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Reaction of a coal liquid with a hydrogen-donor solvent to form a carbon-rich solid
Letters to the Editor
Figure 2 Fluorescence photomicrograph of exudatinite-like material filling cavities in teleutospores. Aquarius brown coal, Queensland, Australia
from descriptions given by Teichmullerr9 and Murchison4, to differentiate the present exudatinite-like material from the exudatinite in bituminous coals, and it is probable that exudatinite actually occurs in coals of a much wider range of rank than previously thought. The question arises as to whether the resinous material which has physically exuded into open cavities without undergoing significant chemical alteration should be given a new maceral name. Put in another way, can differences in form alone justify regarding exudatinite and resinite as two distinct mace&? It would be desirable to establish the general principles of defining macerals in order to avoid possible confusion in the future.
Reaction of a coal liquid with a hydrogen-donor rich solid Robert
Fluorescent material other than resinite has been obser. This process may have an ved to exude from exinite 1~295 entirely different significance from the exudation of resinite, but before this can be decided, a more thorough investigation is necessary. There is an important practical consequence of these observations. If exudatinite occurs in brown coals, its presence cannot be indicative of the generation of oil in sediments because the dispersed organic material, which is equivalent to the rank of brown coals, is definitely too immature to generate oil. Exudatinite can be formed if resinous material or part of it is plastic enough to exude into old or newly-formed open spaces. In bituminous coals, a fairly high pressure may be necessary to cause it to exude, but in brown coals or peats some resinous materials may be fluid enough to fill cavities in teleutospores and fusinite. Consequently, the occurrence of ‘exudatinite’ may have no significance as an indicator of a particular degree of coalification or of maturity of organic material dispersed in sediments.
REFERENCES Teichmtiller, M. in Advances in Organic Geochemistry, 1973 (Eds. B. Tissot and F. Bienner), Technip, Paris, 1974, pp 379-407 Teichmttller, M. in Stach‘s Textbook of Coal Petrololy, Gebriider Borntraeger, Berlin, 1975, pp 176-238 Murchison. D. G. in Coal Science (Ed. R. F. Gould). Adv. in Chem. Series No. 55, American Chemical Society, Washington, D. C., 1966, p 307 Murchison, D. G. Fuel 1976,55,79 Shibaoka, M. Fuel 1978,57, 73
solvent to form a carbon-
J. Hooper* and David G. Evanst
*Department of Chemical tCentre for Environmental (Received 13 June 19781
Engineering, University of Melbourne, Parkville, 3052, Victoria, Australia Studies, University of Melbourne, Parkville, 3052, Victoria, Australia
Does the solid residue left after hydrogenating coal in a hydrogen-donor solvent consist solely of material which has never reacted, or is some of it at least formed by condensation or cross-linking reactions? This is an important question for two reasons: 1. If it is possible for a liquid product formed from the coal by reaction with the solvent to regress to a solid, it becomes crucial in industrial practice to optimize the reaction conditions to produce the maximum yield of liquids; 2. If it is necessary to seek such an optimum, batch hydrogenation tests carried out under standardized but arbitrary laboratory conditions for the purpose of evaluating the liquefaction potential of coals may be quite meaningless. Several workers1-3 have recently suggested that with prolonged treatment liquid material may indeed regress to solid material. The following indirect evidence has been advanced: 1. Microscopic examination of residues indicates that some particles consist of a granular carbonaceous shell surrounding a mineral particle which has apparently acted as a nucleation site3;
2. Conversion of coal to material soluble in, say, pyridine or benzene appears, under some conditions, to increase with time, reach a maximum, then decrease with further reaction2p4. We have now obtained direct evidence that conversion of coal liquids to solids can occur under liquefaction reaction conditions, as follows: Morwell brown coal was solubilized by reacting with phenol, in the presence of puratoluenesulphonic acid catalyst, at a temperature of 183’C, under conditions suggested by Imuta and Ouch?. The product of this reaction was then fractionatedinto broad chemical types: first it was dissolved in an azeotropic mixture of benzene and ethanol; the insolubles were set aside (fraction D) and the soluble material was treated with an excess of pentane; pentane-soluble material was designated fraction A and the precipitate was extracted to yield fraction B, benzene-soluble, and fraction C, benzene-insoluble. The four fractions, especially A and I?, contained considerable amounts of combined phenol and some excess solvent which could not be removed by evaporation in a vacuum oven. Analysis by i.r. and proton n.m.r. showed that frac-
0016-2361178/120799-03$02.ClO 0 1978 IPC Business Press
FUEL, 1978, Vol57,
December
799
Letters to the Editor tion A was predominantly aliphatic and monoaromatic, fraction B d&aromatic, and fraction C, the most polar fraction, consisted almost entirely of di- and poly-aromatic fragments. It appears that, under the reaction conditions used, certain structures in the coal alkylate the phenol, and in so doing are themselves broken off from the main coal structure by rupture of carbon-carbon bonds to leave the residue, fraction D. It seems reasonable to assume that breakage of bonds under these conditions is similar to that occurring by thermal cracking during coal hydrogenation. The four fractions were reacted separately for 4 h at 450°C with a large excess of tetralin, but no hydrogen. Any solid residue was removed and the liquid product was distilled to remove excess tetralin and material with a boiling point lower than that of tetralin. Distillation was continued until sublimation of naphthalene ceased (naphthalene boils at a temperature a few degrees above the boiling point of tetralin). The remaining liquid bottoms product was then set aside for analysis. Fractions A and B were liquids, and produced only liquid and gaseous products. Fraction D was a solid, and produced both a liquid and a solid product, as expected. However, although fraction C, the material soluble in the benzene/ethanol azeotrope, was completely soluble in tetralin before reaction and the reactor feed was therefore liquid, it also produced both a liquid and solid product. It is, of course, possible that the coal fragments produced by the addition of phenol behave quite differently from the coal fragments produced by thermal breakdown during liquefaction by hydrogenation, in which case the appearance of a solid residue from a phenolated coal might not be indicative of what could be expected from the coal itself. However, the evidence from the various papers by Heredy and co-worker&’ and Ouchi and co-worker@ on the catalytic reaction of phenol with coal is that the phenol adds in such a way that hydrogenation of the chemically attached phenol would yield monoaromatic benzene rings, not polyaromatic material. This is borne out by other evidence from the present study: fractions A and B, which contained by far the greatest proportions of combined phenol, both produced liquid products but no solid residue on hydrogenation, and proton n.m.r. analysis of these liquids showed a large proportion of the hydrogen present to be monoaromatic and none of it di- or polyaromatic. We will now examine the solid residue from fraction C and its possible mode of formation in some detail. Table 1 gives the elemental compositions and yields of fraction C and its two products, together with the composition of phenol and the original coal for comparison. Figure f shows the infrared spectra. Table 1 Elemental
analyses and yields of various materials,
1
I
I
I
1600
1200
go0
Wavenumber
I cm-‘)
Fraction C is similar in many ways to the original whole coal. Elemental analysis of the fraction shows its carbon and hydrogen contents to have increased over that of the original coal and its oxygen content to have decreased, but this is due in part to dilution with phenol. (Other evidence showed that this fraction contains approximately 25% by weight of chemically attached phenol.) The aliphatic peaks at 2920 cm-l and 2850 cm-l present in the spectrum of the original coal are almost absent from the spectrum of fraction C; otherwise the two spectra are quite similar. As expected, both the bottoms product and the residue after reaction have substantially higher carbon and lower oxygen contents than the original fraction C, but whereas the bottoms product has an increased hydrogen content, in the residue it is reduced. Both the bottoms product and the residue now show the aromatic C-H stretch absorption at 3030 cm-l. Analysis by n.m.r. showed that the aromatic hydrogen in the bottoms product was largely monoaromatic; thus the aromatic content of the bottoms must be due partly, at least, to residual solvent and phenol combined with the fraction. The spectra of both reaction products
dry basis (wt %j
C
H
0
Ash
Unaccounted
Yield (g/ 100 g original dry coal 1
62.4 76.6 69.0 86.4 89.3
4.8 6.4 5.0 6.8 4.2
25.3 17.0 21.0 6.Ba 2.6
4.1 -
3.4 -
100.0 -
1.9
3.1
-b
3.9c
aAdjustedfor
residual naphthaldne present in the bAsh not determined CThe unaccounted-for material will contain some dThe material not accounted for by the bottoms converted by the reaction to gas or to low-boiling
800
I
2000
Figure 7 Infrared spectra of various materials: (a) original coal; (b) fraction C before reaction; (c) bottoms from distillation of liquid product from reaction of fraction c; fd) solid reaction product from fraction C
Composition
Original coal Phenol Fraction C before reaction Bottoms from liquid reaction product Solid reaction product
I
3000
FUEL, 1978, Vol 57, December
product
and normalized
78.3d 29.0d 2l.ld
to 100%
ash product and the solid reaction product material recovered with the distillate
(28.2
g) represents thet part of fraction
C which was
Letters
show that carbonyl groups (absorption at 1700 cm-l) have been destroyed. The absence from the spectrum of the bottoms product of the broad absorption in the region 1OOO- 1200 cm-l, which is due to oxygen-containing functional groups, shows, as would be expected, that these also have been destroyed during the reaction. The large hydrogen-bonded OH peak at 3400 cm-l present in the spectrum of the unreacted material has virtually disappeared from both reaction products, showing that the remaining oxygen is not due to phenol. The strong absorption in the region 1000-1200 cm-l shown by the residue (and by the original fraction) has probably been enhanced by the presence of silica, a major constituent of the ash of this coal, but the absorption at 1170 cm-l in the spectrum of the residue may be due, possibly, to the presence of benzofuran type structures in the residueg. The presence of such structures in the residue and the fact that this material is deficient in hydrogen even though the reaction system contained exchangeable hydrogen, suggests that condensation reactions may be involved in its formation. All the evidence points to the operation of parallel reaction paths in the hydrogenation reaction, with part of the
to the Editor
coal appearing as an aliphatic/monoaromatic liquid product, and part appearing as a carbon-rich condensed material with surprisingly little oxygen. ACKNOWLEDGEMENTS We thank the New Zealand DSIR and the Australian Research Grants Committee for supporting this work, and Dr. H. A. J. Battaerd for many helpful suggestions. REFERENCES Walk, R. H., Lebowitz, H. E., Rovesti, W. C. and Stewart, N. C., Paper presented at Pache ‘11, Denver, Colorado, Aug. 1911 Whitehurst, D. D., Farcasiu, M., Mitchell, T. 0. and Dickert, J. J. Jr, EPRIAF-480, July 1911 Mitchell, G. D., Davis, A. and Spa&man, M., Liquid Fuels from Coal (Ed. R. T. Ellington), Academic Press, New York, 1911, pp 255-269 Neavel, R. C. Fuel 1916,55, 231 Imuta, K. and Ouchi, K. Fuel 1913,52, 114 Heredy, L. A. and Neuworth, M. B. Fuel 1962,41, 211 Heredy, L. A., Kostyo, A. E. and Neuworth, M. B. Fuel 1964, 43,414 Ouchi, K. and Brooks, J. D. Fuel 1961,46,361 Ouchi, K. Fuel 1961,46,319
Effect of the speciesof alkali on the reaction of alcohol-alkali-coal Masataka
Makabe,
Sachihide
Fuse and Koji Ouchi
Faculty of Engineering, Hokkaido University, Sapporo OSO, Japan (Received 5 July 19781
In a previous paper’ the authors reported the effect of reaction conditions and rank of coal on the reaction with alcohol-alkali. Almost 100% solubilization in pyridine could be obtained for the reaction of coals younger than 82% C with ethanol and sodium hydroxide. It was suggested that the main reaction would be hydrolysis accompanying hydrogenation. This hydrogen in the hydrogenation came from the reaction thus:
This was tested by work described in this note. The species of alkali may also be expected to have some effects on the solubilization of the product. From the industrial viewpoint it is commendable to use cheaper alkali such as calcium hydroxide or sodium carbonate. This problem is also treated in this note. Taiheiyo coal (76.7% C 6.4% H) was crushed below 100 Tab/e 1 Effect of species of alcohol and alkali
Hz II
CH,C-OH
-
f?
CH,-Cf;j--
CH,-C
02
=0
. 2H, t
AH
Alcohol
Ross’ also reported an increase in solubilization with the reaction between isopropyl alcohol, sodium hydroxide and coal. In this case the reaction may be: ‘:
(7
(CH,I,=C-OH+(CH,l,.
C -6=+CH,12
.C:O+Ht
If the same type of reaction takes place for all the alcohols it can also be expected for methanol, which is a cheaper alcohol.
Cl+,-OH
-
-e
‘1 r_
H-C,-0
oHL
-HC=O
I
6H
l
2H, f
Yield of product
Yield of pyridine extract
(%I
(%)
Amount of alkali
Yield of product (%I 0.15
6g
Yield of pyridine extract (%I mol
NaOH
Ethanol
86.6
94.7
-
-
NaOH
Methanol
84.3
,?Z,a
84.3
96.3 t42.91a
KOH
Methanol
86.7
(:::,a
87.0
99.2 wzi.31a
Ca(OH),
Methanol
96.7
29.7
97.6
21 .o
Ca(OH),’
Methanol
-
-
96.1
47.0
Na2COs
Methanol
98.0
27.6
89.6
31.1
aYield of ethanol extraction. Temperature: 350°C. b4OO’C. Yield of pyridine extraction of original coal: 14.1%
0016-2361/78/120801-02$02.00 0 1978 IPC Business Press
FUEL,
1978,
Vol57,
December
801
Figure 2 Fluorescence photomicrograph of exudatinite-like material filling cavities in teleutospores. Aquarius brown coal, Queensland, Australia
from descriptions given by Teichmullerr9 and Murchison4, to differentiate the present exudatinite-like material from the exudatinite in bituminous coals, and it is probable that exudatinite actually occurs in coals of a much wider range of rank than previously thought. The question arises as to whether the resinous material which has physically exuded into open cavities without undergoing significant chemical alteration should be given a new maceral name. Put in another way, can differences in form alone justify regarding exudatinite and resinite as two distinct mace&? It would be desirable to establish the general principles of defining macerals in order to avoid possible confusion in the future.
Reaction of a coal liquid with a hydrogen-donor rich solid Robert
Fluorescent material other than resinite has been obser. This process may have an ved to exude from exinite 1~295 entirely different significance from the exudation of resinite, but before this can be decided, a more thorough investigation is necessary. There is an important practical consequence of these observations. If exudatinite occurs in brown coals, its presence cannot be indicative of the generation of oil in sediments because the dispersed organic material, which is equivalent to the rank of brown coals, is definitely too immature to generate oil. Exudatinite can be formed if resinous material or part of it is plastic enough to exude into old or newly-formed open spaces. In bituminous coals, a fairly high pressure may be necessary to cause it to exude, but in brown coals or peats some resinous materials may be fluid enough to fill cavities in teleutospores and fusinite. Consequently, the occurrence of ‘exudatinite’ may have no significance as an indicator of a particular degree of coalification or of maturity of organic material dispersed in sediments.
REFERENCES Teichmtiller, M. in Advances in Organic Geochemistry, 1973 (Eds. B. Tissot and F. Bienner), Technip, Paris, 1974, pp 379-407 Teichmttller, M. in Stach‘s Textbook of Coal Petrololy, Gebriider Borntraeger, Berlin, 1975, pp 176-238 Murchison. D. G. in Coal Science (Ed. R. F. Gould). Adv. in Chem. Series No. 55, American Chemical Society, Washington, D. C., 1966, p 307 Murchison, D. G. Fuel 1976,55,79 Shibaoka, M. Fuel 1978,57, 73
solvent to form a carbon-
J. Hooper* and David G. Evanst
*Department of Chemical tCentre for Environmental (Received 13 June 19781
Engineering, University of Melbourne, Parkville, 3052, Victoria, Australia Studies, University of Melbourne, Parkville, 3052, Victoria, Australia
Does the solid residue left after hydrogenating coal in a hydrogen-donor solvent consist solely of material which has never reacted, or is some of it at least formed by condensation or cross-linking reactions? This is an important question for two reasons: 1. If it is possible for a liquid product formed from the coal by reaction with the solvent to regress to a solid, it becomes crucial in industrial practice to optimize the reaction conditions to produce the maximum yield of liquids; 2. If it is necessary to seek such an optimum, batch hydrogenation tests carried out under standardized but arbitrary laboratory conditions for the purpose of evaluating the liquefaction potential of coals may be quite meaningless. Several workers1-3 have recently suggested that with prolonged treatment liquid material may indeed regress to solid material. The following indirect evidence has been advanced: 1. Microscopic examination of residues indicates that some particles consist of a granular carbonaceous shell surrounding a mineral particle which has apparently acted as a nucleation site3;
2. Conversion of coal to material soluble in, say, pyridine or benzene appears, under some conditions, to increase with time, reach a maximum, then decrease with further reaction2p4. We have now obtained direct evidence that conversion of coal liquids to solids can occur under liquefaction reaction conditions, as follows: Morwell brown coal was solubilized by reacting with phenol, in the presence of puratoluenesulphonic acid catalyst, at a temperature of 183’C, under conditions suggested by Imuta and Ouch?. The product of this reaction was then fractionatedinto broad chemical types: first it was dissolved in an azeotropic mixture of benzene and ethanol; the insolubles were set aside (fraction D) and the soluble material was treated with an excess of pentane; pentane-soluble material was designated fraction A and the precipitate was extracted to yield fraction B, benzene-soluble, and fraction C, benzene-insoluble. The four fractions, especially A and I?, contained considerable amounts of combined phenol and some excess solvent which could not be removed by evaporation in a vacuum oven. Analysis by i.r. and proton n.m.r. showed that frac-
0016-2361178/120799-03$02.ClO 0 1978 IPC Business Press
FUEL, 1978, Vol57,
December
799
Letters to the Editor tion A was predominantly aliphatic and monoaromatic, fraction B d&aromatic, and fraction C, the most polar fraction, consisted almost entirely of di- and poly-aromatic fragments. It appears that, under the reaction conditions used, certain structures in the coal alkylate the phenol, and in so doing are themselves broken off from the main coal structure by rupture of carbon-carbon bonds to leave the residue, fraction D. It seems reasonable to assume that breakage of bonds under these conditions is similar to that occurring by thermal cracking during coal hydrogenation. The four fractions were reacted separately for 4 h at 450°C with a large excess of tetralin, but no hydrogen. Any solid residue was removed and the liquid product was distilled to remove excess tetralin and material with a boiling point lower than that of tetralin. Distillation was continued until sublimation of naphthalene ceased (naphthalene boils at a temperature a few degrees above the boiling point of tetralin). The remaining liquid bottoms product was then set aside for analysis. Fractions A and B were liquids, and produced only liquid and gaseous products. Fraction D was a solid, and produced both a liquid and a solid product, as expected. However, although fraction C, the material soluble in the benzene/ethanol azeotrope, was completely soluble in tetralin before reaction and the reactor feed was therefore liquid, it also produced both a liquid and solid product. It is, of course, possible that the coal fragments produced by the addition of phenol behave quite differently from the coal fragments produced by thermal breakdown during liquefaction by hydrogenation, in which case the appearance of a solid residue from a phenolated coal might not be indicative of what could be expected from the coal itself. However, the evidence from the various papers by Heredy and co-worker&’ and Ouchi and co-worker@ on the catalytic reaction of phenol with coal is that the phenol adds in such a way that hydrogenation of the chemically attached phenol would yield monoaromatic benzene rings, not polyaromatic material. This is borne out by other evidence from the present study: fractions A and B, which contained by far the greatest proportions of combined phenol, both produced liquid products but no solid residue on hydrogenation, and proton n.m.r. analysis of these liquids showed a large proportion of the hydrogen present to be monoaromatic and none of it di- or polyaromatic. We will now examine the solid residue from fraction C and its possible mode of formation in some detail. Table 1 gives the elemental compositions and yields of fraction C and its two products, together with the composition of phenol and the original coal for comparison. Figure f shows the infrared spectra. Table 1 Elemental
analyses and yields of various materials,
1
I
I
I
1600
1200
go0
Wavenumber
I cm-‘)
Fraction C is similar in many ways to the original whole coal. Elemental analysis of the fraction shows its carbon and hydrogen contents to have increased over that of the original coal and its oxygen content to have decreased, but this is due in part to dilution with phenol. (Other evidence showed that this fraction contains approximately 25% by weight of chemically attached phenol.) The aliphatic peaks at 2920 cm-l and 2850 cm-l present in the spectrum of the original coal are almost absent from the spectrum of fraction C; otherwise the two spectra are quite similar. As expected, both the bottoms product and the residue after reaction have substantially higher carbon and lower oxygen contents than the original fraction C, but whereas the bottoms product has an increased hydrogen content, in the residue it is reduced. Both the bottoms product and the residue now show the aromatic C-H stretch absorption at 3030 cm-l. Analysis by n.m.r. showed that the aromatic hydrogen in the bottoms product was largely monoaromatic; thus the aromatic content of the bottoms must be due partly, at least, to residual solvent and phenol combined with the fraction. The spectra of both reaction products
dry basis (wt %j
C
H
0
Ash
Unaccounted
Yield (g/ 100 g original dry coal 1
62.4 76.6 69.0 86.4 89.3
4.8 6.4 5.0 6.8 4.2
25.3 17.0 21.0 6.Ba 2.6
4.1 -
3.4 -
100.0 -
1.9
3.1
-b
3.9c
aAdjustedfor
residual naphthaldne present in the bAsh not determined CThe unaccounted-for material will contain some dThe material not accounted for by the bottoms converted by the reaction to gas or to low-boiling
800
I
2000
Figure 7 Infrared spectra of various materials: (a) original coal; (b) fraction C before reaction; (c) bottoms from distillation of liquid product from reaction of fraction c; fd) solid reaction product from fraction C
Composition
Original coal Phenol Fraction C before reaction Bottoms from liquid reaction product Solid reaction product
I
3000
FUEL, 1978, Vol 57, December
product
and normalized
78.3d 29.0d 2l.ld
to 100%
ash product and the solid reaction product material recovered with the distillate
(28.2
g) represents thet part of fraction
C which was
Letters
show that carbonyl groups (absorption at 1700 cm-l) have been destroyed. The absence from the spectrum of the bottoms product of the broad absorption in the region 1OOO- 1200 cm-l, which is due to oxygen-containing functional groups, shows, as would be expected, that these also have been destroyed during the reaction. The large hydrogen-bonded OH peak at 3400 cm-l present in the spectrum of the unreacted material has virtually disappeared from both reaction products, showing that the remaining oxygen is not due to phenol. The strong absorption in the region 1000-1200 cm-l shown by the residue (and by the original fraction) has probably been enhanced by the presence of silica, a major constituent of the ash of this coal, but the absorption at 1170 cm-l in the spectrum of the residue may be due, possibly, to the presence of benzofuran type structures in the residueg. The presence of such structures in the residue and the fact that this material is deficient in hydrogen even though the reaction system contained exchangeable hydrogen, suggests that condensation reactions may be involved in its formation. All the evidence points to the operation of parallel reaction paths in the hydrogenation reaction, with part of the
to the Editor
coal appearing as an aliphatic/monoaromatic liquid product, and part appearing as a carbon-rich condensed material with surprisingly little oxygen. ACKNOWLEDGEMENTS We thank the New Zealand DSIR and the Australian Research Grants Committee for supporting this work, and Dr. H. A. J. Battaerd for many helpful suggestions. REFERENCES Walk, R. H., Lebowitz, H. E., Rovesti, W. C. and Stewart, N. C., Paper presented at Pache ‘11, Denver, Colorado, Aug. 1911 Whitehurst, D. D., Farcasiu, M., Mitchell, T. 0. and Dickert, J. J. Jr, EPRIAF-480, July 1911 Mitchell, G. D., Davis, A. and Spa&man, M., Liquid Fuels from Coal (Ed. R. T. Ellington), Academic Press, New York, 1911, pp 255-269 Neavel, R. C. Fuel 1916,55, 231 Imuta, K. and Ouchi, K. Fuel 1913,52, 114 Heredy, L. A. and Neuworth, M. B. Fuel 1962,41, 211 Heredy, L. A., Kostyo, A. E. and Neuworth, M. B. Fuel 1964, 43,414 Ouchi, K. and Brooks, J. D. Fuel 1961,46,361 Ouchi, K. Fuel 1961,46,319
Effect of the speciesof alkali on the reaction of alcohol-alkali-coal Masataka
Makabe,
Sachihide
Fuse and Koji Ouchi
Faculty of Engineering, Hokkaido University, Sapporo OSO, Japan (Received 5 July 19781
In a previous paper’ the authors reported the effect of reaction conditions and rank of coal on the reaction with alcohol-alkali. Almost 100% solubilization in pyridine could be obtained for the reaction of coals younger than 82% C with ethanol and sodium hydroxide. It was suggested that the main reaction would be hydrolysis accompanying hydrogenation. This hydrogen in the hydrogenation came from the reaction thus:
This was tested by work described in this note. The species of alkali may also be expected to have some effects on the solubilization of the product. From the industrial viewpoint it is commendable to use cheaper alkali such as calcium hydroxide or sodium carbonate. This problem is also treated in this note. Taiheiyo coal (76.7% C 6.4% H) was crushed below 100 Tab/e 1 Effect of species of alcohol and alkali
Hz II
CH,C-OH
-
f?
CH,-Cf;j--
CH,-C
02
=0
. 2H, t
AH
Alcohol
Ross’ also reported an increase in solubilization with the reaction between isopropyl alcohol, sodium hydroxide and coal. In this case the reaction may be: ‘:
(7
(CH,I,=C-OH+(CH,l,.
C -6=+CH,12
.C:O+Ht
If the same type of reaction takes place for all the alcohols it can also be expected for methanol, which is a cheaper alcohol.
Cl+,-OH
-
-e
‘1 r_
H-C,-0
oHL
-HC=O
I
6H
l
2H, f
Yield of product
Yield of pyridine extract
(%I
(%)
Amount of alkali
Yield of product (%I 0.15
6g
Yield of pyridine extract (%I mol
NaOH
Ethanol
86.6
94.7
-
-
NaOH
Methanol
84.3
,?Z,a
84.3
96.3 t42.91a
KOH
Methanol
86.7
(:::,a
87.0
99.2 wzi.31a
Ca(OH),
Methanol
96.7
29.7
97.6
21 .o
Ca(OH),’
Methanol
-
-
96.1
47.0
Na2COs
Methanol
98.0
27.6
89.6
31.1
aYield of ethanol extraction. Temperature: 350°C. b4OO’C. Yield of pyridine extraction of original coal: 14.1%
0016-2361/78/120801-02$02.00 0 1978 IPC Business Press
FUEL,
1978,
Vol57,
December
801