Effect of CO<sub>2</sub> content on NO reduction during sewage sludge reburning

XIAO Xiang; FANG Ping; HUANG Jian-hang; TANG Zi-jun; CHEN Xiong-bo; WU Hai-wen; CEN Chao-ping; TANG Zhi-xiong

Volume 47 Issue 2

Feb. 2019

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Article Navigation > Journal of Fuel Chemistry and Technology > 2019 > 47(2): 233-241

XIAO Xiang, FANG Ping, HUANG Jian-hang, TANG Zi-jun, CHEN Xiong-bo, WU Hai-wen, CEN Chao-ping, TANG Zhi-xiong. Effect of CO2 content on NO reduction during sewage sludge reburning[J]. Journal of Fuel Chemistry and Technology, 2019, 47(2): 233-241.

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XIAO Xiang, FANG Ping, HUANG Jian-hang, TANG Zi-jun, CHEN Xiong-bo, WU Hai-wen, CEN Chao-ping, TANG Zhi-xiong. Effect of CO₂ content on NO reduction during sewage sludge reburning[J]. Journal of Fuel Chemistry and Technology, 2019, 47(2): 233-241.

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Effect of CO₂ content on NO reduction during sewage sludge reburning

XIAO Xiang^{1, 2},
FANG Ping^{1, 2
,
,},
HUANG Jian-hang^{1, 2},
TANG Zi-jun^{1, 2},
CHEN Xiong-bo^{1, 2},
WU Hai-wen^{1, 2},
CEN Chao-ping^{1, 2},
TANG Zhi-xiong^{1, 2}

1.
South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China
2.
The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Guangzhou 510655, China

Funds:

the National Natural Science Foundation of China NSFC-51778264

the Pearl River S & T Nova Program of Guangzhou 201610010150

the Youth Top-Notch Talent Special Support Program of Guangdong Province 2016TQ03Z576

the Project of Science and Technology Program of Guangdong Province 2017B020237002

the Project of Science and Technology Program of Guangdong Province 2018B020208002

the Central-Level Nonprofit Scientific Institutes for Basic R & D Operations PM-zx703-201803-077

More Information

Corresponding author: FANG Ping, Tel：020-85648560，Fax：020-85648560, E-mail：fangping@scies.org
Received Date: 2018-10-29
Rev Recd Date: 2018-12-14

Available Online: 2021-01-23

Publish Date: 2019-02-10

Abstract

Abstract

The effect of CO₂ content(volume fraction 0-35%) on the reducing gas release characteristics from sewage sludge re-burning and the dynamic properties of NO reduction by sewage sludge and char were investigated in a simulated experimental platform of cement pre-calciner. The experimental results show that the reducing gas release from sewage sludge combustion are mainly HCN, NH₃, CH₄ and CO. With the increase of CO₂ content from 0 to 25%, the release of HCN, NH₃ and CH₄ slowly decreased due to the enhancing effect of sludge gasification by CO₂, while the release of CO increased significantly, eventually promoting the NO reduction rate from 51% to 61%. As continually increasing CO₂ content to 35%, the local thermal instability was enhanced due to the radiation absorption of CO₂, and the weakening of gasification resulted in the decrease of CO release. Moreover, HCN release decreased significantly, while NH₃ release did not change much, CH₄ release increased to a certain extent, and the combined effect makes the NO reduction rate gradually decreased to 55%. The results show that sludge re-burning can efficiently reduce NO in flue gas. It is also found that the homogeneous and heterogeneous reduction of NO are concurrence during sludge re-burning, while the experimental studies revealed that the NO reduction rate over the sludge char was only 18%, it implied that sludge denitration is dominated by gas-gas homogeneous reduction.
- CO₂,
- reducing gas,
- sewage sludge,
- char,
- NO reduction

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References(20)

References

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