September 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
(92F) Swan, G. (to Beck, Koller and Co., Ltd.), Brit. Patent 690,180 (April 15, 1953). (93F) Thompson, R. B. (to Universal Oil Products Co.), U. S. Patent 2,625,534 (Jan. 13, 1953). (94F) Ibid., 2,636,021 (April 21, 1953). (95F) Thurston, J. T. (to American Cyanamid Co.). Ibid., 2,640,046; 2,640,047 (May 26, 1953). (QGF) Vogelsang, G. K. (to Borden Co.), I b i d . , 2,629,703 (Feb. 24, 1953). (97F) Wagner, G. H. (to Cnion Carbide and Carbon Corp.), Ibid., 2,632,013 (March 17, 1953). (98F) Warrick, E. L. (to Dow Corning Corp.), Ibid., 2,634,252 (April 7, 1953). (99F) Waters, D. L., and Wilson, D. L. (to Courtaulda, Ltd.), I b i d . , 2,647,108 (July 28, 1953). (100F) Whetstone, R. R., and Ballard, S.A. (to Shell Development Co.), Ibid., 2,640,815 (June 2, 1953). (101F) Wingfoot Corp., Brit. Patent 693,645 (July 1 , 1953). (102F) Winslow, F. H. (to Bell Telephone Laboratories, Inc.), U. 8. Patent 2,642,415 (June 16, 1953). IPROCESSES, E Q U I P M E N T , AND P L A N T S
(lG) Adams, J. J. (to Dow Chemical Co.), U. 9. Patent 2,655,496 (Oct. 13, 1953). (2G) Betts, R. L., and Leslie, J. D. (to Standard Oil Development Co.), Ibid., 2,626,291 (Jan. 20,1953). '(3G) Bruner, W. M., and Kvalnes, H. M. (to E. I. du Pont de Nemours & Co.), Ibid., 2,640,041 (May 2 6 , 1953). '(4G) Coleman, G. A., Greene, R. B., and associates (to Allied Chemical 15Dye Corp.),I b i d . , 2,658,054 (Nov. 4, 1953). (5G) Fell, W. K., and Leslie, J. D. (to Standard Oil Development Co.), Ibid., 2,626,290 (Jan. 20,1953). (GG) Feldon, Xi.,McCann. R. F., and Laundrie, R. W., India Rubber W o r l d , 128, 51 (1953). (7G) Frank, C. E., Kraus, G . , and Haefner, A. J., J . Polymer Sci., 10, 441 (1953). (8G) Gornowski, E. J. (to Standard Oil Development Co.), U. S. Patent 2,626,292 (Jan. 20, 1953). (9G) Hofrichter, C. F., Jr. (to E. I. du Pont de Nemours & Co.), Ibid., 2,650,213 (Aug. 25, 1953). (IOG) Hohenstein, W. P. (to R7hitney Blake Co.), I b i d . , 2,653,145 (Sept. 22, 1953).
1881
Horikx, M. M., and Hermans, J. J., J . Polymer Sea., 11, 325 (1953).
Howe, R. F., and Halloway, F. A. L (to Standard Oil Development Co.), U. 9. Patent 2,636,025 (.kprd 21, 1953). Howland, L. H., Neklutin, V. C., and associates, IND.ENG. CHEM.,45, 1304 (1953). Howland, L. H., Reynolds, J. A., and Brown, R. W., Ihzd., p. 2738.
Ludewig, H., Chem. Tech. ( B e r l i n ) , 4, 523 (1952). Manning, W. R. D., Rubber A g e and Synthetics, 34, 308 (1953). May, W. G., and Matheson, G. L. (to Standard 011Development Co.), U. S.Patent 2,658,933 (Nov. 10, 1953). Nelson, J. F. (to Standard Oil Development Co.), Ibzd., 2,636,026 (April 21, 1953). Norris, F. H. (to Monsanto Chemical Co.), I b i d . , 2,635,086 (April 14. 1953) Nozaki, K. (to Shell Developinent Co ), Ibid., 2,628,222 (Feb. 10, 1953).
N. V. de Bataafsche Petroleum lfaatschappij, Brit. Patent 687,984 (Feb. 25, 1953).
Odell, W.W. (to Standard Oil Development Co.), U. S.Patent 2,631,921 (March 17, 1953). Pryor, B. C., Harrington, E. W., and Druesedow, D., IND. ENG.CHEM.,45,1311 (1953). Richards, J. C. (to E. I. du Pont de Nemours & Co.), U. S Patent 2,628,223 (Feb. 10, 1953). Ronay, G. S., and Vinograd, J. R. (to Shell Development Co.). Ibid., 2,663,701 (Dec. 22, 1953). Russell, F. R. (to Standard Oil Development Co.), Ibid.. 2,626,289 (Jan. 20,1953). Tegge, B. R. (to Standard Oil Development Co.), Ibid.. 2,643,993 (June 30, 1953). Vandenburg, E. J. (to Hercules Powder Co.), Ibid., 2,648,655; 2,648,656; 2,648,657; 2,648,658 (Aug. 11, 1953). Wallman, H. (to American Cyanamid Co.), Zbid., 2,652,386 (Sept. 15, 1953). Welsh, C. E., and Holdstock, N. G. (to General Electric Co.). Ibid., 2,661,348 (Dee. 1, 1963). Wenning, H. (to Chemische Werke Hiils G.m.b.H.), Ibid., 2,642,418 (June 16, 1953). Wright, J. D., and Shipley, J. H., Petroleum Engr.. 25, KO. 9, C3 (1953).
Pyrolysis of Coal and Shale T h e activation energies for coal pyrolysis are of the same order of magnitude as those for carbon-carbon fission and for separation of macromolecules. Low temperature carbonization rates are a function of degree of volatilization of oxygen and sulfur compounds, and approach zero-order. Low specific surface area is only incidental to coke formation. Recent German studies suggest petrographic analysis as a control in coal blending. Revision of the single shatter test for coke is desirable. Further alkaline oxidation studies confirm the absence of any aromatic structures in Colorado oil shales. O n l y 30% of this shale organic matter is solubilized on dehydrogenation. A process for separating kerogen by use of bacteria at 20" to 75" C. has been patented. Also patented i s the use of superheated water at 700' F. and 200 atmospheres for extraction of kerogen.
HIS is the seventh annual review on the pyrolysis of coal and oil shale. I n accordance with recent editorial policy this
T
current review is restricted to the most significant and timely papers. Work of borderline quality or primarily applicable only t o specific local situations has been omitted. This approach has reduced the coverage of related subjects to coal and shale pyrolysis previously included-raw material propertics, by-product characteristics, analysis and testing meth-
GENERAL
ods, and equipment patents. But n more critical discussion is permitted of mechanism, kinetics, and significant process details. Essentially the period under review extende from June 1953 through April 1954, except for previous omissions arising from normal publication lag. Some 160 papers were screened arid examined during the process of selection for inclusion here.
COAL PYROLYSIS
A few papers of general interest on coal pyrolysis merit attention. Jones (W9A)presented a critical review of recent American developments in coal carbonization, gasification, and synthetic fuels development. A survey ( S O A ) of the current outlook for coking operations in the U. S. covers recent trends in markets,
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I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
coke quality, processes employed, and production. Plans now call for a 25% increase in coking capacity in the near future. A novel use of a coke oven for hydrogen production is described (t7.4). The process consibts of injecting a fuel-oil-steam mixture into an empty heated oven and passing the products of thermal decomposition into an adjoining oven to complete the reaction. ,4315 B.t.u. per cu. ft. gas results from which hydrcgen may be separated b y liquefaction. &vietoslawski (56A) published a new reference book on the physical chemistry of coals and of coking processes. Barritt ( $ A ) traced the development of the coke oven to its present design and its influence on the types of coal that may be carbonized. H e discusses such new coking procedures as the National Fuel process, the Baumco process, and the Brennstoff-Technik process, together with their basic theory. MECHANISM, KINETICS, THERMOCHEMSTRY
Smit.h and Brown (6QA) concisely summarized the knowledge of coke forinat,ion mechanism. Carbonization is the result, of eimultaneous depolymerization, solvent extraction, vaporization, t,hermal decomposition, and polymerization reactions; each is governed by its own kinetic relationships. In order to secure a well-fused and coherent coke residue
1. Fusion of an appreciable fraction of the coal substance Ehould occur a t elevated temperature. 2. Concurrent polymerization and decomposition should t,ake place a t or near the fusion temperature. 3. Vapor presmre of the fluid residue undergoing 1 and 2 should be quite low. According t o Riley (49A) where macromolecules in the original coal exceed 80 carbon atoms in size, the energy of molecular separation is the same order as t h a t for rupture of a C-C bond (58.6 kcal.). A s a result explanation of the coking mechanism in terms of interatomic bonding becomes extremely complex and of dubious accuracy. Recent and future studies on high polymers may, however, shed light on this problem. The Einstein equation may be applied to the relationship betiveen the viscosity and the per cent solids present in a liquefied coal-solids mixture (where the solids are pyrolytic decomposition products). The pyrolysis reaction rate constants by which the solids are formed may be calculated by assuming a first-order process and finally activation energies. A recent paper ( 6 A ) present,s the results obt,ained for 4 coals. Activation energies (47.3 to 54.2 kcal. per mol.) similar to those for breaking the C-C bond in mineral oils are reported. These values approximate those mentioned for macromolecular separa,tions. Boyer (4.4) followed the process of coal carbonization during heating at either constant or increasing temperature by use of a thermobalance. To t8he point of semicoke format'ion (400" to 500" C.) the process conforms t o the Arrhenius equat'ion. Beyond this point the weight-temperature curves were grouped in families with the oxygen content of the semicoke as parameter. Rates of low temperature carbonization (770' to 1125' F.) in a fluidized bed ( 5 5 A ) are a function of temperature and degree of volatilization of oxygen and sulfur compounds. I n the first stages, during loss of oxygen and sulfur compounds, the reactions were first-order. During the final stages, however, devolatilization approached a zero-order reaction. Hadzi and coworkers (,%A) added t o the knowledge of coal pyrolysis by investigating the thermal decomposition of such pure compounds as di-2-dinaphthyl-sulfone, various hydrocarbon reaction products of naphthalene and anthracene, and pyrolytic decomposition products of polyvinyl chloride. The character of the various cokes obtained is d-cribed. From these &dies i t is concluded that coking is not a simple fusion process, and that the presence of sulfur and the percenkge of oxygen present are not determining factors. The latter conclusion is subject to question, this reviewer believes, if extended to coal pyrolysis. Kitaaaki, Yagishita, and coworkers published a series of four
Vol. 46, No. 9
papers of fundamental studies of the coking process, which were discussed in the previous unit process revierv on coal and shale pyrolysis. The fourth paper in this series devoted t,o heat of wetting research suggested that, as pyrolysis temperature reaches 400" C., crystal macromolecules are formed in the amorphous region. These molecules slide against one another in unit' segments as the coal melts, thus decreasing the crystal region. -4s. the temperat,ure reaches 600" C., however, crystal regioln growth increases once more, because of aromatic condensation. The fifth paper in this series (3JA) reports on further conclusions drawn from iodine ion adsorption studies. Agrawal ( 1 A ) determined the specific surface of brights and durains of a number of British coals using argon adsorpt,ion a t 90" I
