Process for producing cellulose from lignin containing raw materials using an enzyme or microorganism while monitoring and maintaining the redox potential
OwnerHans-Peter Callinventor
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Abstract
A process and an apparatus capable of removing and/or transforming lignin or its degradation products present in material containing lignocellulose. In the present process, a redox potential is set between 200 and 500 mV by the addition to an acid aqueous solution, which contains lignitic raw materials, of oxidizing agents and/or reducing agents and/or salts and/or phenolic compounds. The lignin degrading reaction and its attendant simultaneous bleaching effect is initiated by the addition of enzymes, microorganisms, animal or plant cells. Continuous stirring allows the reaction to be maintained for several hours at a value that fluctuates about a constant redox potential value, and a constant temperature.
Claims18
A process for degrading lignin in lignocellulosic raw material, comprising the steps of:
- supplying an aqueous solution of lignocellulosic raw material containing lignin to a reaction vessel;
- adjusting the aqueous solution to an acidic pH;
- setting a redox potential at a range of about between 200 and 500 mV by adding redox chemical agents comprising at least one oxidizing agent, at least one reducing agent, at least one salt, at least one phenolic compound and at least one organic acid;
- adding to the reaction vessel a lignin degradation reaction agent selected from the group consisting of enzymes and microorganisms;
- and reacting the ingredients in the reaction vessel while stirring to degrade the lignin in the lignocellulosic material, continuously monitoring and maintaining the redox potential within said range by adding further amounts of said redox chemical agents, and maintaining substantially constant the pH and temperature of the reaction.
Dependencies are inferred from the claim text.