Journal of the Korea Organic Resources Recycling Association (유기물자원화)

Korea Organic Resources Recycling Association (유기성자원학회)
권호 표지
DOI QR코드

DOI QR Code

Rheological Characteristics of Hydrogen Fermented Food Waste and Review on the Agitation Intensity

음식물류폐기물 수소 발효액의 유변학적 특성과 교반강도 고찰

  • 김민균 (인하대학교 사회인프라공학과) ;
  • 이모권 (인하대학교 사회인프라공학과) ;
  • 임성원 (인하대학교 사회인프라공학과) ;
  • 신상룡 (인하대학교 사회인프라공학과) ;
  • 김동훈 (인하대학교 사회인프라공학과)
  • Received : 2017.12.13
  • Accepted : 2017.12.18
  • Published : 2017.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

The design of proper agitation system is requisite in biological waste treatment and energy generation plant, which is affected by viscosity, impeller types, and power consumption. In the present work, hydrogen fermentation of food waste was conducted at various operational pHs (4.5~6.5) and substrate concentrations (10~50 g Carbo. COD/L), and the viscosity of fermented broth was analyzed. The $H_2$ yield significantly varied from 0.51 to $1.77mol\;H_2/mol\;hexose_{added}$ depending on the pH value, where the highest performance was achieved at pH 5.5. The viscosity gradually dropped with shear rate increase, indicating a shear thinning property. With the disintegration of carbohydrate, the viscosity dropped after fermentation, but it did not change depending on the operational pH. At the same pH level, the $H_2$ yield was not affected much, ranging $1.40{\sim}1.86mol\;H_2/mol\;hexose_{added}$ at 10~50 g Carbo. COD/L. The zero viscosity and infinite viscosity of fermented broth increased with substrate concentrations, from 10.4 to $346.2mPa{\cdot}s$, and from 1.7 to $5.3mPa{\cdot}s$, respectively. There was little difference in the viscosity value of fermented broth at 10 and 20 g Carbo. COD/L. As a result of designing the agitation intensity based on the experimental results, it is expected that the agitation intensity can be reduced during hydrogen fermentation. The initial and final agitation intensity of 30 g Carbo. COD/L in hydrogen fermentation were 26.0 and 10.0 rpm, respectively. As fermentation went on, the viscosity gradually decreased, indicating that the power consumption for agitation of food waste can be reduced.

점도, 임펠러 종류, 소비전력 등에 의해 영향을 받는 생물학적 폐기물 처리시설 및 에너지 생산 플랜트에서 적절한 교반 시스템의 설계는 필수적이다. 본 연구에서는 적절한 교반 시스템의 설계를 위해 음식물류폐기물을 이용하여 다양한 조건(운전 pH 및 농도)에서의 수소발효 시 유변학적 특성의 변화를 조사한 후, 이를 기반으로 교반강도를 설계하였다. 운전 pH에 따른 수소발효 실험에서 수소전환율은 $0.51{\sim}1.77mol\;H_2/mol\;hexose_{added}$였고, 가장 높은 수소전환율은 운전 pH 5.5에서 나타났다. 발효액은 전단속도가 증가함에 따라 점도가 감소하는 Shear thinning 거동을 보였다. 탄수화물이 분해되면서 발효 이후 점도는 초기 점도보다 감소하는 경향을 보였으나, 운전 pH의 변화에 따른 발효액의 점도 변화는 크지 않았다. 탄수화물 농도 10~50 g Carbo. COD/L에서 수소전환율은 $1.40{\sim}1.86mol\;H_2/mol\;hexose_{added}$로 운전 pH 조건이 수소전환율에 미친 영향과 비교했을 때 큰 차이는 없었다. 발효액의 Zero viscosity와 Infinite viscosity는 탄수화물 농도에 따라 각각 $10.4{\sim}346.2mPa{\cdot}s$와 $1.7{\sim}5.3mPa{\cdot}s$로 나타났는데, 10 g Carbo. COD/L와 20 g Carbo. COD/L에서 발효액의 점도 값은 거의 차이가 없었다. 실험 결과에 기초하여 교반강도를 설계한 결과, 기질농도 30 g Carbo. COD/L의 수소발효 초기 및 발효 후 교반강도는 각각 26.0, 10.0 rpm으로 약 2.5배 정도의 교반강도를 줄임으로써 에너지를 절약할 수 있을 것으로 사료된다.

Keywords

References

  1. [김의영, 홍영규, 신세계, 오택근, 이창훈, 이덕배, 김성철, "국내 음식물 폐기물의 자원화 및 감량화 정책 변화 고찰", 한국토양비료학회지] Kim, E.Y., Hong, Y.G., Shin, S.G., Oh, T.K., Lee, C.H., Lee, D.B., Kim, S.C., "Review of food waste utilization and reduction policy in Korea", Korean Journal of Soil Science and Fertilizer, pp. 229-229. (2015).
  2. [녹생성장위원회, 음식물쓰레기 줄이기 종합대책] Green Growth Korea, "Comprehensive measures to reduce food waste", (2010).
  3. [최근호, 엄태호, "정보기술을 활용한 지방정부 환경규제의 성과에 관한 연구: 음식물쓰레기종량제를 중심으로", 지방정부연구학회] Choi, K.H., Eom, T.H., "A Study on the performance of environmental regulation of local government utilizing information technology: Focusing on the food waste system", The Korean Journal of Local Goverment Studies, 21(2), pp. 77-102. (2017). https://doi.org/10.20484/klog.21.2.4
  4. [박종웅, 최동혁, "음폐수를 탄소원으로 이용시 생분해 및 탈질특성에 미치는 영향", 한국도시환경학회지] Park, J.W., Choi, D.H., "Effect of Biodegradation and Denitrification Characteristics using Carbon Source with Food Wastes Leachate", Journal of Korean Society of Urban Environment, 11(1), pp. 41-48. (2011).
  5. Ghosh, S., Buoy, K., Dressel, L., Miller, T., Wilcox, G., Loos, D., "Pilot-and full-scale two-phase anaerobic digestion of municipal sludge", Water Environ Res, 67(2), pp. 206-214. (1995). https://doi.org/10.2175/106143095X131367
  6. [황보준권, 서재건, 윤희철, 박현건, 이보원, "단상 및 이상혐기성소화공정을 이용한 음폐수의 바이오에너지화", 토지주택연구원 학술지] Hwangbo, J.K., Seo, J.G., Yoon, H.C., Park, H.G., Lee, B.W., "The single- and two-phase anaerobic digestion of food waste effluent", LHI Journal, 2(1), pp. 87-92. (2011).
  7. Zhang, C., Su, H., Baeyens, J., Tan, T., "Reviewing the anaerobic digestion of food waste for biogas production", Renew. Sustain. Energy Rev., 38, pp. 383-392. (2014). https://doi.org/10.1016/j.rser.2014.05.038
  8. Ueno, Y., Fukui, H., Goto, M., "Operation of a two-stage fermentation process producing hydrogen and methane from organic waste", Environ. Sci. Technol., 41(4), 1413-1419. (2007). https://doi.org/10.1021/es062127f
  9. Nagao, N., Tajima, N., Kawai, M., Niwa, C., Kurosawa, N., Matsuyama, T., Yusoff, F.M., Toda, T., "Maximum organic loading rate for the single-stage wet anaerobic digestion of food waste", Bioresour Technol, 118, pp. 210-218. (2012). https://doi.org/10.1016/j.biortech.2012.05.045
  10. [김홍석, 이태진, "슬러지 저감을 위한 혐기성 소화조 개선에 관한 연구", 대한환경공학회] Kim, H.S., Lee, T.J., "A study of the improvement in an anaerobic digester for sludge reduction", Korean Society of Environmental Engineers, 33(7), pp. 516-522. (2011). https://doi.org/10.4491/KSEE.2011.33.7.516
  11. [환경부, 음식물류폐기물 바이오가스화시설 기 술지침서 2nd Edition] Ministry of Environment, "Food waste biogasification facility technical guide book: 2nd Edition", (2015).
  12. [경기개발연구원, 소화조 효율개선 및 에너지 자원화사업 타당성 평가] Gyeonggi Research Institute, "Improvement of digestion tank efficiency and feasibility study on biomass gas use", pp. 1-145. (2011).
  13. Hreiz, R., Adouani, N., Funfschilling, D., Marchal, P., Pons, M. N., "Rheological characterization of raw and anaerobically digested cow slurry", Chem Eng Res Des, 119, pp. 47-57. (2017). https://doi.org/10.1016/j.cherd.2017.01.005
  14. Baroutian, S., Eshtiaghi, N., Gapes, D. J., "Rheology of a primary and secondary sewage sludge mixture: dependency on temperature and solid concentration", Bioresour Technol, 140, pp. 227-233. (2013). https://doi.org/10.1016/j.biortech.2013.04.114
  15. Baudez, J. C., Markis, F., Eshtiaghi, N., Slatter, P., "The rheological behaviour of anaerobic digested sludge", Water Res, 45(17), pp. 5675-5680. (2011). https://doi.org/10.1016/j.watres.2011.08.035
  16. Wang, H. F., Hu, H., Yang, H. Y., Zeng, R. J., "Characterization of anaerobic granular sludge using a rheological approach", Water Res, 106, pp. 116-125. (2016). https://doi.org/10.1016/j.watres.2016.09.045
  17. [김동훈, 이모권, 임소영, 김미선, "혐기 발효공정을 통한 음식물류폐기물 탈리액으로부터 수소 생산", 한국수소 및 신에너지학회] Kim, D.H., Lee, M.K., Lim, S.Y., Kim, M.S., "Dark fermentative hydrogen production using the wastewater generated from food waste recycling facilities", Trans. of the Korean Hydrogen and New Energy Society, 22(3), pp. 326-332. (2011).
  18. Kim, D.H., Kim, S.H., Kim, H.W., Kim, M.S., Shin, H.S., "Sewage sludge addition to food waste synergistically enhances hydrogen fermentation performance", Bioresour Technol, 102(18), pp. 8501-8506. (2011). https://doi.org/10.1016/j.biortech.2011.04.089
  19. Eshtiaghi, N., Markis, F., Yap, S. D., Baudez, J. C., Slatter, P., "Rheological characterisation of municipal sludge: a review", Water Res, 47(5), pp. 5493-5510. (2013). https://doi.org/10.1016/j.watres.2013.07.001
  20. Karthikeyan, O. P., Trably, E., Mehariya, S., Bernet, N., Wong, J. W., Carrere, H., "Pretreatment of food waste for methane and hydrogen recovery: A review", Bioresour Technol, (2017).
  21. Lay, J. J., Fan, K. S., Ku, C. H., "Influence of chemical nature of organic wastes on their conversion to hydrogen by heat-shock digested sludge", Int J Hydrogen Energy, 28(12), pp. 1361-1367. (2003). https://doi.org/10.1016/S0360-3199(03)00027-2
  22. Kim, D. H., Kim, S. H., Jung, K. W., Kim, M. S., Shin, H. S., "Effect of initial pH independent of operational pH on hydrogen fermentation of food waste", Bioresour Technol, 102(18), pp. 8646-8652. (2011). https://doi.org/10.1016/j.biortech.2011.03.030
  23. APHA., "Standard Methods for the Examination of Water and Wastewater", 21th Edition. (2005).
  24. Baudez, J. C., Gupta, R. K., Eshtiaghi, N., Slatter, P., "The viscoelastic behaviour of raw and anaerobic digested sludge: strong similarities with soft-glassy materials", Water Res, 47(1), pp. 173-180. (2013). https://doi.org/10.1016/j.watres.2012.09.048
  25. Jiang, J., Wu, J., Poncin, S., Li, H. Z., "Rheological characteristics of highly concentrated anaerobic digested sludge", Biochem Eng J, 86, pp. 57-61. (2014). https://doi.org/10.1016/j.bej.2014.03.007
  26. Casson, N., "Flow equation for pigment-oil suspension of the print ing ink type. In: rheology of disperse systems", C.C. Mill, Ed., pp. 84-102, (1959).
  27. Markis, F., Baudez, J. C., Parthasarathy, R., Slatter, P., Eshtiaghi, N., "Rheological characterisation of primary and secondary sludge: Impact of solids concentration", Chem Eng J, 253, pp. 526-537. (2014). https://doi.org/10.1016/j.cej.2014.05.085
  28. Mu, Y., Chen, X. H., Yu, H. Q., "Rheological properties of anaerobic hydrogen-producing flocs", Biochem Eng J, 34(1), pp. 87-91. (2007). https://doi.org/10.1016/j.bej.2006.12.001
  29. Dai, X., Gai, X., Dong, B., "Rheology evolution of sludge through high-solid anaerobic digestion", Bioresour Technol, 174, pp. 6-10. (2014). https://doi.org/10.1016/j.biortech.2014.09.122
  30. Ratkovich, N., Horn, W., Helmus, F. P., Rosenberger, S., Naessens, W., Nopens, I., Bentzen, T. R., "Activated sludge rheology: a critical review on data collection and modelling", Water Res, 47(2), pp. 463-482. (2013). https://doi.org/10.1016/j.watres.2012.11.021
  31. Brodkey, R. S., Hershey, H. C., "Transport phenomena: a unified approach: Chapter 9", McGraw-Hill, pp. 359-399. (2003).
  32. Noike, T., Takabatake, H., Mizuno, O., Ohba, M., "Inhibition of hydrogen fermentation of organic wastes by lactic acid bacteria", Int J Hydrogen Energy, 27(11), pp. 1367-1371. (2002). https://doi.org/10.1016/S0360-3199(02)00120-9
  33. Khanal, S. K., Chen, W. H., Li, L., Sung, S., "Biological hydrogen production: effects of pH and intermediate products", Int J Hydrogen Energy, 29(11), pp. 1123-1131. (2004). https://doi.org/10.1016/j.ijhydene.2003.11.002
  34. Baroutian, S., Munir, M. T., Sun, J., Eshtiaghi, N., Young, B. R., "Rheological characterisation of biologically treated and non-treated putrescible food waste", Waste Manag. (2017).
  35. Seyssiecq, I., Marrot, B., Djerroud, D., Roche, N., "In situ triphasic rheological characterisation of activated sludge, in an aerated bioreactor", Chem Eng J, 142(1), pp. 40-47. (2008). https://doi.org/10.1016/j.cej.2007.11.007
  36. Cao, X., Jiang, Z., Cui, W., Wang, Y., Yang, P., "Rheological properties of municipal sewage sludge: dependency on solid concentration and temperature", Procedia Environ Sci, 31, pp. 113-121. (2016). https://doi.org/10.1016/j.proenv.2016.02.016
  37. Farno, E., Baudez, J. C., Parthasarathy, R., Eshtiaghi, N., "Rheological characterisation of thermally-treated anaerobic digested sludge: Impact of temperature and thermal history", Water Res, 56, pp. 156-161. (2014). https://doi.org/10.1016/j.watres.2014.02.048
  38. Farno, E., Baudez, J. C., Parthasarathy, R., Eshtiaghi, N., "The viscoelastic characterisation of thermally-treated waste activated sludge", Chem Eng J, 304, pp. 362-368. (2016). https://doi.org/10.1016/j.cej.2016.06.082