Effects of pressure and oxygen concentration on the combustion of different coals

T. Joutsenoja (Corresponding Author), Jaakko Saastamoinen, Martti Aho, Rolf Hernberg

Research output: Contribution to journalArticleScientificpeer-review

34 Citations (Scopus)

Abstract

A pyrometric method was used for simultaneous in situ measurement of the temperature and size of individual coal particles in a pressurized entrained flow reactor. Several series of measurements were made in the gas temperature range 1150−1270 K to study the effects of pressure (0.2−1.0 MPa) and oxygen volume fraction (3−30 vol %) on the particle temperature and size distributions and on the mean degree of burnoff at well-defined residence times. The fuels used in the experiments varied strongly in their reactivity:  lignite from France (Gardanne), high-volatile bituminous (hvb) coals from Germany (Westerholt, Göttelborn) and Poland (mixture), and anthracite from Germany (Niederberg). Milled fuel was sieved into nominal-size fractions in the range from 75 to 180 μm. The strongest increase in combustion rate at increased pressure occurred for anthracite, which was the least reactive among the fuels studied. This is shown by increasing the mass-loss rate and increasing particle temperatures. Pressure had no effect on the combustion of the lignite sample, the most reactive fuel studied. Some evidence of swelling of hvb coal particles was observed during the early stages of combustion. The particle size remained roughly unchanged until the degree of burnoff exceeded 90%, whereafter the particle size started to decrease due to fragmentation. Experimental results from particle temperature measurements at various oxygen concentrations are compared with literature data. Results from in situ particle measurements including size and temperature recording have not been presented previously at elevated pressures for such a wide range of coals. Measurements on combustion rates, particle temperatures and particle sizes were analyzed with a single-particle combustion model. The effect of pressure on the surface reaction kinetics for an anthracite was found to be small compared to the oxygen content and temperature.
Original languageEnglish
Pages (from-to)130-145
Number of pages16
JournalEnergy & Fuels
Volume13
Issue number1
DOIs
Publication statusPublished - 1999
MoE publication typeA1 Journal article-refereed

Fingerprint

Coal
Oxygen
Anthracite
Bituminous coal
Particle size
Lignite
Temperature
Surface reactions
Reaction kinetics
Temperature measurement
Swelling
Volume fraction
Temperature distribution
Gases
Experiments

Keywords

  • fuels
  • solid fuels
  • coal
  • combustion
  • pressure
  • oxygen

Cite this

Joutsenoja, T., Saastamoinen, J., Aho, M., & Hernberg, R. (1999). Effects of pressure and oxygen concentration on the combustion of different coals. Energy & Fuels, 13(1), 130-145. https://doi.org/10.1021/ef980139j
Joutsenoja, T. ; Saastamoinen, Jaakko ; Aho, Martti ; Hernberg, Rolf. / Effects of pressure and oxygen concentration on the combustion of different coals. In: Energy & Fuels. 1999 ; Vol. 13, No. 1. pp. 130-145.
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abstract = "A pyrometric method was used for simultaneous in situ measurement of the temperature and size of individual coal particles in a pressurized entrained flow reactor. Several series of measurements were made in the gas temperature range 1150−1270 K to study the effects of pressure (0.2−1.0 MPa) and oxygen volume fraction (3−30 vol {\%}) on the particle temperature and size distributions and on the mean degree of burnoff at well-defined residence times. The fuels used in the experiments varied strongly in their reactivity:  lignite from France (Gardanne), high-volatile bituminous (hvb) coals from Germany (Westerholt, G{\"o}ttelborn) and Poland (mixture), and anthracite from Germany (Niederberg). Milled fuel was sieved into nominal-size fractions in the range from 75 to 180 μm. The strongest increase in combustion rate at increased pressure occurred for anthracite, which was the least reactive among the fuels studied. This is shown by increasing the mass-loss rate and increasing particle temperatures. Pressure had no effect on the combustion of the lignite sample, the most reactive fuel studied. Some evidence of swelling of hvb coal particles was observed during the early stages of combustion. The particle size remained roughly unchanged until the degree of burnoff exceeded 90{\%}, whereafter the particle size started to decrease due to fragmentation. Experimental results from particle temperature measurements at various oxygen concentrations are compared with literature data. Results from in situ particle measurements including size and temperature recording have not been presented previously at elevated pressures for such a wide range of coals. Measurements on combustion rates, particle temperatures and particle sizes were analyzed with a single-particle combustion model. The effect of pressure on the surface reaction kinetics for an anthracite was found to be small compared to the oxygen content and temperature.",
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Joutsenoja, T, Saastamoinen, J, Aho, M & Hernberg, R 1999, 'Effects of pressure and oxygen concentration on the combustion of different coals', Energy & Fuels, vol. 13, no. 1, pp. 130-145. https://doi.org/10.1021/ef980139j

Effects of pressure and oxygen concentration on the combustion of different coals. / Joutsenoja, T. (Corresponding Author); Saastamoinen, Jaakko; Aho, Martti; Hernberg, Rolf.

In: Energy & Fuels, Vol. 13, No. 1, 1999, p. 130-145.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Effects of pressure and oxygen concentration on the combustion of different coals

AU - Joutsenoja, T.

AU - Saastamoinen, Jaakko

AU - Aho, Martti

AU - Hernberg, Rolf

PY - 1999

Y1 - 1999

N2 - A pyrometric method was used for simultaneous in situ measurement of the temperature and size of individual coal particles in a pressurized entrained flow reactor. Several series of measurements were made in the gas temperature range 1150−1270 K to study the effects of pressure (0.2−1.0 MPa) and oxygen volume fraction (3−30 vol %) on the particle temperature and size distributions and on the mean degree of burnoff at well-defined residence times. The fuels used in the experiments varied strongly in their reactivity:  lignite from France (Gardanne), high-volatile bituminous (hvb) coals from Germany (Westerholt, Göttelborn) and Poland (mixture), and anthracite from Germany (Niederberg). Milled fuel was sieved into nominal-size fractions in the range from 75 to 180 μm. The strongest increase in combustion rate at increased pressure occurred for anthracite, which was the least reactive among the fuels studied. This is shown by increasing the mass-loss rate and increasing particle temperatures. Pressure had no effect on the combustion of the lignite sample, the most reactive fuel studied. Some evidence of swelling of hvb coal particles was observed during the early stages of combustion. The particle size remained roughly unchanged until the degree of burnoff exceeded 90%, whereafter the particle size started to decrease due to fragmentation. Experimental results from particle temperature measurements at various oxygen concentrations are compared with literature data. Results from in situ particle measurements including size and temperature recording have not been presented previously at elevated pressures for such a wide range of coals. Measurements on combustion rates, particle temperatures and particle sizes were analyzed with a single-particle combustion model. The effect of pressure on the surface reaction kinetics for an anthracite was found to be small compared to the oxygen content and temperature.

AB - A pyrometric method was used for simultaneous in situ measurement of the temperature and size of individual coal particles in a pressurized entrained flow reactor. Several series of measurements were made in the gas temperature range 1150−1270 K to study the effects of pressure (0.2−1.0 MPa) and oxygen volume fraction (3−30 vol %) on the particle temperature and size distributions and on the mean degree of burnoff at well-defined residence times. The fuels used in the experiments varied strongly in their reactivity:  lignite from France (Gardanne), high-volatile bituminous (hvb) coals from Germany (Westerholt, Göttelborn) and Poland (mixture), and anthracite from Germany (Niederberg). Milled fuel was sieved into nominal-size fractions in the range from 75 to 180 μm. The strongest increase in combustion rate at increased pressure occurred for anthracite, which was the least reactive among the fuels studied. This is shown by increasing the mass-loss rate and increasing particle temperatures. Pressure had no effect on the combustion of the lignite sample, the most reactive fuel studied. Some evidence of swelling of hvb coal particles was observed during the early stages of combustion. The particle size remained roughly unchanged until the degree of burnoff exceeded 90%, whereafter the particle size started to decrease due to fragmentation. Experimental results from particle temperature measurements at various oxygen concentrations are compared with literature data. Results from in situ particle measurements including size and temperature recording have not been presented previously at elevated pressures for such a wide range of coals. Measurements on combustion rates, particle temperatures and particle sizes were analyzed with a single-particle combustion model. The effect of pressure on the surface reaction kinetics for an anthracite was found to be small compared to the oxygen content and temperature.

KW - fuels

KW - solid fuels

KW - coal

KW - combustion

KW - pressure

KW - oxygen

U2 - 10.1021/ef980139j

DO - 10.1021/ef980139j

M3 - Article

VL - 13

SP - 130

EP - 145

JO - Energy & Fuels

JF - Energy & Fuels

SN - 0887-0624

IS - 1

ER -