DOI QR코드

DOI QR Code

A Study on Increasing the Efficiency of Biogas Production using Mixed Sludge in an Improved Single-Phase Anaerobic Digestion Process

개량형 단상 혐기성 소화공정에서의 혼합슬러지를 이용한 바이오가스 생산효율 증대방안 연구

  • Jung, Jong-Cheal (Department of Fusion Technology for Climate Change, Hoseo University) ;
  • Chung, Jln-Do (Department of Environmental Engineering, Hoseo University) ;
  • Kim, San (Department of Fusion Technology for Climate Change, Hoseo University)
  • 정종철 (호서대학교 기후변화융합기술학과) ;
  • 정진도 (호서대학교 환경공학과) ;
  • 김산 (호서대학교 기후변화융합기술학과)
  • Received : 2016.03.24
  • Accepted : 2016.06.02
  • Published : 2016.06.30

Abstract

In this study, we attempted to improve the biogas production efficiency by varying the mixing ratio of the mixed sludge of organic wastes in the improved single-phase anaerobic digestion process. The types of organic waste used in this study were raw sewage sludge, food wastewater leachate and livestock excretions. The biomethane potential was determined through the BMP test. The results showed that the biomethane potential of the livestock excretions was the highest at $1.55m^3CN4/kgVS$, and that the highest value of the composite sample, containing primary sludge, food waste leachate and livestock excretions at proportions of 50%, 30% and 20% respectively) was $0.43m^3CN4/kgVS$. On the other hand, the optimal mixture ratio of composite sludge in the demonstration plant was 68.5 (raw sludge) : 18.0 (food waste leachate) : 13.5 (livestock excretions), which was a somewhat different result from that obtained in the BMP test. This difference was attributed to the changes in the composite sludge properties and digester operating conditions, such as the retention time. The amount of biogas produced in the single-phase anaerobic digestion process was $2,514m^3/d$ with a methane content of 62.8%. Considering the value of $2,319m^3/d$ of biogas produced as its design capacity, it was considered that this process demonstrated the maximum capacity. Also, through this study, it was shown that, in the case of the anaerobic digestion process, the two-phase digestion process is better in terms of its stable tank operation and high efficiency, whereas the existing single-phase digestion process allows for the improvement of the digestion efficiency and performance.

본 연구는 유기성폐기물의 혼합슬러지를 개량형 단상 혐기성 소화공정에서 각각의 혼합비율에 따른 바이오가스 생산효율 향상에 관한 연구로, 연구에 사용된 유기성폐기물의 종류는 하수 생슬러지, 음폐수 및 가축분뇨이다. BMP test를 통해 잠재적 메탄발생량을 확인한 결과 단일시료의 경우 가축분뇨가 $1.55m^3CN4/kgVS$로 가장 높게 평가되었고, 혼합시료(생슬러지, 음폐수, 가축분뇨)의 경우는 각각의 비율을 50% : 30% : 20%로 하였을 때 $0.43m^3CN4/kgVS$로 가장 높게 나타났다. 반면 실증플랜트에서 혼합슬러지 최적 혼합비율은 생슬러지(68.5) : 음폐수(18.0) : 가축분뇨(13.5)로 나타나 BMP test와 다소 상이한 결과를 보였다. 이는 혼합슬러지 성상변화와 체류시간 등 소화조 운전조건 변화에 기인한 결과로 판단되며, 단상 혐기성 소화조의 바이오가스 생산량이 $2,514m^3/d$, 메탄함량 62.8%로 조사되어 설계능력인 바이오가스 생산량 $2,319m^3/d$ 기준으로 볼 때 최대성능을 발휘하는 것으로 평가되었다. 아울러 본 연구를 통해 혐기성 소화방식에 있어 소화조의 안정적인 운영과 소화효율 측면에서 고효율 방식인 2상 소화방식을 도입하는 것이 유리하나 기존의 단상 소화방식에 있어서도 소화효율 개선 및 성능향상이 가능하다는 것을 알 수 있었다.

Keywords

References

  1. Angelidaki I. and Ahring B. K., "Anaerobic digestion of manure at different ammonia loads : effect of temperature", Water Research, Vol. 28, 727-731, 1994. DOI: http://dx.doi.org/10.1016/0043-1354(94)90153-8
  2. Gerardi M. H., "The microbiology of anaerobic digesters", Wily-Interscience, 99-103, 2003.
  3. Odeegard H., "Treatment of anaerobically pretreated effluents", Proc. 5th International Symp. On Anaerobic Digestion, 225-230, 1988.
  4. Kim, N.C, Yoo, K.Y., Ahn, J.W., Kim, Y.J., Heo, K., Jung, Y.G., Bae, J.G., " Principles and applications of biogas production technology by anaerobic digestion", J. of KOWREA, Vol. 10(1), 7-23, 2002.
  5. Demirer, G.N, Chen, S., "Two-Phase anaerobic digestion of unscreened dairy mamure", Process Biochem., Vol. 40, 3542-3549, 2005. DOI: http://dx.doi.org/10.1016/j.procbio.2005.03.062
  6. Ministray of Environment, "Environmental Assessment and Activation Plan of Renewable Energy", Korea Environment Institute, 2010.
  7. Ministray of Environment, "Comprehensive research on Waste-to-Energy measures", Korea Environment Institute, 2008.
  8. Jules B. van Lier, Katja C. F., Alfons J. M. S., Everly C. M., Gatze L., "Start-up of a thermophilic upflow anaerobic sludge bed(UASB) reactor with mesophilic granular sludge", Applied Microbiology Biotechnology, Vol. 37, 130-135, 1992. DOI: http://dx.doi.org/10.1007/BF00174217
  9. Owen, W.F., Stuckey, D.C., Healy, J.B., Young, L.Y., McCarty, P.L., "Bioassay for monitoring biochemical methane potential and anaerobic toxicity", Water Res., Vol. 13, 485-492, 1979. DOI: http://dx.doi.org/10.1016/0043-1354(79)90043-5
  10. Stainer R. Y., Adelberg E. A. and Ingraham J. L., The Microbial World 4th ed., 705-706, Prentice Hall Inc. New Jersey, 1976.
  11. Pfeffer J. T., "Temperature effects on anaerobic fermentation of domestic refuse", Biotech. and Bioeng., Vol. 16, 771, 1974. https://doi.org/10.1002/bit.260160607