Upm-kymmene Corporation

Betulium Oy

Timo Pääkkönen

Markus Nuopponen

Tapani Vuorinen

Antti Laukkanen

Isko Kajanto

Sami Saarela

Marko Lauraeus

Taisto Tienvieri

Jason McKee

Tapio Saarinen

Tero Ojala

Raili Ponni

Raili PÖNNI

A method for producing parenchymal cell cellulose by using a high consistency alkali treatment and an optional refinement step, as well as an apparatus for its manufacture.

Method for producing parenchymal cell cellulose

A method for catalytic oxidation of cellulose using a heterocyclic nitroxyl radical as catalyst, main oxidant acting as oxygen source, and an activator of the heterocyclic nitroxyl radical, comprises&#x2014;a preliminary activation step of the heterocyclic nitroxyl radical with hypochlorite to activated catalyst, and after the preliminary activation step, a cellulose oxidation step using the activated catalyst and hypochlorite as the main oxidant to oxidize cellulose. In the cellulose oxidation step, fibrous starting material is subjected to the oxidation to oxidize the cellulose, whereafter the oxidized fibrous raw material is disintegrated to nanofibrillar cellulose (NFC).

Method for catalytic oxidation of cellulose and method for making a cellulose product

Cellulose is oxidized catalytically using a heterocyclic nitroxyl radical as catalyst, main oxidant acting as oxygen source, and an activator of the heterocyclic nitroxyl radical. The oxidation is performed in a reaction medium which is at medium consistency of cellulosic pulp, which is above 6%, more preferably equal to or higher than 8%, and most preferably in the range of 8-12%. The reaction medium is mixed in a reactor through circulation of the reaction medium back to the reactor.

A method for catalytic oxidation of cellulose using a heterocyclic nitroxyl radical as catalyst and main oxidant acting as oxygen source comprises, before the catalytic oxidation of the cellulose, pretreatment of the cellulose&#x2014;in an alkaline pretreatment step, where the cellulose is treated in alkaline solution having hydroxide concentration of above 0.3 M, and&#x2014;in a washing step, where the cellulose treated in the alkaline solution is washed to lower the pH.

In a method for catalytic oxidation of cellulose a heterocyclic nitroxyl radical is used as catalyst, hypochlorite is used as main oxidant acting as oxygen source, and a tertiary amine or chlorine dioxide as an activator of the heterocyclic nitroxyl radical.

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Helsinki, Finland

Timo Pääkkönen