June, 1929
INDUSTRIAL AND ENGINEERISG CHEMISTRY
28--Bruckner, Chem.-Zlg., 62, 637 (1928). 29-(a) Mund and Koch, Bull. sot. chim. Belg., 34, 119 (1925); ( b ) Mund and Bogaert, Ibid., 56, 19 (1927); ( 6 ) Mund, Ibid., 36, 19 (1.927). 30-(a) Lind, Bardwell, and Perry, J . A m . Chem. SOC.,48, 1556 (1926); ( b ) Lind and Bardwell, .[bid., 48, 2335 (1926).
537
al-Richards, Proc. Cambridge Phil. Soc., 23, 516 (1927). 32-(a) Coolidge, Science, 62, 441 (1925); ( b ) J . Franklin Znsf,, 202, 693 ( 1 9 2 6 ) ; A m . J . Roenlgenol. Radium Therapy, 19, 313 (1928). 33-Novj7, Roehm, and Soule, 3. Infectious Diseases, 86, 109 (1925). 34--Masson, J . Chem. Soc., 97, 831 (1909).
Motor Fuels and Other Products from the Cracking of Wood Tars' Jacque C. Morrell and Gustav Egloff UNIVERSAL OIL PRODUCTS COMPANY, CHICAGO, ILL.
The possibilities of the utilization of waste wood A large yield of gas for fuel NE of the purposes of products, particularly tars from the destructive disis also obtained. the present work is t o tillation of wood, by conversion into motor fuels and The 70,000,000 gallons of point the way to the other products by the cracking process are pointed tar will produce by cracking, utilization of some of the out by means of data obtained by cracking three types according to present research, tremendous quantity of maof wood tar. These data indicate that, in general, the 23,300,000 gallons of motor terial that is wasted by the products obtained from the pine tar are most suitable fuel equal in antiknock proplumber industry, in addition for solvents and paint thinners, the hardwood tar may erties to benzene, in addition to a wider utilization of one be utilized for the manufacture of low-boiling tar t o approximately 6,000,000 of the present principal prodacids and phenols, and the Douglas fir tar produces gallons of low-boiling tar u c t s of wood distilhtiona highly acids or Dhenols for antisew namelv. Conver- . antiknock motor fuel. " , the tars. tic, disinfectant, and other sion of this waste material into useful products is of great importance in thi, conserva- uses. Further, approximately 125,000 tons of high-grade coke tion of our national resources. The conversion of such waste and 1,830,000,000 cubic feet of gas will be made in the crackwood products through the medium of wood tars into motor ing operation. The above is representative of only one kind of wood. fuel, solvents, and turpentine-like material or flotation oils by the cracking process has been accomplished in the present For the other kinds the yields of other products may be similarly shown. Yellow pine heads the list in production work. The development of a practical and economic means of with over 12.5 billion board feet (in 1924), and Douglas fir converting wood waste into motor fuels has a deeper signifi- is second with over 7.5 billion board feet. The yellow pine cance than the immediately important factor of conser- and Douglas fir are both softwoods of the coniferous group. vation-it provides a source of motor fuels for the future A hardwood tar made from oak and hickory woods was also which is under the direct control of man. Our great store selected. houses of potential motor fuel from petroleum, coal, and oil Products of Wood Distillation shales are heritages from past ages, while wood tars and other vegetable oils are producible under controlled condiThe products of wood distillation may be divided into tions. four groups-pyroligneous acid, tar, gas, and charcoal. According to statistics given by the Forest Service of the United States Department of Agriculture, approximately These four products vary in amount depending on the species of wood and the conditions of distillation, but the average 24 per cent of the standing tree-i. e., the total wood in the forest-is converted into useful products, while 76 per cent yields from hardwood body mood a t atmospheric pressure is wasted. About 31 per cent of the wood used for making and 350" to 400' C. maximum temperature are as follows: lumber based on the log is available for carbonization for the Per cent 45 Pyroligneous acid production of charcoal, tar, and other products. The fac7 Total tars tory waste in working up the lumber represents another 20 Gases 19 Charcoal 29 per cent based on the log, making a total of over 50 per cent, not including the bark, of the total log available a t the mill A great many chemical individuals have been identified and factory. As an example of the possibilities of the utilization of this among the products of wood distillation.2 The chief comwaste, from an average annual yield of 7.5 billion board feet mercial products obtained aside from charcoal are acetic (Bureau of Census) of Douglas fir the equivalent of 2.5 million acid, acetone, methanol, and the wood tar. Beechwood cords, or 4.2 million tons, is available for destructive dis- creosote is an important medicinal product manufactured from the destructive distillation of any of the hardwoods, tillation, yielding the following products: but preferably beech. It is derived mostly from the soluble Gallons tars recovered by the refining of the pyroligneous acid. TurTurpentine and light oils 8,500,000 pentine and rosin are among the most important of the prodTar 70,000,000 Wood alcohol 9,780,000 ucts obtained from the distillation of resinous wood. Pine Pounds oil is another important product. Their uses are numerous Acetate of lime 187,500,000 Charcoal 2,440,000,000 and well known. The recovery of by-products from resinous wood is carried 1 Based on paper presented under the title "Cracking of Wood Tars" on by one of two methods-destructive distillation and the before the Division of Industrial and Engineering Chemistry at the 72nd
0
1
hfeeting of the American Chemical Society, Philadelphia, Pa., September 5 t o 11, 1926. Received September 12, 1928.
2 Hamley and Wise, "The Chemistry of Wood," p. 199, Chemical. Catalog C o
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
538
steam and solvent process. The material used is old stumps from the long-leaf pine; the ordinary sawmill waste or green timber does not contain sufficient pitch to make the process profitable as practiced a t present. Douglas fir and Sorway pine have been used t o some extent, but in neither case can commercial quantities of wood be collected equal in quality to the long-leaf pine wood. Processes and equipment for handling this long-leaf pine wood or, in fact, any of the softwoods have not been standardized. This, of course, is a handicap to the industry owing to difference in the products. Ordinary unselected san--mill waste and green timber from long-leaf pine produces about 27 gallons of black tar per ton of wood, while the light wood will produce from 50 to 80 galloiis of oily or tarry material per ton of drywood. The weight of ordinary long-leaf pine wood with about 15 per cent moisture and 5 per cent rosin is about 42.5 pounds per cubic foot, which gives an average of about 3'700 pound> per cord, and for 15 per cent rosin content mill yield 75 gallons of oil or tar oil; for 30 per cent rosin content the weight will go up to approximately 4100 pounds per cord and \Till yield 152 gallons of total oily products. Benson and Darrin3 show the following yields of products from Douglas fir and western yellow pine: TURPENTINE &'SIGHT PER
MATERIAL
CORD Lbs a
AND
LIGHT OIL Gal d
Douglas fir, commercial 3330n 3.40 mill waste Douglas fir, selected resinous waste 4250b 1 0 . 8 6 Douglas fir, s t u m p wood 32600 J ,59 Western yellow pine mill waste 28406 4.91 yellow pine Western 6.06 s t u m p wood 2620b Western hemlock mill waste 3 2 7 0 ~ 2.76 a'Based on 15 half-cords. b Based on 4 half-cords. c Based on 5 half-cords. d U. S. gallons.
ACETATE WOOD OF CHAR-
TAR
.kCOHOL
Ga1.d
Gal d
LIMB
CO.4I.
Lbs.
Lbs.
27.80
3.90
75 0
977
46.37 19.88
3.71 2.60
74.3 55,8
900 675
24.80
3.25
73.4
478
23.05
1.83
60.8
520
21.60
5.00
94.0
936
F.
740 3,93
c.
Pressure, lbs. per sq. in
.~ ~
~
c. 332 344 346 346 14.4
ACIDITY
Per cent 0.4
...
...
a n d Darrin, J. SOC.Chem. Ind., 34, 1201 (1915); J. IND.
770 410 120 44.5 21.8 0.9230 None 21.4 98 955 27.2 22.0 16.3 34.1
--
~~
32.2 29.2 0.8805 137-434 25.9 19.5 10.3 0.9979 115 1120
Approximately 30 per cent of tar-acid-free motor fuel can be made from the gas oil by recycling, thus bringing up the yield of tar-acid-free motor fuel to a maximum of 33 per cent. The pressure distillate oil derived from the cracking reaction was subjected to Hempel distillation analysis and fractionated into motor fuel and gas oil bottoms. (Table 111) Table 111-Analysis of Pressure Distillate Oil Derived from Cracking Douglas Fir Wood Tar A. P. I. gravity 19.3 21.1 21.8 Specific gravity 0.9383 0.9278 0.9230
F.
'F. C. Per cent over 'F. 172 60 630 10 342 228 70 651 20 443 263 80 655 506 30 288 85 655 40 550 50 597 314 Coke, per cent by weight., . . . . . . . . . . . . . . . . . . . . . . . . . . .
760 404 100
15
SUMMARY OF RESULTS (Per cent based on charge) Pressure distillate, per cent 48.6 46.5 A. P. I. gravity 19.3 91 1 Specific gravity 0.9383 0,9273 Residuum Sone ITone 19.3 20.5 Water, per cent Coke, Ibs. per bbl. 84 Gas. cu. ft. Der bbl. Ai7 i.,n _-. SIot'or fuel, fraction per cent 26.3 27.1 Tar-acid-free motor fuel, per cent 21.2 21.9 Gas oil (recycle stock) 21.4 18.2 Coke, gas, a n d loss, per cent 32.1 33.0 MOTOR FCELA N D GAS OIL (Per cent based on dry wood t a r ) Motor fuel, fraction per cent 31.0 32.1 A . P. I. gravity 27.7 30.2 Specific gravity 0,8888 0.8751 Initial boiling point t o end point, O F. 146-440 137-436 Tar-acid-free motor fuel, per cent 25.0 25.8 G a s oil (recycle stock) 25.0 21.8 A. P . I. gravity 9.5 10.1 Specific gravity 1.003 0.9992 Coke, Ibs. per bbl. 127 97 Gas, cu. ft. per bbl. 735 880
0
Per cent over
I Benson
Temperature:
93 34
88 31
102 39
c.
420
420 216
425 218
216
Per cent over 10 20 30 40 48.3 50 53.9 54.6 55.3 5S.Z
61.0 Aldehydes. Trace
284 315 338 377 410
"C. 140 157 170 192 210
420
216
O F .
O F .
166 324 342 364
.,.
. . . . . .
396
. . . . . . ... . . . . .
410
.
.
...
...
48
Unsaturates, per cent
Analysis of Douglas Fir Wood Tar (A. S.T. M . ) Specific gravity.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.061 1.7 A. P. I. gravity.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initial boiling point: O F . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
END. CEEM.,7, 916 (1915).
Data on Cracking of Douglas Fir Wood Tar OPERATING CONDITIONS
c.
Table I-Distillation
Per cent 15.5 61.5 23.0
Table 11-Summarized
En$ point:
A wood tar derived from the thermal decomposition of Douglas fir was subjected to the cracking process under pressures of 7 5 , 100, and 120. pounds per square inch and temperatures ranging from 393" to 405" C. The yield of taracid-free motor fuel based upon the dry wood tar was approximately 26 per cent. The antiknock properties of the motor fuel were better than the aromatic 'hydrocarbon, benzene. An automotive engine test rated the motor fuel as loo+ per cent benzene equivalent. Analysis of the Douglas fir wood tar used in the cracking test is shown in Table I.
Aqueous distillate Oil Coke, gas, a n d loss
A summary of the cracking tests and yields of products is shown in Table 11.
Initial boiling point: F.
Cracking of Douglas Fir Wood Tar
Vol. 21, No. 6
.
.
...
"C. 74 162 172 184
iai iio
. . . . . . 216 ..
420
...
O F .
232 314 340 372
" C 111 157 171 189
i& ......
igi
. . . . . .
410 210 425 . . . . 218 . .
Distillation analysis of the motor fuel is given in Table IV. The gum present in the motor fuel was determined by the U. S. Bureau of Nines method and showed 140 mg. per 100 cc. The tar acids in the motor fuel mere determined and found to average 19 per cent. These tar acids are suitable for antiseptic, disinfectant, and other uses. To produce a finished motor fuel the tar acids should be removed by caustic soda treatment. A chemical analysis of the motor fuels showed the content of aromatic and unsaturated hydrocarbons to be 97.2 per cent, whereas the paraffin and naphthenes showed a total of only 2.8 per cent. The motor fuels produced from cracking wood tars show a high benzene equivalent (loo+ per cent) when tested in an automotive engine-far higher than the usual cracked gasoline obtainable from petroleum, coal, or shale oil. Distillation analyses of the gas oil or bottoms from the pressure-distillate oil are given in Table V.
I.VDC,STRIAL A IVD ENGINEERING CHEMISTRY
June, 1929 T a b l e IV-Distillation
A. P. I . gravity Specific gravity Initial boiling point:
' F. c.
Analyses of M o t o r F u e l from D o u g l a s F i r Wood Tar (A. S . T. M . ) 27.7 30.2 29.2 0,8888 0.8751 0.8806 140 137 137 63 5s 58
E n d point: F. Unsaturates, C. per cent P e r cent mer 5
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 97 98 99
440 227 38 O F .
436 224 ... "C.
'I;.
434 223 ...
" C
184 2 57 294 308 317 327 332 336 342 348 352 358
. . . . . . 440
436
224
178 251 285 301 313 322 329 335 341 347 351 356 362 366 372 381 389 400 418
"C 81 122 141 149 156 161 165 168 172 175 177 180 183 186 189 194 198 204 214
i3i
ii3
OF.
T a b l e V-Distillation Analyses of P r e s s u r e - D i s t i l l a t e 13ottoms from D o u g l a s F i r Wood Tar (A. S . T. M.) 10.3 A. P. I. gravity 9.5 10.1 0.9979 Specific gravity 1,003 0.9993 Initial boiling point: 440 F. 455 448 227 0 c. 235 231 E n d point: 760 835 740 ' F. 404 446 393 c.
Per cent o w r
F.
The fraction obtained under dehydrated charging stock and the distillate from it designated as aromatic, paraffin, and naphthene hydrocarbons was too small to make an accurate analysis for the determination of these components. The analysis for hydrocarbon groups nras made by the method of Egloff and Alorrell.4 Traces of aldehydes were found in both charging stock and pressure distillate. T a b l e VII-Products O t h e r than M o t o r F u e l Derivable from P r e s s u r e D i s t i l l a t e from D o u g l a s Fir Wood Tar
FRACTION
c.
F.
C.
O
C.
a
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 9.5 98 99
...
740
...
393
F. 452 474 476 478 488 496 502 510 516 526 540 544 563 582 624 546 368 390 748 760
Per cent
To 154 Light solvents 154-190 Turpentine substitute 190-230 Pine oil equivalent Pressure-distillate bottoms Tar acids ANALYSISO F ' r U R P E N T I N E SUBSTITUTE Cut containing t a r acids Per cent 12.5 Tar acids 2.0 Bases 23.5 Unsaturated hydrocarbons 4 8.0 Aromatics 14.0 Paraffins and naphthenes
. . . . . .
227
539
T a b l e VIII-Distillation Specific gravity A . P. I. gravity Initial boiling point: F. C. En$ point: F. O
Per cent ouer
Per cent
..
27:s 57.0 15.5
271 133
416 213
706 374
718 381
F.
c.
' F.
c.
165 179 192 204 221 141 260 184 306 324 334 344 350 353 362 365 368 372 374
462 470 514 529 572 613 635 652 662 670 675 675 700 708 710 714 718 718
239 243 268 276 300 323 335 344 350 358 357 357 37 1 376 377 379 381 381
O
330 354 377 400 431 465 500 543 583 615 634 652 662 668 683 690 695 702 706
C. 233 246 247 248 253 258 261 266 269 274 282 284 295 306 329 341 353 365 398 404
Tar-acid-free
Analyses of P i n e Tar Oils PINETAR MEDIUMP I N E TAK 1.026 1.072 6.3 0.2
c.
a
4.7 17.0 20.0 36.0 22.3
. . I
4.7
...
ioa
...
4.5
371
T a b l e IX-Cracking of P i n e T a r s CONDITIONS OPERATING Pine t a r Medium pine tar
of D o u g l a s F i r Wood T a r a n d C r a c k e d Pressure Distillate Temperature: BASEDO N 815 DISTILLATE = F. 830 435 FROM BASEDO N c. 443 DEHYDRATED DEHYDRATEIJ 100 Pressure, Ibs. per sq. in. 80 CHARGING CHARGING PRESSURE SUMMARY OF PRODUCTS STOCK STOCK DISTILLATE (Per cent based on tar oil) Per cent Per cent Per cent Pressure distillate, per cent 60.4 54.0 T a r acids 33.35 24.15 22.35 A. P. I. gravity 21.3 14.9 T a r bases 0.80 0.59 0.25 Specific gravity 0.926 0.9665 Unsaturated hydrocarbons 62.70 45.34 15.10 Kesiduum None None Aromatic hydrocarbons .. 60.00 Water, per cent 4.2 4.8 Paraffins and nauhthenes (by diff.) .. 2.30 Coke, lbs. per bbl. 69 75 Aromatics, paraffins, and dapbthehes Gas, cu. f t . per bbl. 822 940 (by diff.) 3.15 2.31 ... DISTILLATEWITHIN MOTORFUELBOILINGKANGB Coke and pitch 27.61 ... Per cent of t a r oil 40.9 21.6 GASOIL 31.7 59.1 The gas oil or pressure-distillate bottoms make excellent Per cent of t a r oil T a b l e VI-Comparison
...
recycle or blending stock for recracking. A comparison of the composition of wood t;tr and the cracked pressure-distillate oil was made relative to their content of tar acids, tar bases, and the hydrocarbon groups. The dehydrated wood-tar charging stock was distilled to coke to obtain a clean distillate on which to make the analysis. The percentages were calculated on the basis of the dehydrated wood tar and distillate from dehydrated wood tar. The pressure distillate contained 2.4 per cent water. The percentages were calculated on the basis of anhydrous pressure distillate. The results are summarized in Table VI.
It may be that products derivable from the cracking of Douglas fir tar have greater economic value for other purposes than their utilization for motor fuel and gas oil. Hence the pressure-distillate oil was subjected also t o Hempel distillation and fractionated into light solvent, turpentine substitute, pine oil equivalent, and pressure-distillate oil bottoms. A chemical analysis was also made of the turpentine substitute fraction. The results are given in Table VII. The gum formation in the motor fuel by the usual A. S. T. M. 4
Ed05 and Morrell, IND.END.CHEM.,18, 354 (1926).
ISDL'STRIAL A N D ENGIiVEERIAVVGCHEMISTRY
540
test is approximately 350 mg. per 100 cc. by ordinary refining and can be reduced greatly by special refining. T a b l e X-Distillation
A. P. I . gravity Specific gravity Initial boiling point:
A n a l y s e s of Pressure Distillate f r o m P i n e T a r Oils (A. S. T. M.) PINET A R MEDIUMPINET A R 14.9 21.3 0.9666 0,926
F.
O
e.
86 30
108 42.2
435 224
420 216
E n d point:
F. C.
Per cent oz'er 10 20 30 38 40 50 60 63.8 67.7
F. 267 303 328
c. 131 151 164
...
169 176 2 04 210 224
F. 274 324 367 410 420
... ... ...
.
134 162 186 210 216
...
...
Cracking of Pine Tars
Pine tar oils from the destructive distillation of lightwood were subjected to the cracking process. The yields of distillate oil boiling within motor fuel range mere approximately 22 and 41 per cent. I n the event that the economic situation does not justify motor fuel production from the cracking of pine tar, the cracked products may be fractionated into solvent oil, turpentine substitute, and pine oil equivalent for flotation oils. The distillation of pine tar and medium pine tar which were used in the two cracking tests are given in Table VIII.
Vol. 21, No. 6
The summary of the operating conditions and yields of pressure-distillate oil, coke, gas, and motor. fuel boilingrange material and gas oil is shown in Table I X . The pressure-distillate oils produced from the cracking process were subjected t o distillation analysis to determine their motor fuel content. Analyses are given in Table X. Depending upon the products desired, the pressure-distillate oil may be distilled into motor fuel and gas oil, or solvent oil, turpentine substitute, and pine oil equivalent. The distillation analyses with the percentage yield and properties of these substances are given in Table XI. A composite sample of the light solvent, turpentine substitute, and pine oil corresponding to motor fuel of U. s. motor fuel specifications was tested for its gum-forming properties by the usual Bureau of hfines method. The determination upon the refined and redistilled product showed 1.193 grams for 100 cc., which is far too high to permit the use of this distillate for motor fuel. It is therefore believed that the cracking of pine tars will be directed towards the manufacture of solvent oils, turpentine substitutes, flotation oils, paint thinners, etc., rather than for the production of motor fuels. In order t o compare the solvent properties of the light distillate (indicated as solvent oil) with other usual solvents, a series of tests was made upon crude rubber. The order of the dispersive power for crude rubber is as follows for the distillates tested: light solvent distillate, turpentine substitute from cracking, wood turpentine (known as spirits of wood turpentine) from the destructive distillation of lightwood, and petroleum ether. It is concluded from this that the light solvent would have wide use as a solvent for crude
T a b l e XI-Distillation Analyses of P r o d u c t s f r o m P r e s s u r e Distillate f r o m P i n e Tars (A. S . T. M.) DISTILLATEWITHIN MOTORFUEL BOILINGR A N G E PRESSURE-DISTILLATE BOTTOMS Pine tar Medium pine tar Pine tar Medium pine tar 6.5 A. P. I. gravlty 31.2 29 16 A. P . I. gravity 6.2 0 , 8 7 8 3 Specific gravity . 1.027 1.025 Specific gravity 0.8697 Initial boiling point: Initial boiling point: 424 F. 455 154 158 F. 218 c. 235 68 70 O End point: End point: 735 745 43s F. 433 F. 39 1 396 223 c. 226
c. e.
P e r cent over
F.
c.
229 272 283 297 304 308 316 321 328 332 336 340 344 347 353 360 367 382 415
109 133 139 147 151 153 158 161 164 167 169 171 173 175 178 182 186 194 213
c.
To 154
154-190
190-230
c. 91 119 131 137 143 148 154 158 162 166 168 173 176 180 183 188 194 201 215 226
P e r cent over
F.
c.
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 98
480
249 254 260 266 274 285 296 304 316 324 332 343 349 357 361 365 371 377 391 396
49 0 500 510 525 545 565 580 600 615 630 650 660 675 682 690 700 710 735 745
... ... 223 FROM PRESSURE DISTILLATE OTHERT H A N M O T O RFUELA N D GAS OIL PRODUCTS DERIVABLE Pine tar Medium pine tar Pine tar Product P e r cent Solvent oil 12.8 42.0 41.4 A. P . I. gravity 0.8155 0.8184 Specific gravity 123' F., 51' C. 134' F., 57' C. Initial boiling point 371' F.. 188' C. 393' F., 201" C. End Doint Turpentine substitute 21.9 27.7 A. P. I. gravity 30.1 0 8756 0.8888 Specific gravity Initial boiling point 202'F 94'C 208' F . , 98' C . E n d point 396O F:: 202' C : 413' F . , 212" C . Pine oil equivalent 7.7 16.0 A. P. I. gravity 18.4 Specific gravity 0.9440 0 9593 316' F., 158' C . 331' F., 166' C. Initial boiling point 495' F., 257' C. 474' F., 246' C. End point Gas oil 17.9 A. P. I. gravity .. . .... Specific gravity 1.039 1.014 LOSS 0.1 433
Fraction
...
F. 196 246 268 279 290 299 309 316 324 330 335 343 349 356 362 370 382 393 419 438
.
F. 448 460 476 492 502 520 538 556 576 594 615 630 647 662 675 686 696 709 724 735
c. 231 238 247 256 261 271 281 291 302 312 324 332 342 350 357 363 369 376 384 39 1
Medium pine t a r
Per cent 8.7
6.2
10.6
27.0
1.5
INDUXTRIlL A X D EN(7INEERING CHEMIXTR Y
June, 1929
rubber, especially a', the odor and color are favorable t o such use. In cracking pine 1ar it must be remembered that the charging stock is so costly as to prohibit cracking the raw material down t o coke and distillate. Hence the guiding factor is t o crack so that the residue remains suitable for the uses to which the original pine tar is applied. Under these conditions the following distribution of products can be expected from each 100 gallons of charging stock: Gallons Solvent distillate Turpentine substitute Pine oil equivalent Residual pine tar Coke, gas, and loss
10 10 12 65 3
Cracking of Hardwood Tars
A mixture of tar derived from the thermal decomposition of hickory and oak was subjected to cracking conditions of 90 pounds per square inch pressure and 720" F. (382" C.). A yield of approximately 24 per cent of high antiknock motor fuel was produced. The cracking stock of hardwood tar was subjected to distillation analysis and the percentage of tar acids, tar bases, and neutral oil present were determined by several methods. The data are given in Table XII. A creosote cut (240" C.) was taken from each of these oils and this cut was extracted for tar acids and bases. (Table XIII) A summary of the cracking of hardwood tar with the products of pressure-distillate oil, coke and gas, motor fuel, and gas oil is given in Table XIV. The gas oil or recycle stock may be used directly as a disinfectant or wood preservative, or may be recycled in the cracking process for additional yields of products. Analysis of the pressure-distillate oil derived from the pressure distillation of the wood tar is given in Table XV. Analysis of the 420" F. (216" C.) fraction derived from the pressure-distillate oil by Hempel distillation is given in Table XVI. The distillate boiling within the motor fuel range contained 52 per cent of tar acids and 6 per cent of tar bases. An analysis of the pressure-distillate bottoms or gas oil derived from the Hempel distillation of the cracked oil is shown in Table XVII. It is apparent that the tar acid content of cracked distillates from hardwood tar is too high to make it economically profitable to crack the hardwood tars for motor fuels alone. I n the thermal decomposition of tar acids, the products are lower molecular weight and lower boiling tar acids, coke, gas, water, and a small percentage of hydrocarbons. From an economic viewpoint, it is believed that it will be most profitable to crack hardwood tars for the simultaneous prcduction of motor fuel and low-boiling tar acids with the manufacture of antiknock motor fuel as a secondary object. The lower boiling tar acids possess higher toxicity than the higher boiling tar acids. I n this way the cracking process increases the commercial value of the tars. Refining of Cracked Distillates from Wood Tars
The refining of cracked distillates from wood tars is similar to the refining of cracked distillates from low-temperature coal tars and shale oils. Where a high percentage of tar acids is present, the tar acids are removed first by treatment Tvith a 20 to 25 per cent solution of sodium hydroxide. Treatment in several steps is desirable for complete removal of the tar acids. The cracked distillate is then water-washed and treated with dilute sulfuric acid. If the amount of bases present
541
exceeds several per cent, treatment with first a 10 per cent and then a 95 per cent solution of sulfuric acid is desirable. An alternative treatment is the use of 60 t o 85 per cent sulfuric acid with no concentrated acid following, and is applied when the percentage of bases is low. The sludge from the acid treatment is withdrawn and the distillate is waterwashed and neutralized nith sodium hydroxide. The strength of the sodium hydroxide solution may vary from 5 per cent upward-usually 5 to 10 per cent. on Hardwood Tar Cracking Stock DISTILLATION ANALYSIS A. S. T . M. Hempel method Specific gravity 1,1119 1.1119 Initial boiling point: F. 210 195 91 c. 99 End oint: Table XII-Data
08c.
610
321
O
A. P. I . Specific gravity gravity F. C. F. a C. 175 347 207 405 388 19s 10.6 0.9958 223 433 235 455 440 227 5.5 1.0336 241 465 251 483 458 237 1.9 1.0598 502 261 515 268 480 249 1.0692 0.7 275 527 281 538 517 270 1,0758 0.1 285 545 289 552 565 296 1.0812 295 562 321 610 319 606 299 570 weight, 1 9 . 1 TARACIDS,BASES,A N D NEUTRAL OIL PRESENTIN T A R (Per cent based on tar) Tar acids Tar bases Neutral oil Tar at 24OOC. Raw 24OOC. Raw 24OOC. Raw 240'C. cut oil cut oil cut oi I
Per cent oaer
R
%
70
%
%
%
%
24 5
57 7
14.1
12.7
3.1
29.6
7.3
Table XIII-Distillation
of Hardwood Tar TARACIDS T A RBASES Cut Raw oil Cut Raw oil
Charge Pyroligneous acid Cut, 420° F. (216' C.) Cut. Ditch Bottoms Water
Loss
AND
%
%
20.9 5.4
3.2 2.0
1.0 0.6
--
-
--
DISTILLATION
540 176 43 245 14 63
32.0 8.0 45.2 2.5 11.4
540
100.0
-
Total
STEAM
70
%
Grams Per cent FIRE
__
66.4 67.6
~
26.3
1.6
V A C U U X DISTILLATION
Cbaree
594
Total
594
- 100.0
Table XIV-Cracking of Hardwood T a r (Mixture of tar from hickory and oak) OPERATIIGCONDITIONS Temperature:
F.
c.
0.8
25.2
Pressure, lbs. per sq. in. SUMMARY OF RESULTS (Per cent based on charge) Pressure distillate, per cent A. P. I. gravity Specific gravity Water, per cent Residuum Coke, Ibs. per bbl. Gas, cu. f t . per bbl. Coke, gas, and loss, per cent Motor fuel, per cent (tar-acid and tar-base free) Tar acids to 450" F. (232' C.) Tar bases to 450' F. (232' C.) Gas oil or recycle stock
720 382 90 34.0 12.4 0.9833 2.1 None 127 329 65.0 9.9 12.4 1.4 8.0
I X D U S T R I A L A1YD EKGIA-EERTNG CHEMISTRY
542
Vol. 21, No. 6
The distillate is finally distilled in the presence of steam. With some types it is desirable to stabilize the overhead product from the distillation by using a small amount of fuller’s earth or activated clay in the still. Distillation over alkaline solutions and mild polymerizing agents also assists in stabilizing the final distillate and lowering the gum content.
to prevent condensation of the steam. A temperature of 121” to 135” C. is satisfactory. The final product may be further stabilized by treatment with a small amount of fuller’s earth and is improved in odor by subsequent washing with a dilute solution of sodium hydroxide. After a final waterwashing the treatment is complete.
Table XV-Pressure-Distillate Oil Derived f r o m Cracking Hardwood Tars (A. S. T . M.) A. P. I. g r a v i t y . . .................................... 12.4 Specific gravity. ..................................... 0,9833 Initial boiling point:
Table XVI-Distillation Analysis of Distillate f r o m Hardwood Tars w i t h Motor Fuel Boiling R a n g e (A. S. T . M.) A. P. I. g r a v i t y . . .................................... 15.4 Specific gravity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9632 Initial boiling point:
O F . . .
..............................................
O C ................................................. En? oint O
8C . .. . ,.. i. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ........................................................
Per cent over 10 20 30 40 50 60
70
73.1 79.8 Water, per cent
. .
11.2
81 88 109 166 192 199 208 ~ 210 216
......
147
End aint.
02.. ............................................... 437 . . . . . . . . . . . . . . . . . . . 225
420 216
OC. . . . . . . . . . . . . . . . .
HzO
c.
F. 177 190 228 331 378 391 4nfi ~ 410 420
127 53
cc.
Per cent omr
22 32 36
5 10 15 20 25 30 35 40 45 50
. .
The final product may be treated with a dilute solution of sodium hydroxide, which improves the odor. Final contact with a small percentage of fuller’s earth also assists in the stabilization. As an example of the treatment of a cracked distillate from wood tars, the following is shown for pine tar distillate. The cracked distillate is treated with 10 to 15 pounds of 60 per cent concentration sulfuric acid per barrel of distillate. The sludge is withdrawn. The distillate is then water-n-ashed and neutralized with about 2 per cent of a 10 per cent solution of sodium hydroxide alone or containing litharge dissolved in it. The treated cracked distillate is distilled over about 1 pound of fuller’s earth per barrel, using top steam and maintaining the temperature just above that required
F.
C.
166 173 180 187 203 245 293 318 345 357
74 78 82 86 95 118 145 159 174 181
c.
F.
Per cent over 55
366 375 381 388 39 1 395 402 411 431 437
60
65 70 75 80 85 90 95 98
186 191 194 198 199 202 206 211 222 225
Table XVII-Distillation Analysis of G a s Oil (A. S. T. M.) A. P. I. g r a v i t y . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.O Specific gravity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,066 Initial boiling paint:
E F.
....
O 0
F. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Per cent over 5 10 15 20 25 30 35 40 45 50 Trace of coke ~
432 222
....
C. End point:
F. 435 437 439 441 444 447 450 453 456 458
C.
Per cent over 55 60 65 70 75 80 85 90 95 98
O
F.
462 468 473 479 486 497 514 539 549 556
556 291 O
c.
239 242 245 248 252 258 268 282 287 291
~~~
Sulfonated Oxidation Products of Petroleum as Insecticide Activators’ M. T. Inman, Jr. KAY LABORATORIES. INC..WEST NYACK, N. Y.
HE continuous search for cheaper and more effective methods of controlling insect pests has given the chemists a very enticing problem. To a chemist not in intimate contact with entomological problems a general spray mixture for all troubles-a cure-all-would seem t o be the product to develop. Upon close study of the variables in spraying the many species of destructive insects, a product that would increase markedly the efficiency of any specific control would be well worth while. I n view of this fact a thorough study of the application of the oxidation products of petroleum to the insecticide field has been conducted for the past four years in cooperation with state entomologists and the Crop Protection Institute. As a result of this work a definite procedure in attacking softbodied sucking insects, such as aphis and leaf hoppers, was developed. By the addition of chemically treated oxidation products of Pennsylvania gas oil to a solution of nicotine sulfate, the efficiency of the poison was strikingly increased. For example, where these oxidation products have been
T
%ReceivedMarch 1, 1929.
added, a t the rate of 1 to 200, to nicotine sulfate spraying solutions, a satisfactory kill has been obtained with only onethird to one-fifth of the nicotine commonly employed when soap is used as a spreader. The underlying principle is, briefly, the increase of the efficiency, or the activation, of an insecticide by bringing about certain physical changes in the resultant spray mixture. This group of chemically treated oxidation products of Pennsylvania gas oil has been termed “activator” in explanation of its performance in the insecticide field. Properties Desirable in a C o n t a c t Spray
A spray intended for sucking insects should be: (1). Safe to foliage under all climatic conditions a t all effective dilutions with allowance for ample margin of safety. (2) Easily measured and handled. (3) Readily miscible with a variety of natural waters. (4) Toxic to the most resistant individuals of the species of insect sprayed. The final kill may be affected by the follow( a ) absolute lethal effect, ( b ) coverage on the ing properties:
