Enhancement of Na formation from the nitrogen in carbon and coal by calcium

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Naoto Tsubouchi
  • Yasuhiro Ohshima
  • Chunbao Xu
  • Yasuo Ohtsuka

Detail(s)

Original languageEnglish
Pages (from-to)158-162
Journal / PublicationEnergy and Fuels
Volume15
Issue number1
Publication statusPublished - 2001
Externally publishedYes

Abstract

The effects of Ca catalysts on nitrogen release during heat treatment of polyacrylonitrile-derived carbon and pyrolysis of low rank coals have been studied with a fixed bed quartz reactor in a stream of high purity He. In the temperature-programmed treatment at 10 "C/rnin of the carbon with 3 wt % Ca, the Ca promotes N2 information at 850-1000 °C and the catalytic effect is larger at a higher temperature. When a low rank coal, after demineralization and subsequent addition of 3 wt % Ca, is pyrolyzed in the same manner as above, the Ca enhances the rate of N2 formation at 850-1100 °C at largest by a factor of 15. In the fast heating pyrolysis at 400 °C/min of the demineralized samples, the Ca at loading of 1-3 wt % also increases N2 yields at 1200-1350 °C irrespective of type of coal. These observations and nitrogen distribution:indicate that the N2 increased by Ca addition arises mainly from solid-phase reactions of heterocyclic nitrogen forms. The X-ray diffraction measurements after heat treatment and pyrolysis reveal that .catalyst particles are too fine on the carbon to be detected and as small as 45-65 nm in size on the chars. The catalysis of N2 formation at solid phase by the Ca is discussed in terms of the mobility of CaO particles, their agglomeration, and sulfur poisoning. © 2001 American Chemical Society.

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Citation Format(s)

Enhancement of Na formation from the nitrogen in carbon and coal by calcium. / Tsubouchi, Naoto; Ohshima, Yasuhiro; Xu, Chunbao et al.
In: Energy and Fuels, Vol. 15, No. 1, 2001, p. 158-162.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review