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The reaction of coal with ferric chloride
2
300°C. But the accurate evaluation of rate constants has been considered difficult because of the uncertainty of products analysis.
3
4 5
REFERENCES 1
Dryden, 1. G. C., ‘Chemistry of Coal Utilization’, Suppl. Vol. (Ed. H. H. Lowry), John Wiley, New York, 1963, Ch. 6
6
Sato, Y., Yamakawa, T., Onishi, R., Kameyama, H. and Amano, A. J. Japan Petrol. Inst. 1978,21(2), 110 Benjamin, B. M., Raaen, V. F., Maupin, P. H., Brown, L. L. and Collins. C. .I. Fuel 1978.57.269; Beniamin. B. M. Fuel _ 1978,57,3.78 Kblling, G. and Hausigk, D. Brennst.-Chem. 1969,50,65 Copeland, P. G., Dean, R. E. and McNeil, D. J. Chem. Sot. 1961,1232 Lin, M. C. and Back, M. H. Can. J. Chem. 1966,44,2357
The reaction of coal with ferric chloride Herbert Beall Department of Chemistry, Worcester (Received 16 November 19781
Polytechnic
Institute,
It is well known that graphite will undergo reactions with a variety of reagents to form intercalation compounds where the graphite layers are separated to accommodate a variety of species between them’J. It is of interest to establish if such intercalation compounds can be prepared from coal and, in fact, a recent report very strongly indicates that such compounds can be prepared from coal and potassium3. This report concerns the reaction of coal with anhydrous ferric chloride (FeC13) to produce what may be intercalation compounds. The experiments were carried out on three different coals: PSOC-379, Pennsylvania semi-anthracite (I’ & M ‘B’); PSOC- 15 1, New Mexico high volatile C bituminous (Lower Split of Blue); and PSOC-240, Washington subbituminous B (Big Dirty). These three coals were treated after pulverization and air drying at 120°C directly with FeC13, and were also treated with FeC13 after a demineralization4 which involved washing with 1% HCl at 5O’C for 18-24 h followed by air drying at 120°C. Debye-Scherrer X-ray diffraction patterns of the untreated and demineralized coals were essentially identical except that enhanced crystallinity of the demineralized samples was indicated by the shorter diffraction times needed to obtain equivalent diffraction patterns. PSOC- 15 1 and PSOC-240 showed principally the 002 graphite band, whereas PSOC-379 gave this band strongly as well as other bands from crystalline matter. In each of the six reactions with FeC13, approximately 1.O g of coal and 0.6 g of FeC13 were mixed and then heated to 230°C for 10 min. No obvious evidence of reaction was observed and the final products looked similar to the coal starting material. Incorporation of the FeC13 into the coal was suggested by the failure of the reaction products to react readily with water to form the yellow-brown hydrate which the unreacted FeC13 forms. The Debye-Scherrer diffraction patterns of the coal-FeClg products of PSOC-15 1 and PSOC-240 do not include the 002 graphite band which was prevalent in the coal starting material, and this band is almost completely eliminated from PSOC379. More rigorous conditions using 2 g of FeC13 per gram of coal, and heating for 36 min at up to 25O”C, were found to produce products in which the 002 graphite band was eliminated from PSOC-379. The products under these more rigorous conditions were observed to be more gray and powdery
Worcester,
0016-2361/79/0403194182.00 0 1979 IPC Business Press
Massachusetts
01609,
USA
than the starting coal. The more rigorous conditions required for PSOC379 could be attributed to more extensive graphite-like structures in the semi-anthracite coal. The PSOC-379-FeC13 product was then washed with 1% HCl for 18 h and subsequently dried in air at 120°C. The Debye-Scherrer diffraction pattern obtained from the sample after washing was identical with that of the coal sample prior to reaction with FeC13, except that a longer time seemed to be needed to obtain the same intensity of diffraction, possibly indicating some breakdown of the crystallinity. Thus the reaction with FeC13 is largely reversible. These reactions of coal with FeC13 are strikingly similar to the formation of graphite-FeC13 intercalation compounds both in their formation and in their decomposition with dilute acid. Comparison experiments run in this laboratory with amorphous carbon powder (microcrystalline graphite) yielded observations which were parallel to those obtained with coal, except that more FeC13 and more rigorous conditions were required to eliminate completely the 002 diffraction band with the amorphous carbon. The carbon would be expected to be able to intercalate more FeC13 than the much more heterogeneous coal structure. Experiments in progress or contemplated include study of the chemistry and structure of the coal-FeC13 adducts, determining the scope of coal-metal salt reactions, and examining the reactivity of these coal adducts.
ACKNOWLEDGEMENT The author is grateful to Dr Alan Davis of the Coal Research Section of the Pennsylvania State University who supplied the coal samples. REFERENCES 1 2 3 4
Rudorff, W. Advances in Inorganic Chemistry and Radiochemistry 1959, 1,223 Henning, G. R. Progress in Inorganic Chemistry 1959, 1, 125 Lazarov, L., Rashkov, I. and Angelov, S. Fuel 1978,57,637 Jenkins, R. G., Nandi, S. P. and Walker, P. L. Jr Fuel 1973, 52.288
FUEL, 1979, Vol 58, April
319
300°C. But the accurate evaluation of rate constants has been considered difficult because of the uncertainty of products analysis.
3
4 5
REFERENCES 1
Dryden, 1. G. C., ‘Chemistry of Coal Utilization’, Suppl. Vol. (Ed. H. H. Lowry), John Wiley, New York, 1963, Ch. 6
6
Sato, Y., Yamakawa, T., Onishi, R., Kameyama, H. and Amano, A. J. Japan Petrol. Inst. 1978,21(2), 110 Benjamin, B. M., Raaen, V. F., Maupin, P. H., Brown, L. L. and Collins. C. .I. Fuel 1978.57.269; Beniamin. B. M. Fuel _ 1978,57,3.78 Kblling, G. and Hausigk, D. Brennst.-Chem. 1969,50,65 Copeland, P. G., Dean, R. E. and McNeil, D. J. Chem. Sot. 1961,1232 Lin, M. C. and Back, M. H. Can. J. Chem. 1966,44,2357
The reaction of coal with ferric chloride Herbert Beall Department of Chemistry, Worcester (Received 16 November 19781
Polytechnic
Institute,
It is well known that graphite will undergo reactions with a variety of reagents to form intercalation compounds where the graphite layers are separated to accommodate a variety of species between them’J. It is of interest to establish if such intercalation compounds can be prepared from coal and, in fact, a recent report very strongly indicates that such compounds can be prepared from coal and potassium3. This report concerns the reaction of coal with anhydrous ferric chloride (FeC13) to produce what may be intercalation compounds. The experiments were carried out on three different coals: PSOC-379, Pennsylvania semi-anthracite (I’ & M ‘B’); PSOC- 15 1, New Mexico high volatile C bituminous (Lower Split of Blue); and PSOC-240, Washington subbituminous B (Big Dirty). These three coals were treated after pulverization and air drying at 120°C directly with FeC13, and were also treated with FeC13 after a demineralization4 which involved washing with 1% HCl at 5O’C for 18-24 h followed by air drying at 120°C. Debye-Scherrer X-ray diffraction patterns of the untreated and demineralized coals were essentially identical except that enhanced crystallinity of the demineralized samples was indicated by the shorter diffraction times needed to obtain equivalent diffraction patterns. PSOC- 15 1 and PSOC-240 showed principally the 002 graphite band, whereas PSOC-379 gave this band strongly as well as other bands from crystalline matter. In each of the six reactions with FeC13, approximately 1.O g of coal and 0.6 g of FeC13 were mixed and then heated to 230°C for 10 min. No obvious evidence of reaction was observed and the final products looked similar to the coal starting material. Incorporation of the FeC13 into the coal was suggested by the failure of the reaction products to react readily with water to form the yellow-brown hydrate which the unreacted FeC13 forms. The Debye-Scherrer diffraction patterns of the coal-FeClg products of PSOC-15 1 and PSOC-240 do not include the 002 graphite band which was prevalent in the coal starting material, and this band is almost completely eliminated from PSOC379. More rigorous conditions using 2 g of FeC13 per gram of coal, and heating for 36 min at up to 25O”C, were found to produce products in which the 002 graphite band was eliminated from PSOC-379. The products under these more rigorous conditions were observed to be more gray and powdery
Worcester,
0016-2361/79/0403194182.00 0 1979 IPC Business Press
Massachusetts
01609,
USA
than the starting coal. The more rigorous conditions required for PSOC379 could be attributed to more extensive graphite-like structures in the semi-anthracite coal. The PSOC-379-FeC13 product was then washed with 1% HCl for 18 h and subsequently dried in air at 120°C. The Debye-Scherrer diffraction pattern obtained from the sample after washing was identical with that of the coal sample prior to reaction with FeC13, except that a longer time seemed to be needed to obtain the same intensity of diffraction, possibly indicating some breakdown of the crystallinity. Thus the reaction with FeC13 is largely reversible. These reactions of coal with FeC13 are strikingly similar to the formation of graphite-FeC13 intercalation compounds both in their formation and in their decomposition with dilute acid. Comparison experiments run in this laboratory with amorphous carbon powder (microcrystalline graphite) yielded observations which were parallel to those obtained with coal, except that more FeC13 and more rigorous conditions were required to eliminate completely the 002 diffraction band with the amorphous carbon. The carbon would be expected to be able to intercalate more FeC13 than the much more heterogeneous coal structure. Experiments in progress or contemplated include study of the chemistry and structure of the coal-FeC13 adducts, determining the scope of coal-metal salt reactions, and examining the reactivity of these coal adducts.
ACKNOWLEDGEMENT The author is grateful to Dr Alan Davis of the Coal Research Section of the Pennsylvania State University who supplied the coal samples. REFERENCES 1 2 3 4
Rudorff, W. Advances in Inorganic Chemistry and Radiochemistry 1959, 1,223 Henning, G. R. Progress in Inorganic Chemistry 1959, 1, 125 Lazarov, L., Rashkov, I. and Angelov, S. Fuel 1978,57,637 Jenkins, R. G., Nandi, S. P. and Walker, P. L. Jr Fuel 1973, 52.288
FUEL, 1979, Vol 58, April
319