Separation of high purity indole from coal tar by high pressure crystallization

Yoshitaka Yamamoto, Yoshiki Sato, Takeo Ebina, Chiaki Yokoyama, Sinji Takahasi, Yutaka Mito, Harumasa Tanabe, Nobuhiko Nishiguchi, Kohichi Nagaoka

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


High pressure crystallization has been applied to the separation and purification of indole from a model mixture of crude coal tar. Indole with 98.6 wt% purity was separated at 50 °C under a pressure of 2000 kgf cm-2 from the model mixture contaning 69.3 wt% indole. Successive 'depressurization sweating' increased the purity of indole up to 99.5 wt%. The equilibrium of the system under high pressure was also studied.

Original languageEnglish
Pages (from-to)565-566
Number of pages2
Issue number4
Publication statusPublished - 1991 Apr


  • coal tar
  • crystallization
  • separation

ASJC Scopus subject areas

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


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