Initial phase of sodium bisulphite pulping of spruce. Part I

• A sodium bisulphite cooking study has been performed on spruce chips with the aim of monitoring the impregnation and the initial phase of such a cook performed at pH 4.5. Both pulp and liquor analyses have been carried out and the experiments have been done with a laboratory-prepared cooking acid, in comparison with a mill cooking acid. The pulping experiments have been performed down to a total pulp yield of 60%. The objective was to verify and extend the current knowledge of bisulphite pulping with a focus on the initial phase of the cook. With the help of a kinetic model that has been developed in the project, the pulp composition during the cook with respect to cellulose, lignin, glucomannan and xylan can now be predicted. The side reactions with respect to thiosulphate formation were also analyzed in this study.

Nyckelord

Bisulphite cooking

Cellulose

Glucomannan

Kinetics

Lignin

Spruce

Thiosulphate and xylan

Enzyme kinetics

Sodium

Kinetic modeling

Pulp composition

Side reactions

Sodium bisulphite

Thiosulphates

Total pulp yield

Pulp cooking

Glucomannans

Heating

Lignins

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)