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DualC™ Cooking for Dissolving Grade

The DUALC™ cooking process is based on combination of advantages from SuperBatch® and RDH™ displacement cooking technologies. The displacement batch cooking technique gives the best opportunities for optimal conditions and flexibility
in cooking.

In dissolving grade, hemicelluloses are removed/adjusted in acidic conditions created by auto hydrolysis that comes from removal of acetyl groups of wood material. No additional chemical is needed for steam hydrolysis reactions.

The cooking can be adapted to chip quality. No compromise needs to be made in chip preparation and the material flow can be more efficiently utilized for pulp production. Production increases can be achieved without compromise in pulp properties. Preventive maintenance can be performed without shutting down the entire cooking plant.

Displacement batch cooking plant comprises continuous operations as well. These include tank farm heat transfer processes, condensate and gas collection system and black liquor transfer to evaporation.

Dissolving kraft cooking plant is equipped with efficient steam prehydrolysis step. The prehydrolysed material is washed and neutralized in the following neutralization and hot liquor fill stage.

  • Removal/adjusting hemicelluloses in acidic hydrolysis
  • Acidic conditions result in hydrolysis, breaking bonds in hemicelluloses, dissolving them
  • Acidic conditions come from auto hydrolysis (no chemicals) by acid groups of wood material
  • Steam hydrolysis
  • Neutralization to stop hydrolysis
  • Possibility to collect hydrolysate with additional equipment
  • Lignin removal in alkaline cooking
  • Digesters: Acid proof wetted parts (Acidic hydrolysis)
  • Accumulators, tanks, liquor piping and equipment in contact with pulp/liquor: Stainless steel or higher grade wetted parts (For low metal content in pulp)
  • Swing production between paper grade and dissolving grade
  • Efficient solutions for typical scaling problems related to dissolving process
  • Simultaneous production different pulp grades including paper grade and dissolving pulp production
  • In batch process, acid and alkaline stages take place in the same reaction vessel
  • Optimized pulp properties, especially reactivity of dissolving pulp
  • Less maintenance shut-downs
  • Fast start-up
  • Better uniformity
  • Multiple species cooking
  • Tailor made pulp
general requests

DualC™ Cooking for Dissolving Grade

The DUALC™ cooking process is based on combination of advantages from SuperBatch® and RDH™ displacement cooking technologies. The displacement batch cooking technique gives the best opportunities for optimal conditions and flexibility
in cooking.

In dissolving grade, hemicelluloses are removed/adjusted in acidic conditions created by auto hydrolysis that comes from removal of acetyl groups of wood material. No additional chemical is needed for steam hydrolysis reactions.

  • Further Details

    The cooking can be adapted to chip quality. No compromise needs to be made in chip preparation and the material flow can be more efficiently utilized for pulp production. Production increases can be achieved without compromise in pulp properties. Preventive maintenance can be performed without shutting down the entire cooking plant.

    Displacement batch cooking plant comprises continuous operations as well. These include tank farm heat transfer processes, condensate and gas collection system and black liquor transfer to evaporation.

    Dissolving kraft cooking plant is equipped with efficient steam prehydrolysis step. The prehydrolysed material is washed and neutralized in the following neutralization and hot liquor fill stage.

  • Technical Information

    • Removal/adjusting hemicelluloses in acidic hydrolysis
    • Acidic conditions result in hydrolysis, breaking bonds in hemicelluloses, dissolving them
    • Acidic conditions come from auto hydrolysis (no chemicals) by acid groups of wood material
    • Steam hydrolysis
    • Neutralization to stop hydrolysis
    • Possibility to collect hydrolysate with additional equipment
    • Lignin removal in alkaline cooking
    • Digesters: Acid proof wetted parts (Acidic hydrolysis)
    • Accumulators, tanks, liquor piping and equipment in contact with pulp/liquor: Stainless steel or higher grade wetted parts (For low metal content in pulp)
    • Swing production between paper grade and dissolving grade

  • Benefits

    • Efficient solutions for typical scaling problems related to dissolving process
    • Simultaneous production different pulp grades including paper grade and dissolving pulp production
    • In batch process, acid and alkaline stages take place in the same reaction vessel
    • Optimized pulp properties, especially reactivity of dissolving pulp
    • Less maintenance shut-downs
    • Fast start-up
    • Better uniformity
    • Multiple species cooking
    • Tailor made pulp

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