IR Spectroscopic Characterization of Lignite as a Tool to Predict the Product Range of Catalytic Decomposition

Valentin  Cepus; Markus  Borth; Mathias  Seitz

doi:10.4236/ijcce.2016.51002

Valentin Cepus^*, Markus Borth, Mathias Seitz

Abstract: The catalytic pyrolysis of lignites is a technical process whose development is complex and time-consuming with the goal to maximize the yield of the desired low-volatile hydrocarbons of choice and to minimize the yield of solid residual products. Not every type of lignite is suitable for this process due to its particular chemical composition. In order to be able to predict which lignite specimen will be an especially promising raw material for the pyrolytic liberation of target products, the chemical classification by IR spectroscopic methods was investigated. MIR spectroscopy has been demonstrated to be a valuable tool to characterize the the molecular composition of lignites and to determine the concentrations of aliphatic and aromatic functional groups in lignite as well as alcoholic OH and other forms of bound oxygen. These data provide a comprehensive chemical characterization of the material and help to predict the composition of the chemical components liberated by catalytic decomposition. With a complementary NIR spectroscopic approach, a chemometric method has been developed with which the elemental com-position of the lignites can be determined in a fast and pragmatic way leading to a prediction of the product range of a theoretical pyrolytic product range. Thus, this spectroscopic investigation is a toolbox that can answer the question if the commercial exploitation of catalytic pyrolysis of a lignite sample in question will make sense without preliminary conduction of long and time-consuming testing.

Keywords: Coal, Lignite, IR Spectroscopy, Characterization, MIR, NIR, Pyrolysis

Cite this paper: Cepus, V. , Borth, M. and Seitz, M. (2016) IR Spectroscopic Characterization of Lignite as a Tool to Predict the Product Range of Catalytic Decomposition. International Journal of Clean Coal and Energy, 5, 13-22. doi: 10.4236/ijcce.2016.51002.

References

[1] Seitz, M., Heschel, W., Nagler, T., Nowak, S., Zimmermann, J., Stam-Creutz, T., et al. (2014) Influence of Catalysts on the Pyrolysis of Lignites. Fuel, 134, 669-676. http://dx.doi.org/10.1016/j.fuel.2014.05.042

[2] Seitz, M., Nagler, T., Welscher, J., Nowak, S., Zimmermann, J., Hahn, T. and Schwieger, W. (2014) Catalytic Cracking of Lignites. Erdol, Erdgas, Kohle, 130, 80-84.

[3] Cerny, J. (2007) Aliphatic C-H Bond Responses in the 900 - 700 cm-1 Region of the FTIR Spectra of Coal Tars. Fuel Science and Technology International, 13, 807-818. http://dx.doi.org/10.1080/08843759508947707

[4] de Aragao, B.J.G. and Messaddeq, Y. (2008) Peak Separation by Derivative Spectroscopy Applied to FTIR Analysis of Hydrolyzed Silica. Journal of the Brazilian Chemical Society, 8, 1582-1594. http://dx.doi.org/10.1590/S0103-50532008000800019

[5] Ramaswamy, K. and Venkatachalapathy, R. (2006) Infrared Spectroscopic Study of Neyveli Lignite Samples from Mine Cut-I and II. Spectroscopy Letters: An International Journal for Rapid Communication, 24, 759-778. http://dx.doi.org/10.1080/00387019108018157

[6] Pretsch, E., Clerc, T., Seibl, J. and Simon, W. (1990) Tabellen zur Strukturaufklarung organischer Verbindungen mit spektroskopischen Methoden. 3. Auflage, Springer-Verlag Berlin Heidelberg, New York.

[7] Ibarra, J., Royo, C., Monzón, A. and Santamaría, J. (1995) Fourier Transform Infrared Spectroscopic Study of Coke Deposits on a Cr2O3-Al2O3 Catalyst. Elsevier Science, 9, 191-196.

[8] Ibarra, J., Munoz, E. and Moliner, R. (1996) FTIR Study of the Evolution of Coal Structure during the Coalification Process. Journal of Organic Geochemistry, 24, 725-735.

[9] Schmalfeld, J. (2008) Die Veredlung und Umwandlung von Kohle: Technologien und Projekte 1970 bis 2000 in Deutschland. Deutsche Wissenschaftliche Gesellschaft für Erdol, Erdgas und Kohle e.V.

[10] Oikonomopoulos, I., Perraki, T. and Tougiannidis, N. (2010) FTIR Study of Two Different Lignite Lithotypes from Neocene Achlada Lignite Deposits in Greece. Bulletin of the Geological Society of Greece, 5, 2284-2293.

[11] Chodak, M., Niklińska, M. and Beese, F. (2007) The Use of Near Infrared Spectroscopy to Quantify Lignite-Derived Carbon in Humus-Lignite Mixtures. Journal of Near-Infrared Spectroscopy, 15, 195-200. http://dx.doi.org/10.1255/jnirs.724