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Hittade 2 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Förbehandling av sulfatmassa och sulfatlignin med kväveoxider

   Författare :Urban Öjteg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; delignifiering nitrogen dioxide; carbon dioxide; kraft pulps; pretreatment; bleaching; spent liquors; carboxylic acids; dinitrogen oxide; nitric acid; lignins; oxygen;

   Sammanfattning : .... LÄS MER

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

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

   Sammanfattning : 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). LÄS MER