IDEAS home Printed from https://ideas.repec.org/a/eee/energy/v323y2025ics0360544225014896.html
   My bibliography  Save this article

Co-combustion of sewage sludge and high ash coal: Thermal behavior, ash formation behavior, interaction mechanisms and economic analysis

Author

Listed:
  • Qin, Shuning
  • He, Xuefu
  • Li, Zikuo
  • Jia, Li
  • Qiao, Xiaolei
  • Chang, Xinyue
  • Cheng, Peng
  • Jin, Yan

Abstract

Co-combustion of sewage sludge with high ash coal enables both waste valorization and sustainable disposal, yet its combined impacts on boiler efficiency, slagging risks, and economic viability require systematic investigation. This study developed a comprehensive evaluation system including combustion characteristics, operational safety, and techno-economic analysis to reveal the interactions between components and mineral evolution during sewage sludge-high ash coal co-combustion. The results demonstrated that blending sewage sludge significantly improved the ignition performance of high ash coal. When the sewage sludge blending ratio exceeded 50 %, combustion transitioned from a fixed carbon-dominant to a volatile-dominated mode. A 50 % sewage sludge blend (sewage sludge to high ash coal mass ratio of 5:5) achieved a comprehensive combustion characteristic index of 4.80 × 10−8, representing a 100.58 % enhancement compared with coal. Synergistic interactions enhanced the combustion efficiency of fixed carbon, as evidenced by a 25.12 % increase in the fixed carbon weight-loss rate for the 60 % sewage sludge blend, compared to theoretical predictions. Minerals (CaO, Fe2O3, AlPO4) exhibited dual catalytic-inhibitory regulation: optimal concentrations enhanced combustion via catalytic cracking and oxygen storage-release mechanisms, while excessive minerals promoted slag formation impeding oxygen diffusion, with the efficacy hierarchy following CaO > AlPO4 > Fe2O3. Ash chemistry analysis revealed that the addition of sewage sludge increased the alkaline oxide content, promoting silicate network depolymerization. At blending ratios exceeding 50 %, the ash deformation temperature sharply decreased to 1157 °C, increasing the risks of slagging. Economic evaluation indicated dynamic payback periods of 2.91 years for a 50 % blend and 7.67 years for a 60 % blend. Multi-objective optimization identified the optimal sludge-to-coal ratio as 5:5, achieving balanced improvements in combustion efficiency, ash fusion control, and economic viability. This study explores the feasibility of sewage sludge-high ash coal co-combustion, providing a new approach for intensive sewage sludge treatment.

Suggested Citation

  • Qin, Shuning & He, Xuefu & Li, Zikuo & Jia, Li & Qiao, Xiaolei & Chang, Xinyue & Cheng, Peng & Jin, Yan, 2025. "Co-combustion of sewage sludge and high ash coal: Thermal behavior, ash formation behavior, interaction mechanisms and economic analysis," Energy, Elsevier, vol. 323(C).
    • Handle: RePEc:eee:energy:v:323:y:2025:i:c:s0360544225014896
    DOI: 10.1016/j.energy.2025.135847
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/S0360544225014896
    Download Restriction: Full text for ScienceDirect subscribers only
    File URL: https://libkey.io/10.1016/j.energy.2025.135847?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to

    for a different version of it.

    References listed on IDEAS

    as
    1. Masnadi, Mohammad S. & Grace, John R. & Bi, Xiaotao T. & Lim, C. Jim & Ellis, Naoko, 2015. "From fossil fuels towards renewables: Inhibitory and catalytic effects on carbon thermochemical conversion during co-gasification of biomass with fossil fuels," Applied Energy, Elsevier, vol. 140(C), pages 196-209.
    2. Chen, Zhibin & Wang, Li & Huang, Zhiwei & Zhuang, Ping & Shi, Yiguang & Evrendilek, Fatih & Huang, Shengzheng & He, Yao & Liu, Jingyong, 2024. "Dynamic and optimal ash-to-gas responses of oxy-fuel and air combustions of soil remediation biomass," Renewable Energy, Elsevier, vol. 225(C).
    3. Masnadi, Mohammad S. & Grace, John R. & Bi, Xiaotao T. & Ellis, Naoko & Lim, C. Jim & Butler, James W., 2015. "Biomass/coal steam co-gasification integrated with in-situ CO2 capture," Energy, Elsevier, vol. 83(C), pages 326-336.
    4. Chunyu Liu & Changtao Yue & Yue Ma, 2024. "Pollutant Emissions and Heavy Metal Migration in Co-Combustion of Sewage Sludge and Coal," Energies, MDPI, vol. 17(11), pages 1-15, May.
    5. Xu, Tong & Wang, Chunbo & Hong, Dikun & Li, Song & Yue, Shuang, 2023. "The synergistic effect during co-combustion of municipal sludge and coal: Experimental and ReaxFF molecular dynamic study," Energy, Elsevier, vol. 262(PB).
    6. He, Yongjun & Deng, Jun & Yi, Xin & Xiao, Yang & Deng, Yin & Chen, Weile, 2023. "Effect of rare-earth-containing inhibitors on the low-temperature oxidation characteristics and thermodynamic properties of coal," Energy, Elsevier, vol. 281(C).
    7. Li, Fenghai & Zhou, Meijie & zhao, Wei & Liu, Xuefei & Yang, Ziqiang & Fan, Hongli & Han, Guopeng & Li, Junguo & Xu, Meiling & Fang, Yitian, 2024. "Ash fusion behavior modification mechanisms of high-calcium coal by coal blending and its ash viscosity predication," Energy, Elsevier, vol. 288(C).
    8. Masnadi, Mohammad S. & Grace, John R. & Bi, Xiaotao T. & Lim, C. Jim & Ellis, Naoko & Li, Yong Hua & Watkinson, A. Paul, 2015. "From coal towards renewables: Catalytic/synergistic effects during steam co-gasification of switchgrass and coal in a pilot-scale bubbling fluidized bed," Renewable Energy, Elsevier, vol. 83(C), pages 918-930.
    9. Li, Fenghai & Zhao, Wei & Li, Junguo & Fan, Hongli & Xu, Meiling & Han, Guopeng & Guo, Mingxi & Wang, Zhiqing & Huang, Jiejie & Fang, Yitian, 2023. "Investigation on influencing mechanisms of phosphogypsum (PG) on the ash fusion behaviors of coal," Energy, Elsevier, vol. 268(C).
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Andrey Zhuikov & Tatyana Pyanykh & Mikhail Kolosov & Irina Grishina & Yana Zhuikova & Petr Kuznetsov & Stanislav Chicherin, 2025. "Improving Energy Efficiency of Wastewater Residue Biomass Utilisation by Co-Combustion with Coal," Energies, MDPI, vol. 18(11), pages 1-17, June.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Shahbaz, Muhammad & Al-Ansari, Tareq & Inayat, Muddasser & Sulaiman, Shaharin A. & Parthasarathy, Prakash & McKay, Gordon, 2020. "A critical review on the influence of process parameters in catalytic co-gasification: Current performance and challenges for a future prospectus," Renewable and Sustainable Energy Reviews, Elsevier, vol. 134(C).
    2. Sun, Minmin & Zhang, Jianliang & Li, Kejiang & Barati, Mansoor & Liu, Zhibin, 2022. "Co-gasification characteristics of coke blended with hydro-char and pyro-char from bamboo," Energy, Elsevier, vol. 241(C).
    3. Inayat, Muddasser & Sulaiman, Shaharin A. & Kurnia, Jundika Candra & Shahbaz, Muhammad, 2019. "Effect of various blended fuels on syngas quality and performance in catalytic co-gasification: A review," Renewable and Sustainable Energy Reviews, Elsevier, vol. 105(C), pages 252-267.
    4. Laougé, Zakari Boubacar & Merdun, Hasan, 2021. "Investigation of thermal behavior of pine sawdust and coal during co-pyrolysis and co-combustion," Energy, Elsevier, vol. 231(C).
    5. Wang, Shuxiao & Shan, Rui & Lu, Tao & Zhang, Yuyuan & Yuan, Haoran & Chen, Yong, 2020. "Pyrolysis char derived from waste peat for catalytic reforming of tar model compound," Applied Energy, Elsevier, vol. 263(C).
    6. Yang, Ziqi & Wu, Yuanqing & Zhang, Zisheng & Li, Hong & Li, Xingang & Egorov, Roman I. & Strizhak, Pavel A. & Gao, Xin, 2019. "Recent advances in co-thermochemical conversions of biomass with fossil fuels focusing on the synergistic effects," Renewable and Sustainable Energy Reviews, Elsevier, vol. 103(C), pages 384-398.
    7. Wei, Juntao & Gong, Yan & Guo, Qinghua & Chen, Xueli & Ding, Lu & Yu, Guangsuo, 2019. "A mechanism investigation of synergy behaviour variations during blended char co-gasification of biomass and different rank coals," Renewable Energy, Elsevier, vol. 131(C), pages 597-605.
    8. Jeong, Yong-Seong & Kim, Jong-Woo & Seo, Myung-Won & Mun, Tae-Young & Kim, Joo-Sik, 2021. "Characteristics of two-stage air gasification of polystyrene with active carbon as a tar removal agent," Energy, Elsevier, vol. 219(C).
    9. Wei, Juntao & Guo, Qinghua & Ding, Lu & Yoshikawa, Kunio & Yu, Guangsuo, 2017. "Synergy mechanism analysis of petroleum coke and municipal solid waste (MSW)-derived hydrochar co-gasification," Applied Energy, Elsevier, vol. 206(C), pages 1354-1363.
    10. Saebea, Dang & Magistri, Loredana & Massardo, Aristide & Arpornwichanop, Amornchai, 2017. "Cycle analysis of solid oxide fuel cell-gas turbine hybrid systems integrated ethanol steam reformer: Energy management," Energy, Elsevier, vol. 127(C), pages 743-755.
    11. Masnadi, Mohammad S. & Grace, John R. & Bi, Xiaotao T. & Ellis, Naoko & Lim, C. Jim & Butler, James W., 2015. "Biomass/coal steam co-gasification integrated with in-situ CO2 capture," Energy, Elsevier, vol. 83(C), pages 326-336.
    12. Qi, Huini & Li, Fashe & Wang, Shuang & Sui, Meng & Lu, Fengju, 2024. "Pyrolysis and co-pyrolysis of cattle manure, rape straw, and their blend: Physicochemical characterization, kinetic triplets, reaction mechanism, and thermodynamic analysis," Energy, Elsevier, vol. 292(C).
    13. Wang, Fu & Zhao, Jun & Zhang, Houcheng & Miao, He & Zhao, Jiapei & Wang, Jiatang & Yuan, Jinliang & Yan, Jinyue, 2018. "Efficiency evaluation of a coal-fired power plant integrated with chilled ammonia process using an absorption refrigerator," Applied Energy, Elsevier, vol. 230(C), pages 267-276.
    14. He, Yahui & Li, Xiaofu & Meng, Li & Zhang, Wenqi & Wang, Yinfeng & Wang, Lei & Bi, Xiaotao & Zhu, Yuezhao, 2024. "Experimental investigation on high-temperature co-gasification and melting behavior of petrochemical sludge and bituminous coal in CO2 atmosphere," Energy, Elsevier, vol. 303(C).
    15. Li, Fenghai & Liu, Quanrun & Li, Meng & Fang, Yitian, 2018. "Understanding fly-ash formation during fluidized-bed gasification of high-silicon-aluminum coal based on its characteristics," Energy, Elsevier, vol. 150(C), pages 142-152.
    16. Ahmed M. Salem & Harnek S. Dhami & Manosh C. Paul, 2022. "Syngas Production and Combined Heat and Power from Scottish Agricultural Waste Gasification—A Computational Study," Sustainability, MDPI, vol. 14(7), pages 1-18, March.
    17. Patel, Vimal R. & Patel, Darshil & Varia, Nandan S. & Patel, Rajesh N., 2017. "Co-gasification of lignite and waste wood in a pilot-scale (10 kWe) downdraft gasifier," Energy, Elsevier, vol. 119(C), pages 834-844.
    18. Wei, Juntao & Guo, Qinghua & Gong, Yan & Ding, Lu & Yu, Guangsuo, 2020. "Effect of biomass leachates on structure evolution and reactivity characteristic of petroleum coke gasification," Renewable Energy, Elsevier, vol. 155(C), pages 111-120.
    19. Anna Trubetskaya, 2022. "Reactivity Effects of Inorganic Content in Biomass Gasification: A Review," Energies, MDPI, vol. 15(9), pages 1-36, April.
    20. Hossain, Md. Sanowar & Paul, Sanjay & Das, Barun K. & Das, Pronob & Nuhash, Sadman Soumik, 2025. "Techno-econo-environmental feasibility analysis and investigation of engine performance, combustion, and emission characteristics using co-pyrolytic oil derived from tea waste and potato skin," Applied Energy, Elsevier, vol. 377(PA).

    More about this item

    Keywords

    ;
    ;
    ;
    ;
    ;

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:energy:v:323:y:2025:i:c:s0360544225014896. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: http://www.journals.elsevier.com/energy .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.