Insight into KOH and KCl release behavior of burning wood and straw pellets using quantitative in situ optical measurements
(2023) In Proceedings of the Combustion Institute 39(3). p.3239-3248- Abstract
Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was employed to quantitatively visualize the potassium hydroxide (KOH) and potassium chloride (KCl) vapor in the plume above burning wood and straw pellets. In the LIPF measurement, two excitation lasers at 266 and 193 nm were adopted to discriminate KOH and KCl. Meanwhile, tunable diode laser absorption spectroscopy (TDLAS), laser-induced breakdown spectroscopy (LIBS) and two-color pyrometry were used to measure the atomic potassium concentration, total elemental potassium concentration and surface temperature of the burning pellets, respectively. The combustion environment had a temperature of 1550 K and an oxygen concentration of 4.6 vol.%. Two peaks were observed... (More)
Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was employed to quantitatively visualize the potassium hydroxide (KOH) and potassium chloride (KCl) vapor in the plume above burning wood and straw pellets. In the LIPF measurement, two excitation lasers at 266 and 193 nm were adopted to discriminate KOH and KCl. Meanwhile, tunable diode laser absorption spectroscopy (TDLAS), laser-induced breakdown spectroscopy (LIBS) and two-color pyrometry were used to measure the atomic potassium concentration, total elemental potassium concentration and surface temperature of the burning pellets, respectively. The combustion environment had a temperature of 1550 K and an oxygen concentration of 4.6 vol.%. Two peaks were observed from the temporal potassium release profile of the burning wood, corresponding to the devolatilization and char oxidation stage, while only a single release peak was observed from the burning straw attributed to its high ash content. During the char oxidation and ash cooking stages, KOH was observed to be the dominant potassium species released from the wood, while only KCl was observed for the straw which had a high content of chlorine. About 45% of the total potassium in the wood samples and about 10% in the straw samples were measured to be released during the combustion process. The high content of silicon in the straw retained a considerable amount of potassium in the ash. The wood had the potassium release mainly in the char oxidation stage (53% of the total release), while the straw had the main release during the ash cooking stage (49% of the total release). During the char oxidation and ash cooking stages, about 32% of Cl was released from the straw pellets in KCl, while the other part of Cl was considered to be released during the devolatilization stage in other Cl species form, such as HCl.
(Less)
- author
- Weng, Wubin LU ; Aldén, Marcus LU and Li, Zhongshan LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Biomass, Chlorine, Laser-induced photofragmentation fluorescence, Potassium, Quantitatively imaging
- in
- Proceedings of the Combustion Institute
- volume
- 39
- issue
- 3
- pages
- 3239 - 3248
- publisher
- Elsevier
- external identifiers
-
- scopus:85137220751
- ISSN
- 1540-7489
- DOI
- 10.1016/j.proci.2022.07.079
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: The work was financially supported by the Swedish Energy Agency [KC-CECOST, biomass project], the Knut & Alice Wallenberg Foundation [Cocald], European Research Council [TUCLA] and the Swedish Research Council (VR). We thank Peter Glarborg and Hao Wu from the Technical University of Denmark for providing the biomass material. Publisher Copyright: © 2022 Elsevier Inc. All rights reserved.
- id
- cef4dc58-6d94-4896-84e0-ac180c08562d
- date added to LUP
- 2022-09-22 14:03:07
- date last changed
- 2023-11-06 22:15:15
@article{cef4dc58-6d94-4896-84e0-ac180c08562d,
abstract = {{<p>Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was employed to quantitatively visualize the potassium hydroxide (KOH) and potassium chloride (KCl) vapor in the plume above burning wood and straw pellets. In the LIPF measurement, two excitation lasers at 266 and 193 nm were adopted to discriminate KOH and KCl. Meanwhile, tunable diode laser absorption spectroscopy (TDLAS), laser-induced breakdown spectroscopy (LIBS) and two-color pyrometry were used to measure the atomic potassium concentration, total elemental potassium concentration and surface temperature of the burning pellets, respectively. The combustion environment had a temperature of 1550 K and an oxygen concentration of 4.6 vol.%. Two peaks were observed from the temporal potassium release profile of the burning wood, corresponding to the devolatilization and char oxidation stage, while only a single release peak was observed from the burning straw attributed to its high ash content. During the char oxidation and ash cooking stages, KOH was observed to be the dominant potassium species released from the wood, while only KCl was observed for the straw which had a high content of chlorine. About 45% of the total potassium in the wood samples and about 10% in the straw samples were measured to be released during the combustion process. The high content of silicon in the straw retained a considerable amount of potassium in the ash. The wood had the potassium release mainly in the char oxidation stage (53% of the total release), while the straw had the main release during the ash cooking stage (49% of the total release). During the char oxidation and ash cooking stages, about 32% of Cl was released from the straw pellets in KCl, while the other part of Cl was considered to be released during the devolatilization stage in other Cl species form, such as HCl.</p>}},
author = {{Weng, Wubin and Aldén, Marcus and Li, Zhongshan}},
issn = {{1540-7489}},
keywords = {{Biomass; Chlorine; Laser-induced photofragmentation fluorescence; Potassium; Quantitatively imaging}},
language = {{eng}},
number = {{3}},
pages = {{3239--3248}},
publisher = {{Elsevier}},
series = {{Proceedings of the Combustion Institute}},
title = {{Insight into KOH and KCl release behavior of burning wood and straw pellets using quantitative in situ optical measurements}},
url = {{http://dx.doi.org/10.1016/j.proci.2022.07.079}},
doi = {{10.1016/j.proci.2022.07.079}},
volume = {{39}},
year = {{2023}},
}