Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
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Drying Characteristics of High Moisture Low Rank Coal using a Steam Fluidized-bed Dryer

스팀 유동층 건조기를 이용한 고수분 저등급 석탄의 건조 특성

  • Kim, Gi Yeong (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Rhee, Young-Woo (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Park, Jae Hyeok (Chemical and Biomolecular Engineering, Yonsei University) ;
  • Shun, Dowon (Greenhouse Gas Laboratory, Korea Institute of Energy Research) ;
  • Bae, Dal-Hee (Greenhouse Gas Laboratory, Korea Institute of Energy Research) ;
  • Shin, Jong-Seon (Greenhouse Gas Laboratory, Korea Institute of Energy Research) ;
  • Ryu, Ho-Jung (Greenhouse Gas Laboratory, Korea Institute of Energy Research) ;
  • Park, Jaehyeon (Greenhouse Gas Laboratory, Korea Institute of Energy Research)
  • 김기영 (충남대학교 에너지과학기술대학원) ;
  • 이영우 (충남대학교 에너지과학기술대학원) ;
  • 박재혁 (연세대학교 화공생명공학과) ;
  • 선도원 (한국에너지기술연구원 온실가스연구실) ;
  • 배달희 (한국에너지기술연구원 온실가스연구실) ;
  • 신종선 (한국에너지기술연구원 온실가스연구실) ;
  • 류호정 (한국에너지기술연구원 온실가스연구실) ;
  • 박재현 (한국에너지기술연구원 온실가스연구실)
  • Received : 2014.08.06
  • Accepted : 2014.09.19
  • Published : 2014.09.30
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Abstract

In this study, Indonesia low rank coal, which has moisture content of around 26%, is dried less than 5% by using a laboratory-scale (batch type) steam fluidized-bed dryer in order to produce the low-moisture, high rank coal. Normally, CCS (carbon capture and storage) process discharges $CO_2$ and steam mixture gas around $100-150^{\circ}C$ of temperature after regeneration reactor. The final purpose of this research is to dry low rank coal by using the outlet gas of CCS process. At this stage, steam is used as heat source for drying through the heat exchanger and $CO_2$ is used as fluidizing gas to the dryer. The experimental variables were the steam flow rate ranging from 0.3 to 1.1 kg/hr, steam temperature ranging from 100 to $130^{\circ}C$, and bed height ranging from 9 to 25 cm. The characteristics of the coal, before and after drying, were analyzed by a proximate analysis, the heating value analysis and particle size analysis. In summary, the drying rate of low rank coal was increased as steam flow rate and steam temperature increased and increased as bed height decreased.

본 연구에서는 고수분 저등급 석탄을 저수분 석탄으로 만들기 위하여 실험실 규모의 회분식 스팀 유동층 건조기를 사용하여 수분이 약 26%함유된 인도네시아산 저등급 석탄을 5% 이하로 건조하였다. 일반적으로 이산화탄소 포집 및 저장기술(carbon capture and storage, CCS)은 $CO_2$를 재생하는 공정에서 $100{\sim}150^{\circ}C$의 스팀과 $CO_2$혼합가스를 배출한다. 이때 배출되는 가스의 열을 사용하여 저등급 석탄을 건조하는 것이 본 연구의 최종 목적이다. 이를 위하여 본 연구에서는 건조의 열원으로 스팀을 사용하고, 유동화 가스는 $CO_2$를 사용하여 저등급 석탄을 건조하였다. 연구에 사용한 스팀의 유량은 0.3~1.1 kg/hr, 온도는 $100~130^{\circ}C$, 석탄의 층높이는 9~25 cm로 변화시켰다. 건조 후 석탄의 특성 변화는 공업분석, 발열량분석 그리고 입자크기 분석을 통하여 확인하였다. 변수 실험을 수행한 결과 원탄의 건조속도는 스팀의 유량과 온도가 증가함에 따라 증가하였고, 층높이가 감소할수록 건조속도가 증가하였다.

Keywords

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