Search for dissertations about: "lignin transport"

Showing result 1 - 5 of 33 swedish dissertations containing the words lignin transport.

2. 1. Mass transfer challenges in wood decomposition

   Author : Roujin Ghaffari; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; diffusion cells; kraft process; lignin; lignin transport;

   Abstract : Even though the kraft cooking operation is more than 100 years old, the rate-determining step of this operation has not been fully elucidated. Recent studies point in the direction of mass transport of liberated lignin fragments from the fibers' walls into black liquor being influential in rate determination of kraft cooking. READ MORE

4. 2. Air-gap spinning of lignin-cellulose fibers

   Author : Jenny Bengtsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; carbon fibers; ionic liquid; lignin; air-gap spinning;

   Abstract : Co-processing of lignin and cellulose, the two main constituents of wood, has previously been identified as a potential route for the production of inexpensive and bio-based carbon fibers. The first step in this process is to spin a precursor fiber. READ MORE

5. 3. New regulators of xylem lignification in arabidopsis

   Author : Bernadette Sztojka; Hannele Tuominen; Simon Hawkins; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Xylem; lignin; Arabidopsis; secondary cell wall; transcriptional regulation; lignin-biosynthetic gene; S G lignin ratio;

   Abstract : The ability of land plants to grow upright, bear their own weight and withstand adverse environmental conditions is largely dependent on the secondary xylem tissues of the stem. The xylem cells acquire thick secondary cell walls which are composed of cellulose, hemicellulose and lignin. READ MORE

6. 4. Lignin Exraction from Black Liquor: Precipitation, filtration and washing

   Author : Henrik Wallmo; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Lignin; Filtration; Separation; Black liquor; Precipitation; Washing.; Absorption;

   Abstract : Lignin extraction is a very interesting option for pulp mills today. Lignin is one major component, present as a dissolved organic compound, in black liquor, which is a by-product in the alkaline pulping of wood. After the digestion of wood chips, the black liquor is separated from the cellulose. READ MORE

7. 5. Fate and transport of POPs in the aquatic environment : with focus on contaminated sediments

   Author : Sarah Josefsson; Karin Wiberg; Mats Tysklind; Kjell Leonardsson; Jonas S Gunnarsson; Jussi Kukkonen; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; bioturbation; bioirrigation; bioaccumulation; secondary sources; buried contaminants; sediment remediation; active capping; thin-layer capping; Marenzelleria spp.; Baltic Sea; polychlorinated dibenzo-p-dioxins; polychlorinated dibenzofurans; polychlorinated biphenyls; hexachlorobenzene; octachloro¬styrene; polybrominated diphenyl ethers; PCDD Fs; PCBs; HCB; OCS; PBDEs; water sampling; passive sampling; particulate fraction; freely dissolved; apparently dissolved; colloid; organic carbon; activated carbon; lignin; sediment-to-water flux; spring bloom; Environmental chemistry; Miljökemi; Persistent organic compounds; Persistenta organiska föreningar; Environmental Science; miljövetenskap;

   Abstract : Persistent organic pollutants (POPs) are hydrophobic substances that readily sorb to organic matter in particles and colloids instead of being freely dissolved in the water phase. This sorption affects the bio­availability and environmental transport of the POPs. READ MORE