Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Kinetic of Catalytic CO2 Gasification for Cyprus Coal by Gas-Solid Reaction Model

기-고체 반응모델을 이용한 Cyprus탄의 CO2 저온촉매가스화 반응거동

  • Hwang, Soon Choel (Graduate school of energy science and technology, Chungnam National University) ;
  • Lee, Do Kyun (Department of Applied Chemistry and Biological Engineering, Chungnam National University) ;
  • Kim, Sang Kyum (Graduate school of energy science and technology, Chungnam National University) ;
  • Lee, Si Hyun (Korea Institute of Energy Research) ;
  • Rhee, Young Woo (Graduate school of energy science and technology, Chungnam National University)
  • 황순철 (충남대학교 에너지과학기술대학원) ;
  • 이도균 (충남대학교 바이오응용화학과) ;
  • 김상겸 (충남대학교 에너지과학기술대학원) ;
  • 이시훈 (한국에너지기술연구원) ;
  • 이영우 (충남대학교 에너지과학기술대학원)
  • Received : 2014.12.16
  • Accepted : 2015.01.20
  • Published : 2015.10.01
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Abstract

In general, the coal gasification has to be operated under high temperature ($1300{\sim}1400^{\circ}C$) and pressure (30~40 bar). However, to keep this conditions, it needs unnecessary and excessive energy. In this work, to reduce the temperature of process, alkali catalysts such as $K_2CO_3$ and $Na_2CO_3$ were added into Cyprus coal. We investigated the kinetic of Cyprus char-$CO_2$ gasification. To determine the gasification conditions, the coal (with and without catalysts) gasified with fixed variables (catalyst loading, catalytic effects of $Na_2CO_3$ and $K_2CO_3$, temperatures) by using TGA. When catalysts are added by physical mixing method into Cyprus coal the reaction rate of coal added 7 wt% $Na_2CO_3$ is faster than raw coal for Cyprus char-$CO_2$ gasification. The activation energy of coal added 7 wt% $Na_2CO_3$ was calculated as 63 kJ/mol which was lower than raw char. It indicates that $Na_2CO_3$ can improve the reactivity of char-$CO_2$ gasification.

일반적으로 가스화는 고온($1300{\sim}1400^{\circ}C$), 고압(30~40 bar)에서 공정이 가동되나 이를 유지하기 위해 과도한 에너지가 사용된다. 본 연구에서는 공정 온도를 줄이기 위해 알칼리 촉매 중 $K_2CO_3$과 $Na_2CO_3$을 저등급의 사이프러스(Cyprus) 탄에 첨가하였고, 이산화탄소 분위기에서 가스화시켰을 때 나타나는 반응특성을 연구하였다. 열중량분석기를 활용하여 촉매의 함량, 촉매의 종류, 온도를 변수로서 가스화 공정조건을 결정하였다. 고체상 물리적 혼합법으로 촉매를 도입 시, 7 wt%의 $Na_2CO_3$가 첨가된 시료가 원탄보다 높은 활성을 보였다. 탄소전환율 거동을 예측하기 위해 시료별로 반응모델을 적용해본 결과, volumetric reaction model(VRM)이 탄소전환율 거동을 가장 잘 묘사하였다. 7 wt%의 $Na_2CO_3$을 첨가한 사이프러스 탄의 활성화 에너지는 63 kJ/mol로 원탄보다 낮으며, 이는 이산화탄소 분위기에서 석탄가스화의 반응성을 향상시킨다는 것을 보여주었다.

Keywords

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