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Role of Infrared Spectroscopy in Coal Analysis—An Investigation

DOI: 10.4236/ajac.2014.56044, PP. 367-372

Keywords: Coal, Leaching, FT-IR, Bioleaching, Organic Acid

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Abstract:

Fourier transform infrared (FT-IR) spectroscopy is a widely used analytical technique for determining the different functional groups of a coal structure. This method, being able to reveal carbo-hydrogenated structures (aromatic and aliphatic) and heteroatomic functions (mainly oxygenated), as well as to detect the presence of minerals, is currently one of the most powerful techniques for coal characterization and thus is of paramount importance in the various utilization procedures of coal (industrial combustion, coke production processes, etc.). FT-IR study shows the presence of aliphatic -CH, -CH2 and -CH3 groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking. It is conjectured that, the two-stage leaching using HNO3 followed by HF remarkably reduced the ash content as well as the minerals including Al, Si and Ca. The solubilization of samples with buffered EDTA could not eliminate the minerals in coal. The silicate and kaolinite bands showed a systematic lowering on EDTA and carboxylic acid treatment. The fungal leaching was most beneficial for aromatic molecules with different degrees of substitution. The intensity of bands due to carbonyl groups was increased, when treated with fungi, whereas that due to oxygen functional groups showed a reverse trend. The mineral bands due to silicates also decreased in intensity, on post treatment with fungal culture.

References

[1]  Andreas, G., Andreas, I. and Victoria, K. (2003) Study of Low Rank Greek Coals Using FT-IR Spectroscopy. Energy sources, 25, 995-1005.
[2]  Basaran, Y., Denizli, A., Sakintuna, B., et al. (2003) Bio-Liquefaction/Solubilization of Low-Rank Turkish Lignites. Energy Fuel, 17, 1068-1074.
http://dx.doi.org/10.1021/ef020210s
[3]  Cerny, J. (1996) Structural Dependence of CH Bond Absorptivities and Consequences for FTIR Analysis of Coals. Fuel, 75, 1301-1306.
http://dx.doi.org/10.1016/0016-2361(96)00103-2
[4]  Debashis, B. (2005) Study of Kinetics of Iron Minerals in Coal by Fe-57 Mossbauer and FT-IR Spectroscopy during Natural Burning. Hyperfine Interactions, 163, 167-176.
[5]  Manoj, B. (2013) Bio-Demineralization of Indian Bituminous Coal by Aspergillus niger and Characterization of Products. Research Journal of Biotechnology, 8, 49-54.
[6]  Manoj, B. and Kunjomana, A.G. (2012) Structural Characterization of Selected Indian Coals by X-Ray Diffraction and Spectroscopic Techniques. Trends in Applied Sciences Research, 7, 434-444.
[7]  Manoj, B. and Kunjomana, A.G. (2012) Chemical Leaching of an Indian Bituminous Coal and Characterization of the Products by Vibrational Spectroscopic Techniques. International Journal of Minerals, Metallurgy and Materials, 19, 279-283.
http://dx.doi.org/10.1007/s12613-012-0551-0
[8]  Manoj, B. and Elcey, C.D. (2010) Demineralization of Coal by Stepwise Leaching: A Study of Sub-Bituminous Indian Coal by FTIR and SEM. Journal of the University Chemical Technology and Metallurgy, 45, 385-390.
[9]  Manoj, B. and Kunjomana, A.G. (2010) Chemical Solubilization of Coal Using HF and Characterization of the Products by FTIR, FT Raman, SEM and Elemental Analysis. Journal of Minerals and Materials Characterization and Engineering, 9, 919-928.
[10]  Manoj, B. and Kunjomana, A.G. (2010) FT-Raman Spectroscopic Study of Indian Bituminous and Sub-Bituminous Coal. Asian Journal of Material Science, 2, 204-210.
[11]  Manoj, B., Kunjomana, A.G. and Chandrasekharan, K.A. (2009) Chemical Leaching of Low Rank Coal and Its Characterization Using SEM/EDAX and FTIR. Journal of Minerals and Materials Characterization and Engineering, 8, 821-832.
[12]  Manoj, B. and Elcey, C.D. (2013), Demineralization of Sub-Bituminous Coal by Fungal Leaching—A Structural Characterization by X-Ray and FTIR Analysis. Research Journal of Chemistry and Environment, 17, 11-15.
[13]  Narayanan, P. and Manoj, B. (2013) Study of Changes to the Organic Functional Groups of a High Volatile Bituminous Coal during Organic Acid Treatment Process by FTIR Spectroscopy. Journal of Minerals and Materials Characterization and Engineering, 1, 39-43.
[14]  Sharma, D.K. and Wadhwa, G. (1997) Demineralization of Coal by Stepwise Bioleaching: A Comparative Study of Three Indian Coals by Fourier Transform Infrared and X-Ray Diffraction Techniques. World Journal of Microbiology and Biotechnology, 13, 29-36.
http://dx.doi.org/10.1007/BF02770804
[15]  Supaluknari, S., Larkins, F.P., Redlich, P., et al. (1988) An FTIR Study of Australian Coals: Characterization of Oxygen Functional Groups. Fuel Processing Technology, 19, 123-140.
http://dx.doi.org/10.1016/0378-3820(88)90061-6

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