Abstract
The paper contains a numerical analysis of the electron paramagnetic resonance (EPR) spectra of coal macerals (exinite, vitrinite, inertinite) obtained from Polish medium-rank coal (85.6 wt% C). We determine the lineshapes and the parameters of the component lines, i.e., the intensities and linewidths. As a result, we find that the EPR spectra of the studied macerals are superpositions of broad Gaussian, broad Lorentzian 1 and narrow Lorentzian 3 lines for vitrinite and exinite and two narrow Lorentzian 2 and Lorentzian 3 lines for inertinite. The influence of microwave power on the component lines of the EPR spectrum is studied. A comparison of the results obtained at 223 and 293 K shows that the EPR lines at both temperatures saturate at the same microwave power. It also indicates similar changes of the linewidths with changes of microwave power at both temperatures, a slight increase with increasing microwave power.
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References
Winans R.E., Crelling J.C. (eds.): Chemistry and Characterization of Coal Macerals, American Chemical Society Symposium Series 252. Washington, D.C.: American Chemical Society 1984.
Silbernagel B.G., Gebhard L.A., Dyrkacz G.R. in: Magnetic Resonance: Introduction, Advanced Topics and Applications to Fossil Energy (Petrakis L., Fraissard J.P., eds.), pp. 645–654. Dordrecht: Reidel 1984.
Silbernagel B.G., Gebhard L.A., Dyrkacz G.R., Bloomquist C.A.: Fuel65, 558–565 (1986)
Mazumdar B.K., Chakrabartty S.K., Lahiri A.: Fuel41, 129–139 (1962)
Smidt J., Van Krevelen D.W.: Fuel,37, 355–368 (1959)
Weil J.A., Bolton J.R., Wertz J.E.: Electron Paramagnetic Resonance: Elementary Theory and Practical Application, p. 506. New York: Wiley 1994.
Poole C.P.: Electron Spin Resonance, New York: Wiley 1967.
Petrakis L., Grandy D.W.: Free Radicals in Coals and Synthetic Fuels, Coal Science and Technology, vol. 5. Amsterdam: Elsevier 1983.
Van Krevelen D.W.: Coal: Typology — Chemistry — Constitution, chapt. 15, p. 451. Amsterdam: Elsevier 1993.
Pilawa B., Więckowski A.B., Lewandowski G., Nassalski G.: Erdöl Erdgas Kohle114, 37–40 (1998)
Clarkson R.B., Wei Wang, Brown D.R., Crookham H.C., Belford R.L. in: Magnetic Resonance of Carbonaceous Solids, Developed from a Symposium Sponsored by the International Chemical Congress of the Pacific Basin Societies. Advances in Chemistry Series (Botto R.E., Sanada Y., eds.), vol. 229, pp. 507–528. Washington: American Chemical Society 1993.
Pilawa B., Więckowski A.B.: Fuel76, 1173–1177 (1997)
Pilawa B., Trzebicka B., Więckowski A.B., Hanak B., Komorek J., Pusz S.: Erhöl Kohle Erdgas Petrochem. Hydrocarbon Technol.44, 421–425 (1991)
Marzec A.: J. Anal. Appl. Pyrolysis8, 241–254 (1985)
Given P.H., Marzec A., Barton W.A., Lynch L.J., Gerstein B.G.: Fuel65, 155–163 (1986)
Pilawa B., Trzebicka B., Więckowski A.B.: Fuel70, 1109–1110 (1991)
Uebersfeld J., Erb E.: Third Biennial Carbon Conference Francep, p. 103, 1958.
Więckowski A.B., Pilawa B., Świątkowska L., Wojtowicz W., Stowik G.P., Lewandowski M.: J. Magn. Reson.145, 62–67 (2000)
Schlick S., Narayana M., Kevan L.: Fuel62, 1250–1254 (1983)
Schlick S., Kevan L. in: Magnetic Resonance: Introduction, Advanced Topics and Applications to Fossil Energy (Petrakis L., Fraissard J.P., eds.), pp. 655–665. Dordrecht: Reidel 1984.
Ito O., Seki H., Iino M.: Bull. Chem. Soc. Jpn.60, 2967–2975 (1987)
Dack S.W., Hobday M.D., Smith T.D., Pilbrow J.R.: Fuel64, 219–221 (1985)
Pilawa B., Więckowski A.B., Lewandowski M.: Fuel74, 1654–1657 (1995)
Silbernagel B.G., Gebhard L.A., Dyrkacz G.R., Bloomquist C.A. in: Chemistry and C Characterization of Coal Macerals (Winans R.E., Crelling J.C., eds.), p. 121, American Chemical Society Symposium Series 252. Washington, D.C.: American Chemical Society 1984.
Pilawa B., Więckowski A.B., Trzebicka B.: Radiat. Phys. Chem.45, 899–908 (1995)
Pilawa B., Więckowski A.B., Trzebicka B.: Mol. Phys. Rep.4, 245–250 (1994)
Jeunet A., Nickel B., Rassat A.: Fuel.68, 883–889 (1989)
Pake G.E.: Paramagnetic Resonance. New York: W.A. Benjamin, Inc. 1962.
Więckowski A.: Fiz. Dielektr. Radiospektrosk.7, 101–119 (1975)
Więckowski A.: Fiz. Dielektr. Radiospektrosk.7, 223–245 (1975)
Retcofsky H.L., Stark J.M., Friedel R.A.: Anal. Chem.40, 1699–1704 (1968)
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Słowik, G.P., Więckowski, A.B. Influence of microwave power on EPR spectra of coal macerals. Appl. Magn. Reson. 24, 437–445 (2003). https://doi.org/10.1007/BF03166947
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DOI: https://doi.org/10.1007/BF03166947