-Fuel The units of these constants are such t h a t the equation will bold when conversion is expressed as the fraction of carbon dioxide converted, partial pressures are in atmospheres, feed rate is in pound-moles of carbon dioxide per hour, the weight of catalyst is in pounds, and rate is defined as d r / d ( W / F ) . The effect of diffusion through the gas film at the surface of the catalyst ia negligible. This was shown by the fact that at a constant W / F value the conversion does not vary with mass velocity. The reaction will not proceed a t all at this temperature except in the presence of the catalyst. Runs were made using a n inert filler in place of the catalyst and no conversion was obtained.
0 I6
,
012
0 04
g
0
o
0
Figure 9 .
4
8
12 L
16 20 CATILYST-HR
24
28
32
LI ( L B 8MOLC GO, IN FEED Plot of Equation 1-2 for a Feed of 80% Carbon Dioxide
Gasification-
nection with the preparation of the manuscript for this paper. Acknowledgment is also made of the assistance rendered by L. J. Kane of the Bureau of Mines staff in connection with the laboratory work.
Nomenclature a, b, c, etc. = empirical constants ca, c b , etc. = effective concentration of active centers occupied
by components A , B elc. CI = effective concentra&on of unoccupied active centers on catalyst surface F = pound-moles of carbon dioxide feed per hour h: = reaction rate constant kl,kp = specific rate constants for individual steps of a reaction K = equilibrium constant K A ,KB, etc. = adsorption equilibrium constants K,, K , = equilibrium constants for individual steps in a reaction I = symbol for an active center on the catalyst surface L = effective concentration of all active centers (occupied or unoccupied) on catalyst surface P = partial pressure; subscripts A , B , R, and S refer t o carbon dioxide, hydrogen, carbon monoxide, and water, respectively r = reaction rate, pound-moles converted per hour per pound of catalyst W = pounds of catalyst W / F = pounds of catalyst per pound-mole of carbon dioxide feed per hour x = pound-moles carbon dioxide converted per pound-mole of carbon dioxide in feed
Literature Cited
It is realized that the work of this investigation could well represent the beginning of a long-time project involving a study of the kinetics of this reaction over wide ranges of operating condi-
(1) Hougen, 0.A., and Watson, K. M., “Chemical Process Principles,’’Vol. 3. New York, John Wiley & Sons, 1947. ( 2 ) Hougen, 0.A., and Watson, K. M , IND.ENG.CHEM.,35, 529 (1943). (3) Sands, A. E., Wainwright, H. W., and Egleson, G. C., U. S. Bur. Mines, Re@. Invest. 4699 (1950). (4) Strimbeck, G. R.,Holden, J. H., Rockenbach. L. P., Cordiner, J. B., and Schmidt, L. D., Zbid., 4733 (1950). (5) Wagnian, D. D., Kilpatrick J. E., Taylor, W. J., Pitzer, K. S., and Rossini, F. D., Natl. Bur. Standards, Research Paper RP1643 (1945). (6) Yang, K. H., and Hougen, 0. A., Chem. Eng. Progress, 46, 146 (1950).
tions. Further work is being done t o investigate the effect of temperature on the constants of the rate equation. It is hoped t h a t in the future this study may be advanced by determining the effect of pressure and by investigating other catalysts.
Acknowledgment The authors wish t o express their deep appreciation t o E. D. Arnold, West Virginia University Engineering Experiment Station, for the extremely valuable assistance rendered in con-
RECEIVED for review July 31, 1951.
ACCEPTEDFebruary 8,1952.
Gasification of Solid Fuels at Elevated Pressures Wilhelm Gumz, BATTELLE
MEMORIAL INSTITUTE, COLUMBUS, OHIO
Gasification of solid fuels under pressures of 20 to 30 atmospheres offers advantages in high capacity and high fuel rates, low oxygen consumption, and decrease in cost of labor and product gas. It may have applications in pressurized boiler furnaces, gas turbines, and in the production of synthesis gas and high-B.t.u. fuel gas. The effect of pressure on gas composition, pressure drop in the fuel bed, and terminal velocity of suspended particles is calculated and compared with experimental data.
G
ASIFICATION under pressures of 20 to 30 atmospheres has become a proved technique and offers distinct advantages with respect to high capaoity and high fuel rates, low oxygen consumption, and decrease of labor and product-gas costs. Prospective applications are in pressurized boiler furnaces, gas turbines, and produetion of synthesis gas and high-B*t.u. fuel gas.
May 1952
*
The effect of pressure and other operating variables can be clearlydemonstrated by calculation (5,6,9,11,12,14,16),by solving a set of simultaneous equations representing thematerial balances of carbon, hydrogen, oxygen, nitrogen, and sulfur, theequilibria of the Boudouard or producer-gas reaction, of the heterogeneous water-gas reaction, and of the formation of methane and sulfur compounds, hydrogen sulfide, carbonyl sulfide, carbon disulfide, and sulfur vapor, and finally the heat balance. The required reactions are well known ( 6 , 1 6 ) , and data data on the C-H2--02 on equilibria of sulfur compounds can be derived from the work of Ferguson (S), Lewis and Randall ( l S ) , Lepsoe ( I I ) ,and Cross ( 2 ) . Table I gives an excerpt of equilibrium constants of sulfur compounds. The solution of a set of simultaneous equations involving the 13 unknowns-carbon monoxide, carbon dioxide, hydrogen, water,
INDUSTRIAL AND ENGINEERING CHEMISTRY
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Fuel Gasification other sulfur compounds are present only in trace amounts. The mathematical effort is thus reduced in such a way that a table calculator is entirely sufficient, as no more work is involved than KPHzs K;28 KPcos KIcOS was required by earlier methods which neglected sulfur entirely. P C O P H B PCOS PHzS pcosPHz _______ A number of methods for the solution have been shown (6, 6, 9). Temp., ’ C . PAh’PHa PCOSPHz pi62PC0 PCOPH2S An estimate of the degree of approach t o equilibrium is neces400 2 154 X 104 15 16 1 421 X 102 0 06597 500 2.974 X 10; 17 10 1 681 X 101 0 05651 sary. It has been shown experimentally (5, 6 , 9 ) that in counter600 6.369 X 10 19 63 32 39 current fixed-bed systems the Boudouard and water-gas reactions 700 1.844 X 102 21 05 8 762 800 66 65 22 0 4 3 024 0 04537 reach equilibrium with respect t o the 22 73 1 251 0 04399 900 28 44 “reaction or equilibrium temperature” which can be determined by the heat KCS1 K&? K%? K*Ps2 K& K*Pso2 2 2 2 2 balance within the reaction zones of the PCSzPHa pcs2pco PSzPHa PSZPCO PCSz PSOapH2 gas producer. The equilibrium of Temp., 2 2 2 a 2 PH2S pH29 Pcos Pcos PHzSP CO methane formation is approached only C. %a 400 2 5 . 5 6 5 . 4 9 5 x 10-6 1 . 2 6 6 X 10-6 2 . 1 5 0 X 10-9 4 . 9 5 2 X 10-7 1 . 6 3 2 X lo-’? to a degree in between 25 to 30% ofthe 500 1 8 . 7 2 2 . 1 1 7 X 10-6 6 . 6 2 8 X 10-4 1 . 1 3 1 X lo-’ 3 . 5 4 1 X lo-; 3.507 X lo-” 600 1 4 . 7 2 3 . 6 4 0 x io-’ 1 . 4 0 3 x 10-2 2 . 4 7 3 x 10-0 9 . 5 3 0 x io3 . 8 2 6 x 10-10 equilibrium constant. 700 1 2 . 1 6 3 . 5 7 6 X 10-4 0 . 1 5 8 4 2 941 X 10-6 1 . 3 0 3 X 10-2 2 . 6 0 0 x lo-* A re-evaluation of a full scale test with 1.139 2 . 2 5 1 X 10-4 0,1094 1 . 2 5 9 X 10-8 800 10.41 2 . 3 4 3 x 10-8 5 850 1 . 2 4 5 X 10-8 0.6389 4 . 7 1 5 X 10-8 semianthracite (6, lO)-thus eliminating 9 . 1 5 7 1 . 1 4 0 X 10-2 900 the influence of volatile matter-has dis: closed that the degree of approach of the methane formation is . z ~= 0.281. Sulfur dioxide is theoretically nil, and carbon disulfide and eulfur vapor are negligible in the presence of ample water vapor. Carbonyl sulfide was not measured, but hydrogen sulfide is in fair agreement with the calculated value. A comparison of calculated and measured data is given in Table 11. Table I.
Equilibrium Constants of Sulfur Compounds
-_.
;!!:;E.
-
-
-
Table 11.
Gas Composition
(Gasification of semianthracite with oxygen and steam at 20 atm. pressure) Measured Deviation Wet Dry Drya Absolute % co, % 9.31 14.63 14.43 t0.20 1.39 COS, 7 0 20.27 31.86 31.45 +0.41 1.30 Hat % 27.11 42.60 43.10 -0.50 -1.16 HzO, % 36.37 CHI, % 6.15 9:67 9:70 -0:03 - ‘0: 31 HzS, % O,l5 0.24 0.27 -0.03 -11.11 172, % 0.64 1.00 1.05 -0.05 -4.76 100.00 100.00 100.00 a Recalculated on oxy en illuminants-free basis. Original analysis included 0.25% Oa and 0.24% huminants, originating from volatile matter. Basis
+ +
- __
Pressure shifts the Boudouard and water-gas reactions toward increased carbon dioxide and water content of the make-gas, and the methane formation toward higher methane content. At the 110
H20,
PER CENT
Figure 1. Distribution of Sulfur Compounds in Product Gas Cumulative compounds as a function of moisture content of blast
methane, hydrogen sulfide, carbonyl sulfide, sulfur dioxide, sulfur, cdrbon disulfide, and nitrogen, the amount of fuel, and the amount of gasifying agent required per unit volume of product gas a t a given temperature-resorts to the Newtonian approximation method by selecting three of the unknowns as “primary unknowns”-e.g., carbon monoxide, hydrogen, and hydrogen sulfide-and expressing the rest of them as functions of the primary unknowns ( 7 ) . The mathematical operations involved are simple in principle, although laborious because of the number of unknowns. The use of matrix calculation is recommended (9,
0‘
0
1
2
3
4
5
6
7
6
I
9
12). Calculations can be greatly simplified by neglecting all sulfur compounds with the exception of hydrogen sulfide or, in some cases, both hydrogen sulfide and carbonyl sulfide. Figure 1 shows that this simplification is justified for most practical cases because the
1072
PRESSURE,
Figure 2.
P,,
ATMOSPHERES
Pressure Drop in Downdraft Fuel Beds
yo of pressure drop at atmospheric pressure
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
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~
same time the equilibrium temperature rises, resulting in only slight differences in heating value of t h e product gas up t o about 10 atm., in agreement with experimental findings (I). The pressure drop in the fuel bed is inversely proportional to the pressure. Figure 2 compares pressure operation with atmospheric pressure in the same fuel bed. The solid line represents the theoretical proportionality; the circles are derived from experimental data. The small deviations from the theoretical curve are due t o unavoidable inaccuracies of measurement or variations in operating conditions, as well as differences in size consist of two batches of coke breeze (designated as 1 and 2). 100
I
I-
z 0 W K W P
>-
5 sw
-I
a
z Ew c
Table 111.
Terminal Velocity of Coal Particles i n Producer Gas
(Gas temperature, 500° C particle density, 1000 kg. per 0.1. meter: particle didmeter, 0.1 1 10 mm.) Pressure, Atmospheres 1 3 6 9 15 20 30 Gas density p,kg./eu.deter 0 . 4 0 1 9 1.2057 2.4114 3 6171 6 0285 8 038012 057 Kin. viscosity, v10* 28.19 9.439 4.760 3.196 1 . 9 4 5 1 . 4 7 7 1.009 Terminal vel., meters/sec. 0.307 0.271 0.249 0.219 d=O.lmm. 0.420 0 , 3 7 4 0.334 3 . 3 3 3 2 . 6 1 8 2.281 1 . 8 7 4 4.023 d = 1.0 mm. 8.806 5.618 11.28 8.73 7.58 6.18 d = 10.0mm. 3 3 . 8 5 19.159 1 3 . 8 1
- -
Gumz, Kapp, and Blecher, “Joint Report of Mining Association (Essen) and Lurgi (Frankfurt/Main) ,” Tech. Oil Mission Reel 188, Item 34 R (1943). Kandiner, H. J., and Brinkley, S. R., Jr., IND.ENG.CHEM.,42. 850-5 (1950). Lepsoe, Robert, Ibid., 30, 92-100 (1938). Lewis, G. N., and Randall, Merle. “Thermodynamics and the Free Energy of Chemical Substances,” New York, McGrawHill Book Co., 1923. Traustel, Sergei, 2. Ver. deut. I n g . , 88, No. 51/52, 688-90 (1944). Traustt.1, Sergei, and Wilhelm Gumz, Bergbau u. Energiewirt., 2, NO. 3, 4/5, 69-75, 85-7 (1949). Wagman, D. D., Kilpatrick, J. E., Taylor, W. J., Pitzer, S., and Rossini, F. D., J . Research Natl. Bur. Standards, 34, 143-61 11945).
W
z + a
-I
IO
w
K
“0
Selected Bibliography on High-pressure Gasification I 10 PRESSURE,
20
30
ATMOSPHERES
Terminal Velocity of Particles 0.01 to 10 Mm. in Diameter a function of pressure. yo of terminal velocity at
Figure 3. As
atmospheric pressure
Pressure also affects t h e terminal velocity of fuel particles and thus t h e probable amount of carry-over losses. Figure 3 and Table I11 present calculated data for a wide range of pressures and particle sizes (4, 8). Within the range of Stokes’ law pressure influence is nil, but it increases as the validity of Newton’s law is approached. The range of practical concern, particle diameter of 0.1 to 1 mm., shows a definite decrease in terminal velocity, and, as a practical result, fuel rates can be increased roughly with the square root of the absolute pressure without increasing carry-over losses ( 1 ) . Terminal velocity being also the determining factor in mass exchange of particles gasified in suspension, it can be concluded that high-pressure gasification of pulverized fuel will increase reaction rates by a factor between P and d F , depending upon fineness of pulverization.
Literature Cited (1) Buckland, B. O., Hillman, A. Y., Jr., and Nelson, H. W., “Producer Gas for Gas Turbines,” ASME Paper 50-SA-33 (August 1950); Gen. Elec. Rev., 54, No. 12, 12-26 (1951). (2) Cross, P. C., J . Chem. Phys., 3, 168-9, 825-7 (1935). (3) Ferguson, J. B., J . Am. Chem. SOC., 40, 1626-44 (1918). (4) Gumz, Wilhelm, Arch. gesamt. Warmetechn, 1 , No. 2, 25-6 (1950). (5) Gumz, Wilhelm, Brennsto$-Wtlrme-Kra~t, 4, No. 1, 13-16 (1952). (6) Gumz, Wilhelm, “Gas Producers and Blast Furnaces. Theory and Methods of Calculation,” New York, John Wiley & Sons, 1950. (7) Ibid., p. 63. (8) Gumz, Wilhelm, “Theorie und Berechnung der Kohlenstaubfeuerungen,” Berlin, Springer-Verlag, 1939. (9) Gumz, Wilhelm, “Vergasung fester Brennstoffe. Stoffbilanz und Gleichgewicht. Eine Darstellung praktischer Berechnungsverfahren,” Berlin-Gottingen-Heidelberg, Springer-Verlag (in press).
May 1952
(1) Allan, G. W. C., J . SOC.Glass Technol., Trans., 34, 40-54 (1950). Recent Development in Gas Producers. (2) Allan, G. W. C., Sparham, G. A., and Brsosowski, T. J., “Final Report on Gas Producer Trial Carried Out a t Increased Pressure,” British Coal Utilization Research Association, Document A/CON/520 (February 1949). (3) Brnckner, Horst, Brennstof-Chem., 20, No. 19, 346-8 (1939). Bildung von Methan aus Kohlenoxyd Wasserstoffgemischen an Schwelkoks bei erhohtem Druck (nach Versuchen von C. C. Wong). (4) Briickner, Hors;, “Handbuch der Gasindustrie,” Vol. 2, “Generatoren, pp. 2/77-2/85, Berlin and Miinchen. R. Oldenbourg, 1940. ( 5 ) Buckland, B. O., Hillman, A. Y., Jr., and Nelson, H. W., “Producer Gas for Gas Turbines,” ASME Paper 50-SA-33 (1950): Gen. Elec. Rev., 54, No. 12, 12-26 (1951). (6) Coke Smokeless-Fuel Age, 8, No. 82, 49-50, 54 (1946). The Lurgi Process. (7) Cooperman, J., Davis, J. D., Seymour, W., and Ruckes, W. L., U. S. Bur, Mines, Bull. 498 (1951). Complete Gasification of Coals with Steam and Oxygen under Pressure by the Lurgi Process. (8) Danulat, F.. Brennstof-Wlirme-Kraft, 4, No. 1, 2-6 (1952). Die Druckvergasung fester Brennstoffe. (9) Danulat, Friedrich, “Die restlose Vergasung fester Brennstoffe mit Sauerstofl unter hohem Druck,” thesis, Berlin-charlottenburg, 1936. (10) Danulat. F., Gas- u. Wasserfach, 84, No. 40, 549-52 (1941). Sauerstoff-Druckvergasung fester Brennstoffe. (11) Zbid., 85, No. 49/50, 557-62 (1942). Wechselvirkungen zwischen Gap rind Brennstoff bei der Druckvergasung. (12) Danulat, F., Mitt. Metallges., 1938,No. 13, 14. Druckvergasung fester Brennstoffe mit Sauerstoff. (13) Dent, F. J., “Catalytic Synthesis of Methan:,as a Method of Enrichment in Town Gas Manufacture, Gas Research Board, Comm. GRB 51 (1949). (14) Deschamps, Jules, “Les Gasoghnes,”pp. 258-72, Paris, C. Dunod, 1902. (15) Domann, Friedrich, Gas- u. Wasserfach, 91, No. 13, 161-4 (1950). Das Walzgasverfahren bei atmospharischem und hoherem Druck. (16) Dorschner, O., Erddl u. Kohle, 2, 59 (1941). Methanferngas durch Druckvergasung und Synthese. (17) Drawe, Rudolf, Arch. Warmewirt., 19, No. 8, 201-3 (1938). Erfolge der Druckvergasung mit Sauerstoff. (18) Drawe, Rudolf, Bi-aunkohle, Wltrme, Energie, 3, No. 5/6, 87-91 (1951). Die Bedeutung der Braunkohle fur die neuzeitliche Brennstoff veredlung. (19) Drawe, Rudolf, Gas- u. Wasserfach, 76, No. 28, 541-5 (1933). Starkgas durch Brennstoffvergasung mit Sauerstoff. (20) Ibid., 80, 806-10 (1937). Wege zur gesteigerten Brennstoffveredlung.
INDUSTRIAL AND ENGINEERING CHEMISTRY
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(21) Drawe, Rudolf, and Schone, Otto, Bergbau u. Energiewirf., 2, No. 9, 264-70 (1949). Wirtschaftliche Verwertung der Braunkkohle durch Veredlung. ( 2 2 ) Drawe, Rudolf, and Traustel, Sergei, Gas- u . Wasserfach, 85, NO. 17/18, 184-91 (1942). Grundbedingungen der Vergasung. Ein Beitrag zur theoretischen Vergasungstechnik. ( 2 3 ) Gas Research Board, “Investigation of Use of Oxygen and High Pressure in Gasification. IV. Synthesis of Gaseous Hydrocarbons a t High Pressure,” 50th Rept. Joint Research Committee of Gas Reeearch Board and University of Leeds, Publ. GRB 26 (1946). 124) Greiner, Bodo, Gas- u . WasseTjach, 90, No. 1, 1-8 (1949). Erfahrungen beim Bau und Betrieb von Sauerstoff-Druckvergasungsanlagen. ( 2 5 ) Gross, H. W., Erdol u. Kohle, 3, No. 5, 218-22 (1950). Herstellung von entgiftetem Ferngas durch Druokvergasung und Synthese mit Eisenkontakten. (26) Gums, Wilhelm, “Gas Producers and Blast Furnaces,” pp. 16070, New York, John Wiley &- Sons, 1950. 127) Gums, Wilhelm, Gas- u. Wasserfach, 88, No. 5, 129-36 (1947). Stand und Entnicklungsaussichten der Vergasungstechnik. ( 2 8 ) Ibid., 91, No. 9, 97-104 (1950). Der Abstichgaserzeuger. 129) Gums, W., and Lessnig, R., 2. Ver. deut. Ing., Verfahrenstechnik, No. 2, 35-42 (1940). Verfahren zur Herstellung von Synthesegas. (30) Hoeven, B. J. C. van der, “Producers and Producer Gas,” in “Chemistry of Coal Utilization,” H. H. Lowry, ed., Vol. 11, pp. 1586-672. New York, John Wiley & Sons, 1945. (31) Hollings, H., Hopton, G. U.,and Spivey, E., “Lurgi High-Pressure Gasification,” B I O S Final Rept. 521 (1946). ( 3 2 ) Hubmann. C., M i t t . M e l a l l g e s . , 1933, No. 8, 9-15. Erseugung von wasserstoffreichem Gas fur Stadteversorgung und Synthese. (33) Institute of Gas Technology, Chicago, “Gas-Making Processes,” 1945. (34) Johnson, C. il., Buschow, H. F., and Carlsmith. 1 . E., “Gasification of Coal,” F I A T R e p t . 938 (Oct. 2, 1946). (35) King, J. C., “Complete Gasification of Coal and Methane Synthesis,” Inst. Gas Eng., London, Publ. 197/80 (1938). (36) King, J. G., J . I n s t . Fuel, 24, N o . 138, 147-64 (1951). (37) Lopmann, E., Gas- u . Wasserjach, 91, No. 3, 44 (1950). Zur R a g e der Gasentgiftungsverfahren. (38) Millett, H. C., J. I n s t . F d , 10, N o . 49, 15-21 (1936). Luigi
Process for Complete Gasification of Coal with Oxygen under Pressure. (39) Ylinistry of Fuel and Power, “Report on Petroleum and Synthetic Oil Industry of Germany,” London, H. M . Stationery Office, BIOS Over-All Bept. 1 (1947). (40) Sewman, L. L., IND.ENG.Cxmr., 40, 559-82 (1948). Oxygen in the Production of Synthesis Gas. (41) Newman, L. L., “Recent European Developments in the Use of Oxygen in Gas Manufacture,” Am. Gas Sssoc. Production and Chemical Conference, Paper PC-51-1, New York, May 1951. (42) Sewman, L. L., T r a n s . Am. Inst. M i n i n g Met., 168, 3 2 9 4 5 (1946). Oxygen Gasification Processes in Germany. (43) Odell, W. W., U. S.Bur. Mines, Inform. Circ., 7415 (November 1947). Gasification of Solid Fuels in Germany by the Lurgi, Winkler, and Leuna Slagging-Type Gas-Producer Processes. (44) Offenberg, W., Stahl u. Eisen, 63, KO,51, 936-9 (1943). Sauerstoff-Druokvergasung fester Brennstoffe. (45) Riedi, R., Paliva a Voda, 26, No. 8 (1946). Manufacture of Illuminating Gas in Pressure Generator. (46) Seiden, Rudolph, IND.ENG.CHEM.,NEWSED.,16, KO.19, 535 (1938). Gasification of Solid Fuels by Oxygen under Pressure. (47) Thau, ri., Oel u n d Kohle, 38, No. 21-26, 589-601, 617-24, 68590, 721-7, 749-65 (1942). Grosswassergaserzeugng fur chemische Sgnthesen. (48) Thomas, H., Bergbau u. Energiewirt., 4, No. 5, 218-26, 237-8 (1951). Starkgas-Erzeugung und Stadtgas-Versorgung auf einheimischer Braunkohlenbasis. (49) Thring, M. W., Bull. Brit. Coal Utilisation Rwearch Bssoc., 8 , No. 3 (1944). Gasification Methods. (50) Weil, B. H., and Lane, J. C., “Synthetic Petroleum from the Synthine Process,” Brooklyn, Pi. Y . , Remsen Press Division, Chemical Publishing Co., 1948. (51) Weir, Horace, ISD.ENG.Cxmi., 39, 48-54 (1947). High-Pressure Gasification in Germany. (52) Kilke, G., Chem. Fabrik, 11, No. 51/52, 563--8 (1938). Die Erseugung und Iteinigung von Synthesegas fur die Benzinsynthese. RECEIVED for review July 31, 1961. ACCEPTED March 5 , 1952. T h e full text of t h e paper (revised) has been deposited with the American Documentation Institute, Washington, D. C.
Gasification of Pulverized Coal with Oxygen and Steam in a Vortex Reactor M. A. Elliott, BUREAU OF MINES, BRUCETON, PA. Harry Perry, BUREAU OF MINES, WASHINGTON, D. c. James Jonakin, R. C. Corey, and M. L. Khullar, BUREAU OF MINES, T h e gasification of pulverized bituminous C coal with oxygen a n d steam in a vortex reactor has been studied to assess the potentialities of this type of reactor for producing synthesis gas for synthetic liquid fuels and to obtain basic information on the critical variables affecting gasification under these conditions. T h e effect of the ratio of oxygen to coal a n d depth of reactor on carbon conversion a n d production of carbon monoxide plus hydrogen per pound of coal is discussed in detail. T h e best gasification results were obtained when part of the oxygen was admitted with the coal a n d when 10.6 pounds of coal were supplied per cubic foot of reactor volume per hour. Extrapolation of these results to adiabatic conditions indicates that when oxygen costs 20 cents per thousand cubic feet a n d coal costs $3 to $4 per ton the cost of synthesis gas would be a minimum at 7.3 cubic feet of oxygen p e r pound of coal a n d with 34 pounds of coal a n d 247 cubic feet of oxygen per thousand cubic feet of carbon monoxide plus hydrogen.
1074
PITTSBURGH, PA.
T h e unit was operated u n d e r slagging conditions, a n d no difficulties were encountered in controlling process conditions or slag removaL T h e results indicate that vortex reactors can be used effectively in producing synthesis gas. Important relations have been developed between the factors affecting the rate of gasification reactions of pulverized coal a n d methods have been devised for correcting gasification results obtained under nonadiabatic conditions to results that would be expected in reactors operating adiabatically.
T
HE production of mixtures of carbon monoxide and hydrogen from pulverized coal by gasification with oxygen and steam is one method for obtaining synthesis gas for the Fischer-Tropsch process and hydrogen for the hydrogenation of coal (3-6,7 , 9). This gasification system has been studied in vortex reactors to obtain information on t h e performance of such reactors under gasification conditions and on some of the factors affecting the
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 5
