Skip to main content

Energy analysis of sewage sludge energy conversion processes for Turkey—investigation of existing drying and combustion plants

Abstract

Thermal energy content of sewage sludge offers opportunities in terms of energy production. Incineration is extensively used for energy conversion of sludge. Dewatered sludge needs to be dried prior to incineration or supplementary fuel should be supplied to the incinerator. Energy production rate is exaggerated when dryer energy is neglected. Net energy production rate depends on dryer energy consumption. The effect of the dryer energy consumption on the net energy production is not emphasized. Energy consumption data of the sludge management process is collected from wastewater management utilities. Thermal and electrical energy conversion of sludge is studied within a scenario analysis. Energy consumption of the examining drying plants (11000–3900 kJ/kg water) is higher than literature (4320–3000 kJ/kg water) data. In order for the dewatered sludge to be burned and dried with its own energy (90% solid), the ratio of its lower calorific value to the specific energy consumption of drying should be 2.8. Net energy production with fully dried sludge is only possible in Plant 4. In the case of auto-thermal combustion, with partially dried (50% solid) sludge, net energy production is possible in 3 of the 4 plants examined. Twenty-five to seventy-five percent of the energy consumption of the wastewater treatment plant can be met by electricity generated using biogas and sludge.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Data availability

Not Applicable.

Abbreviations

DM:

Dry matter

E:

Electrical energy

Hevap :

Latent heat of water evaporation

LHV:

Lower heating value

MSW:

Municipal solid waste

NG:

Natural gas

Q:

Thermal energy

SEC:

Specific energy consumption

SF:

Supplementary fuel

SS:

Sewage sludge

V:

Volumetric flow rate

WWTP:

Wastewater treatment plant

m:

Mass flow rate of sludge

wb:

Wet base

X in,DM :

Humidity of dewatered sludge

X out,DM :

Humidity of dried sludge

η conversion :

Electrical conversion efficiency

η thermal :

Thermal efficiency of incineration plant

References

  1. Kirchem D, Lynch M, Bertsch V, Casey E (2020) Modelling demand response with process models and energy systems models: potential applications for wastewater treatment within the energy-water nexus. Appl Energy 260:114321. https://doi.org/10.1016/j.apenergy.2019.114321

    Article  Google Scholar 

  2. Kacprzak M, Neczaj E, Fijałkowski K et al (2017) Sewage sludge disposal strategies for sustainable development. Environ Res 156:39–46. https://doi.org/10.1016/j.envres.2017.03.010

    Article  Google Scholar 

  3. Cao Y, Pawłowski A (2012) Sewage sludge-to-energy approaches based on anaerobic digestion and pyrolysis: brief overview and energy efficiency assessment. Renew Sustain Energy Rev 16:1657–1665. https://doi.org/10.1016/j.rser.2011.12.014

    Article  Google Scholar 

  4. Groß B, Eder C, Grziwa P et al (2008) Energy recovery from sewage sludge by means of fluidised bed gasification. Waste Manag 28:1819–1826. https://doi.org/10.1016/j.wasman.2007.08.016

    Article  Google Scholar 

  5. Tańczuk M, Kostowski W, Karaś M (2016) Applying waste heat recovery system in a sewage sludge dryer – a technical and economic optimization. Energy Convers Manag 125:1–20. https://doi.org/10.1016/j.enconman.2016.02.064

    Article  Google Scholar 

  6. Tunçal T, Uslu O (2014) A review of dehydration of various industrial sludges. Dry Technol 32:1642–1654. https://doi.org/10.1080/07373937.2014.909846

    Article  Google Scholar 

  7. Milhé M, Charlou C, Sauceau M, Arlabosse P (2015) Modeling of sewage sludge flow in a continuous paddle dryer. Dry Technol 33:1061–1067. https://doi.org/10.1080/07373937.2014.982252

    Article  Google Scholar 

  8. Syed-Hassan SSA, Wang Y, Hu S et al (2017) Thermochemical processing of sewage sludge to energy and fuel: fundamentals, challenges and considerations. Renew Sustain Energy Rev 80:888–913. https://doi.org/10.1016/j.rser.2017.05.262

    Article  Google Scholar 

  9. Bianchini A, Bonfiglioli L, Pellegrini M, Saccani C (2015) Sewage sludge drying process integration with a waste-to-energy power plant. Waste Manag 42:159–165. https://doi.org/10.1016/j.wasman.2015.04.020

    Article  Google Scholar 

  10. Demirbas A, Coban V, Taylan O, Kabli M (2017) Aerobic digestion of sewage sludge for waste treatment. Energy Sources, Part A Recover Util Environ Eff 39:1056–1062. https://doi.org/10.1080/15567036.2017.1289282

    Article  Google Scholar 

  11. Gorazda K, Tarko B, Werle S, Wzorek Z (2018) Sewage sludge as a fuel and raw material for phosphorus recovery: combined process of gasification and P extraction. Waste Manag 73:404–415. https://doi.org/10.1016/j.wasman.2017.10.032

    Article  Google Scholar 

  12. Ma J, Zhang L, Li A (2016) Energy-efficient co-biodrying of dewatered sludge and food waste: synergistic enhancement and variables investigation. Waste Manag 56:411–422. https://doi.org/10.1016/j.wasman.2016.06.007

    Article  Google Scholar 

  13. Cambero CA, Arlabosse P, Lecomte D (2004) Thermal efficiency in sewage sludge fry drying. Proc Int Dry Symp 972–978

  14. Font R, Gomez-Rico MF, Fullana A (2011) Skin effect in the heat and mass transfer model for sewage sludge drying. Sep Purif Technol 77:146–161. https://doi.org/10.1016/j.seppur.2010.12.001

    Article  Google Scholar 

  15. Rulkens W (2008) Sewage sludge as a biomass resource for the production of energy: overview and assessment of the various options. Energy Fuels 22:9–15. https://doi.org/10.1021/ef700267m

    Article  Google Scholar 

  16. Yilmaz E, Wzorek M, Akçay S (2018) Co-pelletization of sewage sludge and agricultural wastes. J Environ Manag 216:169–175. https://doi.org/10.1016/j.jenvman.2017.09.012

    Article  Google Scholar 

  17. Zhao P, Shen Y, Ge S, Yoshikawa K (2014) Energy recycling from sewage sludge by producing solid biofuel with hydrothermal carbonization. Energy Convers Manag 78:815–821. https://doi.org/10.1016/j.enconman.2013.11.026

    Article  Google Scholar 

  18. Quan LM, Kamyab H, Yuzir A et al (2022) Review of the application of gasification and combustion technology and waste-to-energy technologies in sewage sludge treatment. Fuel 316:123199. https://doi.org/10.1016/j.fuel.2022.123199

    Article  Google Scholar 

  19. Tańczuk M, Kostowski W, Karaś M (2016) Applying waste heat recovery system in a sewage sludge dryer – a technical and economic optimization. Energy Convers Manag 1–20. https://doi.org/10.1016/j.enconman.2016.02.064

  20. Hernández AB, Ferrasse JH, Roche N (2013) Limiting the pollutant content in the sewage sludge producer gas through staged gasification. Chem Eng Technol 36:1985–1996. https://doi.org/10.1002/ceat.201300103

    Article  Google Scholar 

  21. Ayol A, Tezer Yurdakos O, Gurgen A (2019) Investigation of municipal sludge gasification potential: gasification characteristics of dried sludge in a pilot-scale downdraft fixed bed gasifier. Int J Hydrogen Energy 44:17397–17410. https://doi.org/10.1016/j.ijhydene.2019.01.014

    Article  Google Scholar 

  22. Kelessidis A, Stasinakis AS (2012) Comparative study of the methods used for treatment and final disposal of sewage sludge in European countries. Waste Manag 32:1186–1195. https://doi.org/10.1016/J.WASMAN.2012.01.012

    Article  Google Scholar 

  23. Figueiredo C, Lopes H, Coser T et al (2018) Influence of pyrolysis temperature on chemical and physical properties of biochar from sewage sludge. Arch Agron Soil Sci 64:881–889. https://doi.org/10.1080/03650340.2017.1407870

    Article  Google Scholar 

  24. Wacławek S, Grübel K, Silvestri D et al (2018) Disintegration of wastewater activated sludge (WAS) for Improved biogas production. Energies 12:21. https://doi.org/10.3390/en12010021

    Article  Google Scholar 

  25. Mills N, Pearce P, Farrow J et al (2014) Environmental & economic life cycle assessment of current & future sewage sludge to energy technologies. Waste Manag 34:185–195. https://doi.org/10.1016/j.wasman.2013.08.024

    Article  Google Scholar 

  26. Đurđević D, Blecich P, Jurić Ž (2019) Energy recovery from sewage sludge: the case study of Croatia. Energies 12:1927. https://doi.org/10.3390/en12101927

    Article  Google Scholar 

  27. Werther J, Ogada T (1999) Sewage sludge combustion. Prog Energy Combust Sci 25:55–116. https://doi.org/10.1016/S0360-1285(98)00020-3

    Article  Google Scholar 

  28. Meisel K, Clemens A, Fühner C et al (2019) Comparative life cycle assessment of HTC concepts valorizing sewage sludge for energetic and agricultural use. Energies 12:786. https://doi.org/10.3390/en12050786

    Article  Google Scholar 

  29. Li B, Wang F, Chi Y, Yan JH (2014) Study on optimal energy efficiency of a sludge drying-incineration combined system. J Mater Cycles Waste Manag 16:684–692. https://doi.org/10.1007/s10163-014-0293-3

    Article  Google Scholar 

  30. Léonard A, Blacher S, Marchot P et al (2005) Convective drying of wastewater sludges: influence of air temperature, superficial velocity, and humidity on the kinetics. Dry Technol 23:1667–1679. https://doi.org/10.1081/DRT-200065082

    Article  Google Scholar 

  31. Ferrasse JH, Arlabosse P, Lecomte D (2002) Heat, momentum, and mass transfer measurements in indirect agitated sludge dryer. Dry Technol 20:749–769. https://doi.org/10.1081/DRT-120003755

    Article  Google Scholar 

  32. Arlabosse P, Chitu T (2007) Identification of the limiting mechanism in contact drying of agitated sewage sludge. Dry Technol 25:557–567. https://doi.org/10.1080/07373930701226955

    Article  Google Scholar 

  33. Deng W, Yan J-H, Li X-D et al (2009) Measurement and simulation of the contact drying of sewage sludge in a Nara-type paddle dryer. Chem Eng Sci 64:5117–5124. https://doi.org/10.1016/j.ces.2009.08.015

    Article  Google Scholar 

  34. Gude VG (2015) Energy and water autarky of wastewater treatment and power generation systems. Renew Sustain Energy Rev 45:52–68. https://doi.org/10.1016/j.rser.2015.01.055

    Article  Google Scholar 

  35. Moško J, Pohořelý M, Zach B et al (2018) Fluidized bed incineration of sewage sludge in O 2 /N 2 and O 2 /CO 2 atmospheres. Energy Fuels 32:2355–2365. https://doi.org/10.1021/acs.energyfuels.7b02908

    Article  Google Scholar 

  36. Singh V, Phuleria HC, Chandel MK (2020) Estimation of energy recovery potential of sewage sludge in India: waste to watt approach. J Clean Prod 276:122538. https://doi.org/10.1016/j.jclepro.2020.122538

    Article  Google Scholar 

  37. Vamvuka D, Alexandrakis S, Galetakis M (2019) Combustion performance of sludge from a wastewater treatment plant in fluidized bed. Factorial Modeling and Optimization of Emissions. Front Energy Res 7:1–10. https://doi.org/10.3389/fenrg.2019.00043

    Article  Google Scholar 

  38. Seginer I, Bux M (2006) Modeling solar drying rate of waste water sludge. Dry Technol 24:1353–1363. https://doi.org/10.1080/07373930600952362

    Article  Google Scholar 

  39. Oikonomidis I, Marinos C (2014) Solar sludge drying in Pafos wastewater treatment plant: Operational experiences. Water Pract Technol 9:62–70. https://doi.org/10.2166/wpt.2014.007

    Article  Google Scholar 

  40. Dai Z, Su M, Ma X et al (2018) Direct thermal drying of sludge using flue gas and its environmental benefits. Dry Technol 36:1006–1016. https://doi.org/10.1080/07373937.2017.1368541

    Article  Google Scholar 

  41. Gezer Gorgec A, Insel G, Yağci N et al (2016) Comparison of energy efficiencies for advanced anaerobic digestion, incineration, and gasification processes in municipal sludge management. J Residuals Sci Technol 13:57–64. https://doi.org/10.12783/issn.1544-8053/13/1/8

    Article  Google Scholar 

  42. Lyu L, Chen S, Wang F (2021) Two dimensional modeling of sewage sludge flow in a double-axis continuous paddle dryer. Waste Manag 124:63–71. https://doi.org/10.1016/j.wasman.2021.01.018

    Article  Google Scholar 

  43. Olivier J, Mahmoud A, Vaxelaire J et al (2014) Electro-dewatering of anaerobically digested and activated sludges: an energy aspect analysis. Dry Technol 32:1091–1103. https://doi.org/10.1080/07373937.2014.884133

    Article  Google Scholar 

  44. Hassebrauck M, Gerrit E (1996) Two examples of thermal drying of sewage sludge. Water Sci Technol 33:10–17. https://doi.org/10.1016/0273-1223(96)00478-7

    Article  Google Scholar 

  45. Wzorek M, Tańczuk M (2015) Production of biosolid fuels from municipal sewage sludge: technical and economic optimisation. Waste Manag Res 33:704–714. https://doi.org/10.1177/0734242X15588584

    Article  Google Scholar 

  46. Deng W, Yu L, Chen Y et al (2021) Sludge preheating and viscosity reduction by waste heat from the exhaust gas of sludge paddle dryer. Dry Technol. https://doi.org/10.1080/07373937.2021.1957926

    Article  Google Scholar 

  47. Lyu L, Chen S, Wang F (2022) Research on sludge drying characteristics in a double-axis paddle dryer by coupling Markov chain and penetration theory. Waste and Biomass Valorization. https://doi.org/10.1007/S12649-022-01734-9

    Article  Google Scholar 

  48. Gururani P, Bhatnagar P, Bisht B et al (2022) Recent advances and viability in sustainable thermochemical conversion of sludge to bio-fuel production. Fuel 316:123351. https://doi.org/10.1016/J.FUEL.2022.123351

    Article  Google Scholar 

  49. Houssayne E, Khadir E, Idlimam A, Lamharrar A (2018) Experimental study of hygroscopic equilibrium and thermodynamic properties of sewage sludge. Appl Therm Eng 143:521–531. https://doi.org/10.1016/j.applthermaleng.2018.07.048

    Article  Google Scholar 

  50. Murakami T, Suzuki Y, Nagasawa H et al (2009) Combustion characteristics of sewage sludge in an incineration plant for energy recovery. Fuel Process Technol 90:778–783. https://doi.org/10.1016/j.fuproc.2009.03.003

    Article  Google Scholar 

  51. Fedorov AV, Dubinin YV, Yeletsky PM et al (2021) Combustion of sewage sludge in a fluidized bed of catalyst: ASPEN PLUS model. J Hazard Mater 405:124196. https://doi.org/10.1016/j.jhazmat.2020.124196

    Article  Google Scholar 

Download references

Acknowledgements

The authors would like to warmly thank the Water and Sewage Administration of Antalya (ASAT), Bursa (BUSKİ), İstanbul (İSKİ), and Kocaeli (İSU) Metropolitan Municipalities for their helpful cooperation and for providing the sludge treatment data.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to the conceptualization of the research and writing the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Süleyman Sapmaz.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Additional information

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sapmaz, S., Kılıçaslan, İ. Energy analysis of sewage sludge energy conversion processes for Turkey—investigation of existing drying and combustion plants. Biomass Conv. Bioref. (2022). https://doi.org/10.1007/s13399-022-02773-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s13399-022-02773-x

Keywords

  • Combustion
  • Electricity generation
  • Energy efficiency
  • Industrial dryer
  • Sewage sludge