Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash

L. Kelebopile, R. Sun, X. Zhang, P. Xu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Previous experiments using thermo-gravimetric analysis (TGA) concluded a high carbon fly ash obtained from a circulating fluidized bed (CFB) gasifier by firing an anthracite coal to be less reactive compared to other high ash content chars that were prepared under laboratory conditions in a drop tube furnace (DTF) from a parent bituminous coal. This fly ash had internal surface (BET) area and pore volume of an order of magnitude larger than the laboratory prepared chars and so a further investigation was carried out by determining the influence of the fly ash residence time (10-20s) in the CFB on its structural ordering. The structural analysis was carried out by using Raman spectroscopy and X-ray diffraction (XRD). Raman spectroscopy with a 457.9nm laser, was used to compare the structural ordering of the fly ash carbon with those of its parent (anthracite) coal; a char prepared from the same parent coal at the same heat treatment temperature as the fly ash but under laboratory conditions; and the other chars prepared from a bituminous parent coal (under laboratory conditions) whose reactivities were found to be higher than the fly ash. It was concluded that the long residence times enhanced the decomposition of the anthracite coal, consumption of the amorphous carbon and the ordering of aromatic units and the crystalline structure as gasification progressed. The structural behavior of fly ash was also investigated after different conversions in DTF through reactions with oxygen at 5% and 20% concentration at a temperature of 1300°C. At low residence times, the fly ash became less ordered due to further decomposition and release of loose organic matrix and after longer residence time the fly ash then became more ordered due to aromatic ring growth. XRD experiments were used to validate the structural analysis result from Raman spectroscopy. The results concluded fly ash and a laboratory char prepared at high temperature to be the most ordered. There was also the linear relationship between the volatile content of the chars including the fly ash when compared with their structural parameters.

Original languageEnglish
Title of host publicationCleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion
PublisherSpringer-Verlag Berlin Heidelberg
Pages447-452
Number of pages6
ISBN (Print)3540356061, 9783642304446
Publication statusPublished - Jan 1 2012
Event7th International Symposium on Coal Combustion: Cleaner Combustion and Sustainable World, ISCC - Harbin, China
Duration: Jul 17 2011Jul 20 2011

Other

Other7th International Symposium on Coal Combustion: Cleaner Combustion and Sustainable World, ISCC
CountryChina
CityHarbin
Period7/17/117/20/11

Fingerprint

Fly ash
Gasification
Fluidized beds
X ray diffraction analysis
Raman spectroscopy
Anthracite
Coal
Bituminous coal
Ashes
Structural analysis
Furnaces
Decomposition
X ray diffraction
Carbon
Amorphous carbon
Temperature
Thermogravimetric analysis
Experiments
Heat treatment
Crystalline materials

All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Fuel Technology
  • Renewable Energy, Sustainability and the Environment

Cite this

Kelebopile, L., Sun, R., Zhang, X., & Xu, P. (2012). Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash. In Cleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion (pp. 447-452). Springer-Verlag Berlin Heidelberg.
Kelebopile, L. ; Sun, R. ; Zhang, X. ; Xu, P. / Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash. Cleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion. Springer-Verlag Berlin Heidelberg, 2012. pp. 447-452
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Kelebopile, L, Sun, R, Zhang, X & Xu, P 2012, Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash. in Cleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion. Springer-Verlag Berlin Heidelberg, pp. 447-452, 7th International Symposium on Coal Combustion: Cleaner Combustion and Sustainable World, ISCC, Harbin, China, 7/17/11.

Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash. / Kelebopile, L.; Sun, R.; Zhang, X.; Xu, P.

Cleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion. Springer-Verlag Berlin Heidelberg, 2012. p. 447-452.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Kelebopile L, Sun R, Zhang X, Xu P. Raman spectroscopy and X-ray diffraction analysis of the structural characteristics of fluidized bed gasification fly ash. In Cleaner Combustion and Sustainable World - Proceedings of the 7th International Symposium on Coal Combustion. Springer-Verlag Berlin Heidelberg. 2012. p. 447-452