Sökning: "Lignin-carbohydrate-complexes"

Visar resultat 1 - 5 av 14 avhandlingar innehållade ordet Lignin-carbohydrate-complexes.

1. 1. Lignin-carbohydrate complexes: Model compounds synthesis

   Författare :Filip Nylander; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Lignin-carbohydrate complex; lignin model compounds; lignocellulose;

   Sammanfattning : In lignocellulose there is a recalcitrant interaction by covalent and non-covalent bonds called the lignin-carbohydrate complex. This interaction has been the subject of studies trying to unveil its chemical structure, to understand the mechanims involved in its formation and to determine its influence on practical applications such as the process of turning biomass into ethanol. LÄS MER

3. 2. Fundamental Aspects of Lignin Carbohydrate Complexes (LCC) : Mechanisms, Recalcitrance and Material concepts

   Författare :Nicola Giummarella; Martin Lawoko; Gunnar Henriksson; Arthur J. Ragauskas; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Lignin Carbohydrates Complexes; Phenyl Glycosides; Benzyl Ethers; Benzyl and γ-esters; Universal Mild Quantitative fractionation; LCC mechanism formation; Extracellular lignin; Dehydogenation polymer; Autohydrolysis; Recalcitrance; Acetylation role; HSQC; HMBC; HSQC-TOCSY; 13C; 31P NMR; Thioacidolysis-GC; SEC; Green; Biomimetic; One-pot-lignin functionalization; Lignin platform material.; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Covalent bonds between lignin and carbohydrates, forming a matrix referred to as lignin carbohydrate complexes (LCC), remain one of the most controversial topics in wood chemistry. A key issue is whether they are formed during chemical and mechanical pretreatments of the compact wood structure or actually present in wood prior to isolation. LÄS MER

4. 3. The initial phase of sodium sulfite pulping of softwood : A comparison of different pulping options

   Författare :Raghu Deshpande; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; acid sulfite pulping; bisulfite pulping; cellulose; delignification; dissolving pulp; extractives; glucomannan; hemicelluloses; lignin; lignin condensation; lignin carbohydrate complexes; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

   Sammanfattning : Single stage and two-stage sodium sulfite cooking were carried out on either spruce, pine or pure pine heartwood chips to investigate the influence of several process parameters on the initial phase of such a cook down to about 60 % pulp yield. The cooking experiments were carried out in the laboratory with either a lab-prepared or a mill-prepared cooking acid and the temperature and time were varied. LÄS MER

5. 4. Galactoglucomannan recovery from softwood spent sulfite liquor: Challenges, process design and techno-economic evaluations

   Författare :Basel Al-Rudainy; Avdelningen för kemiteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Galactoglucomannan; Lignin; Lignosulfonates; Lignin-carbohydrate-complexes; Membrane filtration; Dead-end filtration; Precipitation; Adsorption;

   Sammanfattning : In the production of pulp and paper, water-soluble components, such as hemicellulose, monosaccharides, and lignin, are released and accumulate in the process water. The process water is usually concentrated and incinerated for heat generation and the recovery of pulping chemicals, such as in the Kraft and sulfite processes. LÄS MER

7. 5. Adsorption of xylans on cellulosic fibres -Influence of xylan composition on adsorption characteristics and kraft pulp properties

   Författare :Tobias Köhnke; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Xylan; Hornification; Lignin-carbohydrate complexes; Cationization; Isolation; Softwood kraft pulp; Extraction; Adsorption;

   Sammanfattning : Xylans are polysaccharides present in large amounts in cell walls of vascular plants. They possess an inherent affinity to cellulose and will thus adsorb irreversibly on cellulose surfaces. LÄS MER