Analysis of coal swelling behavior during carbonization

Youichi Takizawa, Takashi Kimura, Kentarou Higuchi, Yoshio Morozumi, Hideyuki Aoki, Takatoshi Miura, Kazuya Uebo, Koichi Fukuda

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


The swelling behavior of a softening coal particle during carbonization was numerically analyzed. In this study, since the swelling of a coal particle was caused by the growth of bubbles in the coal particle, the bubble growth due to the inflow of volatile matters to the bubbles was calculated involving nucleation. coalescence in the coal particle and emission of bubbles to particle outside during the softening stage. The production of volatile matters was evaluated by the FLASHCHAIN model. The pyrolysis experiment of a coal particle was carried out and the expansion behavior was photographed. Then, the swelling ratio was obtained. The calculated results of swelling ratio differed from experimental results because the gas evolution from coal particle was incorrect. In addition, the secondary decomposition of tar and the model of the coal softening behavior were required for the accurate prediction of the swelling behavior. Bubble growth rate was assumed to be the function of viscosity in this study. In order to understand the effect of the viscosity on swelling ratio, the variation of swelling ratio of the coal with viscosity change was investigated by varying assumed viscosity. The swelling ratio calculated with low viscosity was low because bubble nucleation was decreased by low viscosity. The swelling ratio with high viscosity was inhibited because high viscosity leads to low bubble growth rate. The property of softening coal, which is difficult to measure, can be estimated by more accurate analysis.

Original languageEnglish
Pages (from-to)198-205
Number of pages8
JournalTetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
Issue number3
Publication statusPublished - 2006 Mar


  • Bubble
  • Coal particle
  • Pyrolysis
  • Swelling

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Analysis of coal swelling behavior during carbonization'. Together they form a unique fingerprint.

Cite this