Metsa Fibre Oy

Metsa Spring Oy

Andritz Oy

Esko Turunen

Kari Kovasin

Ismo Reilama

A method of producing regenerated cellulose and hemicellulose from a fiber pulp which is prepared by using chemical cooking. Hemicellulose and, correspondingly, cellulose is separated from the pulp, in order to form separate fractions, by dissolving them in such a solvent or an aqueous solution of it, from which they are precipitated by adding water, after which the regenerated hemicellulose and cellulose can be recovered. Hemicellulose-containing pulp, which for example is used as raw material of paper, can be efficiently fractionated into polymeric hemicellulose-rich fractions and very pure cellulose fractions, such as regenerated cellulose fiber, various cellulose particles or cellulose films.

Method of producing regenerated cellulose and hemicellulose

A method of defibring lignocellulose-bearing raw material with a polysulphide-bearing cooking liquor in a continuous digester. The cooking liquor is mixed into the raw material which is to be defibred before the cooking, and the cooking liquor is allowed to absorb into the raw material at a temperature which is at maximum approximately 130&#xb0; C. The cooking liquor is then separated from the treated raw material, heated to a temperature of approximately 140-170&#xb0; C., and mixed back into the treated raw material, possibly together with a fresh feed of cooking liquor, whereby the raw material is defibred to generate pulp which has a desired kappa number.

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Metsä, Finland

Esko Turunen