Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Modeling of Wet Flue Gas Desulfurization Process for Utilization of Low-Grade Limestone

저품위 석회석 활용을 위한 습식 배연탈황 공정 모델링 연구

  • Lim, Jonghun (Chemical and Biochemical Engineering, Dongguk university) ;
  • Choi, Yeongryeol (Chemical Engineering, Ulsan National Institute Science and Technology) ;
  • Kim, Geonyeol (Chemical and Biomolecular Engineering, Yonsei University) ;
  • Song, Hojun (Green Materials and Processes Group, Korea Institute of Industrial Technology) ;
  • Kim, Junghwan (Green Materials and Processes Group, Korea Institute of Industrial Technology)
  • 임종훈 (동국대학교 화공생물공학과) ;
  • 최영렬 (울산과학기술원 에너지및화학공학부 화학공학과) ;
  • 김건열 (연세대학교 화공생명공학과) ;
  • 송호준 (한국생산기술연구원 친환경재료공정그룹) ;
  • 김정환 (한국생산기술연구원 친환경재료공정그룹)
  • Received : 2019.04.23
  • Accepted : 2019.06.24
  • Published : 2019.10.01
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Abstract

This study focuses on the simulation of wet flue gas desulfurization process for improving the production of gypsum by the utilization of low-grade limestone. At present, high-grade limestone with a $CaCO_3$ content of 94% is used for producing merchantable gypsum. In modeling process, a lot of reactions are considered to develop model. First, the limestone dissolution is simulated by RSTOIC model. Second, SOx absorption and crystallization is used by RCSTR model. Finally the gypsum is separated by using SEPERATORS model. Modeling steps make it easy to reflect further side reactions and physical disturbances. In optimization condition, constraints are set to 93% purity of gypsum, 94% desulfurization efficiency, and total use of limestone at 3710 kg/hr. Under these constraints, the mass flow of low-grade limestone was maximized. As a result, the maximum blending quantity of low-grade limestone for 2,100 kg of high-grade limestone that satisfies constraints is about 1,610 kg.

본 연구에서는 저품위 석회석 활용 가능성 향상을 위하여 실제 화력 발전소의 습식 배연탈황설비를 공정 모사 하였고, 품위 별 석회석 혼합 비율에 따른 탈황 석고 품질을 예측하는 모델을 개발하였다. 현재 화력 발전소에서는 판매 가능한 순도(93%)의 탈황 석고를 생산하기 위해 $CaCO_3$함량 93% 이상의 고품위 석회석을 활용하고 있으나 자원 고갈에 대한 해결책이 필요하다. 공정 모델링에 있어서 여러 반응이 모델 개발에 고려되었는데 4단계로 나누어 주었다. 첫 번째로 석회석 용해 반응은 RSTOIC 모델을 사용했고 두 번째로 황산화물 흡수 및 결정화 반응은 RCSTR 모델을 사용했다. 마지막으로 최종 생성물을 SEPERATORS 모델을 사용해 분리해 주었다. 각 반응 단계를 나누어 모델링 하여 부반응 및 물리적 방해 요인 조절에 용이하도록 했다. 최적화 조건으로는 석고 순도 93%, 탈황효율 94%, 총 석회석 사용량 3710 kg/hr를 제약조건으로 설정해주었다. 제약조건 상에서 저품위 석회석의 mass flow를 최대화하는 것을 목적함수로 최적화를 진행해 주었다. 최적화 결과 제약조건에 대하여 고품위 석회석 2,100 kg 당 저품위 석회석 1,610 kg 혼합 가능함을 확인했다.

Keywords

References

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