Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
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Kinetic study on Low-rank Coal Including K2CO3, Na2CO3, CaCO3 and Dolomite Gasification under CO2 Atmosphere

이산화탄소 분위기에서 K2CO3, Na2CO3, CaCO3 및 Dolomite가 첨가된 저급탄의 가스화에 대한 반응특성연구

  • Hwang, Soon Choel (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Kim, Sang Kyum (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Park, Ji Yun (Department of Applied Chemistry and Biological Engineering, Chungnam National University) ;
  • Lee, Do Kyun (Department of Applied Chemistry and Biological Engineering, Chungnam National University) ;
  • Lee, Si Hyun (Clean Coal Center, Korea Institute of Energy Research) ;
  • Rhee, Young Woo (Graduate School of Energy Science and Technology, Chungnam National University)
  • 황순철 (충남대학교 에너지과학기술대학원) ;
  • 김상겸 (충남대학교 에너지과학기술대학원) ;
  • 박지윤 (충남대학교 바이오응용화학과) ;
  • 이도균 (충남대학교 바이오응용화학과) ;
  • 이시훈 (한국에너지기술연구원) ;
  • 이영우 (충남대학교 에너지과학기술대학원)
  • Received : 2013.11.11
  • Accepted : 2014.01.10
  • Published : 2014.03.31
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Abstract

We have investigated the effects of various additives on Eco coal gasification under $CO_2$ atmosphere. The temperature ranges from $750{\sim}900^{\circ}C$ and the gasification experimental was carried out with Eco coal adding 7 wt% $K_2CO_3$, $Na_2CO_3$, $CaCO_3$, Dolomite, and non-additive under $N_2$ and $CO_2$ gas mixture. At $850^{\circ}C$, we observed that the reaction rate increased when the concentration of $CO_2$ increased. However, we also observed that the increment of reaction rate was small at more than 70% of the concentration of $CO_2$. The additives activity was ranked as 7 wt% $Na_2CO_3$ > 7 wt% $K_2CO_3$ > non-additive > 7 wt% Dolomite > 7 wt% $CaCO_3$ at $850^{\circ}C$. At the temperatures of $750^{\circ}C$, $800^{\circ}C$, $850^{\circ}C$, and $900^{\circ}C$, when the temperature increased, the gasification rate increased. The gasification was suitably described by the volumetric reaction model. Using volumetric reaction model, the activation energy of Eco coal including 7 wt% $Na_2CO_3$ gasification was 83 kJ/mol, which was the lowest value among all the alkaline additives.

열중량분석기를 이용하여 이산화탄소 분위기에서 알칼리계 염류가 에코(Eco)탄의 가스화 반응에 미치는 영향을 알아보았다. $750{\sim}900^{\circ}C$에서 탄산칼륨, 탄산나트륨, 탄산칼슘, 백운석(Dolomite) 7 wt%의 알칼리염을 첨가한 것과 원탄을 이용하여 실험을 진행하였다. $850^{\circ}C$에서의 가스화 결과, 이산화탄소의 농도가 증가할수록 반응속도가 증가하는 경향을 관찰하였다. 그러나 70% 이상의 농도에서는 반응속도의 증가량이 크게 증가하지 않음을 관찰하였다. 가스화 반응속도는 7 wt% 탄산나트륨 > 7 wt% 탄산칼륨 > 원탄> 7 wt% 백운석 > 7 wt% 탄산칼슘 순으로 나타났다. $700^{\circ}C$, $800^{\circ}C$, $850^{\circ}C$ 그리고 $900^{\circ}C$의 등온, 상압조건에서 가스화 실험 결과, 온도가 증가할수록 반응속도가 증가함을 관찰하였다. 차(char)-이산화탄소 가스화 반응의 기-고체 모델은 volumetric reaction model (VRM)이 탄소 전환율 거동을 가장 잘 묘사했다. 이를 이용하여 얻은 탄산나트륨의 활성화 에너지는 83 kJ/mol로 가장 낮게 얻어졌다.

Keywords

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