Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
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In-situ Methane Enrichment System Coupled with External $CO_2$ Stripper in Mesophilic Anaerobic Digestion

중온혐기성소화조에서 외부 $CO_2$ Stripping을 이용한 In-situ 고순도 메탄회수 공정 개발

  • Kang, Ho (Department of Environmental Engineering, Chungnam National University) ;
  • Jeong, Ji-Hyun (Department of Environmental Engineering, Chungnam National University) ;
  • Lim, Seon-Ae (Department of Environmental Engineering, Chungnam National University) ;
  • Lee, Hye-Mi (Department of Environmental Engineering, Chungnam National University)
  • 강호 (충남대학교 환경공학과) ;
  • 정지현 (충남대학교 환경공학과) ;
  • 임선애 (충남대학교 환경공학과) ;
  • 이혜미 (충남대학교 환경공학과)
  • Received : 2012.02.09
  • Accepted : 2012.03.16
  • Published : 2012.03.30
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Abstract

A simple in-situ methane enrichment system in mesophilic anaerobic digestion was developed to take advantage of the differing solubilities of $CO_2$ and methane. The methane enhancement systems consisted of low solids plug-flow maize digester coupled with a leachate recycle loop to an external $CO_2$ stripper. The effects of leachate recycle rate (LRR) and reactor alkalinity on the resulting offgas $CH_4$ contents, biogas productivity and TVS removal efficiency were quantitively evaluated. The results showed that offgas $CH_4$ contents of over 94% was achieved at 3 volume of leachate recycle per volume of reactor per day (3 v/v-d) and at the reactor alkalinity of 4 g/L as $CaCO_3$, as the optimum operating conditions. The TVS removal efficiency of the methane enhancement system was 79% which corresponds to 94% of the control reactor and the methane productivity appeared to be 0.71 v/v-d. Offgas methane contents correlated well with LRR. However excessively high LRR led to the decrease in TVS removal efficiency.

본 연구에서는 고순도 메탄을 회수하기 위해서 Plug Flow Reactor와 External $CO_2$ Stripper를 결합한 중온 Methane Enhancement System을 개발하였다. 반응조 운전인자로서 알칼리도와 Leachate 순환율(LRR, Leachate Recycle Rate)이 바이오가스의 조성과 생성량 및 TVS 제거효율에 미치는 영향을 규명하였다. 고순도 메탄회수 공정 운전결과 OLR 2 g TVS/L-d, 알칼리도 4 g/L as $CaCO_3$, Leachate 순환율 3 v/v-d일 때 평균 94%의 높은 메탄함량을 나타내 고순도 메탄회수를 위한 최적조건임이 밝혀졌다. 이때 1일 반응조 단위 부피당 0.71부피의 메탄이 생성되었으며, TVS 제거율은 79%로서 Control Reactor의 94% 수준을 달성하였다.

Keywords

References

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