72 100 Gage pressure, Ib./sq. in. loo 232 Temp. O C. 232 Inlet i a s rate, cu. ft./hr./lb. of catalyst 1,7 0.9 Olefin content of gas: 43.9 42.6 Propylene and butylenes, % 20.2 21.6 Ethylene, % Olefin polymerization: 84 94 Propylene and butylenes, 9% 9 25 Ethylene, % Gal./1000 cu. ft. of gas: 8.5 7.6 Liquid polymer 6.3 7.1 Gasoline" a Initial boiling point, 142' F. (61" C.): end point, 414' F. (212'
Fraction NO.
This gas was obtained from the top of the fractionating column used in the stabilization of gasoline produced by vapor-phase cracking. The gas contained 39.1 per cent of propylene-butylenes, 3.3 per cent of butadiene, and 20.0 per cent of ethylene. The butadiene was determined by the maleic anhydride method.' For the purposes of calculation, the butadiene was included with the propylene-butylenes. The following are typical analytical data for stabilizer gas (in per cent):
~
Per Cent Distilled Over
-Boiling
10 11 12
13
14 15 16 Bottoms
Loss
5.2 4.0 3.4 1.9 5.8 6.0 5.9 6.5 2.5 S I 7.1 6.1 7.9 5.7 6.3 4.1 2.0 9.8 1.7
Point-
c.
F. Below 54 54-163 163-187 187-201 201-217 217-226 226-244 244-266 266-281 281-286 286-315 315-336 336-363 363-399 399-425 42 5-45 1 Above 451
Below 12 12-73 73-86 86-94 94-103 103-108 108-118 118-130 130-138.5 138.5-141 141-157 157-169 169-184 184-204 204-218.5 218.5-233 Above 233
......
.......
0
......
.......
Polymerization of Stabilizer Reflux (from VaporPhase Cracking) The average olefin content of this gas was 64.1 per cent of propylene-butylenes, 3.0 per cent of butadiene, and 0.8 per cent of ethylene. For the purposes of calculation the propyl-
SEPTEMBER, 1935
INDUSTRIAL AND ENGIISEERING CIIERIISTRY
TABLEVI. PROPERTIES OF POLYMER FROM STABILIZER GAS
O A. P. I. a t 60° F. S gr ,&t 60' F. &lor ' Saybolt Color'stability G u m (copper dish) mg./lM) cc. Gum 0.025% wbod dist. inhibitor Sulfur. "/, Induotihi period, min. Induction period 0.025% wood dist. inhibitor Octane No. C F. R. motor method) Octane blending value (25% in fuel A-3; C. F. R. motor method) Reid vapor pressure a t looo F., lb.
Gr.,
SteamDistd. Polymer 60.2 0.738 25 19 72 0.02
Crude Polymer 57.1 0.750
... ... ...
+
... . ,83 ... 9.5
n nR ...
+
n
04
55 610 82
,
116 5.2
100-Cc. A. S. T. M. Distillation Initial b. p. Per cent distilled over: 5 10 20 30 40 50 60 70
SO
90 E n d point
F.
C.
F.
c.
113
45
142
61
177
81
228 245 267 287 320 350 395 456 548
93 109 118 131 142 160 177 202 236 287
178 194 216 234 251 266 284 304 324 360 414
81 90 102 112 122 130 140 151 162 182 212
zoo
~~
1081
A typical percentage gas analysis is as follows: Propylene Propane Butylenes Butane Pentane
45.2 30.2 1!3.9 4 .6 0. 1
+ butadiene +
The decrease in gas volume caused by passing the gas through the polymerizing unit was 74.3 per cent, i. e., for every hundred cubic feet of inlet gas, there were 25.7 cubic feet of outlet gas. Table VI1 lists data illustrative of the operating conditions, the olefin content of the gas being processed, the extent of polymerization, and the liquid yield on a once-through basis. The Reid vapor pressures of the crude polymer were high, ranging from 11.6 to 14.3 pounds. Distillation and other characteristics of the crude and of the steam-distilled polymer are presented in Table VIII. The distillation characteristics of the crude liquid polymer are further illustrated by the following Podbielniak distillation data (Figure 5 ) : Fraction
No.
Per Cent Distilled Over
-Boiling
F.
TABLEVII.
RUNDATAON STABILIZER REFLUX
Operating conditions: 72 72 Hours on test Gage pressure, lbs./sq. in. 200 200 204 204 Temp.. C. Inlet gas rate, cu. ft./hr./lb. oi catalyst 3.7 2.4 Olefin content of gas: (Propylene and butylenes), yo 70.4 69.2 Olefin polymerization: (Propylene and butylenes), 3'% 84 93 Ga1/1000 cu. f t . of gas: Liquid polymer 12.4 14.2 Gasolinea 9.7 11.1 a Initial boiling point, 132O F. (56O (2.1; end point, 406' F. (205'
4
72 200 204 0.8
5 6 7 8 9 10
69.4
11
99 15.0 12.0 C.).
12 13 14 15 16 17 Bottoms
TABLEVIII. PROPERTIES OF POLYMER FROM STABILIZER REFLUX
Gr., O A. P . I. a t 60' F. S gr.,&t 60' F. &lor, Saybolt Color stability Gum (copper dish), mg./100 00. Gum 0.025% wood dist. inhibitor Sulfur, 70 Induction period, min. Induction period 0.025% wood dist. inhibitor Octane No. (C.F. R . motor method) Octane blending value (25% i n fuel A-3; C. F. R. motor method) Reid vapor pressure a t 100' F., Ib.
.
+
+
SteamDistd. Polymer 60.3 0.738
Crude Polymer 58.5 0.745
C Below 12 12-83 83-86 86-89 89-95 95-100 100-108 108-119 119-130 130-142 142-152 152-157 157-165 165-170 170-182 182-201 201-218.5 218.5-235 Above 235
Acknowledgment
RECEIVED April 13, 1935.
*+a
+
*+a
4 0.02 60 735 82
...
81
115 5.2
,..
14.2
100-Cc. A. 9.T. hl. Dietillation ' F. a C. Initial b. p. 112 44 Per cent distilled over: 5 160 71 194 90 10 234 112 20 260 127 30 284 140 40 310 154 50 334 168 60 366 186 70 414 212 80 512 267 90 283 542 E n d point
Below 54 64-181 181-187 187-192 192-203 203-212 212-226 226-246 246-266 266-288 288-306 306-315 316-329 329-338 338-360 360-394 394-424 424-455 Above 455
The authors wish to acknowledge the contributions of I. Kurbatov and ill. A. Smith.
E 61
... 0.02 ...
12.4 3.8 3.5 3.8 3.5 4.8 3.2 3.8 4.1 5.7 5.2 6.0 5.5 4.7 5.4 5.8 5.1 3.3 10.4
Gas 1 2 3
Point---
a
F.
' C.
132
56
184 206 236 254 268 286 302 322 338 364 406
84 97 113 123 131 141 150 161 170 184 208
ene-butylene content was taken as 67.1 per cent-i. e., the sum of the propylene-butylenes and the butadiene. This gas was processed a t 204" and 232' C. a t 200 pounds per square inch gage pressure. The conversion of propylenebutylenes into liquid polymer varied from 84 to 99 per cent, depending on the operating conditions. At the feed rates studied, the two temperatures, 204" and 232" C., were equivalent in polymerizing effectiveness.
Courtesy, li. S. Bureau of Mines
A LOUISIASA
PETROLEUM REFINERY,SHOWING CRACKIKG EQUIPMFNT IN THE FOREGROUND
