Cellulase Treatment for Dissolving Pulp Viscosity Control

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Solution Overview

Problem

Conventional dissolving pulp production processes face challenges in viscosity control and chemical usage, particularly in the production of bleached dissolving pulp, leading to inefficiencies and environmental impacts.

Innovation Solution

The application of cellulases to unbleached or partially bleached dissolving pulp during the production process for improved viscosity control and reactivity, allowing for reduced chemical usage and enhanced processability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional chemical bleaching processes are used to produce dissolving pulp, then brightness and cellulose purity are improved, but viscosity control becomes difficult and chemical usage increases

Engineering Contradiction:
Improveviscosity controlVSAvoidchemical usage
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The cellulase treatment is applied preliminarily during the bleaching process rather than after, enabling viscosity control to be established early in the process. This preliminary enzymatic action modifies the cellulose structure in advance, making subsequent chemical bleaching more efficient and reducing the need for excessive chemical usage to achieve target viscosity specifications.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Cellulase enzymes serve as an intermediary between the raw pulp and the chemical bleaching agents. The enzyme partially modifies the cellulose structure first, creating a more accessible substrate for chemical treatment and enabling better viscosity control without requiring high doses of chemicals. This intermediary biological step facilitates more efficient chemical utilization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If cellulase treatment is applied to control viscosity, then chemical usage is reduced, but the complexity of the production process increases

Engineering Contradiction:
Improvechemical usageVSAvoidprocess complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The cellulase treatment step is merged with the existing chemical bleaching process rather than being implemented as a separate, standalone operation. The enzymatic treatment is integrated into the bleaching line, allowing both biological and chemical processes to occur in a unified workflow. This integration minimizes additional equipment requirements and reduces operational complexity despite adding functional capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cellulase treatment serves multiple functions simultaneously: it controls viscosity, improves chemical accessibility of cellulose, and prepares the pulp for more efficient chemical bleaching. This multi-functionality means that a single additional step achieves multiple objectives, reducing the need for multiple separate process modifications and thereby limiting the increase in overall process complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If traditional chemical methods are used for viscosity control, then reactivity of dissolving pulp is maintained, but environmental impact and production costs increase

Engineering Contradiction:
Improveenvironmental impactVSAvoidreactivity control
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent converts the traditionally harmful excessive chemical usage into a benefit by using minimal chemical doses combined with enzymatic treatment. The cellulase enzyme naturally modifies the pulp structure in an environmentally friendly manner, and the reduced chemical dosage transforms what was previously a harmful factor (high chemical consumption with associated environmental impact) into a beneficial outcome (lower environmental footprint while maintaining or improving reactivity).

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach results in precise viscosity control, reduced production of off-grade pulp, and increased reactivity of the final dissolving pulp, leading to cost savings and improved environmental sustainability.

Implementation Method 1

treating unbleached or partially bleached or alkaline extracted dissolving pulp with one or more cellulases

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP3365493A1Use of cellulase to improve viscosity control of dissolving pulp
Publication Date: 2018.08.29 NOVOZYMES AS

AI summary

The present invention relates to treatment of unbleached or partially bleached or alkaline extracted dissolving pulp with one or more cellulases. The cellulase treatment results in increased viscosity control, reduced viscosity and/or increased reactivity of the final dissolving pulp.