Endre søk
Begrens søket
1 - 4 of 4
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Ghoreishi, Solmaz
    et al.
    University of Bergen, Norway.
    Løhre, Camilla
    University of Bergen, Norway.
    Hermundsgård, Dag Helge
    University of Bergen, Norway; Arbaflame AS, Norway.
    Lindgaard Molnes, Joakim
    University of Bergen, Norway.
    Tanase Opedal, Mihaela
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Brusletto, Rune
    Arbaflame AS, Norway.
    Barth, Tanja
    University of Bergen, Norway.
    Identification and quantification of valuable platform chemicals in aqueous product streams from a preliminary study of a large pilot-scale steam explosion of woody biomass using quantitative nuclear magnetic resonance spectroscopy2024Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823, Vol. 14, s. 3331-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Steam explosion breaks down the polymeric matrix and enables the recovery of valuable compounds from lignocellulosic feedstock. In the steam explosion process, biomass is treated with high-pressure steam which subsequently generates large quantities of a condensed aqueous liquid (process effluent) and a filtered aqueous liquid (filtrate) that contain furfural, 5-hydroxymethylfurfural, 5-methylfurfural, methanol, and acetic acid as major constituents. This study addresses the identification and quantification of value-added chemicals in the aqueous product streams using quantitative analytical nuclear magnetic resonance spectroscopy with water suppression. This work reports a screening study for two different types of sawdust (Norway spruce and birch) at two different scales (4 L and 10 L reactors) using different reaction temperatures (190–223 °C) and corresponding pressures (13–24 bar), with and without the addition of SO2 gas. The duration of all experiments was 8 min. The process effluents contained acetic acid, methanol, formic acid, 5-methylfurfural, and furfural. Acetic acid (0.5 g/kg dry input biomass) and furfural (1.0 g/kg dry input biomass) were more abundant than methanol, formic acid, and 5-methylfurfural for both feedstocks. The addition of SO2 increased the furfural yields, indicating more efficient hydrolysis of hemicelluloses under acidic conditions. Filtrate samples also contained 5-hydroxymethylfurfural, with the highest concentrations (5.7–6.0 g/kg dry input biomass) in the filtrates from spruce. The different feedstocks and steam explosion temperatures strongly influenced the overall yields of the target compounds, in some cases tripling the concentrations. The results can be used to improve the profit margins in a pellets and chemicals biorefinery, as demonstrated in the ArbaOne pellets plant. © 2022, The Author(s).

    Fulltekst (pdf)
    fulltext
  • 2.
    Hermundsgård, Dag Helge
    et al.
    University of Bergen, Norway; Arbaflame AS, Norway.
    Ghoreishi, Solmaz
    University of Bergen, Norway.
    Opedal, Mihaela Tanase
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Brusletto, Rune
    Arbaflame AS, Norway.
    Barth, Tanja
    University of Bergen, Norway.
    Investigating solids present in the aqueous stream during STEX condensate upgrading—a case study2022Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Steam explosion (STEX) of woody biomass is an efficient pretreatment method in the production of water-resistant wood pellets. The STEX process also generates an aqueous condensate stream containing dissolved organic compounds, with furfural as the most abundant and valuable component. An industrial-scale recovery process for furfural and other organic by-products is therefore in the process of being developed and built. One challenge in the process has turned out to be the formation of solid particulate matter that can clog filters in the process unit. We have analyzed both the solid deposits and the fluids present at different points in the process unit to try to identify the origin of the particles using spectroscopic and chromatographic analysis, elemental analysis, and scanning electron microscopy. The aqueous fluids deriving from condensed steam contain furfural and other small organic molecules, with a separate low-density organic layer occurring at some points. This layer largely consists of wood extractives, typically terpenoids. In addition, a heavy organic phase comprising mostly furfural was found at one sampling point. The particles comprise a black, largely insoluble material with a H/C ratio of 0.88 and an O/C ratio of 0.26 and a very low ash content. IR spectra show a low content of C–H functional groups, and chromatographic analysis supports an interpretation that the particles are dominantly furfural-sourced humin-like polymers with adsorbed or co-polymerized terpenoids. Particle formation has been reproduced in a laboratory setting with conditions similar to those in the full-scale process. © 2022, The Author(s).

  • 3.
    Joseph, Prajin
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Opedal, Mihaela Tanase
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Moe, Störker
    NTNU Norwegian University of Science and Technology, Norway.
    The O-factor: using the H-factor concept to predict the outcome of organosolv pretreatment2023Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823, Vol. 13, s. 6727-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The H-factor, a parameter used extensively to analyze and predict the outcome of kraft pulping, is applied to organosolv pretreatment. The total solid yield after organosolv pretreatment fits well with the H-factor. The concept has been extended to apply to the individual biomass polymers using unique values for the activation energy for the depolymerization of the individual biomass polymers, giving the O-factor concept analogous to the P factor used for analyzing prehydrolysis kinetics. The results showed a linear relationship between ln(L0/L) and O-factor at an activation energy of 96 kJ/mol. The best linear fit for mannan and xylan degradation was obtained at O-factor activation energies of 104 kJ/mol and 142 kJ/mol, respectively, and the formation of furfural and 5-HMF gave a good linear fit using an O-factor activation energy of 150 kJ/mol. The O-factor is thus a useful concept for analyzing organosolv pretreatment when the temperature during pretreatment is not constant. © 2021, The Author(s).

  • 4.
    Palmqvist, Benny
    et al.
    Lund University, Sweden; Novozymes A/S, Denmark.
    Kadić, Adnan
    Lund University, Sweden.
    Hägglund, Karin
    SEKAB E-Technology AB, Sweden.
    Petersson, Anneli
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Lidén, Gunnar
    Lund University, Sweden.
    Scale-up of high-solid enzymatic hydrolysis of steam-pretreated softwood: the effects of reactor flow conditions2016Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823, Vol. 6, nr 2, s. 173-180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The importance of flow conditions during scale-up of high-solid enzymatic hydrolysis of steam-pretreated spruce was demonstrated by comparing hydrolysis rates between laboratory (2 L) and demonstration (4 m3) scale. A positive effect of increased agitation speed on the rate of enzymatic hydrolysis was found regardless of scale. Importantly, the hydrolysis rate was higher at the larger scale when compared at similar specific power inputs. Changes in the rheological properties of the pretreated material during the hydrolysis were followed by off-line measurements of apparent viscosity. This information was used to estimate the flow conditions in the reactors, i.e., average Reynolds numbers, which together with measured mixing power consumptions enabled a more detailed comparison between the scales. The hydrolysis yields correlated better with average Reynolds numbers than specific power input over the different scales. This indicates that mass transport limitations, caused by insufficient bulk flow, likely play a decisive role in determining the rate of enzymatic hydrolysis.

1 - 4 of 4
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
v. 2.43.0