Formation of NO, NO2, and N2O from Gardanne lignite and its char under pressurized conditions

Chantal Mallet (Corresponding Author), Martti Aho, Jouni Hämäläinen, Jean-Robert Richard

Research output: Contribution to journalArticleScientificpeer-review

12 Citations (Scopus)

Abstract

The purpose of this investigation was to distinguish reactor-independent trends in the formation of N2O, NO, and NO2 from trends depending on the mode of combustion. The same char powder was studied with two different devices:  a pressurized thermobalance (PTGA) where the particles are in contact and the gas flows through the char bed, and a pressurized entrained flow reactor (PEFR) where the particles are far from each other, moving in the gas flow. In addition, the proportions of nitrogen oxides formed from volatile-N and char-N were investigated with the PEFR and a modified thermobalance (MTGA), where the sample was burned as single pellets. A French (Gardanne) lignite or its char was used in the experiments. An increase in total pressure decreased the emissions of NO and increased the emissions of NO2 in both the PEFR and the PTGA. However, the effect of oxygen partial pressure was different. In PTGA, carbon monoxide emission was high, increased with PO2, and participated in NO and N2O reduction. Consequently, the partial pressure of oxygen strongly decreased the NO emissions. In PEFR, an increase in oxygen partial pressure increased only the homogeneous conversion of NO to NO2 and has no important effect on NO emissions in the studied range. In the experiments performed to determine the contribution of volatile-N and char-N to nitrogen oxides formation, trends were similar in the PEFR and MTGA devices even though the char preparation was different. Volatile-N was responsible for at least 70% of N2O formation. At atmospheric pressure, char-N and volatile-N participated roughly equally in the formation of NO, but an increase of pressure increased the importance of char-N. Char-N can produce even more NO2 than volatile-N.

Original languageEnglish
Pages (from-to)792 - 800
Number of pages9
JournalEnergy & Fuels
Volume11
Issue number4
DOIs
Publication statusPublished - 1997
MoE publication typeA1 Journal article-refereed

Fingerprint

Coal
Lignite
Partial pressure
Nitrogen Oxides
Nitrogen oxides
Oxygen
Flow of gases
Carbon Monoxide
Carbon monoxide
Powders
Atmospheric pressure
Experiments

Keywords

  • fuels
  • emissions
  • solid fuels
  • coal
  • lignite
  • combustion
  • nitrogen compounds
  • nitrogen oxides
  • nitrous oxide
  • nitric oxide
  • nitrogen dioxide
  • char
  • pressurized combustion

Cite this

Mallet, Chantal ; Aho, Martti ; Hämäläinen, Jouni ; Richard, Jean-Robert. / Formation of NO, NO2, and N2O from Gardanne lignite and its char under pressurized conditions. In: Energy & Fuels. 1997 ; Vol. 11, No. 4. pp. 792 - 800.
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abstract = "The purpose of this investigation was to distinguish reactor-independent trends in the formation of N2O, NO, and NO2 from trends depending on the mode of combustion. The same char powder was studied with two different devices:  a pressurized thermobalance (PTGA) where the particles are in contact and the gas flows through the char bed, and a pressurized entrained flow reactor (PEFR) where the particles are far from each other, moving in the gas flow. In addition, the proportions of nitrogen oxides formed from volatile-N and char-N were investigated with the PEFR and a modified thermobalance (MTGA), where the sample was burned as single pellets. A French (Gardanne) lignite or its char was used in the experiments. An increase in total pressure decreased the emissions of NO and increased the emissions of NO2 in both the PEFR and the PTGA. However, the effect of oxygen partial pressure was different. In PTGA, carbon monoxide emission was high, increased with PO2, and participated in NO and N2O reduction. Consequently, the partial pressure of oxygen strongly decreased the NO emissions. In PEFR, an increase in oxygen partial pressure increased only the homogeneous conversion of NO to NO2 and has no important effect on NO emissions in the studied range. In the experiments performed to determine the contribution of volatile-N and char-N to nitrogen oxides formation, trends were similar in the PEFR and MTGA devices even though the char preparation was different. Volatile-N was responsible for at least 70{\%} of N2O formation. At atmospheric pressure, char-N and volatile-N participated roughly equally in the formation of NO, but an increase of pressure increased the importance of char-N. Char-N can produce even more NO2 than volatile-N.",
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Formation of NO, NO2, and N2O from Gardanne lignite and its char under pressurized conditions. / Mallet, Chantal (Corresponding Author); Aho, Martti; Hämäläinen, Jouni; Richard, Jean-Robert.

In: Energy & Fuels, Vol. 11, No. 4, 1997, p. 792 - 800.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Formation of NO, NO2, and N2O from Gardanne lignite and its char under pressurized conditions

AU - Mallet, Chantal

AU - Aho, Martti

AU - Hämäläinen, Jouni

AU - Richard, Jean-Robert

PY - 1997

Y1 - 1997

N2 - The purpose of this investigation was to distinguish reactor-independent trends in the formation of N2O, NO, and NO2 from trends depending on the mode of combustion. The same char powder was studied with two different devices:  a pressurized thermobalance (PTGA) where the particles are in contact and the gas flows through the char bed, and a pressurized entrained flow reactor (PEFR) where the particles are far from each other, moving in the gas flow. In addition, the proportions of nitrogen oxides formed from volatile-N and char-N were investigated with the PEFR and a modified thermobalance (MTGA), where the sample was burned as single pellets. A French (Gardanne) lignite or its char was used in the experiments. An increase in total pressure decreased the emissions of NO and increased the emissions of NO2 in both the PEFR and the PTGA. However, the effect of oxygen partial pressure was different. In PTGA, carbon monoxide emission was high, increased with PO2, and participated in NO and N2O reduction. Consequently, the partial pressure of oxygen strongly decreased the NO emissions. In PEFR, an increase in oxygen partial pressure increased only the homogeneous conversion of NO to NO2 and has no important effect on NO emissions in the studied range. In the experiments performed to determine the contribution of volatile-N and char-N to nitrogen oxides formation, trends were similar in the PEFR and MTGA devices even though the char preparation was different. Volatile-N was responsible for at least 70% of N2O formation. At atmospheric pressure, char-N and volatile-N participated roughly equally in the formation of NO, but an increase of pressure increased the importance of char-N. Char-N can produce even more NO2 than volatile-N.

AB - The purpose of this investigation was to distinguish reactor-independent trends in the formation of N2O, NO, and NO2 from trends depending on the mode of combustion. The same char powder was studied with two different devices:  a pressurized thermobalance (PTGA) where the particles are in contact and the gas flows through the char bed, and a pressurized entrained flow reactor (PEFR) where the particles are far from each other, moving in the gas flow. In addition, the proportions of nitrogen oxides formed from volatile-N and char-N were investigated with the PEFR and a modified thermobalance (MTGA), where the sample was burned as single pellets. A French (Gardanne) lignite or its char was used in the experiments. An increase in total pressure decreased the emissions of NO and increased the emissions of NO2 in both the PEFR and the PTGA. However, the effect of oxygen partial pressure was different. In PTGA, carbon monoxide emission was high, increased with PO2, and participated in NO and N2O reduction. Consequently, the partial pressure of oxygen strongly decreased the NO emissions. In PEFR, an increase in oxygen partial pressure increased only the homogeneous conversion of NO to NO2 and has no important effect on NO emissions in the studied range. In the experiments performed to determine the contribution of volatile-N and char-N to nitrogen oxides formation, trends were similar in the PEFR and MTGA devices even though the char preparation was different. Volatile-N was responsible for at least 70% of N2O formation. At atmospheric pressure, char-N and volatile-N participated roughly equally in the formation of NO, but an increase of pressure increased the importance of char-N. Char-N can produce even more NO2 than volatile-N.

KW - fuels

KW - emissions

KW - solid fuels

KW - coal

KW - lignite

KW - combustion

KW - nitrogen compounds

KW - nitrogen oxides

KW - nitrous oxide

KW - nitric oxide

KW - nitrogen dioxide

KW - char

KW - pressurized combustion

U2 - 10.1021/ef9601531

DO - 10.1021/ef9601531

M3 - Article

VL - 11

SP - 792

EP - 800

JO - Energy & Fuels

JF - Energy & Fuels

SN - 0887-0624

IS - 4

ER -