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Evaluation of different types of mixed microbial culture for biomethanation of CO2

식종슬러지 종류에 따른 이산화탄소 이용 바이오메탄 생산 비교

  • Kim, Tae-Hoon (Department of Environmental Engineering, Chungbuk National University) ;
  • Lim, Byung-Seo (Environmental Review and Evaluation Institute, Korea Environment Corporation) ;
  • Yi, Sung-Ju (Department of Civil, Environmental and Biomedical Engineering) ;
  • Yun, Gwang-Sue (Department of Environmental Engineering, Chungbuk National University) ;
  • Ahn, Byung-Kyu (Department of Environmental Engineering, Chungbuk National University) ;
  • Enkhtsog, Michidmaa (Department of Environmental Engineering, Chungbuk National University) ;
  • Yun, Yeo-Myeong (Department of Environmental Engineering, Chungbuk National University)
  • 김태훈 (충북대학교 환경공학과) ;
  • 임병서 (한국환경공단 환경전문심사원) ;
  • 이승주 (상명대학교 건설.환경.의생명공학과) ;
  • 윤광수 (충북대학교 환경공학과) ;
  • 안병규 (충북대학교 환경공학과) ;
  • 미치드마 (충북대학교 환경공학과) ;
  • 윤여명 (충북대학교 환경공학과)
  • Received : 2020.02.27
  • Accepted : 2020.03.16
  • Published : 2020.03.30

Abstract

The aims of this study were to compare the biomethanation of CO2 through specific methanogenic activity (SMA) test which was inoculated with four different types of mixed microbial culture obtained from full-scale anaerobic digestion (AD) plants. The experimental results showed that CH4 conversion was the highest in the samples inoculated by seed sludge taken from ADs of food waste and brewery; under this condition, the produced biomethane contains 89.3-91.9% of CH4. Meanwhile, the lowest level was obtained in the sample from sewage sludge. The measured ratio of CH4 production rate to CO2 consumption rate in all reactors was higher than the theoretical value (1) in the middle of the period and soon dropped to 0.7-0.8. It might be due to changed metabolic pathways in the reactor by the degradation of residual organic matter and the increased activity of homoacetogenic bacteria.

본 연구는 초기 식종슬러지 종류별 CO2의 생물학적 바이오메탄 생산 적용 가능성을 비교를 위해 국내 혐기성 소화조로부터 획득한 식종미생물을 종류에 따라 Specific methanogenic activity (SMA) test를 수행한 결과이다. 36일간의 실험 결과 CH4 yield는 2,434-2,051mL CH4/g COD의 범위를 얻었고 생산된 가스 내 CH4 분압은 맥주공장과 음식물류 폐기물 식종슬러지에서 가장 높은 89.3-91.9% CH4 분포를 보인 반면 하수슬러지 식종슬러지로부터 가장 낮은 효율을 나타냈다. 반응조의 CH4 production rate/CO2 consumption rate 비교를 통해 CH4전환 속도 및 CO2소비율의 간접적 물질 수지 비교가 가능했으며 SMA test 실험 기간 중 반응조 내 아세트산의 농도의 검출이 확인되었다. 이는 식종슬러지 내부의 잔류 유기물들의 분해, 식종미생물의 사멸 및 이들의 분해, Homoacetogenic bacteria의 활성에 의해 반응조 내 Metabolic pathway가 부분적으로 Hydrogenotrophic methanogenesis 단계에서 Acetoclasctic methanogenesis로의 변환됨에 따른 결과로 사료된다.

Keywords

References

  1. Yun, Y. M., Sung, S., Shin, H. S., Han, J. I., Kim, H. W. and Kim, D. H., "Producing desulfurized biogas through removal of sulfate in the first-stage of a two-stage anaerobic digestion", Biotechnol. Bioeng., 114(5), pp. 970-979. (2017). https://doi.org/10.1002/bit.26233
  2. Yun, Y. M., Sung, S., Kang, S., Kim, M. S. and Kim, D. H., "Enrichment of hydrogenotrophic methanogens by means of gas recycle and its application in biogas upgrading", Energy, 135, pp. 294-302. (2017). https://doi.org/10.1016/j.energy.2017.06.133
  3. Lee, H., Ko, S. W., Lee, I. D., Jung, I. H. and Ko, J. W., "Development of Biogas Purification System for City Gas Supply", J. Korean Inst. Gas, 23(2), pp. 61-67. (2019). https://doi.org/10.7842/KIGAS.2019.23.2.61
  4. Ferella, F., Cucchiella, F., D'Adamo, I. and Gallucci, K., "A techno-economic assessment of biogas upgrading in a developed market", J. Clean. Prod., 210, pp. 945-957. (2019). https://doi.org/10.1016/j.jclepro.2018.11.073
  5. Meier, L., Martinez, C., Vilchez, C., Bernard, O. and Jeison, D., "Evaluation of the feasibility of photosynthetic biogas upgrading: Simulation of a large-scale system", Energy, 189, p. 116313. (2019). https://doi.org/10.1016/j.energy.2019.116313
  6. Wiesberg, I. L., Brigagao, G. V., Ofelia de Queiroz, F. A. and de Medeiros, J. L., "Carbon dioxide management via exergy-based sustainability assessment: Carbon Capture and Storage versus conversion to methanol", Renew. Sust. Energ. Rev., 112, pp. 720-732. (2019). https://doi.org/10.1016/j.rser.2019.06.032
  7. Luo, G. and Angelidaki, I., "Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture", Biotechnol. Bioeng., 109(11), pp. 2729-2736. (2012). https://doi.org/10.1002/bit.24557
  8. APHA, 1998. Standard methods for the examination of water and wastewater, 20th ed., USA American Public Health Association. Washington, DC, USA.
  9. Kougias, P. G., Treu, L., Benavente, D. P., Boe, K., Campanaro, S. and Angelidaki, I., "Ex-situ biogas upgrading and enhancement in different reactor systems", Bioresource Technol., 225, pp. 429-437. (2017). https://doi.org/10.1016/j.biortech.2016.11.124
  10. Demirel, B. and Scherer, P., "The roles of acetotrophic and hydrogenotrophic methanogens during anaerobic conversion of biomass to methane: a review", Rev. Environ. Sci. Bio., 7(2), pp. 173-190. (2008). https://doi.org/10.1007/s11157-008-9131-1
  11. Yun, Y. M., Kim, M., Kim, H., Kim, D. H., Kwon, E. E. and Kang, S., "Increased biodegradability of low-grade coal wastewater in anaerobic membrane bioreactor by adding yeast wastes", J. Environ. Manage., 234, pp. 36-43. (2019). https://doi.org/10.1016/j.jenvman.2018.12.083