Effects of red mud on emission control of NO                         x                          precursors during sludge pyrolysis: A protein model compound study

Keke Xiao; Ruonan Guan; Jiakuan Yang; Hongsen Li; Zecong Yu; Sha Liang; Wenbo Yu; Jingping Hu; Huijie Hou; Bingchuan Liu

doi:10.1016/j.wasman.2019.01.014

Effects of red mud on emission control of NO _x precursors during sludge pyrolysis: A protein model compound study

Keke Xiao, Ruonan Guan, Jiakuan Yang^*, Hongsen Li, Zecong Yu, Sha Liang, Wenbo Yu, Jingping Hu, Huijie Hou, Bingchuan Liu

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

51 Scopus citations

Abstract

The nitrogen-containing gases pyrolyzed from sewage sludge can be converted into NO _x compounds, which would cause severe environmental pollution. This study developed a new strategy to reduce the emission of NO _x precursors such as ammonia (NH ₃ ) and hydrogen cyanide (HCN) using red mud. The highest reduction efficiencies (15.10% for NH ₃ and 24.72% for HCN) were achieved at 900 °C while compared with those pyrolyzed from raw sludge without the addition of red mud. The transformation and distribution of nitrogenous compounds in three-phase pyrolysates were studied at 400–800 °C for pyrolysis process of a model soybean protein compound. The nitrogenous compounds, i.e., amine-N, heterocyclic-N, and nitrile-N, were identified as the three main intermediates related with the production of NO _x precursors. Ferric oxide (Fe ₂ O ₃ ) and calcium oxide (CaO) presented in red mud were identified as the driving force which facilitated nitrogen stabilization in char (e.g., at 800 °C, 21.63% increase of char-N after addition of Fe ₂ O ₃ , and 41.54% increase of char-N after addition of CaO). These metal oxides possibly reacted with protein-N to form Fe _x N and CaC _x N _y , inhibited the secondary cracking of amine-N compounds in tar (e.g., at 800 °C, 2.33% increase of amine-N after addition of Fe ₂ O ₃ , and 0.38% increase of amine-N after addition of CaO), and reduced the production of nitrile-N (e.g., at 800 °C, 30.41% reduction of nitrile-N after addition of Fe ₂ O ₃ , and 27.40% reduction of nitrile-N after addition of CaO) and heterocyclic-N compounds (e.g., at 800 °C, 21.60% reduction of heterocyclic-N after addition of Fe ₂ O ₃ , and 13.98% reduction of heterocyclic-N after addition of CaO). Hence, the emission of NH ₃ and HCN in gas phase can be controlled. Moreover, Fe ₂ O ₃ showed better capability in controlling the emission of NO _x precursors than CaO (higher reduction of NH ₃ -N and higher reduction of HCN-N). These results indicate that red mud is an efficient catalyst to reduce emission of NO _x precursors through controlling intermediates at 400–800 °C.

Original language	English
Pages (from-to)	452-463
Number of pages	12
Journal	Waste Management
Volume	85
DOIs	https://doi.org/10.1016/j.wasman.2019.01.014
State	Published - 15 Feb 2019
Externally published	Yes

Keywords

Metal oxides
NO precursors
Pyrolysis
Red mud
Sewage sludge

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.wasman.2019.01.014

Cite this

@article{3b709d6be09d4618ab8dad42bd071ab7,

title = "Effects of red mud on emission control of NO x precursors during sludge pyrolysis: A protein model compound study",

abstract = " The nitrogen-containing gases pyrolyzed from sewage sludge can be converted into NO x compounds, which would cause severe environmental pollution. This study developed a new strategy to reduce the emission of NO x precursors such as ammonia (NH 3 ) and hydrogen cyanide (HCN) using red mud. The highest reduction efficiencies (15.10% for NH 3 and 24.72% for HCN) were achieved at 900 °C while compared with those pyrolyzed from raw sludge without the addition of red mud. The transformation and distribution of nitrogenous compounds in three-phase pyrolysates were studied at 400–800 °C for pyrolysis process of a model soybean protein compound. The nitrogenous compounds, i.e., amine-N, heterocyclic-N, and nitrile-N, were identified as the three main intermediates related with the production of NO x precursors. Ferric oxide (Fe 2 O 3 ) and calcium oxide (CaO) presented in red mud were identified as the driving force which facilitated nitrogen stabilization in char (e.g., at 800 °C, 21.63% increase of char-N after addition of Fe 2 O 3 , and 41.54% increase of char-N after addition of CaO). These metal oxides possibly reacted with protein-N to form Fe x N and CaC x N y , inhibited the secondary cracking of amine-N compounds in tar (e.g., at 800 °C, 2.33% increase of amine-N after addition of Fe 2 O 3 , and 0.38% increase of amine-N after addition of CaO), and reduced the production of nitrile-N (e.g., at 800 °C, 30.41% reduction of nitrile-N after addition of Fe 2 O 3 , and 27.40% reduction of nitrile-N after addition of CaO) and heterocyclic-N compounds (e.g., at 800 °C, 21.60% reduction of heterocyclic-N after addition of Fe 2 O 3 , and 13.98% reduction of heterocyclic-N after addition of CaO). Hence, the emission of NH 3 and HCN in gas phase can be controlled. Moreover, Fe 2 O 3 showed better capability in controlling the emission of NO x precursors than CaO (higher reduction of NH 3 -N and higher reduction of HCN-N). These results indicate that red mud is an efficient catalyst to reduce emission of NO x precursors through controlling intermediates at 400–800 °C.",

keywords = "Metal oxides, NO precursors, Pyrolysis, Red mud, Sewage sludge",

author = "Keke Xiao and Ruonan Guan and Jiakuan Yang and Hongsen Li and Zecong Yu and Sha Liang and Wenbo Yu and Jingping Hu and Huijie Hou and Bingchuan Liu",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier Ltd",

year = "2019",

month = feb,

day = "15",

doi = "10.1016/j.wasman.2019.01.014",

language = "英语",

volume = "85",

pages = "452--463",

journal = "Waste Management",

issn = "0956-053X",

publisher = "Elsevier Ltd.",

}

TY - JOUR

T1 - Effects of red mud on emission control of NO x precursors during sludge pyrolysis

T2 - A protein model compound study

AU - Xiao, Keke

AU - Guan, Ruonan

AU - Yang, Jiakuan

AU - Li, Hongsen

AU - Yu, Zecong

AU - Liang, Sha

AU - Yu, Wenbo

AU - Hu, Jingping

AU - Hou, Huijie

AU - Liu, Bingchuan

PY - 2019/2/15

Y1 - 2019/2/15

N2 - The nitrogen-containing gases pyrolyzed from sewage sludge can be converted into NO x compounds, which would cause severe environmental pollution. This study developed a new strategy to reduce the emission of NO x precursors such as ammonia (NH 3 ) and hydrogen cyanide (HCN) using red mud. The highest reduction efficiencies (15.10% for NH 3 and 24.72% for HCN) were achieved at 900 °C while compared with those pyrolyzed from raw sludge without the addition of red mud. The transformation and distribution of nitrogenous compounds in three-phase pyrolysates were studied at 400–800 °C for pyrolysis process of a model soybean protein compound. The nitrogenous compounds, i.e., amine-N, heterocyclic-N, and nitrile-N, were identified as the three main intermediates related with the production of NO x precursors. Ferric oxide (Fe 2 O 3 ) and calcium oxide (CaO) presented in red mud were identified as the driving force which facilitated nitrogen stabilization in char (e.g., at 800 °C, 21.63% increase of char-N after addition of Fe 2 O 3 , and 41.54% increase of char-N after addition of CaO). These metal oxides possibly reacted with protein-N to form Fe x N and CaC x N y , inhibited the secondary cracking of amine-N compounds in tar (e.g., at 800 °C, 2.33% increase of amine-N after addition of Fe 2 O 3 , and 0.38% increase of amine-N after addition of CaO), and reduced the production of nitrile-N (e.g., at 800 °C, 30.41% reduction of nitrile-N after addition of Fe 2 O 3 , and 27.40% reduction of nitrile-N after addition of CaO) and heterocyclic-N compounds (e.g., at 800 °C, 21.60% reduction of heterocyclic-N after addition of Fe 2 O 3 , and 13.98% reduction of heterocyclic-N after addition of CaO). Hence, the emission of NH 3 and HCN in gas phase can be controlled. Moreover, Fe 2 O 3 showed better capability in controlling the emission of NO x precursors than CaO (higher reduction of NH 3 -N and higher reduction of HCN-N). These results indicate that red mud is an efficient catalyst to reduce emission of NO x precursors through controlling intermediates at 400–800 °C.

AB - The nitrogen-containing gases pyrolyzed from sewage sludge can be converted into NO x compounds, which would cause severe environmental pollution. This study developed a new strategy to reduce the emission of NO x precursors such as ammonia (NH 3 ) and hydrogen cyanide (HCN) using red mud. The highest reduction efficiencies (15.10% for NH 3 and 24.72% for HCN) were achieved at 900 °C while compared with those pyrolyzed from raw sludge without the addition of red mud. The transformation and distribution of nitrogenous compounds in three-phase pyrolysates were studied at 400–800 °C for pyrolysis process of a model soybean protein compound. The nitrogenous compounds, i.e., amine-N, heterocyclic-N, and nitrile-N, were identified as the three main intermediates related with the production of NO x precursors. Ferric oxide (Fe 2 O 3 ) and calcium oxide (CaO) presented in red mud were identified as the driving force which facilitated nitrogen stabilization in char (e.g., at 800 °C, 21.63% increase of char-N after addition of Fe 2 O 3 , and 41.54% increase of char-N after addition of CaO). These metal oxides possibly reacted with protein-N to form Fe x N and CaC x N y , inhibited the secondary cracking of amine-N compounds in tar (e.g., at 800 °C, 2.33% increase of amine-N after addition of Fe 2 O 3 , and 0.38% increase of amine-N after addition of CaO), and reduced the production of nitrile-N (e.g., at 800 °C, 30.41% reduction of nitrile-N after addition of Fe 2 O 3 , and 27.40% reduction of nitrile-N after addition of CaO) and heterocyclic-N compounds (e.g., at 800 °C, 21.60% reduction of heterocyclic-N after addition of Fe 2 O 3 , and 13.98% reduction of heterocyclic-N after addition of CaO). Hence, the emission of NH 3 and HCN in gas phase can be controlled. Moreover, Fe 2 O 3 showed better capability in controlling the emission of NO x precursors than CaO (higher reduction of NH 3 -N and higher reduction of HCN-N). These results indicate that red mud is an efficient catalyst to reduce emission of NO x precursors through controlling intermediates at 400–800 °C.

KW - Metal oxides

KW - NO precursors

KW - Pyrolysis

KW - Red mud

KW - Sewage sludge

UR - http://www.scopus.com/inward/record.url?scp=85059870373&partnerID=8YFLogxK

U2 - 10.1016/j.wasman.2019.01.014

DO - 10.1016/j.wasman.2019.01.014

M3 - 文章

C2 - 30803601

AN - SCOPUS:85059870373

SN - 0956-053X

VL - 85

SP - 452

EP - 463

JO - Waste Management

JF - Waste Management

ER -