Umeå universitets logga

umu.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Quantitative real-time in situ measurement of gaseous K, KOH and KCl in a 140 kW entrained-flow biomass gasifier
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
RISE Energy Technology Center, Piteå, Sweden.
RISE Energy Technology Center, Piteå, Sweden.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.ORCID-id: 0000-0002-0555-5924
Visa övriga samt affilieringar
2022 (Engelska)Ingår i: Proceedings of the Combustion Institute, ISSN 1540-7489, E-ISSN 1873-2704Artikel i tidskrift (Refereegranskat) In press
Abstract [en]

Photofragmentation tunable diode laser absorption spectroscopy (PF-TDLAS) was used to simultaneously measure the concentrations of gas phase atomic potassium (K), potassium hydroxide (KOH) and potassium chloride (KCl) in the reactor core of a 140 kWth atmospheric entrained-flow gasifier (EFG). In two gasification experiments at air-to-fuel equivalence ratio of 0.5, the EFG was first run on forest residues (FR) and then on an 80/20 mixture of FR and wheat straw (FR/WS). Combustion at air-to-fuel equivalence ratio of 1.3 was investigated for comparison. A high K(g) absorbance was observed in gasification, requiring the photofragmentation signals from KOH(g) and KCl(g) to be recorded at a fixed detuning of 7.3 cm−1 from the center of the K(g) absorption profile. In combustion, the fragments recombined instantly after the UV pulse within around 10 µs, whereas in gasification, the K(g) fragment concentration first increased further for 30 µs after the UV pulse, before slowly decaying for up to hundreds of µs. According to 0D reaction kinetics simulations, this could be explained by a difference in recombination kinetics, which is dominated by oxygen reactions in combustion and by hydrogen reactions in gasification. The K species concentrations in the EFG were stable on average, but periodic short-term variations due to fuel feeding were observed, as well as a gradual increase in KOH(g) over the day as the reactor approached global equilibrium. A comparison of the average K species concentrations towards the end of each experiment showed a higher total K in the gas phase for FR/WS, with higher K(g) and KCl(g), but lower KOH(g), compared to the FR fuel. The measured values were in reasonable agreement with predictions by thermodynamic equilibrium calculations.

Ort, förlag, år, upplaga, sidor
Elsevier, 2022.
Nyckelord [en]
Biomass, Entrained-flow gasification, Potassium (K), Photofragmentation, Tunable diode laser absorption spectroscopy (TDLAS)
Nationell ämneskategori
Annan fysik Atom- och molekylfysik och optik Kemiska processer
Identifikatorer
URN: urn:nbn:se:umu:diva-199816DOI: 10.1016/j.proci.2022.07.180ISI: 001019037700001Scopus ID: 2-s2.0-85139508080OAI: oai:DiVA.org:umu-199816DiVA, id: diva2:1700002
Forskningsfinansiär
Bio4EnergyKempestiftelserna, JCK-1316Energimyndigheten, 50470-1Energimyndigheten, 36160-1EU, Horisont 2020, 637020Tillgänglig från: 2022-09-29 Skapad: 2022-09-29 Senast uppdaterad: 2023-09-05
Ingår i avhandling
1. Quantitative laser diagnostics of gas-phase potassium species in biomass combustion and gasification
Öppna denna publikation i ny flik eller fönster >>Quantitative laser diagnostics of gas-phase potassium species in biomass combustion and gasification
2023 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Alternativ titel[sv]
Kvantitativ laserdiagnostik av kaliumföreningar i gas-fas vid förbränning och förgasning av biomassa
Abstract [en]

Thermochemical energy conversion processes, such as combustion and gasification, are applied worldwide for generation of electricity, heat and synthesis of chemicals. Today, these processes are mostly run on non-renewable, fossil fuels and constitute a major source of carbon dioxide emissions. A promising renewable energy source with low net carbon dioxide emissions is biomass, in particular rest products from agriculture and forestry. However, biomass usually contains high amounts of volatile inorganic compounds, such as chlorine, potassium (K) and phosphorus (P), which lead to ash-related operational issues, including deposit build-up, slagging and corrosion. Therefore, efficient utilization of biomass requires knowledge of the chemistry and fate of the inorganic compounds during thermochemical conversion. Due to the reactive, high-temperature environments in those processes, gaseous compounds are preferably measured in situ using optical techniques.

This thesis mainly deals with the development of a laser-based technique for simultaneous in situ detection and quantification of the main gaseous K species in biomass combustion and gasification: atomic K, potassium hydroxide (KOH) and potassium chloride (KCl). The novel method combines photofragmentation (PF) with tunable diode laser absorption spectroscopy (TDLAS) and achieves sub-ppm detection limits for all three K species for a path length of 2 cm and a time resolution of 20 ms. Recording the ns-µs PF signal decay due to fragment recombination allows probing the K reaction kinetics. Together with TDLAS sensors for water, methane and gas temperature, the PF-TDLAS system was employed to characterize biomass reactors from laboratory- to pilot-scale. The results were compared to predictions by numerical models. In addition, PF-TDLAS was employed for quantitative wide-field imaging of K species in a laboratory flame during KCl salt and biomass conversion. Finally, in situ detection of phosphorus pentoxide (P4O10) with a time resolution of 140 ms was demonstrated using broadband infrared absorption spectroscopy. Absorption line strengths of P4O10 at temperatures relevant for combustion were determined for the first time. The techniques presented in this thesis can provide unique experimental data for validation and further development of numerical models and advance the understanding of K species chemistry during solid fuel conversion, which is needed to facilitate the utilization of biomass in the energy system.

Ort, förlag, år, upplaga, sidor
Umeå: Umeå University, 2023. s. 99
Nyckelord
Thermochemical conversion, pyrolysis, phosphorus, single pellet, entrained-flow, in situ, spectroscopy, photofragmentation, imaging, numerical modelling
Nationell ämneskategori
Atom- och molekylfysik och optik Energiteknik
Forskningsämne
fysik
Identifikatorer
urn:nbn:se:umu:diva-207313 (URN)978-91-8070-077-1 (ISBN)978-91-8070-078-8 (ISBN)
Disputation
2023-05-25, Lilla hörsalen, KBC-huset, Linnaeus väg 6, Umeå, 09:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2023-05-04 Skapad: 2023-04-27 Senast uppdaterad: 2023-05-03Bibliografiskt granskad

Open Access i DiVA

fulltext(1799 kB)54 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 1799 kBChecksumma SHA-512
fbf521b23f79752899a4e30a1c300aa575ddb593cb80fdb63a7b3c09f58da2650eb7208af18c00e2fd612bf1ebb59bc61c6fa4241e1298f3bf4f2173949d8551
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltextScopus

Person

Thorin, EmilMa, CharlieCarlborg, MarkusBroström, MarkusSchmidt, Florian

Sök vidare i DiVA

Av författaren/redaktören
Thorin, EmilMa, CharlieCarlborg, MarkusBroström, MarkusSchmidt, Florian
Av organisationen
Institutionen för tillämpad fysik och elektronik
I samma tidskrift
Proceedings of the Combustion Institute
Annan fysikAtom- och molekylfysik och optikKemiska processer

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 54 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 231 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf