Sökning: "HexA"

Visar resultat 1 - 5 av 27 avhandlingar innehållade ordet HexA.

1. 1. on the thermal yellowing of TCF- bleached birch kraft pulp

   Författare :Anders Granström; KTH; []
   Nyckelord :Ageing; Brightness reversion; Chalaton; Colour reversion; Dicarboxylic acids; Discoloration; HexA; Hexenuronic acid; Kraft pulp; Metal profile; Thermal yellowing; Xylan;

   Sammanfattning : .... LÄS MER

3. 2. Hexa- and hepta-coordination in niobium and tantalum oxides and oxide fluorides and structurally related compounds

   Författare :Lena Jahnberg; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : .... LÄS MER

4. 3. Aspects of extended impregnation kraft cooking for high-yield pulping of hardwood

   Författare :Helena Wedin; Mikael E. Lindström; Martin Ragnar; Jorge L. Colodette; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Yield; pulp; kraft cook; carbohydrate; xylan; oxygen delignification; Hexenuronic acid; kappa number;

   Sammanfattning : The long-term trend regarding wood is an increase in price. Because wood contributes to a large part of production costs, the efficient utilisation of wood is greatly desired to reduce production costs for kraft pulp producers. During the 1990s, the development of improved modified kraft cooking began, which led to higher yields. LÄS MER

5. 4. On the Interrelation Between Kraft Cooking Conditions and Pulp Composition

   Författare :Catrin Gustavsson; Mikael E. Lindström; Jorge Colodette; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : In the early 1990’s, a lot of work was focused on extending the kraft cook to a low lignin content (low kappa number). The driving force was the need to further reduce the environmental impact of the bleaching, as less delignification work would be needed there. LÄS MER

7. 5. The link between kraft cooking and bleaching : influence on ECF bleachabiblity and bleaching effluent parameters

   Författare :Magnus Björklund; []
   Nyckelord :;

   Sammanfattning : The link between kraft cooking and bleaching was investigated, with the focus on how cooking kappa number, cooking conditions and pre-bleaching stages influence ECF bleachability and environmental parameters in the bleaching effluent. In one part of the study standard cooking conditions were used to produce birch and spruce pulps of different kappa numbers and then we studied how the AOX in the ECF bleaching effluent was affected by oxygen delignification, and hot acid stages. LÄS MER