Hydrogenation of the Banded Constituents of Coal Attrital Matter and Anthraxylon' C. H. FISHER, GEORGE C. SPRUNK, ABNER EISNEK, LOYAL CLARKE, AND H. H. STORCH Central flxperiment Station, U. S. Bureau of Mines, Pittsburgh, Penna.
0
F T H E many varia-
bles ($1) that govern the results obtained b y h y d r o g e n a t i n g coal, probably the most important and least understood is the nature of the coal. Numerous efforts have been made to relate the hydrogenation c h a r a c t e r i s t i c s with either the rank or the petrography of the coal. The results of these studies, which usually emphasized the effect of rank, indicate that hydrogenation yield3 can be predicted best from tho carbon content of the coal; all investigators except one (#) agree that the ease and yield of hydrogenation are roughly inversely proportional to the carbon content (4, 6, 13, 18, #S). Nevertheless, the correlation of hydrogenation charactoristics with other properties is unsatisfactory, and it is still necessary to resort to expensive and timeconsuming testa in a continuous plant to obtain a reF I G U R E 1. POLISHED BLOCK liable picture of the suitaOF PITT~BERCH BED COAL bility of coal for commercial hydrogenation. The proportions and nature of the petrographic constituents have been overlooked in most published studies of coal hydrogenation. Ilaving in mind the possibility that correlation of hydrogenation behavior with other properties might be facilitated by consideration of petrography as well as rank, many samples have been prepared of the mechanically isolable petrographic constituents, and their hydrogenation characteristics have been studied. The results obtained with anthraxylons (vitrains) of different rank and with the I
For the first ~ a p e r~n :his aeries, see literature oltstion 10
differeut componeuts of the attritus (spores, rosins, oil algae, translucent attritus, and opaque matter) are given in this paper. The hydrogenation of fusain, the cheniical and physical properties of which are very different from those of the other coal constituents, was described in a previous paper (10). Although the English pet.rographic nomenclature (30, 34) was found convenient for discussing some of the previous hydrogenation studies, the Bureau of Mines nomenclature (SQ,33, 34) outlined hclorv is used in describing the data obtained here.
Petrographic Constituents : Anthraxylon Anthraxylon is the principal constituent of many well-known coals, such as the I'ittsburgh, Lower Kittanning, Upper K i t t a n n ing, Illinois No. 6 , and o t h e r beds. I n these bright coals it will form from 50 to 75 per cent of the microscopic components, the remainder consisti n g of s p o r e s , r e s i n s , opaque matter, fusains, and other constituents. Typical splint coal beds, such as the High Splint from Kentucky and the Winifrede from W e s t Virginia, will average a p proximately 20 t o 35 per c e n t anthraxylon.
1155
FIGERE 2. CROSSSECTION OF PIWSBURGH BED COALSEOWINQ SMALLEX SIZES OF ANTARAXYLON BANDS ( X 200)
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INDUSTRIAL AND ENGINEERING CHEMISTRY
VOL. 31, NO. 9
TRANSLUCENT ATTRITUS. When magnified 100 diameters or more, translucent attritus can he shown to consist of different constituents, such as (a) translucent degradation matter, (6) spores, pollens, and cuticles, (c) oil algae, (d) resinous matter, and (e) mineral matter. Translucent Degradation Matter makes u p the larger part of the translucent attritus. This term is applied to the small particles of light-colored, cellulosic, or lignocellulosic tissues of wood, phloem, cortex, and leaves. In many instances i t simply represents the debris from the highly fragmented hands of antliraxylon, as in Figure 4, which was taken from a typical woody cannel coal. This type of material grades into and has chemical properties similar to those of pure anthraxylo; ($#, $3). Spores, In thin . . Pollens, and Cuticles. sections of coal, spores are seen readily hecause of thoir clear yellow color and transparency. They are merely the shells or outer A . Re~inous B. Nonreainous walls of spores of the coal-forming plants FIGURE 3. Two COMMON TYPES OF AKTHRAXYLONFOUND IN THE PALEOZOIC such as Calamites. Lenidodendrons. and SieCOALS( X ZOO) illaria. I n cross sectibn they appear, when whole, as collapsed rings, often baring wings Cannel coals, because of their nonbanded mature, usually have or appendages. When seen in horizontal section, they appear as circular to oval, sometimes slightly triangular disks, less than 5 per cent. hut in reality they represent collapsed spheres whose contents In the lump or polished block (Figure 1) the anthraxylon occuis as definite narrow Mack bands or lenticles ranging in have completely or almost completely disappeared. Pollen exines resemble spore exines in general appearance thickness from a fraction of a millimeter to several centiand chemistry, hut they arc always relatively small and very meters. The bands have a dull to glossy appearance, depending on the rank of the coal; usually the higher the rank, thin. the higher the gloss. The smaller sized bands and lenticles The cuticles found in coal represent the former coverings of le+ves and green stems. In thin sections they appear as are not easily detected in the lunip or polished block except bright golden-yellow bands; they are often found in pairs and under the microscope. IIowever, in thin sections under the microscope (Figure 2) all sizes from the largest hands to the commonly have serrated borders. The substances forming tiniest shreds arc apparent. In thin sections of low-rank the cuticles are similar in chemical composition to those coal, such ai3 lignites and subbituminous coals, the hands arc of spore exines and, like them, are extremely resistant to light yellow or golden in color, and in the higher rank bitudecay. Recently the Biireau of Mines received from 8. G . Bergminous coala they change to a ruby red and finally a brownish quist of Michigan State College a sample of high-ash spore red color. The bands represent parts of plants such as stems, limbs, coal (ZSj that offered an unusual opportunity for the separabranches, twigs, and roots that were partially preserved in the tion of spores and study of their hydrogenation properties. peat stage and lat.er, through coalification processes, were The spores mere loosely embedded in the coal mass and were separated easily by crushing, washing, and flotation, The flattened and transforrrrcd into coal. They alumys show some of the original cell structure \Thieh in some instances will separat.ed spores are shown in Figure 5. A previous publica. tion (28) showed that these spores are rich in hydrogen and reveal the kinds of plants that formed the coal. Anthraxylons from the Paleozoic coals may he either resinous or nongive an extraordinarily high yield of tar on distillation. The hydrogenation properties of an exceptionally rich spore and resinous (Figure 3). The two types are often intimately mixed, or one or the other will be found predominantly in pllen oannel coal (Figure 6 ) also were determined. certain zones of the seam. Exowever, the anthraxjdons from Oil Algae. The oil algae or yellow bodies, which are the main constituent of Boghead coals, give high yields of tar the younger lignites and suhhituminous and bituminous coals from the western states, which were formed during the Eocene and oil upon distillation. In this respect they resemble spore and Cretaceous periods, are predominantly resinous. exines. Figure 7 represents the sample oE algae-rich coal The hands usually have a very low ash content, except in that was tested for hydrogenation properties. The sample high-sulfur coals where they may he contaminated with does not quite represent a true Boghead coal because of the small particles of pyrite. In some instances kaolinite or presence of considerable opaque matter. calcite may occur as a filling in the cracks or cleavage planes. OPAQUE ATTRITUJ. The opaque attritus is the cha.racteristic constituent of splint coals or durains (Figure 8). It is not a homogeneous material but has been shown to consist Petrographic Constituents: Attrital Matter of (a) a semiopaque or brown matter that is opaque in m e The attrital or dull portion of any coal represents the microdium thin sections but hecomes light brown in extremely thin debris that is formed by the disintegration of any of the plant sections, and (bj a granular opaque matter that may occur tissues. It may he either translucent, semiopaque, or opaque. as tiny individual particles or groups of particles. It is The translucent attritus is found in all coal, hut more parhelieved that the opaque material is the result of a high degree ticularly in bright coals, whereas t,he opaque to semiopaque of decomposit,ion or rott,ing in the peat stage, and in some attritus characterizes the splint coals. splint coals the decomposition was grcater than in others. It
SEPTEMBER, 1939
INDUSTRIAL AND ENGINEERING CHEMISTRY
is likely that this differencein degree of decomposition is responsible for differences in its hydrogenating characteristics.
Previous Hydrogenation Studies Since the few studies previously made have yielded conflicting data, detailed and definite conclusions regarding the hydrogenation characteristics of constituents cannot he drawn. In some instances failure to treat clarain, durain (attritus), and fusain as mixtures of two or more components, which they properly are, made interpretation of the results difficult or meaningless. However, i t is generally recognized that fusain (10, 1.9, $0, 25, 35, $8) is most difficult to hydrogenate and that bright coals, which contain much anthraxyIon, are more suitable than dull coals. With one exception, the six vitrains and clarains (which contain much anthraxylon) hydrogeuated by English investigators (15, 16, $7) gave fair liquefaction yields, whereas two durains gave poor yields. This is in agreement with the claim of Gordon (14, 17) and the findings of other workers (7) who hydrogenated bright and dull coals. Bakes ( 1 ) found that bright coals react more readily with hydrogen than do dull coals, which a.re composed largely of durain or attrital matter. Petrick, Gaigher, and Groenewoud (24) obtained similar results with South Bfrican bright and dull coals. On the other hand, Gennan workers (Bf, 32) claimed that durain is eminently suitable for hydrogenation. Although low in all instances, widely different hydrogenation yields for durains have been reported hy different investigators (16, 16, B7). This is probably due to the heterogeneous nature of durains (attrital matter), which consist of several components that differ distinctly in ease and ultimate yield of liquefaction. Francis ( I 1 ) discussed the hydrogenation of the constituents occurring in durain and stated that, whereas the opaque matter is resistant, plant skins (spores, pollens, etc.), clarains, resins, and hydrocarbons are amenable to hydrogenation. Erasmus (6) claimed that durains of higli hydrogen content are particularly suitahle for hydrogenation. Spores, one durain component of high hydrogen content, have heen liquefied in excellent yield by hydrogenation (8). The study of fusain hydroRenation has also becn made more understandable hy recognition of the fact that a t least two components (26) are present. It is generally agreed (IO, 18) that the principal component, sometimes termed “fusinite” @6),cannot be liquefied under the conditions cornmonly used in coal hydrogenation.
1157
Samples Hydrogenated The conclusions reached in this paper are based on about ninety hydrogenation experiments made on some sixty samples that were either pure constituents or mixtures oontaining known and preponderant amounts of one constituent. These samples were carefully selected by hand, and their petrographic composition and purity were determined in all instances by niicroscopic examination of thin sections mounted on slides. The magnitude of the sampling error involved in this type of petrographic analysis was reduced hy using small hand-picked samples. The anthraxylons included fourteen samples from hituniinous coals of eastern North America and eleven samples taken from peat, brown coal, lignites, and subbituminous coals of the western United States. Some of the bituminous and most of the low-rank antliraxylons contained considerable amounts of cellular resin. Thirteen of the attrital samples contained considerable amounts of translucent attritus, whereas thirteen others contained large amounts of opaque matter. Pure resins, one sample from a Utah coal and one from a Canadian coal, were hydrogenated; these resins were the extruded type. Pure spores ($8)from a Michigan highash coal, comrnereially available Lycopodium spores, and 8 spore-rich cannel coal were studied. Information regarding the hydrogenation behavior of oil algae was obtained with a Boghead cannel C O ~containing I a large proportion of this material. The hydrogenation of seven fusain samples was described in the previous paper (10). Since this study of the relation between coal hydrogenation and petrography is not finished, some of the conclusions must bo regarded as tentative until more data are available. However, in spite of this fact and errors involved in collecting both petrographic and hydrogenation data, we believe that a definite relation exists and that our results point out the marc important features.
Hydrogenation Procedure To obtain comparable results, nearly all the experiments were made under the following standard conditions: Con1 (100 grems, pulverized to pass ZOO mesh), 100 grams of tetrahydronaphthalene, and 1 gram of stannous sulfide were placed in s 1.2-liter 15-8 stainless steel convcrter. Air was
1158
INDUSTRIAL AND ENGINEERING CHEMISTRY
during ahout 1.5 hours and maintained there for 3 hours. The converter w&s rotated on its longitudinal axis to provide agitation. believed that comparatively mild condit.ions would he superior in revealing differencea in hydrogenation behavior of the various constituents. Owina to differencesin aualitv and auantitv of mineral matter
and hydrogen varied somewhat with the ash and moisture contents. Since liquefaction of spores was virtually complete at 400" C. the standard temperature WBS not used for these experiments. It was observed that several anthraxylons also gave excellent yields at 4W' C. Several samples that gave low liquefaction yields under standard conditions were hydrogenated under more favorable eonditions. Far example, nome of the high-rank anthraxylons and splint samples were hydrogenated at 440' C. for 3 hours with an initial (cold) hydrogen pressure of 1800 pounds per square inch. Some of the low-rank antbraxylons that contained considerable amounts of cellular resins were observed to give higher yields at 400' C. with an increased contact time (6 or 9 hours). Details of the methods used in the separation and analysis of the liquid and solid products have been given in former papers (9, 10). Hydrogenation yields were calculated from the yields of insoluble residue. Since small inanipulative losses of the residue undoubtedly occnrred, the yields reported probably are 2 or 3 per cent high. These yields do not represent oil yields, since, as is especially true for high-oxygen coals, water, carbon dioxide, etc., are formed in considerable quantities.
Although the criterion of liquefaction (yield of residue insoluble in tetrahydronaphthalene, acetone, and benzene) is arbitrary, it is nevertheless satisfactory for the semiquantitative comparisons made in this paper. To make such comparisons more quantitative and consistent with engineering practice, it would he necessary to obtain B vehicle characteristic of the coal constituent by repeating each liquefaction test, using the fluid product of the previous test as vehicle, until the original vehicle is eliminated. Subsequent determination of the yields and nature of residue, heavy oil, light oil, gas, and aqueous liqnor would provide the basis for quantitative and more complete comparison of the coal constituents.
VOL. 31, NO. 9
Results with Anthraxytons Figure 9, in which the insoluble residue is plotted against carbon content of the original anthraxylon, shows that all the anthraxylon samples containing less than 89 per cent carbon were liquefied in excellent yield. Fair liquefaction yields were obtained for some of the anthraxylons having more than 89 per cent carbon. However, all the high-rank anthraxylons gave higher liquefaction yields than splint coals of equal carbon content. It appears from these results that, although composite coal samples containing more than about 86 per cent carbon might cause difficulty in hydrogenation (6, IS, 18, S I ) , anthraxylons similar to some fusains in carbon content can give fair liquefaction yields. When more drastic conditions (440' C. for 3 hours, initial pressure 1800 pounds per square inch) were used with two of the highrank anthraxylons, the carbonaqeous residues were decreased from 20 and 19 per cent to about 5 and 11 per cent, respectively. We are extending this study to include anthraxylons of even higher carbon content. Some of the low-rank anthraxylons gave moderately high yields of organic residues under standard conditions. These residues were different from those obtained from bituminous anthraxylons in that considerable amounts of translucent material were present. Experiments made under various conditions showed that most of this translucent material could be liquefied by using longer contact thne or higher hydrogen pressure. For example, one resin-rich anthraxyion gave 19 per cent yield of organic residue under standard conditions but only 5 per cent residue with higher hydrogen pressure (1800 pounds at 430' C. for 3 lionrs). With the same anthraxylon at 400" C. (1000 pounds initial pressure) the following residue vields were obtained
whether there actually is a &eat difference in amenability to hydrogenation of various types of resin. The resins that apparently cause difficulty have darker colors; this is in line with the behavior of other light and dark coal constituents. Another possible explanation for the fact that the resinous low-rank anthraxylons gave hetter liquefaction yields under special conditions (higher hydrogen pressure or lower temperatures with increased contaot time) than under standard conditions lies in the enhanced reactivity of these samples. Possibly the increase in rate of polymerization or coking with lowering of rank is greater than the increase in rate of lique faction. On this basis it should be expected that higher pressnres and higher ratios of pressure to temperature would facilitate liqnefaction.
SEPTEMBER, 1939
INDUSTRIAL AND ENGINEERING CHEMISTRY
1159
The anthraxylons of lowest rank, obtained from peat and brown coal, contained 57 to 58 per cent carbon and were liquefied readily and almost completely. I n view of these results and those (3, 23) obtained by hydrogenating wood, cellulose, and lignin, it is likely that anthraxylon of even lower carbon content would be amenable. Experiments are being made which may confirm this expectation. Preliminary results indicate that waste lignin (66 per cent carbon and 5.9 per cent hydrogen) is liquefied readily under the conditions used in the present work.
Results w i t h Translucent Attritus The principal difference between the translucent woody matter in the attritus and anthraxylon appears to be physical in nature-that is, the degree of subdivision. Therefore, one could expect translucent woody matter to be similar to anthraxylon in hydrogenation behavior. The results obtained with several samples containing about 30 per cent and with four samples containing 48,58,70, and 85 per cent translucent attritus appear to support this expectation. When excellent liquefaction yields were not obtained, the higher residue yields, as shown below, could be attributed to the presence of considerable amounts of opaque matter in the original sample. Pure spores from Michigan shale and Lycopodium spores were easily liquefied a t 400" C. A cannel coal containing about 70 per cent spores and 16 per cent opaque attritus was also hydrogenated. The higher residue yield (7.4 per cent) that resulted is attributed to the opaque matter. Spores contain much hydrogen, give excellent liquefaction yields, and appear to be an excellent material for conversion into liquid fuels. Owing to similarity in carbon and hydrogen contents, it is to be expected that pollens and other plant skins will behave likewise. As pointed out previously, two samples of virtually pure coal resins were liquefied easily and almost completely. Furthermore, several bituminous anthraxylons that contained around 10 per cent resins were converted almost completely into liquid or benzene soluble products. Therefore, resins appear to be suitable for liquefaction purposes, but the standard conditions of hydrogenation of this study, which are milder than those commonly used commercially, are not satisfactory for all resinous coals. From the results obtained with a Boghead cannel containing 42 per cent oil algae, 30 per cent opaque attritus, and 28 per cent translucent attritus, it appears that oil algae are suitable for hydrogenation purposes. This tentative conclusion is in keeping with the high hydrogen content of oil algae. It is believed that the moderately high yield of residue (about 23 per cent) was caused by the presence of opaque matter. Further experiments will be made with oil algae when samples are available.
Results with Opaque Attritus The results obtained with thirteen samples containing 30 to 80 per cent opaque attritus indicate that, next to fusain, this constituent gives lowest liquefaction yields (Figure 9). Because of the opacity and high carbon-hydrogen ratios of opaque attritus, which approach those of fusain, this should be expected. The average liquefaction yield for opaque attritus under standard conditions (430' C. for 3 hours, initial pressure 1000 pounds) appears to be about 62 per cent, as compared with 95 to 99 per cent yields for anthraxylons of low and intermediate rank. Since pure opaque attritus was not available, it was necessary to estimate its liquefaction yield after making certain assumptions on the basis of previous experiments. For the purpose of calculation, it was assumed that fusain was completely resistant and that all constituents other than
CARBON CONTENT, PERCENT
FIGURE9. YIELDS OF ORGANIC RESIDUE AND CARBON CONTENT OF SAMPLE HYDROGENATED (DRY,ASH-FREEBASIS)
opaque attritus were completely liquefied. Although neither assumption is exactly correct, the results calculated in this manner are useful for comparison. Such calculations show that from 21 to 63 per cent of the opaque attritus is recovered as insoluble residue under standard conditions; the average value is about 38 per cent. The large variation in calculated liquefaction yields of the opaque attritus samples can be attributed to a t least two causes. Probably the most important is the nature of the opaque matter, which ranges from semiopaque material to carbonaceous matter rivaling fusain in opacity. For example, one opaque attritus sample that was composed largely of semiopaque or brown matter gave a fair liquefaction yield (77 per cent), whereas samples that were more opaque gave yields as low as 39 per cent. A second cause of the variations in yield is the inaccuracy of the petrographic determinations. Lower residue yields were obtained from splint samples when more drastic conditions were used. For example, when hydrogenated a t 440' for 3 hours (1800 pounds initial hydrogen pressure), the residue yields from two opaque attritus samples were reduced from 40 and 26 to 22 and 15 per cent, respectively. Insoluble residues obtained from samples containing much opaque attritus and little or no fusain are interesting in that, although possessing high carbon-hydrogen ratios, fusain is not the precursor. Such residues were examined microscopically and compared with residues obtained by hydrogenating fusain. The splint coal residues do not have the characteristic fibrous structure of the fusain residues and, although both are opaque, they are easily distinguished from each other. Figure 10 shows photomicrographs prepared from slides of untreated, hand-picked fusain and hydrogenation residues of both fusain and splint coal. The residues from the splint coal and fusain have very little (probably less than 1 per cent) translucent material other than mineral matter; this indicates that constituents in the splints, such as spores, anthraxylon, and resins, were almost completely converted into liquid or soluble products.
INDUSTRIAL AND ENGIKEERING CHEMISTRY
1160
TABLE I. PROXIMATE AND Sample
NU.
State
AI A2
Penn~.
B1
Ky.
Pittaburgh
Allegheny
As Received bbisture Ash
Mine
Bed
Coilnty
Rruceton
A3
BZ
High Splint
fIarlai,
Clover Splint
84
Cl
cz
Pond Creek
Pike
Majestio
N
0
S
%
%
%
%
1.5 1.2 1.6
1.6 7.2 6.3
39.2 36.2
5.5 5.3 5.6
84.5
1.6 1.5 1.7
1.1
85.6 84.2
8.1
8366
0.8
1.7
8361
1.7
41.4 45.0 31.9
5.7 5.8 4.7 5.6
83.0 85.4 S4.0
83.6
1.5 1.7
8.7 8.8 8.2
0.6 0.7 0.4 0.6
8278 8261 8172 8289
33.1 38.5 36.0
5.3
6.4 5.1 5.8
0.7 0.6 0.8
8506
1.5
2.6 9.2 3.8
1.1
3.9 4.2
Inert -Pelrograpbio Cornpaition. %Meltci --Attiitu% of Residue Sample AntliraxyTrsnaODnRUe YiekI.1, NO. 10" lucent O m w e Fueain Attiitus' % ' AI 100 0 0 0 1.1 A2 37 31 2 25 10.5 30 12 3 30 7.2 A3 03 22 1%1 B6 37 6 1 .. 9.6 mz :$e 58 5 1 7.0 I33 3 35 GO 2 57 40.2 01 100 0 0 0 4.2 CZ 0 48 50 2 42 24.3 a Calculated by sssuming fuanin oumpj~leiyreaistant and all conatituente other than 0par8ue at,lritua completely I~gaetiedby hydrogenation. b Dry. seh-free bnsia. ~~
..
.. ..
Although i t appears that, under the hydrogenation conditions employed, the anthraxylon and translucent attritus portions gave small yields of residue, the residue yields are directly proportional to the opaque matter present. These data give excellent support for the belief stated earlier in this paper and elsewhem (8, 11, S5) that opaque attritus is the constituent, other than fusain, that offers most resistance to liquefaction by hydrogenation.
Correlation of Liquefaction Yields with Rank and Petrography Coals have frequently been classified as suitable or unsuitable for hydrogenation on the hasis of carbon content.
A
4.8
38.8
41.4
:.e
o.D
86.1 87.5 80.3
1.4 1.6
1.5 1.3 1.6
7.3
S.l
1.5
VSlUS
G. eel.
...
8433
8689
Bergius (15) claimed that coals containing less than 85 per cent carbon mere amenable; other authors (1.9, 18) have preferred coals containing 80 to 84 per cent carbon. The success that might be expected from predicting residue yields on the hasis of carbon content alone is ilhlstrated by Figure 9. There is indeed a rough cor~elationbetween carbon content m d yield within the petrographic groups. For example, whcn splint coals .alone are compared, the carbon content, could he used to obtain a rorigh estimate of the yield (Figure 0). In this connection, there is a rough relation between the carbon and opaqne attritus contents of these splint samples. Fosains and anthraxylons of the same carbon contents (around 90 per cent) would he cxpected to give liquefaction yields of ahout 20 and 90 per cent, respectively (Figure 9). Sinallcr differences in yield would he expected from anthraxylons and splint coals of equal car.. bon content. It is interesting to consider the reasons responsihlo for the partial success previously experienced in correlating hydrogenation yields with carbon content. of the sample, usually a bright coal. For relatively homogeneous coals (bright coals), the carbon content, carhon-hydrogen ratio, volatile matter content, etc., are fair iridiccs of rank or degree of coalification (26). Since a,rnenahility to liquefaction decreases with increase in rank and virtually disappears for carbonaceous matter of extremely high carbon content (fusinite, coke, etc.), the importance of carbon content in predicting yields is easily understood. The situation is much more complicated with tho chemically heterogeneous dull or splint coals. For such coals tho carbon content., being only ari average value, may be deceptive and, owing to the influence OS spores, resins, etc., may not reveal the presence of considerable amounts of fusain and opaque attritus. The carhonhydrogen ratio, volatile matter content, etc., also are not very useful since they, too, are amrage values. Petrographic methods, however, are espccially valuable for heterogeneous
HYDROGENATION DATA
~~
Calorifio
C
In some instances several samples were procured from the 5 ~ m ecoal bed and hydrogenated. Proximate and ultimate analyses of these samples, t,aken from the Pittsburgh, High Splint, and Pond Creek beds, are given in Table I. Petrographic analyses and residue yields (dry, ash-free basis) obtained on hydrogenation are shown in Tahle 11. PETRoGRAlXIC AND
Dry, Aah-Fre---
%
Petrographic Samples from Onc Scam
TARLE If.
I€
%
1.4 3.0
c3
Volatile nistler
%
3.6
Ky.
ANALYSES
%
1.5 2.8
I33
---
ULTlMATE
VOL. 31, NO. 9
B
C
FIGURE10. A , BAND-PICXED Fus*m (200 MESH); B, HYDROGEVATIOV RESIDUE RESIDUE FROM SPLINT C O A L
( X 150)
FUSAIX;C, HYDROQENATION
SEPTEMBER, 1939
INDUSTRIAL AND ENGINEERING CHEMISTRY
coals since the presence and quantities of constituents that differ widely in hydrogenation behavior are revealed. A petrographic method (Figure 11) of predicting yields was compared with the frequently used method based on carbon content alone (Figure 9). The yield of residue to be expected from the petrography was estimated by assuming that the different constituents would give the following percentage yields of residue: ash and fusain, 100; opaque attritus, 38; all other constituents, 0. The yields predicted in this manner are plotted against the determined yields in Figure 11. Although far from satisfactory, this correlation of predicted and experimentally determined yields is interesting and warrants further study. After more data are available, it should be possible to predict residue yields with moderate accuracy from the rank and petrography, especially if petrographic analyses can be improved with respect to both precision and scope. For example, it would be helpful to know the amount of semiopaque as well as opaque matter or, better still, to have the quantity of opaque matter and a numerical index of its average opacity. The results of such laboratorv analvses FIGURE 11. and tests should be of considerabie value in limiting the number of coal samples to be tested in a continuous plant in selecting coal (11) for commercial hydrogenation. A very poor liquefaction prediction based on either petrogpaphic analyses or small bomb (12) hydrogenation tests is sufficient reason for rejection of a coal for continuous hydrogenation testing. A good prediction, (131 however, does not preclude the necessity of tests in continu(14) ous plant, for physical factors are involved that cannot be evaluated or predicted by petrographic or small bomb tests. (15)
Acknowledgment The authors are grateful to W. A. Selvig, of the Coal Constitution and Miscellaneous Analysis Section, for his interest and examination of the manuscript, to Hugh O’Donnell for assistance in preparing the petrographic sample% and t o M. L. Fein for analyzing some of the hydrogenation products. Proximate and ultimate analyses of the coal constituents miere made by F‘ Abernethy, and Other members of the Coal Analysis Section.
Literature Cited
’
(1) Bakes, W. E., Dept. Sei. Ind. Research, Tech. Paper 37 (1933). (2) Beuschlein, W. L., and Wright, C. C., IND,ENO. CHEM.,24, 1010-12 (1932). (3) Boomer, E. H., Argue, G. H., and Edwards, J., Can. J. Research, 13B, 3 3 7 4 2 (1935). (4) Boomer, E. H., Saddington, A . W., and Edwards, J., Ibid., 13, 11-27 (1935). (5) Booth, N., Williams, F. A., and King, J. G., Dept. Sei. Ind. Research, Tech,.Paper 44 (1938). ( 6 ) Erasmus, Paul, “Uber die Bildung und den chemisohe Bau der Kohlen,” Stuttgart, Verlag von Ferdinand Enke, 1938. (7) Fischer, F., Peters, K., and Cremer, W., Fuel, 12, 390-4 (1933). (8) Fisher, C. H., IND.EXG.CHEM:., Anal. Ed., 10,374-7 (1938). (9) Fisher, C. H., and Eisner, A . , IND.ENG.CHEM.,29, 1371-6 (1937). (10) Fisher, C. H., Sprunk, G . C., Eisner, A., Clarke, L., and Storch, H. H., [bid., 31, 190-5 (1939).
1161
PREDICTED YIELD, PERCENT
YIELDSOF RESIDUEPREDICTED FROM PETROGRAPHY Francis, W., J . Inst. Fuel, 6,301-8 (1933). Fuchs~ W.7 Gauger, A. W., Hsiao, C. C., Pennn. State Coll., Mineral Ind. (1938). Gordon, K., Colliery Guardian, 151, (1935). Gordon! 348-63 K., (1933). T m m . Inst. M i n i n g Engrs.
C., and Wright, C. Expt. Sta., Bull. 23 985-8,
1005, 1045
(London), 82, Pt. 4,
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ii:;
~ ~ ~ ~ ~ (1938), 145-60 (21) Lehmann, K., and Hoffmann,E., Glackauf, 67, 1-14 (1931).
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(22) Lessing, R.,J.I n s t . Petroleum Tech., 22, 577-82 (1936). (23) Moldavskii and Vainshtein, K h i m . Tverdogo T o p l i ~ a 6, , 656-62 (1935). (24) Petrick, A. J., Gaigher, B., and Groenewoud, P., J . Chem. Met. Mining SOC.S . Africa,38, 122-4 (1937). (25) Pier, M., Fuel, 14, 1 3 6 4 6 (1935). (26) Seyler, C. A., Ibid., 17, 177-86, 200-9, 235-42 (1938). (27) Shatwell, H. G., and Graham, J. I., Ibid., 4, 25-30, 75-81, 127-31,252-5 (1925). (28) Sprunk. G. C., Selvig, W. A., and Ode, W. H., Ibid., 17, 196-9 (1938). (29) Sprunk, G. C., and Thiessen, R., IND. ENO.C H ~ M27, . , 446-51 (1935). (30) Stopes, M. C., Fuel, 14,4-13 (1935). (31) Storch, H. H., IND. ENO.CHEW,29, 1367-71 (1937). (32) Strevens, J. L., J . Inst. Fuel, 4, 317-39 (1932); Colliery Guardi a n , 142, 572-6, 667-8 (1931). (33) Thiessen, R., paper presented before Fuel Engrs. of Appalachian Coals, Inc., Jan., 1937. (34) Thiessen, R . , and Francis, W., U. S. Bur. Mines, Tech. Paper 446 (1929). (35) Wright, C. C., and Gauger, A. W., Am. Mining Congr. Coal Mine Mechanization, Yearbook, pp. 381-3 (1937). (36) Wright, C. C., and Gauger, A. W., Penna. State Coll., Tech. Paper 31 (1936). PnBLIexED
by permission of the Direotor, U. S. Bureau of Mines.
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