INDUSTRIAL AND ENGINEERING CHEMISTRY
440
nometer on the crucible powdered to pass the 100-mesh sieve, is 3.52 * 0.02. The per cent of pore space (that is, sealed pore space, since the crucible is impervious) is then 4.8. Since magnesia has a relatively high coefficient of thermal expansion, the very dense structure of the recrystallized crucibles will not permit sudden large temperature changes without a weakening and possible cracking of the crucible.
TABLE 111. SOLUTION OF MAGNESIA BY MOLTEN Ca0-Fe0-Si02 SLAG TIMEO F CONTACT MgO in slag Minutes % 0 3.88 5 5.36
TIMEOF CONT4CT M g O in slag Minutes % 10 6.71 15 10.21
I n some actual slag tests it was found that the impervious magnesia crucibles will hold molten ferrous oxide over long periods. A slag consisting of 70 per cent ferrous oxide and 30 per cent silicon dioxide was held satisfactorily for 20 minutes a t 1525 * 20" C. Tests made bv C. H. Hertv, of the Pittsburgh Station of the Bureau of Mines, showed ihat a molten hi&temperatureslag, analyzing 50 per centcalcium oxide, 35 per cent ferrous oxide, and 15 per Cent silicon dioxide, did not penetrate the crucible over a period of time, whereas with a
Vol. 24, No. 4
dense but pervious magnesia crucible procured elsewhere, the slag ran out as it melted down. Although this slag was satisfactorily retained by the impervious magnesia crucible, chemical solution took place as shown in Table 111. The two-step formation by pressure, as described for magnesia, has been found equally satisfactory for ZrOz and Al203, but impervious crucibles of these materials have not yet been prepared in the high-frequency furnace with graphite inductor. LITERATURE CITED (1) Adcock a n d Turner, J . Sci. Instruments, 7, 327 (1930). (2) Fairchild and Peters, U. S. P a t e n t 1,545,951 (1925). (3) Hagen, 2. Elektrochem., 25, 375 (1919). (4) Kanolt, Bur. Standards, Sci. Paper 212, 19 (1913). (5) Roller, Bur. Mines, Tech. Paper 490 (1931). ( 6 ) Roller, ISD. ENQ.CKEM..Anal. Ed., 3, 212 (1931). (7) Tritton, Proc. Roy. SOC.(London), 107A, 287 (1925); T r i t t o n and Hansen, J . I r o n Stesl Inst. ( L o n d o n ) , 110, 117 (1924). (8) Walker, Trans. Faraday Soc., 19, 83 (1923); Shaxby and Evans, Ibid., 19, 60 (1923). RECEIVED January 29, 1932. Presented before the Division of Industrial and Engineering Chemistry a t the 82nd Meeting of the American Chemical Society, Buffalo, N. Y., August 31 to September 4, 1931. Published by permission of the Director, u. 8. Bureau of Mines (Not subject tc, COPYright.)
The Cracking of Fish Oil W. F. FARAGHER, GUSTAVEGLOFF,AND J. C. MORRELL Research Laboratories, Universal Oil Products Co., Riverside, Ill.
T
HE present work was undertaken as part of a general
investigation to determine whether motor fuels can be made from fish oils by the cracking process. A study of some of the reactions involved in the thermal and pressure decomposition of fish oil was also included. I n parts of the world, particularly in Japan, there is some difficulty in disposing of the waste oils from fish. Since this work was started, the cracking process has been considered by others as a means of producing valuable by-products from fish oil. Engler and Seidner ( 2 ) distilled menhaden oil under pressure, using the shell still designed by Krey. A charge of 492 kg. of North American menhaden oil, specific gravity 0.930, was distilled under 10 atmospheres pressure at a temperature of approximately 320' C. (608" F,),The pressure dropped gradually during the operation to 4 atmospheres, and the temperature was gradually increased to 420' C. (788" F.). Yields of 319 kg. of distillate (amounting to approximately 60 per cent of the starting material), 77 kg. of coke and asphaltlike residue, and 96 kg. of gas were produced. The average saponifiable material in the distillate was 7.52 per cent. The distillate consisted of an upper layer of oil and a lower layer of water. Both saturated and unsaturated hydrocarbons were reported in the oil layer. The gaseous product analyzed as follows: CO, Olefins
co
% ._ 17.4 7.8 34.5
CHI Noncombustible residue
%
38.3 2.0
When the fish oil was distilled under atmospheric pressure, however, the gas analyzed as follows: CO, Olefins
co
% 26.7 11.4 34.9
% CH4 Noncombustible residue
25.2 1.8
One of the objects of Engler's experiments was to determine the effect of change of the conditions during pressure distillation on the composition of the gas. I n the present work, four products were obtained from the cracking of fish oil-motor fuel, Diesel oil, coke, and gas. The yield of motor fuel was 47.5 per cent, and of Diesel or furnace oil 17.0 per cent. Fifty-seven pounds of coke and 790 cubic feet of fuel gas were made per 42-gallon barrel of fish oil.
EXPERIMENTS ON MENHADEN FISHOIL Menhaden fish oil was used for the cracking tests. This oil had the following characteristics: Specific gravity Initial b. p. C ( " F.) End b. p., C. F.) Coke (b weight), % Water, Sulfur
%
0.9446 307 (585) 377 (711) 2.9 0.5 Trace
EEMPEL D I B T I L L A T I O b (800-CC. C E A R Q E )
DISTILLED OVER 10 20 30 40 50 60
70
80
TEMPERATURE a C. O F. 319 606 321 610 297 567 311 592 318 604 319 606 316 601 310 590
SP. GR, 0.8922 0.8393 0.8877 0.8916 0.8368 0.8654 0.8762
0.8783
Some cracking occurred during the Hempel distillation analysis a t atmospheric pressure. CRACKING OPERATION Menhaden fish oil from San Diego, Calif., was distilled under pressure in a steel cylindrical still equipped with vapor line and reflux pipe, and connected with a condenser and receiver with gas and liquid outlets. The pressure upon the system extended throughout the still, including the receiver. The fish oil was cracked at pressures of 60 and 100 pounds
I N D U S T R I A L A N D 'EN G I N E E R I N G C H E M I S T R Y
April, 1932
per square inch gage, and temperatures from 402" C. (756" F.) to 482" C. (900" F.). The cracking process was operated to produce motor fuel, Diesel oil, coke, and gas. A summary of the results is shown in Table I. OF CRACKING FISHOIL TABLEI. RESULTS
Specific gravity Distillation pressure, lb./sq. in. Temperature, C. TemDerature. F. Cracked disti!late: % of fish oil b y vol. Specific gravity Water, % of fish oil Coke lb./barrel Uncrkcked gasoline, cu. ft./barrel Coke, gas, and loss, % Gasoline: yo of cracked distillate yo of fish oil Specific gravity Initial t o end b. p., ' C. Initial to end b. p . , O F. Diesel oil: of cracked distillate of fish oil Specific gravity
P
Loss:
cracked distillate P ofof fish oil
0.9446 60 402-404 756-759
0.9446 100 427-482 801-900
76.6 0.8137 5.3 47 690 18.1
67.9 0.7831 6.1 57 790 26.0
49.0 37.5 0.765 48-224 118-435
69.9 47.5 0.770 46-225 115-437
47.0 36.0 0.917
25.0 17.0 0.920
4.0 3.1
5.1 3.4
A distillation analysis of the cracked distillate resulted as follows: Specific gravity Initial b. p . , C. (" F.) HEMPEL DISTILLATION
DISTILLED OYER % ._ 10 20 30 40 50 60 70
0.7831 27 (81) (BM-CC. CHARQE) TEMPERATURE c. ' F. 68 154 97 207 127 261 147 297 173 343 198 388 221 430
CHEMICAL TREATMENT O F CRACKED-DISTILLATE OIL. The cracked distillate produced was treated chemically and steam-distilled into finished gasoline, and Diesel or furnace oil. The treatment comprised agitating the pressure distillate with 3 per cent by volume of a 25 per cent solution of sodium hydroxide. The sodium hydroxide sludge was allowed to settle and was then withdrawn. The oil was subjected to treatment with 1.3 per cent by volume of 98 per cent sulfuric acid, the oil and acid being thoroughly agitated. The black sulfuric acid sludge was drawn off after settling for an hour. The cracked distillate was water-washed and finally neutralized with 1.0 per cent by volume of a 10 per cent sodium hydroxide solution. The treated distillate was then steam-distilled a t a temperature of 121" C. (250" F.) into gasoline and a Diesel oil residue. The gasoline was finally treated with a dilute solution of sodium hydroxide. It was water-white and had only a slight fishy odor. CRACKED GASOLINE.The gasoline derived frorn fish oil had the follojving characteristics: Specific gravity 0.7653, Color Water-white Odor Slightly fishy 0.0 Sulfur, yo Initial b. p . , ' C. (" F.) 46 (115) End b. p., ' C. ( " F.) 224 (435) A. 8 . T. M (loo-cc. DISTILLATIOX) DISTILLED OVER TEMPERATURE % c. F. 10 76 169 20 96 205 30 111 232 40 128 261 141 286 50 60 156 313 166 331 70 80 181 358 90 197 387 HYDR0CA4RB0N-GR0UP
OF CRACKED
GBSOLINEs
The refined motor fuel was analyzed for its hydrocarbon-
44 1
group content by the Egloff-Morrell method ( I ) , showing the following percentages: Unsaturated Aromatic
%
19.0 35.0
Naphthenes Paraffin
%
8.0 38.0
One would judge from the percentage of unsaturated and aromatic hydrocarbons present in the motor fuel that it would have a high knock rating in an automotive engine. However, when the gasoline was tested in a standard Ethyl Gasoline Corporation test motor, it showed a knock-rating value equivalent to Pennsylvania kerosene, or an octane number of zero. Upon further investigation of the chemical properties of the cracked gasoline, it was found that, despite the sodium hydroxide and sulfuric acid refining, the gasoline still contained oxygenated compounds which appeared in the chemical analysis as unsaturated and aromatic hydrocarbons, but which exhibited knocking tendencies. These compounds were principally aldehydes and fatty acids. The fatty acids were abundant in the fractions boiling between 104" C. (219" F.) and 205" C. (401O F.), consisting of acetic, propionic, butyric, and homologous acids. The total acidity of the cracked distillate was 7.4 per cent of free organic acids. The fractions boiling below 68" C. (154" F.) showed strong tests for aldehydes, although these compounds were detected in all the fractions up to 177" C. (351" F.) When the cracked distillate was saponified by refluxing with a strong alkali, the knock rating was increased from an octane number of zero to thirty-one. This behavior confirmed the assumption that the oxygen compounds acted as knocking compounds. DIESELOIL. The Diesel oil fraction may also be used for furnace oil, for gas-making, or as cracking stock to increase further the yield of gasoline. The Diesel oil had the following properties: Specific gravity 0.9170 224 (435) Initial b. p. O C. (" F.) End b. p., C. ( " F.) 380 (716) A. 8. T. h i , (loo-cc. DISTILLATION) DISTILLED OVER TEMPERATURE 0 c. F. % 242 468 10 247 477 20 250 482 30 255 49 1 40 260 500 50 266 511 60 273 523 70 80 281 538 590 310 90 98
'
COKEAKD GAS. The coke produced by cracking fish oil had a honeycomb structure. Its content of sulfur and ash was less than 0.1 per cent each. The thermal value of the coke was 15,600 B. t. u. per pound. The incondensable gas produced had a relatively high thermal value. SUMlzL4RY AND CONCLUSIONS 1. Motor fuel has been produced by the cracking of menhaden oil with yields of 37.5 to 47.5 per cent. 2. The removal of saponifiable substances by refluxing with alkali increased the octane number of the motor fuel from fish oil from zero to thirty-one. 3. The production of motor fuel, Diesel oil, coke, and gas may have economic importance in some countries.
LITERATURE CITED Egloff and Morrell, ISD. ENG.CHEM.,18, 364
(1) (2) Engler and Seidner, Dinglers polytech. 271, 515 (1889).
(1926). 136 ( 1 8 8 8 ) ;
J., 269,
RECEIVED December 29, 1931. Presented before the Division of Petroleum Chemistry at the 76th Meeting of the -4merican Chemical Society, SwampScott, )lass., September i o to 14, 1928.
