Kinetic and thermodynamic analysis of municipal sludge combustion characteristics

LI Tenghao; WANG Yin; LIU Bo; ZHANG Shan; BAI Xue

doi:10.13205/j.hjgc.202607005

Volume 44 Issue 7

Jul. 2026

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Article Navigation > ENVIRONMENTAL ENGINEERING > 2026 > 44(7): 42-48

LI Tenghao, WANG Yin, LIU Bo, ZHANG Shan, BAI Xue. Kinetic and thermodynamic analysis of municipal sludge combustion characteristics[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(7): 42-48. doi: 10.13205/j.hjgc.202607005

Citation:

LI Tenghao, WANG Yin, LIU Bo, ZHANG Shan, BAI Xue. Kinetic and thermodynamic analysis of municipal sludge combustion characteristics[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(7): 42-48. doi: 10.13205/j.hjgc.202607005

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Kinetic and thermodynamic analysis of municipal sludge combustion characteristics

doi: 10.13205/j.hjgc.202607005

LI Tenghao^1,2,
WANG Yin¹,
LIU Bo¹,
ZHANG Shan¹,
BAI Xue^{1
,
,}

1. Southwest Municipal Engineering Design & Research Institute, Chengdu 610000, China;
2. College of Excellent Engineers, Dalian Maritime University, Dalian 116000, China

Received Date: 2026-01-22
Available Online: 2026-09-01

Abstract

Abstract

To optimize the municipal sludge incineration process and improve disposal efficiency， municipal sludge from the First Sewage Treatment Plant in Chengdu was selected as the research object， and synchronous thermal analysis technology was employed to comprehensively analyze the thermogravimetric （TG）， derivative thermogravimetric （DTG）， and differential scanning calorimetry （DSC） signals. To verify the accuracy of the Coats-Redfern （CR） integral method， the Achar-Brindley-Sharp （ABS） differential method was additionally employed for comparative calculation. The combustion characteristics， as well as the staged kinetic and thermodynamic behaviors of the sludge， were investigated in air atmosphere at a heating rate of 20 K/min. The results showed that the combustion process can be divided into four stages： moisture evaporation， volatile combustion， fixed carbon combustion， and burnout. The main heat release is concentrated in the volatile combustion and fixed carbon combustion stages. The ignition temperature of the sludge is 220.7 ℃， the burnout temperature is 605.9 ℃， and the comprehensive combustion characteristic index is 6. 32×10^-8 %²/(min²·K³， indicating good combustion stability. Kinetic analysis revealed that the moisture evaporation and volatile combustion stages follow the first-order reaction model （F1）， while the fixed carbon combustion and burnout stages conform to the second-order reaction model （F2）. The apparent activation energies obtained by the two methods deviated by less than 15%， confirming the reliability of the CR results. The apparent activation energies for each stage were 52.24， 48.81， 192.38， 102.27 kJ/mol， respectively. Thermodynamic analysis indicated that the entropy change （ΔS） is negative and the Gibbs free energy （ΔG） is positive in all stages， demonstrating that the sludge incineration process requires external energy input， with higher energy demand in the high-temperature burnout stage. These findings provide a theoretical reference for optimizing municipal sludge incineration processes.
- municipal sludge,
- combustion characteristics,
- thermogravimetric analysis,
- kinetics,
- thermodynamics

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References(16)

References

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