Sökning: "birch lignin"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden birch lignin.

1. 1. Protected Lignin Biorefining: Fundamental Insights on Lignin Reactivity

   Författare :Maria Karlsson; Martin Lawoko; Åsa Emmer; Olena Sevastyanova; John Ralph; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sustainability; lignin; biorefinery; cyclic organosolv extraction; preserved structure; NMR; MALDI-TOF MS; Hållbarhet; lignin; bioraffinaderi; cyklisk organosolv extraktion; bevarad struktur; NMR; MALDI-TOF MS; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : The potential to utilize lignin, which constitutes as much as 15-30% of the biomass, needs further evaluation. In the transition towards a bioeconomy, lignin has the potential to replace fossil-based phenols. Attempts to valorize the available technical lignins are ongoing; however, that lignin suffers from molecular heterogeneity. LÄS MER

3. 2. Fractionation of woody biomass : lignin and suberin in focus

   Författare :Ivan Kumaniaev; Joseph Samec; Claudia Crestini; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lignocellulose; lignin; suberin; biomass; palladium; catalysis; flow chemistry; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis is dedicated to the research of fractionation and valorization of different types of woody biomass. In the first part, oak (Quercus suber) and birch (Betula pendula) barks are considered. Bark is the outer layer of wood and is treated as waste in the current wood processing technologies. LÄS MER

4. 3. Inhibition of light-induced colour reversion of wood-containing papers by means of coating

   Författare :Helena Fjellström; Hans Höglund; Magnus Paulsson; Arthur Ragauskas; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-yield pulp; CTMP; birch; light-induced; ageing; photo-stabilising; lignin; coating; pigment; kaolin; calcium carbonate; titanium dioxide; binder; FWA; Chemical engineering; Kemiteknik;

   Sammanfattning : The main purpose of this thesis was to find ways to maintain a low level of light‐induceddiscolouration at an increased addition of mechanical and chemimechanical pulps in coated highqualityfine paper and magazine paper grades. Current technology allows the production of highyieldpulps such as thermomechanical and chemimechanical pulps with properties suitable formanufacturing high‐quality paper or paperboard with a low basis weight. LÄS MER

5. 4. Some factors affecting the amount of residual phase lignin during kraft pulping

   Författare :Mikael E. Lindström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deligniflcation; Residual phase lignin; Hydrogensulfide ion; Hydroxide ion; Polysulfides; Ionic strength; Temperature; Lignin; Kraftpulping; Selectivity; viscosity; Kappa number; chemical degradation; Disproportionation; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : The amount of lignin which needs to be removed according to the slow residual delignification phase in kraft pulping, i e residual phase lignin, has been studied as a function of the process conditions. The variebles studied were the concentrations of hydroxide ions, hydrogensulfide ions, sodium ions (ionic strength) and temperature. LÄS MER

7. 5. Fast pyrolysis of biomass : primary products and reaction pathways

   Författare :David Usino; Tobias Richards; Weihong Yang; Högskolan i Borås; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fast pyrolysis; Py-GC-MS FID; Primary reactions; Cellulose; Xylan; Lignin; Birch wood; Co-pyrolysis; Mahogany; Iroko; Palm kernel shell; Biomass blend; Biomass interaction; Pretreatment; Resource Recovery; Resursåtervinning;

   Sammanfattning : Pyrolysis of biomass to produce liquid fuel and chemicals has been considered as an alternativeto fossil fuel because biomass has a lower environmental impact; moreover, it is renewable andcould be sustainable. However, the process of bio-oil production involves a series of complexchemical reactions which are dependent on the biomass feedstock and composition,temperature, heating rate as well as residence time. LÄS MER