Search for dissertations about: "lignins"

Showing result 1 - 5 of 36 swedish dissertations containing the word lignins.

  2. 1. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

    Author : Urban Öjteg; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

    Abstract : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). READ MORE

  4. 2. Chemical Properties and Thermal Behaviour of Kraft Lignins

    Author : Ida Brodin; Göran Gellerstedt; Elisabeth Sjöholm; Hans Theliander; Ulrica Edlund; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Analytisk kemi;

    Abstract : Research concerning lignin has increased during the last years due to its renewability and ready availability in black liquor at pulp mills. Today, the kraft lignin found in black liquor is used as a fuel to gain energy in the recovery boiler at the mill. READ MORE

  5. 3. Towards low-emitting and sustainable particle and fibreboards : Formaldehyde emission test methods and adhesives from biorefinery lignins

    Author : Venla Hemmilä; Stergios Adamopoulos; Luísa Maria Hora Carvalho; Linnéuniversitetet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Wood board industry; chamber methods; dynamic microchamber DMC ; bio-based adhesives; lignosulfonates; supercritical water hydrolyzed lignin; crosslinkers; fibreboards; particleboards; Forestry and Wood Technology; Skog och träteknik;

    Abstract : High volumes, fast production speed, and low material costs have been historically the driving factors of the particle- and fibreboard industries. However, in recent years the fossil-fuel dependency and health issues of the formaldehyde-containing adhesives used in the production have gained attention from both legislators and consumers. READ MORE

  6. 4. On the structure of native softwood and hardwood lignins

    Author : Hans Önnerud; KTH; []
    Keywords : ;

    Abstract : .... READ MORE

  7. 5. Some aspects on the physical chemistry of kraft lignins in aqueous solutions : Theoretical considerations and practical implications

    Author : Magnus Norgren; Mittuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; kraft pulping; kraft lignin; phenolic groups; dissociation; pKa; molecular weight; temperature; ionic strength; pOH; polydispersity; coagulation; Poisson-Boltzmann; DLVO; Chemistry; Kemi;

    Abstract : .... READ MORE