Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

J.M. Johansen (Corresponding Author), Martti Aho (Corresponding Author), Kari Paakkinen, Raili Taipale, H. Egsgaard, J.G. Jakobsen, F.J. Frandsen, P. Glarborg

Research output: Contribution to journalArticleScientificpeer-review

60 Citations (Scopus)

Abstract

Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100 kW moving grate pilot facility. The results from the bench-scale reactor indicate that S and K release are not significantly affected by secondary reactions, while Cl is partly recaptured by secondary reactions in the char. A linear increase in K-release was observed from 50% at 906 °C to almost 80 wt.% at 1234 °C when firing only corn stover. A similar release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234 °C with a linear increase from 70% at 906 °C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of corn stover with wood chips is expected to decrease the absolute release of KCl due to the lower feedstock quantity of Cl, however, increase the relative release of Cl as KCl.
Original languageEnglish
Pages (from-to)2363-2372
Number of pages10
JournalProceedings of the Combustion Institute
Volume34
Issue number2
DOIs
Publication statusPublished - 2013
MoE publication typeA1 Journal article-refereed

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corn
Chlorine
biomass
seats
chlorine
beds
Wood
Biomass
chips
Ashes
reactors
flue gases
ashes
Flue gases
Feedstocks
profiles
Temperature
temperature
energy

Keywords

  • biomass combustion
  • chlorine release
  • alkali release
  • co-combustion
  • pilot

Cite this

Johansen, J.M. ; Aho, Martti ; Paakkinen, Kari ; Taipale, Raili ; Egsgaard, H. ; Jakobsen, J.G. ; Frandsen, F.J. ; Glarborg, P. / Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds. In: Proceedings of the Combustion Institute. 2013 ; Vol. 34, No. 2. pp. 2363-2372.
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title = "Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds",
abstract = "Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100 kW moving grate pilot facility. The results from the bench-scale reactor indicate that S and K release are not significantly affected by secondary reactions, while Cl is partly recaptured by secondary reactions in the char. A linear increase in K-release was observed from 50{\%} at 906 °C to almost 80 wt.{\%} at 1234 °C when firing only corn stover. A similar release profile was observed for Cl, from 65{\%} to nearly 100{\%}. Complete release of S was achieved at 1234 °C with a linear increase from 70{\%} at 906 °C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40{\%} to 100{\%} (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0{\%} as the share of wood chips is increased towards 100{\%}. Hence, co-combustion of corn stover with wood chips is expected to decrease the absolute release of KCl due to the lower feedstock quantity of Cl, however, increase the relative release of Cl as KCl.",
keywords = "biomass combustion, chlorine release, alkali release, co-combustion, pilot",
author = "J.M. Johansen and Martti Aho and Kari Paakkinen and Raili Taipale and H. Egsgaard and J.G. Jakobsen and F.J. Frandsen and P. Glarborg",
year = "2013",
doi = "10.1016/j.proci.2012.07.025",
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Johansen, JM, Aho, M, Paakkinen, K, Taipale, R, Egsgaard, H, Jakobsen, JG, Frandsen, FJ & Glarborg, P 2013, 'Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds', Proceedings of the Combustion Institute, vol. 34, no. 2, pp. 2363-2372. https://doi.org/10.1016/j.proci.2012.07.025

Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds. / Johansen, J.M. (Corresponding Author); Aho, Martti (Corresponding Author); Paakkinen, Kari; Taipale, Raili; Egsgaard, H.; Jakobsen, J.G.; Frandsen, F.J.; Glarborg, P.

In: Proceedings of the Combustion Institute, Vol. 34, No. 2, 2013, p. 2363-2372.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

AU - Johansen, J.M.

AU - Aho, Martti

AU - Paakkinen, Kari

AU - Taipale, Raili

AU - Egsgaard, H.

AU - Jakobsen, J.G.

AU - Frandsen, F.J.

AU - Glarborg, P.

PY - 2013

Y1 - 2013

N2 - Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100 kW moving grate pilot facility. The results from the bench-scale reactor indicate that S and K release are not significantly affected by secondary reactions, while Cl is partly recaptured by secondary reactions in the char. A linear increase in K-release was observed from 50% at 906 °C to almost 80 wt.% at 1234 °C when firing only corn stover. A similar release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234 °C with a linear increase from 70% at 906 °C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of corn stover with wood chips is expected to decrease the absolute release of KCl due to the lower feedstock quantity of Cl, however, increase the relative release of Cl as KCl.

AB - Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100 kW moving grate pilot facility. The results from the bench-scale reactor indicate that S and K release are not significantly affected by secondary reactions, while Cl is partly recaptured by secondary reactions in the char. A linear increase in K-release was observed from 50% at 906 °C to almost 80 wt.% at 1234 °C when firing only corn stover. A similar release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234 °C with a linear increase from 70% at 906 °C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of corn stover with wood chips is expected to decrease the absolute release of KCl due to the lower feedstock quantity of Cl, however, increase the relative release of Cl as KCl.

KW - biomass combustion

KW - chlorine release

KW - alkali release

KW - co-combustion

KW - pilot

U2 - 10.1016/j.proci.2012.07.025

DO - 10.1016/j.proci.2012.07.025

M3 - Article

VL - 34

SP - 2363

EP - 2372

JO - Proceedings of the Combustion Institute

JF - Proceedings of the Combustion Institute

SN - 1540-7489

IS - 2

ER -