Method and apparatus for controlling the catalytic oxidation of cellulose
AssigneeUpm-Kymmene Corporation
InventorsIsko Kajanto, Markus Nuopponen
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Abstract
A method for controlling the catalytic oxidation of cellulose includes using a heterocyclic nitroxyl compound as catalyst; oxidizing cellulose in a reaction mixture comprising liquid medium, the catalyst and hypochlorite as main oxidant; analyzing one or more oxidative chlorine species dependent on the hypochlorite concentration of the reaction mixture on line in the reaction mixture or in a gas composition which is in contact with the reaction mixture; and controlling supply of hypochlorite to the reaction mixture on the basis of the analysis.
Claims20
A method for controlling the catalytic oxidation of cellulose, comprising:
- providing cellulose as a fibrous starting material which is pulp;
- using a heterocyclic nitroxyl compound as catalyst,
- oxidizing cellulose in a reaction mixture comprising liquid medium, the catalyst and hypochlorite as main oxidant,
- analyzing one or more oxidative chlorine species derived from decomposition of hypochlorite in the reaction mixture on line in the reaction mixture or in a gas composition which is in contact with the reaction mixture, wherein an amount of the oxidative chlorine species is directly proportional to the hypochlorite concentration in the reaction mixture;
- and
- controlling supply of hypochlorite to the reaction mixture on the basis of the analysis;
- wherein the method is a method for selective oxidation of C6 hydroxyl groups of cellulose molecules to aldehydes and carboxylic acids.
Dependencies are inferred from the claim text.