Extraction of Taiheiyo coal with supercritical water-HCOOH mixture

T. Adschiri, T. Sato, H. Shibuichi, Z. Fang, S. Okazaki, K. Arai

Research output: Contribution to journalConference articlepeer-review

62 Citations (Scopus)


Taiheiyo coals were extracted with supercritical toluene (SC-toluene) (653 K, 20 MPa), supercritical water (SCW) (653 K, 35 MPa) and formic acid (HCOOH)-SCW mixed solvents (653 K, 35 MPa) using a semi-batch type system. The results clearly indicate that the coal conversion (= 1 - weight of residual coal (daf)/weight of loaded coal (daf)) and the liquid yield (= weight of liquid extracts/weight of loaded coal) in HCOOH-SCW were higher than those in SCW and SC-toluene. A considerable portion of coal is thus converted into light oils probably through hydrolysis and hydrogenation in HCOOH-SCW. We conducted another series of experiments for direct in situ observation of coal conversion in SCW and HCOOH-SCW using a diamond anvil cell (DAC). In HCOOH-SCW, the effective and rapid hydrogenation of coal with HCOOH occurs mainly at the early stage of the reaction.

Original languageEnglish
Pages (from-to)243-248
Number of pages6
Issue number3-4
Publication statusPublished - 2000 Feb
EventProceedings of the 1999 International Symposium on Fundamentals for Innovative Coal Utalization - Sapporo, Jpn
Duration: 1999 Feb 21999 Feb 4

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Organic Chemistry


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