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INDUSTRIAL AND ENGINEERING CHEMISTRY
TABLE 111. REMOVAL O F TRITERPEKES B Y VEGETABLE CaRBON (Darco S-51 used with clear first carbonation juice) Triterpenes, Carbon, Lb./ T o n of Beets P.P.M. on RDS
TESTA 0
192 189 134 120 32 14
0 3 0.6 1 2 2.4 4.8 TEST
157 84 24 24
0.9 1.8 3.0
D. R. Haskell, and G. E. Blevins for the triterpene analyses, and E. T. Winslow for hie cooperation and encouragement. It is a pleasure toacknowledge the cooperation of the Western Regional Research Laboratory, U. S. Department of Agriculture, Albany, Calif., for x-ray and spectrographic examination of certain saniples of floc material isolated in the beginning phases of this n-orli. LITERATURE CITED
A
0
Vol. 44, No. 12
Duolite 5-30 and Perinutit DR have been studied, and the latter, in particular, has a n almost specific action for triterpenes. There are unsolved problems involved in their use, however. Ion Exchange. T h e use of cation and anion exchanger resins in pairs, whether on clarified diffusion juice or in addition t o t h e normal defecation process, yields juices low in triterpenes, as in other nonsugars. When a color-adsorbing resin is used between the cation and anion exchange resins, removal of triterpenes is essentially complete. Possibly this advantage may be of importance in niaking the use of ion exchangers more economically practicable in beet-sugar manufacture. ACKVOWLEDGMENT
The separation and identification of floc constituents described in the section on characterization was accomplished by L. W. Clark. The authors are indebted to W.0. Bernhardt for development of the hemolysis test, H. E. Halden and 55;. T. Kakagavia for their perfection of the gravimetric test and general contributions, J. L. Reese for assistance in resin studies, G. E. Sontuni, Max Storz,
(1) ilndrlik, K., and Votocek, E., S e u e Zeit. Zucker~iihe?i-Ind.,40, 39 (1898). (2) Czirfusz, M., 2. Zuckeii-nd. Bohmen-Muhren, 6 7 , 101-4 (1944). (3) D&dek,J., in McGinnis, ed., “Beet-Sugar Technology,” p. 1S5, N e w York, Reinhold Publishing,Corp., 1951. (4) Dodge, F. D., J . Am. Chem. Soc., 40, 1917 (1918). ( 5 ) Ehrlich. F., and Rehorst, K., Be?., 58, 1889 (1926). (6) Goyan, F. M., Enright, J. &I., and Wells, J. bI.,J . A m . Elzu~m. Assoc., Sci. Ed., 33, KO.3 (1944). ( 7 ) Haar, A. JV. van der, Rec. tran. chinz., 46, 775-98 (1927). (8) Hanus, O., 2. Zuckerind. B d h m e n - M u h i e n , 67, 101-4 (1944). (9) Herzog, Be?. pkarm. Ges., 15, 121 (1905). (10) Keppeler, G., and Radbruch, G., Centr. Zuckerind., 48, 799-801, 813-15, 829-31, 841-3, 869-72 (1940). (11) Kollrepp, A , , 2. V e r . deut. Zucker-Ind., 38, 772 (1888); Citein. Zenlr., 1888, 1316. (12) Lippmann, E. O., Z. V e l . Rub. Deulsch. E . , 38, 68-76 (1888). (13) McIlroy, R. J., “The Plant Glycosides,” p. 64, London, Edward Arnold & Co., 1951. (14) Xeuberg and Saneyoshi, Biochem. Z., 36, 55 (1911). (15) N. V. Octrooien Maatschappij “Activit,” French Patent, 778,922 (1936). (16) Ratish, H.D., and Bulona, J. G. I f . , A r c h . Biochem., 2 , 381 (1 943). (17) Rochleder, F., Chem. Zelilr., 1862, 177. (18) Sandberg, F., Svensk. F a r m . Tid., 52, 173 (1948). (19) Scheibler, C., 2. Zuckerind. Bohnien.. 24, 361 (1874). (20) Schiaparelli, Chem. ZelZtT., 36 (1884). (21) Smolenski, K., 2. physiol. Chem., 71, 261 (1911). (22) Sugar Information, Tnc., -Vews Letter (June 1951, January and February 1952). (23) Tollens, B., Ber., 41, 1788 (1908). (24) Veldkamp, C., Deut. Zuckerind., 62, 499-502 (1937). RECEIVED for review April 2 8 , 1952.
ACCEPTED J u l y 2 2 , 1052.
Effect of High-Energy Cathode Rays on Cellulose J
JEROME F. SAEMAN AND MERRILL A. AIILLETT U . S. Forest Products Luborutory, Mudison, Wis.,
ELLIOTT J. LAWTON General Electric Co., Research Laboratory, Schenectady, N. Y .
C
HEMICAL changes in organic materials caused by ionizing radiations have been studied by various authors (5, 4,6, 9, 10,15). In the case of polymers such as cellulose (‘7) where ion mobilities do not play an important part in the chemical reaction, the changes observed are usually the depolymerization of the polymer chain and the destruction of the fundamental polymer unit. The irradiation dose required to produce appreciable change in this type of reaction is large and varies approximately inversely as the molecular weight (8). High-energy cathode rays provide a means of attaining, in a reasonable time, the large irradiation doses required for such reactions. Further study of the effect of cathode rays on cellulose was undertaken because it offers a means of extending knowledge of cellulose chemistry and of radiochemical reactions, I n this paper, data are presented on the destruction of carbohy-
drate by the irradiation of wood, wood pulp, cotton linters, and glucose. The molecular weight of wood pulp and cotton linters was determined after irradiation at various levels. Changes in the crystalline organization of cellulose resulting from irradiation were studied by means of the technique of dilute acid hydrolysis. The effect of irradiation on the amount of sugar produced by subsequent batchwise hydrolysis of cellulose was determined. EXPERIMENTAL iMETHOD
CATHODE RAYSOURCE.The cathode ray source used for this work was a modified 1-m.e.v. x-ray unit of the pressure-insulated, resonant-transformer type (1, 7 ) that was operated a t 800 kv. (peak). With this equipment, a given ionization dose could be accumulated a t a rate of 143,000 roentgens per second, a t a dis-
December 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
tance of 10 em. from the tube window. (The ionization dose was measured with a specially constructed, air ionization chamber.) A photograph of the cathode ray machine is shown in Figure 1. MATERIALS.The pulp subjected t o irradiation was a commercial softwood sulfite pulp sheet of acetylation grade with an a-cellulose content of 96.001,. The cotton linters sample was a commercial sheet with an a-cellulose content of 97.7%. The spruce wood was prepared by cutting 50-mm. disks from green sapiyood, 2.5 mm. thick, in the fiber direction. The wood was extracted with alcohol-benzene, alcohol, and cold water. The glucose was a sample of chemically pure, powdered, anhydrous glucose. The cotton linters and wood PROCEDURE FOR IRRADIATION. pulp materials were cut into disks 50 mm. in diameter and sealed into 63.5-mm.-diameter containers of thin (0.003-inch) polyethylene. Three disks comprised each sample and represented a n equivalent absorber weight of 0.1 gram per square centimeter, a n equivalent thickness t h a t is about one third t h a t of the maximum range of the 800-kv. (peak) electron beam. A nearly uniform irradiation dose could be realized b y irradiating the sample from one side, The thickness of the wood sample was such that i t had t o be irradiated from both sides t o produce a nearly uniform dose throughout. I n the case of the glucose, each sample contained 2 grams of powder, which, when spread out in the container, presented t h e correct absorbing layer for the electron beam. The irradiation was carried out in the presence of air. Some tests made t o determine the approximate temperature during the irradiation showed a rise of about 41' C. at lo7equivalent roentgens. These measurements were made with a thin thermocouple (0.005-inch-diameter wire) embedded in the center of the cotton linters sample. I n those cases where the dose exceeded lo7 equivalent roentgens, the total dose was accumulated in increments of lo7 with a cooling period between increments, so t h a t the maximum temperature rise in any sample never exceeded 41' C. Further, in these cases, the samples were alternately irradiated first from one side and then the other, so as to produce greater uniformity of dose throughout the thickness. Samples receiving a dose of 108 equivalent roentgens or greater were very fragile and slightly discolored. At this dosage, gas was also produced m evidenced by a puffing of the polyethylene bag. No attempt was made t o analyze this gas. ESTIMATION OF MOLECULAR WEIGHT. Average values for the degree of polymerization of the irradiated celluloses were determined by the viscosity method a t 20' C., using cupriethylenediamine as the solvent (15). Flow times were determined in a n Ostwald-Fenske size 50 pipet a t a series of dilutions, and intrinsic viscosities, [ q ] ,were obtained by extrapolation of the curves for reduced viscosity, V ~ J C , as a function of concentration, c, t o zero concentration (6). Values for degree of polymerization, DP, were calculated from the equation D P = K [ q ] ,using Conrad's value of 190 for K ( 2 ) . ANALYTICAL METHODS. Reducing sugar was determined by the Shaffer and Somogyi method (14). The total carbohydrate
Figure 1.
2849
Compact Resonant-Transformer Type of Experimental Cathode-Ray Unit
Showing the pressurized tank and the lead shielding well into which the cathode-ray beam is directed
content of the various cellulosic materials was measured by determining the sugar produced by quantitative saccharification (18).
HYDROLYSIS PROCEDURE. The dilute acid hydrolysis of irradiated cellulosic materials was carried out, using 0.25- to 0.30gram samples sealed in glass tubes with 5 ml. of 0.1 N sulfuric acid. The samples were heated in an autoclave with direct steam at 180" C., as described previously (11). The soluble sugars produced were separated from the insoluble cellulosic residue by filtration through a Gooch crucible. Approximately 0.1 gram of asbestos filter aid was used with all samples. An aliquot of the filtrate was analyze'd for sugar, and the potential sugar remaining in the insoluble cellulosic residue was determined by subjecting the entire asbestos filter pad to quantitative saccharification. RESULTS
DEPOLYMERIZATION OF CELLULOSC.The effect of irradiation on the degree of polymerization of cellulose is shown in Figure 2. A dosage of lo6 equivalent roentgens has a small effect. Large TABLE I. DECOMPOSITION OF CARBOHYDRATE BY IRRADIATION changes occur a t irradiation levels in excess of lo6 equivalent Irradiation Dosage. roentgens. At a dosage of 5 X lo* equivalent roentgens, celluEquiv. Decomposition of Material Roentgens Carbohydratea, % ' lose is converted t o water-soluble materials. I n Figure 2, it is Cotton linters 107 2 seen t h a t cotton linters and wood pulp were depolymerized at 5 x 107 12 nearly the same rate. This is in contrast t o their behavior in 10s 14 5 x 108 44 heterogeneous hydrolysis, where the resistant portion of unirWood pulp 107 5 radiated wood pulp hydrolyzes a t applbximately twice the rate 5 x 107 10 108 17 shown by the resistant portion of unirradiated cotton linters Wood IO? 3 (Figure 3). This behavior suggests t h a t depolymerization is not 108 9 affected b y crystalline organization. 2 Glucose 107 DECOMPOSITION OF CARBOHYDRATE BY IRRADIATION. Samples 108 14 Based on initial carbohydrate content. of glucose were analyzed for reducing sugar before and after irradiation. Similarly, the potential sugar content of the cellulosic Q
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INDUSTRIAL AND ENGINEERING CHEMISTRY
materials was determined before and after irradiation. The loss in apparent carbohydrate content is given in Table I. The values shown were determined by subtraction and include the errors of two potential sugar determinations. Within the limits of error of the experiment, pure glucose and the carbohydrate in cellulose are decomposed at the same rate. The carbohydrate in the mood sample showed less decomposition than t h a t of the ligninfree wood pulp or of the cotton linters.
Vol. 44, No. 12
TABLE11, EFFECTOF IRRADIATION ON THE HYDROLYSIS OF CELLCLOSIC MATERIALS
Xiaterial Cotton linters Wood Pulp
Irradiation Dosage, Equiv. Roentgens 0 107 5 x 107 108 0 107 5 X 107 108
Wood
0
107 108
Half-life of Resistant Cellulose, Min. 120 66 30 7.2 60 33 9 4
69 43 7.5
Max. Sugar Yield Approx. Over-all by Time t o Dilute Avid Max. Sugar Hydrolyslsa, Sugar Yield, Yieldb, % Min. % 23.0 98 23.0 31.0 80 30.4 53.3 42 46.9 72.2 23 62.1 33,s 90 33.5 46.8 70 44.5 68.5 26 61.6 84.5 12 70.2 31.5 37.6 67.0
25 43
15
25.0 36.5 61.0
a Based on initial potential sugar content a f t e r irradiation. b Based on initial cellulose content and taking into account the destruction of carbohydrate by irradiation.
Figure 2. Degree of Polymerization of Cotton Linters and High Alpha Softwood Sulfite Pulp as a Function of Dosage with High-Energy Electrons
EFFECTOF IRRADIATION ON THE HYDROLYSIS OF CELLULOSE. Figure 3 shows that irradiation causes a large change in the course of the dilute acid hydrolysis of cellulosic materials. Extrapolation of the straight lines to zero time of reaction provides a measure of the resistant or “crystalline” fraction and, by difference, the easily hydrolyzed or “amorphous” fraction (16). The rapid hydrolysis of the heavily irradiated samples cause timing errors which make the extrapolation somewhat uncertain. No account is taken of recrystallization resulting from hydrolysis (16). It is apparent, however, that irradiation causes a n increase in the amount of the easily hydrolyzed material. Irradiation also causes a n increase in the rate of hydrolysis of the resistant portion of cellulose. The half-life values, calculated from the slope of the lines in Figure 3, are given in Table 11. The rate of hydrolysis of unirradiated wood pulp is roughly twice the rate of hydrolysis of cotton linters. At all irradiation levels studied, the rate of hydrolysis of wood pulp was higher than the rate of hydrolysis of cotton linters treated similarly. The yield of sugar produced by the hydrolysis of irradiated cellulosic materials is given in Figure 4. I n the idealized case of cellulose free from easily hydrolyzed material, the maximum yield of sugar is a function of the ratio of the rate of hydrolysis t o the rate of sugar decomposition (11). The shape of the yield curve is like the yield curve of consecutive first-order reactions. The data are plotted in Figure 4 in such a way as t o show this similarity. The divergence in the case of wood is caused by the large proportion of carbohydra‘te that is easily hydrolyzed. The maximum sugar yield obtained by the hydrolysis of the various cellulosic materials is given in Table 11, together with the time a t which the maximum yield is reached. A t all irradiation levels tested, the wood pulp samples showed a higher rate of hydrolysis and a higher sugar yield than the cotton linters sample.
The over-all sugar yield, which takes into account the destruction of carbohydrate by the irradiation, is given in column 5 of Table I1 and is shown plotted in Figure 5 for the cotton linters and wood pulp. Also plotted in Figure 5 is the degree of polymerization and the per cent of carbohydrate t h a t was not decomposed by the irradiation. At an irradiation dose of 5 X 108 equivalent roentgens, the residual carbohydrate of the cellulose had decreased to such a n extent that the yield of sugar must have passed through a maximum a t a n irradiation dose between 108 and 5 X lo8 equivalent roentgens. The curves in Figure 5 indicate clearly t h a t in order t o improve significantly the over-all yield of sugar, the cellulose must be depolymerized t o an average chain length of about 200 glucose units. The yield continues to
Figure 3. Hydrolysis of Irradiated Cellulosic Materials with 0.1 N Sulfuric Acid at 180’ C.
December 1952 -80, lu
3
I
, ,
701
INDUSTRIAL AND ENGINEERING CHEMISTRY I
I
l
l
the number of ion pairs formed, is 0.57 for the depolymerization process and 2.9 for the decomposition of carbohydrate. The values were determined for the cotton linters sample using a value of 1.8 X 1018 ion pairs per cubic centimeter per 106 equivalent roentgens.
I
I
I
60
SUMMARY AND
k
IO-
3
80-
4
70-
3 T
i2 ? 60-
$
50-
40-
$ 30-
s
8 h
5
20-
7060-
%
50-
9
40-
5
$
/
EXTRACTED SPRUCE . WOOD
3020-
CONTROL
I 2
2851
/
RESIDUAL POTENTIAL SUGAR (PERCENT OF INITIAL POTENTIAL SUGAR IN IRRADIATED SAMPLE)
Figure 4. Yield of Sugar from Irradiated Cellulosic Material as Function of Extent of Hydrolysis improve with continued depolymerization until an optimum is reached a t about 20 glucose units. Depolymerization of the cellulose chain and decomposition of the fundamental glucose units occur simultaneously, but a t different rates. No significant change in either process takes place, however, until the density of ionization, or the number of ion pairs formed per unit volume of material, becomes an appreciable fraction of the number of cellulose chains or glucose units. The experimental data indicate that an irradiation dose of lo8 equivalent roentgens produces in 1 gram of cotton linters
CONCLUSIONS
Irradiation of cellulose with high-voltage cathode rays causes depolymerization, reduction in crystallinity, and extensive decomposition a t high-dose levels. Cotton linters and a purified wood pulp were depolymerized a t nearly the same rate. At heavy exposures, equal dosage of the two materials resulted in products with nearly the same average chain length. At a dose of 5 X 108 equivalent roentgens, the cotton linters were converted to water-soluble materials. Conversion of the glucose anhydride units to noncarbohydrate material occurs simultaneously with the depolymerization of cellulose. The decomposition of glucose, wood pulp, and cotton linters occurs a t similar rates, amounting to a fraction of a per cent a t 108 equivalent roentgens and, in the case of the cotton linters, to 44% a t 5 X 108 equivalent roentgens. Irradiation appears to cause a random depolymerization and decomposition of cellulose, both in the easily hydrolyzed or amorphous areas and the resistant or crystalline areas. Studies of the kinetics of the dilute acid hydrolysis of irradiated cellulose show an increase in the amount of the easily hydrolyzed portion. The rate of hydrolysis of the resistant cellulose is greatly increased by irradiation, presumably because of the disruption of the cellulose crystallites. With this increased rate of hydrolysis there is an increased ratio between rate of sugar production and destruction and, hence, an increase in sugar yield. An important increase in hydrolysis rate or sugar yield requires that the average chain length be reduced to less than 200 glucose units. The maximum over-all yield of sugar obtainable by the batchwise dilute acid hydrolysis of irradiated cotton linters is about 65%, nearly three times the yield obtainable from the control. The corresponding yield from purified wood pulp is over 70%. LITERATURE CITED
(1) Charlton, E. E.,and Westendorp, W. E., Gen. Elec. Rev., 44, 652-61 . _._ _(1941). --,( 2 ) Conrad, C. M., Tripp, V. W,, and Mares, T., J. Phys. & Colloid Chem., 55,1474 (1951). ( 3 ) Coolidge, W. D., Science, 62,441 (1925). \--
single depolymerization actions. I n this calculation, 915 represents the original number of glucose units in the polymer, and 35, the apparent number a t lo8equivalent roentgens. This determination of the number of depolymerization actions is subject to the errors resulting from the use of weight-average measurement to describe a numerical process. The number of glucose units converted to noncarbohydrate material by the same irradiation dose is 0.14 X 6'031&10'a
=
5.2
x
1020
where 0.14 is the fraction of glucose destroyed by an irradiation dose of 108 equivalent roentgens. The apparent ratio of the number of glucose units destroyed to the number of depolymerizations is 5.1 to 1. The ionizaefficiency, Or the yield, expressed s' the ratio of the number of reactions to
0
0
I
2
LOG
3 4 5 6 7 O f IRRADIATION DOSE /ROENTG€NS)
8
Figure 5. Over-all Sugar Yield Obtained by Hydrolysis, Degree of Polymerization, and Content of Undecomposed Carbohydrate as a Function of Irradiation Dose
INDUSTRIAL A N D E N G INEERING CHEMISTRY Coolidge, 11- D , arid Mooie, C. N., Ge71. Elec. Rev.,35, 413-17 (1932). Cragg, L: H., J Collozd Sci., 1 , 261 (1946). Dainton, F. S , Ann. Repts. on Progress Chem. (Chenz. Soc. London), 45, 5-33 (1948). Lawton, E. J., Bellamy, W. D., Hungate, R. E , Biyant, 11. P., and Hall, E., Sczence, 113, 380-2 (1951). Lea, D. E., “Actions of Radiation on Living Cells,” S e w Y o l k , Macmillan Co., 1947. Lind, S C., et al., J . Phys. & ColZozd Chem., 52, 437-579 (1948). Pollard, Ernest, Am. Sczentzst, 39, No. 1, 99-109 (1951). Saeman, J F , IND.EYG.C H E M37,43 , (1945).
Vol. 44, No. 12
(12) Saeman, J. F., Bubl, J. L., and Harris, E . E., I X D . E m . CHEIM., ANAL.ED.,17,35 (1945). (13) Schmit,z,J. V., and Lawton, E. J., Science, 113, 718-19 (1951). (14) Shaffer, P. A . , and Somogyi, AI., J . Biol. Chem., 100, 695 (1933). (15) Tech. Assoc. Pulp Paper Incl., Paper Trade J . , 124, No. I , 37 (1947). (16) Ward, Kyle, Jr., Textile Research J . , 20, 363 (1950). RECEIVEDfor review M a y 19, 1952. ACCEPTEDAugust 15, 1962. Presented before t h e Division of Cellulose Chemistry at the 121st Meeting of t h e AMERICANCHEMICALSOCIETY,AIilwaukee, Wis., 1952. T h e Forest Products Laboratory is maintained a t Nadison, m’is., in cooperation with the University of Wisconsin.
Composition of Gasoline from
Coal Hydrogenation d
U
JULIAK FELDII-QY ANI) MILTON ORCHIN Synthetic Fuels Research Branch, Bureau of Mines, Bruceton, Pu.
T
HE recent critical shortage of benzene ( 2 ) has focused attention on the necessity of providing additional supplies of this and related aromatic hydrocarbons. In the past, the chief source of benzene has been the light oil derived from coal carbonization. Although the United States possesses enormous reserves of coal, the quantity carbonized is determined principally by the steel industry, the major consumer of coke. Even a considerably greater expansion of the steel industry (and it’s coke requirements) than now contemplated would not provide the quantities of benzene necessary to satisfy the expanding chemical industry. To meet the shortage of benzene on an immediate basis, the petroleum industry has provided new methods for processing gasoline, such as hydroforming and platforming. These result in a substantial conversion of nonaromatic components t o benzene and other light aromatics ( 3 ) . From the long-term point of view, however, it, is possible that coal hydrogenation can continuously satisfy the constantly increasing demands for benzene and other aromatic compounds.
cold-catchpot oil. These conibiiied fractions are hereafter referred to as “vapor-phase feed” because they constitute t,he fresh feed to the second or vapor-phase stage. When a coal hydrogeiiation plant is operated as a chemicals plant, the napht’ha stream is extracted with acid and alkali to recover commercially viiluable phenols and tar bases, and the dephenolized naphtha is employed as part of the vapor-phase feed. However, i n the operation which produced the present, samples, no tar acids or tar bases were removed from the vapor-phase feed. The vapor-phase feed investigated in the present study n-as collected when the plant n-asprocessing a bituminous C coal from Rock Springe, Wyo. (analysis in Table I ) under conditions outlined in Table 11. The estimat,ed yield of vapor-phase feed in this operation was approximately 1.3 barrels (-1000 pounii~)per ton of moisture- and ash-free coal ( 7 ) . The vapor-phase feed was distilled into tw-o fractions in the Bruceton pilot plant, one boiling to 145” C. and the other hetTyeen 145” and 200’ C. The second fraction was washed with acid and alkali and the neutral portion conihined with the first fraction.
DESCRIPTIOIV OF SAMPLES
The oils used in this investigation were produced a t the 200barreI-a-day plant of the Bureau of Mines a t Louisiana, 310. This plant utilizes the conventional two-stage German operation -a primary liquid-phase stage followed by vapor-phase processing of a portion of the liquid-phase product. In the first, or liquidphase stage, a slurry of fresh coal suspended in a heavy recjcle oil containing a catalyst-such as ferrous sulfate-is pumped v it11 high-pressure hydrogen through a preheater into two hot vertical converters in seiies, where conversion of coal t o liquid and gasrous products occurs. The product stream enters a “hot catchpot,” which is held a t a specified temperature. The material collected a t this point contains the unconverted coal, other solids, and the heavy ends of the oil. This material, so-called “heavy-oil-letdown,” or HOLD, is let down to atmospheric pressure. The vapors leaving the hot catchpot enter a “cold catchpot,” where the buIk of the product oil and all of the water of reaction plus some injected a a t e i are condensed. The uncondensed gases leaving the cold catchpot ale scrubbed to recover the light-boiling constituents, which are then combined TI ith the cold-catchpot product. The total cold-catchpot oil is let down to atmospheiic pressure and then flactionated into four fractions: gasoline, naphtha, middle oil, and bottoms. The bottoms are combined with the HOLD and, after a suitable solids purge, this material is used as the recycle oil for suEpending fresh coal. The three distillate fractions constitute approximately 0.5 of the total
Proximate Volatile niattei Fixed carbon Ash Total Cltimate Hydrogen Carbon h-itrogen Oxygen Sulfur Ash Total Heating value
T.4BLE
45.1 49.5
5.4
ion o 5.3 79.3 1.5 14.4
1.1 5.4
io0 0 12,970 B.t.u.
11. OPERATIXG COSDITIONS-LIQUID-PHASE HYDROGENATION O F I t O C K SPRINGS COAL
System prcsaui‘e Temperature No. 1 converter Temperature No. 2 converter Hot-catchpot liquid Hot-catch vapor epace Gas to heater Paste rate Coal rate
7700 p s.i.g. 878’ F. 892’ F. 577’ F. 7500 E. 290,000 cu. f t . / h o u r 1215 gal./hour 57 tons/day, d r y
