Impact of pressure on the carbon structure of char during pyrolysis of bituminous coal in pressurized entrained-flow reactor

Arash Tahmasebi, Kristina Maliutina, Jianglong Yu

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20 Citations (Scopus)

Abstract

The impact of pressure on the carbon structure of a Chinese bituminous coal was investigated using a pressurized entrained-flow reactor in the temperature and pressure ranges of 700-900 °C and 0.1-4.0MPa, respectively. Pyrolysis pressure had a significant influence on the physiochemical and carbon structure of chars. The specific surface area and the swelling ratio of chars reached their highest values at 1.0MPa. Fourier transform infrared spectroscopy (FTIR) analysis showed that higher pressures enhanced the decomposition of functional groups in chars. Raman spectroscopy analysis results revealed that at elevated pressures, the organic matrix and functional groups were removed from the char structure, leading to higher ordering of the carbon structure. During X-ray diffraction (XRD) analysis, parameters such as the stacking height (L c ), interlayer spacing (d 002 ) and lateral size of the graphite structures (L a ) were used to evaluate the graphitic structures in chars. The results showed an increase in L c , L a , and the average number of graphene sheets with pyrolysis pressure, indicating a more ordered carbon structure at elevated pressures. The d-spacing of char was in the range of 3.34-3.37 Å, similar to typical graphitic structures.

Original languageEnglish
Pages (from-to)393-403
Number of pages11
JournalKorean Journal of Chemical Engineering
Volume36
Issue number3
DOIs
Publication statusPublished - Mar 2019
Externally publishedYes

Keywords

  • Bituminous Coal
  • Carbon Materials
  • Carbon Structure
  • Pressurized Entrained-flow Pyrolysis
  • Raman Spectroscopy

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