KOH capture by coal fly ash

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The KOH-capture reaction by coal fly ash at suspension-fired conditions was studied through entrained flow reactor (EFR) experiments and chemical equilibrium calculations. The influence of KOH-concentration (50–1000 ppmv), reaction temperature (800–1450 °C), and coal fly ash particle size (D50 = 6.03–33.70 μm) on the reaction was investigated. The results revealed that, at 50 ppmv KOH (molar ratio of K/(Al + Si) = 0.048 of feed), the measured K-capture level (CK) of coal fly ash was comparable to the equilibrium prediction, while at 250 ppmv KOH and above, the measured data were lower than chemical equilibrium. Similar to the KOH-kaolin reaction reported in our previous study, leucite (KAlSi2O6) and kaliophilite (KAlSiO4) were formed from the KOH-coal fly ash reaction. However, coal fly ash captured KOH less effectively compared to kaolin at 250 ppmv KOH and above. Studies at different temperatures showed that, at 800 °C, the KOH-coal fly ash reaction was probably kinetically controlled. At 900–1300 °C it was diffusion limited, while at 1450 °C, it was equilibrium limited to some extent. At 500 ppmv KOH (molar ratio of K/(Al + Si) = 0.481), and a gas residence time of 1.2 s, 0.063 g K/(g additive) and 0.087 g K/(g additive) was captured by coal fly ash (D50 = 10.20 μm) at 900 and 1450 °C, respectively. Experiments with coal fly ash of different particle sizes showed that a higher K-capture level were obtained using finer particle sizes, indicating some internal diffusion control of the process.
Original languageEnglish
JournalFuel
Volume242
Pages (from-to)828 - 836
ISSN0016-2361
DOIs
Publication statusPublished - 2019

Keywords

  • Coal fly ash
  • Potassium capture
  • Biomass combustion
  • Additive
  • KOH

Cite this

@article{2fc18a4ecba3470fa9a40736e2f9d292,
title = "KOH capture by coal fly ash",
abstract = "The KOH-capture reaction by coal fly ash at suspension-fired conditions was studied through entrained flow reactor (EFR) experiments and chemical equilibrium calculations. The influence of KOH-concentration (50–1000 ppmv), reaction temperature (800–1450 °C), and coal fly ash particle size (D50 = 6.03–33.70 μm) on the reaction was investigated. The results revealed that, at 50 ppmv KOH (molar ratio of K/(Al + Si) = 0.048 of feed), the measured K-capture level (CK) of coal fly ash was comparable to the equilibrium prediction, while at 250 ppmv KOH and above, the measured data were lower than chemical equilibrium. Similar to the KOH-kaolin reaction reported in our previous study, leucite (KAlSi2O6) and kaliophilite (KAlSiO4) were formed from the KOH-coal fly ash reaction. However, coal fly ash captured KOH less effectively compared to kaolin at 250 ppmv KOH and above. Studies at different temperatures showed that, at 800 °C, the KOH-coal fly ash reaction was probably kinetically controlled. At 900–1300 °C it was diffusion limited, while at 1450 °C, it was equilibrium limited to some extent. At 500 ppmv KOH (molar ratio of K/(Al + Si) = 0.481), and a gas residence time of 1.2 s, 0.063 g K/(g additive) and 0.087 g K/(g additive) was captured by coal fly ash (D50 = 10.20 μm) at 900 and 1450 °C, respectively. Experiments with coal fly ash of different particle sizes showed that a higher K-capture level were obtained using finer particle sizes, indicating some internal diffusion control of the process.",
keywords = "Coal fly ash, Potassium capture, Biomass combustion, Additive, KOH",
author = "Guoliang Wang and Jensen, {Peter Arendt} and Hao Wu and Frandsen, {Flemming Jappe} and Yashasvi Laxminarayan and Bo Sander and Peter Glarborg",
year = "2019",
doi = "10.1016/j.fuel.2018.12.088",
language = "English",
volume = "242",
pages = "828 -- 836",
journal = "Fuel",
issn = "0016-2361",
publisher = "Elsevier",

}

KOH capture by coal fly ash. / Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao; Frandsen, Flemming Jappe; Laxminarayan, Yashasvi; Sander, Bo; Glarborg, Peter.

In: Fuel, Vol. 242, 2019, p. 828 - 836.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - KOH capture by coal fly ash

AU - Wang, Guoliang

AU - Jensen, Peter Arendt

AU - Wu, Hao

AU - Frandsen, Flemming Jappe

AU - Laxminarayan, Yashasvi

AU - Sander, Bo

AU - Glarborg, Peter

PY - 2019

Y1 - 2019

N2 - The KOH-capture reaction by coal fly ash at suspension-fired conditions was studied through entrained flow reactor (EFR) experiments and chemical equilibrium calculations. The influence of KOH-concentration (50–1000 ppmv), reaction temperature (800–1450 °C), and coal fly ash particle size (D50 = 6.03–33.70 μm) on the reaction was investigated. The results revealed that, at 50 ppmv KOH (molar ratio of K/(Al + Si) = 0.048 of feed), the measured K-capture level (CK) of coal fly ash was comparable to the equilibrium prediction, while at 250 ppmv KOH and above, the measured data were lower than chemical equilibrium. Similar to the KOH-kaolin reaction reported in our previous study, leucite (KAlSi2O6) and kaliophilite (KAlSiO4) were formed from the KOH-coal fly ash reaction. However, coal fly ash captured KOH less effectively compared to kaolin at 250 ppmv KOH and above. Studies at different temperatures showed that, at 800 °C, the KOH-coal fly ash reaction was probably kinetically controlled. At 900–1300 °C it was diffusion limited, while at 1450 °C, it was equilibrium limited to some extent. At 500 ppmv KOH (molar ratio of K/(Al + Si) = 0.481), and a gas residence time of 1.2 s, 0.063 g K/(g additive) and 0.087 g K/(g additive) was captured by coal fly ash (D50 = 10.20 μm) at 900 and 1450 °C, respectively. Experiments with coal fly ash of different particle sizes showed that a higher K-capture level were obtained using finer particle sizes, indicating some internal diffusion control of the process.

AB - The KOH-capture reaction by coal fly ash at suspension-fired conditions was studied through entrained flow reactor (EFR) experiments and chemical equilibrium calculations. The influence of KOH-concentration (50–1000 ppmv), reaction temperature (800–1450 °C), and coal fly ash particle size (D50 = 6.03–33.70 μm) on the reaction was investigated. The results revealed that, at 50 ppmv KOH (molar ratio of K/(Al + Si) = 0.048 of feed), the measured K-capture level (CK) of coal fly ash was comparable to the equilibrium prediction, while at 250 ppmv KOH and above, the measured data were lower than chemical equilibrium. Similar to the KOH-kaolin reaction reported in our previous study, leucite (KAlSi2O6) and kaliophilite (KAlSiO4) were formed from the KOH-coal fly ash reaction. However, coal fly ash captured KOH less effectively compared to kaolin at 250 ppmv KOH and above. Studies at different temperatures showed that, at 800 °C, the KOH-coal fly ash reaction was probably kinetically controlled. At 900–1300 °C it was diffusion limited, while at 1450 °C, it was equilibrium limited to some extent. At 500 ppmv KOH (molar ratio of K/(Al + Si) = 0.481), and a gas residence time of 1.2 s, 0.063 g K/(g additive) and 0.087 g K/(g additive) was captured by coal fly ash (D50 = 10.20 μm) at 900 and 1450 °C, respectively. Experiments with coal fly ash of different particle sizes showed that a higher K-capture level were obtained using finer particle sizes, indicating some internal diffusion control of the process.

KW - Coal fly ash

KW - Potassium capture

KW - Biomass combustion

KW - Additive

KW - KOH

U2 - 10.1016/j.fuel.2018.12.088

DO - 10.1016/j.fuel.2018.12.088

M3 - Journal article

VL - 242

SP - 828

EP - 836

JO - Fuel

JF - Fuel

SN - 0016-2361

ER -