Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
  • D21C5/005—Treatment of cellulose-containing material with microorganisms or enzymes
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/1084—Bleaching ; Apparatus therefor with reducing compounds
  • D21C9/1089—Bleaching ; Apparatus therefor with reducing compounds with dithionites
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
  • D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/16—Bleaching ; Apparatus therefor with per compounds
  • D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides

Definitions

• the present invention relates to a process for the enzymatic * bleaching of cellulose.
• DE-PS 31 10 117 discloses a process for the production of cellulose from wood or other plant fiber materials, in which the lignocellulose is broken down with the help of white rot fungi.
• the processes using microorganisms have considerable disadvantages. So far it has not been possible to achieve degradation and detachment of the lignin from its companion polymers (cellulose) without simultaneous growth of the microorganisms and without loss of celulose. The simultaneous growth of the fungus leads to very long breakdown times, which can take up to several weeks.
• the object of the present invention is to provide a process for the enzymatic bleaching of cellulose which no longer has the disadvantages of the biological and chemical bleaching processes.
• This object is achieved in that a) with the simultaneous addition of oxidizing and reducing agents and addition of salts and complexing agents to an aqueous cellulose-containing solution, a redox potential in the range between 200 and 500 mV is set, b) a bleaching reaction by adding lignolytic enzymes started and c) the reaction is maintained with constant stirring for 15 minutes to 12 hours. This procedure prevents repolymerization of the lignin and makes depolymerization possible.
• the redox potential is preferably between 250 and 450 mV.
• it can be determined by means of a redox electrode and kept constant by means of a regulator and an actuator during the entire reaction time by adding oxidizing and reducing agents, salts and phenolic compounds.
• Hydrogen peroxide, oxygen and ozone are preferably used as the oxidizing agent.
• Ascorbic acid, dithionite and sodium bisulfite are suitable as reducing agents.
• Copper (II) sulfate is added to the cellulose-containing aqueous solution as the salt.
• MndD sulfate, Mn (IID acetate, Fe (II) sulfate, THIID chloride, CedID nitrate and Ce (IV) ammonium nitrate can also be used as salts, and salts with the elements zinc, antimony and lead are also suitable. Possibly.
• phenolic compounds can be added to the aqueous cellulose-containing solution. Veratryl alcohols have proven particularly useful as such.
• the aqueous cellulose-containing solution can also contain fatty acids, for example oleic acids. Hem compounds such as hemoglobin and bleaching reagents such as sodium perborate can be added. In addition, post-bleaching with common bleaching agents, such as sodium hypochlorite, O 2 , chlorine dioxide. Ozone. H 2 O 2 and sodium ionite are carried out.
• fatty acids for example oleic acids. Hem compounds such as hemoglobin and bleaching reagents such as sodium perborate can be added.
• bleaching reagents such as sodium perborate
• post-bleaching with common bleaching agents such as sodium hypochlorite, O 2 , chlorine dioxide. Ozone. H 2 O 2 and sodium ionite are carried out.
• EDTA ethylenediaminetetraacetic acid
• DTPA Diethylenetriaminepentraacetic acid
• aqueous cellulose-containing solution Sodium hypochlorite, sodium perborate, detergents, surfactants and polysaccharides such as glucans and xanthans are suitable as such.
• Lignolytic enzymes are preferably used as enzymes in the method according to the invention. These include phenol oxidases, laocases and peroxidases. The effectiveness of the method can be increased by using pectinase and / or hemicellulases. Particularly suitable lignolytic enzymes are those which are obtained from the white rot fungus Phanerochaete chrysosporium. The use of such enzymes is already known from US Pat. Nos.
• the pH is usually between 2 and 5.
• a pH of 3 is particularly preferred.
• the temperature is 20 to 60 ° C., preferably 40 ° C. If the conditions are observed, the substances mentioned are added Redox potential set from 200 to 500 mV. This is determined by the ratio of the various substances added in the reaction vessel.
• Redox potential set from 200 to 500 mV. This is determined by the ratio of the various substances added in the reaction vessel.
• the bleaching process is started by simultaneous dosing of H 2 O 2 and sodium bisulfite solution.
• the redox potential of approx. 400 mV is maintained. After the process is started, it continues for 2 hours.
• the process is controlled and regulated by means of a redox electrode and a pump control.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Chemical & Material Sciences (AREA)
• Biochemistry (AREA)
• Microbiology (AREA)
• Paper (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
• Medicinal Preparation (AREA)
• Cosmetics (AREA)
• Detergent Compositions (AREA)
• Breeding Of Plants And Reproduction By Means Of Culturing (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6402620

Family Applications (1)

Country Status (13)

Cited By (1)

Families Citing this family (8)

Citations (2)

Family Cites Families (4)

• 1990
  • 1990-03-20 DE DE4008893A patent/DE4008893A1/de active Granted
  • 1990-12-22 ES ES90125380T patent/ES2072965T3/es not_active Expired - Lifetime
  • 1990-12-22 DK DK90125380.7T patent/DK0447673T3/da active
  • 1990-12-22 EP EP90125380A patent/EP0447673B1/de not_active Expired - Lifetime
  • 1990-12-22 DE DE59008655T patent/DE59008655D1/de not_active Expired - Fee Related
  • 1990-12-22 AT AT90125380T patent/ATE119593T1/de active
• 1991
  • 1991-03-19 BR BR919106411A patent/BR9106411A/pt not_active Application Discontinuation
  • 1991-03-19 WO PCT/EP1991/000540 patent/WO1991014823A1/de active Application Filing
  • 1991-03-19 HU HU922982A patent/HUT64119A/hu unknown
  • 1991-03-19 AU AU75432/91A patent/AU641494B2/en not_active Ceased
  • 1991-03-19 JP JP91506306A patent/JPH05505857A/ja active Pending
  • 1991-03-19 CA CA002078345A patent/CA2078345A1/en not_active Abandoned
• 1992
  • 1992-09-16 NO NO923601A patent/NO180388C/no unknown
  • 1992-09-17 FI FI924169A patent/FI924169L/fi not_active Application Discontinuation

Patent Citations (2)

Non-Patent Citations (1)

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