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A Kinetic Study of Steam Gasification of Woodchip, Sawdust and Lignite

나무칩, 톱밥 바이오매스와 갈탄의 수증기 가스화반응 특성 연구

  • Kim, Kyungwook (Department of Chemical Engineering, Kunsan National University) ;
  • Bungay, Vergel C. (Department of Chemical Engineering, Kunsan National University) ;
  • Song, Byungho (Department of Chemical Engineering, Kunsan National University) ;
  • Choi, Youngtai (Energy System R&D Group, Korea Institute of Industrial Technology) ;
  • Lee, Jeungwoo (SeenTec Co., Ltd.)
  • 김경욱 (군산대학교 화학공학과) ;
  • ;
  • 송병호 (군산대학교 화학공학과) ;
  • 최영태 (한국생산기술연구원 에너지시스템연구그룹) ;
  • 이정우 ((주)신텍)
  • Received : 2013.04.12
  • Accepted : 2013.05.14
  • Published : 2013.08.01

Abstract

Biomass and low-grade coals are known to be better potential sources of energy compared to crude oil and natural gas since these materials are readily available and found to have large reserves, respectively. Gasification of these carbonaceous materials produced syngas for chemical synthesis and power generation. Woodchip, sawdust and lignite were gasified with steam in a thermobalance reactor under atmospheric pressure in order to evaluate their kinetic rate information. The effects of gasification temperature ($600{\sim}900^{\circ}C$) and partial pressure of steam (20~90 kPa) on the gasification rate were investigated. The three different types of gas-solid reaction models were applied to the experimental data to predict the behavior of the gasification reactions. The modified volumetric model predicted the conversion data well, thus the model was used to evaluate kinetic parameters in this study. The observed activation energy of biomass, sawdust and lignite gasification reactions were found to be in reasonable range and their rank was found to be sawdust > woodchip > lignite. The expression of apparent reaction rates for steam gasification of the three solids was proposed to provide basic information on the design of coal gasification processes.

바이오매스 및 저등급 석탄인 갈탄은 잠재력이 큰 에너지원으로 이들을 가스화하여 합성가스를 얻으면 발전을 하거나 수송용 연료를 생산할 수 있다. 본 연구에서는 상압의 열천칭 반응기(thermobalance)에서 woodchip, 톱밥, 갈탄의 수증기 가스화반응의 kinetics를 조사하였다. 가스화 온도 $600{\sim}900^{\circ}C$, 수증기 분압 20~90 kPa 범위에서 수증기 가스화 반응을 수행하였다. 세 가지의 기체-고체 화학반응모델들이 가스화반응의 거동을 묘사하는 능력을 비교하였다. 이들 중에서 탄소전환율의 변화를 가장 잘 나타내는 modified volumetric model을 사용하여 가스화반응의 kinetic 정보를 도출하였다. Arrehenius plot으로부터 얻어진 시료들의 활성화에너지는 문헌상의 범위 내에서 얻어졌으며 톱밥 > woodchip > 갈탄의 순으로 나타났다. 각 시료에 대하여 수증기 분압에 대한 반응차수를 결정하였으며, 가스화공정 설계의 기초 데이터로서 겉보기 반응속도식을 제시하였다.

Keywords

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