Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
권호 표지

Continuous Mesophilic-Dry Anaerobic Digestion of Organic Solid Waste

유기성고형폐기물의 연속 중온 건식혐기성소화

  • Oh, Sae-Eun (Department of Environmental Engineering, Hanbat National University) ;
  • Lee, Mo-Kwon (Department of Environmental Engineering, Hanbat National University) ;
  • Kim, Dong-Hoon (Department of Civil and Environmental Engineering, KAIST)
  • 오세은 (국립한밭대학교 환경공학과) ;
  • 이모권 (국립한밭대학교 환경공학과) ;
  • 김동훈 (한국과학기술원 건설 및 환경공학과)
  • Published : 2009.05.30
Download PDF
⟨ Previous Next ⟩

Abstract

Continuous dry anaerobic digestion of organic solid wastes (30% TS, Total Solids) comprised of food waste and paper was performed under mesophilic condition. During the operation, hydraulic retention time (HRT) was decreased as follows: 150 d, 100 d, 60 d, and 40 d, which corresponded to the solid loading rate of 2.0, 3.0, 5.0, and 7.5 kg TS/$m^3$/d, respectively. Volumetric biogas production rate ($m^3$/$m^3$/d) increased as HRT decreased, and the highest biogas production rate of 3.49${\pm}$0.31 $m^3$/$m^3$/d was achieved at 40 d of HRT. At this HRT, high volatile solids (VS) reduction of 76% was maintained, and methane production yield of 0.25 $m^3$/kg $TS_{added}$ was achieved, indicating 67.4% conversion of organic solid waste to bioenergy. The highest biogas production yield of 0.52 $m^3$/kg $TS_{added}$ was achieved at 100 d of HRT, but it did not change much with respect to HRT. For the ease feed pumping, some amount of digester sludge was recycled and mixed with fresh feed to decrease the solid content. Recirculation volume of 5Q was found to be the optimal in this experimental condition. Specific methanogenic activity (SMA) of microorganisms at mesophilic-dry condition was 2.66, 1.94, and 1.20 mL $CH_4$/g VS/d using acetate, butyrate, and propionate as a substrate, respectively.

음식물쓰레기와 종이류로 구성된 유기성고형폐기물(고형물 함량 30% TS)을 대상으로 중온 건식혐기성소화를 시도하였고, 연속 운전 중 수리학적 체류 시간(HRT)을 150일, 100일, 60일, 40일로 감소시켰다. 기질의 고형물 농도를 30% TS (Total Solids)로 고정하였기 때문에 각각의 HRT에 해당하는 고형물 부하는 2.0, 3.0, 5.0, 7.5 kg TS/$m^3$/d였다. HRT를 줄임에 따라 단위용적 당 바이오가스 생산 속도는 증가하였고, HRT 40일에서 3.49${\pm}$0.31 $m^3/m^3/d$로 가장 높은 성능을 보였다. 이 때, 76%의 휘발성 고형물(VS) 분해율이 유지되었고, 0.25 $m^3$/kg $TS_{added}$의 메탄 생산 전환율을 보였으며, 이는 기질의 67.4%에 해당하는 에너지가 메탄 가스로 전환된 것을 의미한다. HRT 100일에서 0.52 $m^3$/kg $TS_{added}$로 가장 높은 바이오가스 전환율을 보였지만, 모든 HRT에서 0.45${\sim}$0.52 $m^3$/kg $TS_{added}$로 큰 차이가 나지 않았다. 고형물 함량이 높은 기질의 원활한 주입을 위해 소화조 발효액의 일부를 기질 투입구로 반송하여 기질과 혼합 후 주입하였다. 주입하고자 하는 기질의 5배에 해당하는 양의 소화조 발효액을 반송하여 혼합하였을 때, 가장 효과적인 기질 주입이 이루어졌다. 중온 건식 조건에서 서식하는 메탄 소화균의 활성도를 측정한 결과, 아세트산, 뷰틸산, 프로피온산을 이용할 경우 각각 2.66, 1.94, 1.20 mL $CH_4/g$ VS/d였다.

Keywords

References

  1. 환경부, 2007 전국 폐기물 발생 및 처리 현황
  2. 환경부, 제3차 (2006${\sim}$2007년) 전국폐기물통계조사
  3. Intergovernmental Panel on Climate Change (IPCC), Report of the Twelfth season of the IPCC, Mexico City, 11-13 Sep.(1996)
  4. Themelis, N. J. and Ulloa, P. A, "Methane generation in landfills," Renewable Energy, 32, 1243-1257(2007) https://doi.org/10.1016/j.renene.2006.04.020
  5. Forster-Cameiro, N., Perez, M., and Romero, L. I., "Anaerobic digestion of municipal solid wastes: Dry thermophilic performance," Bioresour. Technol., 99, 8180-8184(2008) https://doi.org/10.1016/j.biortech.2008.03.021
  6. Bolzonella, D., Innocenti, L, Pavan, P., Traverso, P., and Cecchi, F., "Semi-dry thermophilic anaerobic digestion of the organic fraction of municipal solid waste: focusing on the start-up phase," Bioresour. Technol., 86, 123-129 (2003) https://doi.org/10.1016/S0960-8524(02)00161-X
  7. Pavan, P., Battistoni, P., and Mata-Alvarez, J., "Performance of thermophilic semi-dry anaerobic digestion process changing the feed biodegradability," Water Sci. Technol., 41, 75-81(2000)
  8. Six, W. and De Baere, L., "Dry anaerobic conversion of municipal solid waste by means of the DRANCO process," Water Sci. Technol., 25, 295-300(1992)
  9. Laclos, H. F., Desbois, S., and Saint-Joly, C. "Anaerobic digestion of municipal solid waste: V ALORGA fullscale plant in Tilburg, the Netherlands," Water Sci. Technol., 36(6-7), 457-462(1997) https://doi.org/10.1016/S0273-1223(97)00555-6
  10. Willinger, A., Wyder, K., and Metzler. A C., "KOMPOGAS-a new system for the anaerovic treatment of source separated waste," Water Sci, Technol., 27(2), 153-158(1993)
  11. Montero, B., Garcia-Morales, J. L., Sales, D., and Solera, R., "Analysis of methanogenic activity in a thermophilicdry anaerobic reactor: Use of fluorescent in situ hybridization," Waste Manage., 29, 1144-1151(2009) https://doi.org/10.1016/j.wasman.2008.08.010
  12. Kim, D. H., Han, S. K., Kim, S. H., and Shin, H. S., "Effect of gas sparging on continuous fermentative hydrogen production," Int. J. Hydrogen Energy, 31, 2158-2169(2006) https://doi.org/10.1016/j.ijhydene.2006.02.012
  13. APHA, AWWA and WEF, "Standard methods for the examination of water and wastewater," 20th ed. Baltimore, American Public Health Association, 2, 57-59 (1998)
  14. Ward, A J., Hobbs, P. J., Holliman, P. J., and Jones, D. L., "Optimisation of the anaerobic digestion of agricultural resources," Bioresour. Technol., 99(17), 7928-7940(2008) https://doi.org/10.1016/j.biortech.2008.02.044
  15. Metcalf & Eddy, Wastewater Engineering, 3rd edition, 830-834
  16. Zwietering, M. H., Jongenburger, I., Rombouts, F. M., and Van's Riet, K., "Modeling of the bacterial growth curve," Appl. Environ. Microbiol., 56, 1875-1881(1990)