Waste and Biomass Valorization

, Volume 9, Issue 3, pp 429–442 | Cite as

Improving the Energy-Related Aspects of Biowaste Treatment in an Experimental Hydrothermal Carbonization Reactor

  • Christian Riuji Lohri
  • Imanol Zabaleta
  • Manuel Rohr
  • Urs Baier
  • Christian Zurbrügg
Original Paper


Hydrothermal carbonization (HTC) is a thermochemical conversion process with the potential to treat the prevalent wet urban biowaste in low- and middle-income countries. The generated hydrochar solids are a hygienic, homogenized, carbon rich and energy dense product with economic value that can be used as an alternative to wood-based charcoal or fossil fuel. Obtaining a satisfactory energy efficiency of the process is, however, one of the prerequisites for the possible breakthrough of this technology. In an experimental HTC reactor, a model kitchen/market waste feedstock (17.8 MJ/kgdb) was hydrothermally carbonized with varying loading rates (TS 20 and 25 %) under mild operational conditions with peak temperatures of 160–190 °C and process times of 2–10 h above 160 °C. The aim was to evaluate the energy ratio of the process under these conditions while examining the impact on the hydrochar quality. Results show that the chemical properties of the produced hydrochar and its heating value were of moderate quality (21.1–24.4 MJ/kgdb), showing similar characteristics like torrefied products. HTC of a 25 % TS-load during 2 h at 180 °C and maximum pressure of 18.3 bar resulted in a char chemical output energy that is twice as high as the electrical energy consumed in the process. If considering the theoretical methane potential of the process water, the energy ratio could be increased to 2.6; while reactor insulation could further enhance this ratio to 3. This article reveals the merits of mild HTC and provides relevant knowledge for attaining an optimized, energy efficient HTC system.


Organic waste Energy efficiency Energy ratio HTC Hydrochar Thermochemical conversion 



The authors wish to acknowledge Zeno Robbiani and Paola Dea Marchetti for their preliminary work on HTC at Eawag/Sandec. Many thanks to the Zurich University of Applied Sciences (ZHAW; Dr. Rolf Krebs, Andreas Schönborn, Gabriel Gerner, Alexander Treichler, Rahel Wanner), and the Paul Scherrer Instiute (PSI; Timon Käser) for their technical support. The financial support of the Swiss Agency for Development and Cooperation (SDC) is gratefully recognized.


  1. 1.
    Scheinberg, A., Wilson, D.C., Rodic, L.: Solid Waste Management in the World’s Cities. UN-Habitat’s Third Global Report on the State of Water and Sanitation in the World’s Cities. Earthscan for UN Habitat, London (2010)Google Scholar
  2. 2.
    Wilson, D.C., Rodic, L., Modak, P., Soos, R., Carpintero, A., Velis, C.A., Iyer, M., Simonett, O.: United Nations Environment Programme (UNEP) and International Solid Waste Association (ISWA). In: Wilson, D.C. (ed.) Global Waste Management Outlook. UNEP International Environment Technology Centre, Osaka (2015)Google Scholar
  3. 3.
    Guerrero, L.A., Maas, G., Hogland, W.: Solid waste management challenges for cities in developing countries. Waste Manag. 33(1), 220–232 (2012)CrossRefGoogle Scholar
  4. 4.
    Hoornweg, D., Bhada-Tata, P.: What a Waste—A Global Review of Solid Waste Management. Urban Development & Local Government Unit, World Bank, Washington, DC (2012)Google Scholar
  5. 5.
    Wilson, D.C., Velis, C.A., Rodic L.: Integrated sustainable waste management in developing countries. Waste Manag. Res. 166(WR2), 52–68 (2013)Google Scholar
  6. 6.
    Wilson, D.C., Rodic, L., Scheinberg, A., Velis, C.A., Alabaster, G.: Comparative analysis of solid waste management in 20 cities. Waste Manag. Res. 30(3), 237–254 (2012)CrossRefGoogle Scholar
  7. 7.
    Cointreau, S.J.: Occupational and Environmental Health Issues of Solid Waste Management—Special Emphasis on Middle- and Lower-Income Countries. The International Bank for Reconstruction and Development/The World Bank, Washington, DC (2006)Google Scholar
  8. 8.
    Manga, E.: Urban waste management in Cameroon: a new policy perspective? In: Diaz, L.F., Eggerth, L.L., Savage, G.M. (eds.) Management of Solid Waste in Developing Countries, pp. 95–104. Padova, CISA (2007)Google Scholar
  9. 9.
    Bogner, J., Pipattim, R., Hashimoto, S., Diaz, C., Mareckova, K., Diaz, L., Kjeldsen, P., Monni, S., Faaij, A., Gao, Q., Zhang, T., Ahmed, M.A., Sutamihardja, R.T.M., Gregory, R.: Mitigation of global greenhouse gas emissions from waste: conclusions and strategies from the Intergovernmental Panel on Climate Change (IPCC)—fourth assessment report. working group III (Mitigation). Waste Manag. Res. 26, 11–32 (2008)CrossRefGoogle Scholar
  10. 10.
    Bleck, D., Wettberg, W.: Waste collection in developing countries—tackling occupational safety and health hazards at their source. Waste Manag. 32, 2009–2017 (2012)CrossRefGoogle Scholar
  11. 11.
    Rothenberger, S., Zurbrügg, C., Enayetullah, I., Sinha, A.H.M.M.: Decentralised Composting for Cities of Low- and Middle-Income Countries—A User’s Manual. Sandec/Eawag and Waste Concern, Dhaka (2006)Google Scholar
  12. 12.
    Diener, S., Studt Solano, N.M., Zurbrügg, C., Tockner, K.: Biological treatment of municipal solid waste using black soldier fly larvae. Waste Biomass Valoriz. 2, 357–363 (2011)CrossRefGoogle Scholar
  13. 13.
    Vögeli, Y., Lohri, C., Gallardo, A., Diener, S., Zurbrügg, C.: Anaerobic Digestion of Biowaste in Developing Countries. Practical Information and Case Studies. Eawag/Sandec publication, Dhaka (2014)Google Scholar
  14. 14.
    Lohri, C.R., Camenzind, E., Zurbrügg, C.: Financial sustainability of municipal solid waste management system—costs and revenues in Bahir Dar, Ethiopia. Waste Manag. 34, 542–552 (2014)CrossRefGoogle Scholar
  15. 15.
    Lohri, C.R., Faraji, A., Ephata, E., Rajabu, H.M., Zurbrügg, C.: Urban biowaste for solid fuel production—waste suitability assessment and experimental carbonization in Dar es Salaam, Tanzania. Waste Manag. Res. 33(2), 175–182 (2015)CrossRefGoogle Scholar
  16. 16.
    Bergius, F.: Die Anwendung hoher Drücke bei Chemischen Vorgängen und eine Nachbildung des Entstehungsprozesses der Steinkohle, pp. 33–58. Verlag Wilhelm Knapp, Halle an der Saale, Cologne (1913)Google Scholar
  17. 17.
    Titirici, M.-M., Arne, T., Antoniette, M.: Back in the black: hydrothermal carbonization of plant material as an efficient chemical process to treat the CO2 problem? New J. Chem. 31, 787–789 (2007)CrossRefGoogle Scholar
  18. 18.
    Ramke, H.-G., Blöhse, D., Lehmann, H.-J., Fettig, J.: Hydrothermal carbonization of organic waste. Hydrothermal carbonization of organic waste. In: Cossu, R., Diaz, L.F., Stegmann, R. (eds.) 2009: Sardinia 2009: Twelfth International Waste Management and Landfill Symposium, Sardinia, Italy, 05–09 October 2009, Proceedings, CISA Publisher (2009)Google Scholar
  19. 19.
    Berge, N., Ro, K., Mao, J., Flora, J.R.V., Chappell, M., Bae, S.: Hydrothermal carbonization of municipal waste streams. Environ. Sci. Technol. 45, 5696–5703 (2011)CrossRefGoogle Scholar
  20. 20.
    Basso, D., Castello, D., Baratieri, M., Fiori, L.: Hydrothermal carbonization of waste biomass: progress report and prospects. 21st European Biomass Conference and Exhibition, 3–7 June, Copenhagen, Denmark (2013)Google Scholar
  21. 21.
    Funke, A., Ziegler, F.: Hydrothermal carbonization of biomass: a summary and discussion of chemical mechanisms for process engineering. Biofuels Bioprod. Biorefin. 4, 160–177 (2010)CrossRefGoogle Scholar
  22. 22.
    Lu, X., Jordan, B., Berge, N.D.: Thermal conversion of municipal solid waste via hydrothermal carbonization: comparison of carbonization products to products from current waste management techniques. Waste Manag. 32, 1353–1365 (2012)CrossRefGoogle Scholar
  23. 23.
    Glasner, C., Deerberg, G., Lyko, H.: Hydrothermale Carbonisierung: Ein Überblick. Chem. Ing. Tech. 83(11), 1932–1943 (2011)CrossRefGoogle Scholar
  24. 24.
    Lehmann, J., Joseph, S.: Biochar for Environmental Management-Science and Technology. Earthscan, London (2009)Google Scholar
  25. 25.
    Libra, J.A., Ro, K.S., Kammann, C., Funke, A., Berge, N.D., Neubauer, Y., Titirici, M.-M., Fühner, C., Bens, O., Kern, J., Emmerich, K.-H.: Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels 2(1), 89–124 (2011)CrossRefGoogle Scholar
  26. 26.
    Marchetti Dea, P.: Hydrothermal Carbonization (HTC) of Food Waste—Testing of a HTC Prototype Research Unit for Developing Countries. Universita’ degli studi di Pavia—Facolta’ di ingegneria in collaboration with Eawag/Sandec (2013)Google Scholar
  27. 27.
    Ruyter, H.P.: Coalification model. Fuel 61, 1182–1187 (1982)CrossRefGoogle Scholar
  28. 28.
    Krause, A.: Hydrothermal carbonization as innovative technology in sustainable sanitation in Tanzania. Project carbonization as sanitation (CaSa). Technical University Berlin and Engineers without Borders Berlin, Germany. In: Schäfer, M., Kebir, N., Philipp, D. (eds.): Micro Perspectives for Decentralized Energy Supply. Proceedings of the International Conference, Technische Universität Berlin, 7th–8th of Apr 2011. Universitätsverlag der TU Berlin, Berlin (2011)Google Scholar
  29. 29.
    Robbiani, Z.: Hydrothermal carbonization of biowaste/faecal sludge. Conception and construction of a HTC prototype research unit for developing countries. Department of Mechanical Engineering ETHZ in collaboration with Eawag/Sandec (2013)Google Scholar
  30. 30.
    Peterson, A.A., Vogel, F., Lachance, R.P., Fröling, M., Antal, M.J., Tester, J.W.: Thermochemical biofuel production in hydrothermal media: a review of sub- and supercritical water technologies. Energy Environ. Sci. 1, 32–65 (2008)CrossRefGoogle Scholar
  31. 31.
    Deutsche-Edelstahlwerke. 1.4307 Chromium-Nickel Austenitic Stainless Steel with Low Carbon Content. (2007). Accessed 17 Sept 2015
  32. 32.
    Outo-Kumpu. Standard Cr–Ni–Mo Stainless Steels. (2006). Accessed 17 Sept 2015
  33. 33.
    Stemann, J., Ziegler, F.: Assessment of the energetic efficiency of a continuously operating plant for hydrothermal carbonisation of biomass. World Renewable Energy Congress 2011, Sweden, pp. 125–132 (2011). doi: 10.3384/ecp11057125
  34. 34.
    Antal, M.J., Allen, S.G., Dai, X., Shimizu, B., Tam, M.S., Grønli, M.G.: Attainment of the theoretical yield of carbon from biomass. Ind. Eng. Chem. Res. 39, 4024 (2000)CrossRefGoogle Scholar
  35. 35.
    Danso-Boateng, E., Shama, G., Wheatley, A.D., Martin, S.J., Holdich, R.G.: Hydrothermal carbonisation of sewage sludge: effect of process conditions on product characteristics and methane production. Bioresour. Technol. 177, 318–327 (2015)CrossRefGoogle Scholar
  36. 36.
    Funke, A.: Hydrothermale Verfahren (HTC, VTC) in der energetische Verwertungskette. In: Fricke et al., (eds.) Biokohle im Blick. Proceedings of Second INTERREG NSR Biochar Conference Berlin, 73. Symposium des ANS e.V., 2012, pp. 35–44 (2012)Google Scholar
  37. 37.
    Lu, L., Namioka, T., Yoshikawa, K.: Effects of hydrothermal treatment on characteristics and combustion behaviors of municipal solid wastes. Appl. Energy 88, 3659–3664 (2011)CrossRefGoogle Scholar
  38. 38.
    FAO (Food and Agriculture Association). Using charcoal efficiently, chapter 10. In: Simple Technologies for Charcoal Making. Chapter 10—Using Charcoal Efficiently. First printed 1983, reprinted 1987. Accessed 19 Oct 2015
  39. 39.
    Antal, M.J., Grønli, M.: The art, science, and technology of charcoal production. Ind. Eng. Chem. Res. 42, 1619–1640 (2003)CrossRefGoogle Scholar
  40. 40.
    Foley, G.: Charcoal Making in Developing Countries. Earthscan, London (1986)Google Scholar
  41. 41.
    Berge, N.D., Li, L., Flora, J.R.V., Ro, K.S.: Assessing the environmental impact of energy production form hydrochar generated viy hydrothermal carbonization of food wastes. Waste Manag. 43, 203–217 (2015)CrossRefGoogle Scholar
  42. 42.
    Lynam, J.G., Reza, M.T., Vasquez, V.R., Coronella, C.J.: Effect of salt addition on hydrothermal carbonization of lignocellulosic biomass. Fuel 99, 271–273 (2012)CrossRefGoogle Scholar
  43. 43.
    Kang, S., Li, X., Fan, J., Chang, J.: Characterization of hydrochars produced by hydrothermal carbonization of lignin, cellulose, d-xylose, and wood meal. Ind. Eng. Chem. Res. 51, 9023–9031 (2012)CrossRefGoogle Scholar
  44. 44.
    Liu, Z., Balusubramanian, R.: Upgrading of waste biomass by hydrothermal carbonization (HTC) and low temperature pyrolysis (LTP): a comparative evaluation. Appl. Energy 114, 857–864 (2014)CrossRefGoogle Scholar
  45. 45.
    Clingan, W.R.: Process for Production of Fuels and Chemicals from Biomass Feedstocks. (2013). Accessed 14 Oct 2015
  46. 46.
    Mumme, J., Eckervogt, L., Pielert, J., Diakité, M., Rupp, F., Kern, J.: Hydrothermal carbonization of anaerobically digested maize silage. Bioresour. Technol. 102, 9255–9260 (2011)CrossRefGoogle Scholar
  47. 47.
    Kleinschmidt, C.: Overview of International Developments in Torrefaction. (2011). Accessed 19 Oct 2015
  48. 48.
    Medic, D.: Investigation of torrefaction process parameters and characterization of torrefied biomass. Graduate Theses and Dissertations. Paper 12403. Iowa State University (2012)Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • Christian Riuji Lohri
    • 1
  • Imanol Zabaleta
    • 1
  • Manuel Rohr
    • 1
  • Urs Baier
    • 2
  • Christian Zurbrügg
    • 1
  1. 1.Eawag: Swiss Federal Institute of Aquatic Science and Technology, Department of Sanitation, Water and Solid Waste for Development (Sandec)DübendorfSwitzerland
  2. 2.ZHAW: Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Institute of Chemistry and BiotechnologyWädenswilSwitzerland

Personalised recommendations