Cellulose Dissolving Process with Chemical Recovery
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Solution Overview
Problem
Current industrial processes for producing regenerated cellulose fibers, such as the viscose process, have a high environmental burden and energy demand, and lack efficient chemical recovery systems for spent dissolving and coagulation chemicals, necessitating a more efficient and environmentally superior method for cellulose production.
Innovation Solution
A process integrating the production of cellulose fibers in a kraft, sulfite, or soda pulp mill using an alkaline or acidic solvent system with amphiphilic additives for dissolving cellulose, where at least part of the spent solvent and delignification chemicals are recovered and recycled within the pulp mill chemical recovery cycle, enabling the production of high-quality cellulose fibers and derivatives with reduced lignin content and lower environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the viscose process is used for manufacturing regenerated cellulose fibers, then cellulose production is achieved, but environmental burden and energy demand increase significantly
Solution Approach 1:
The patent changes the chemical parameters of the dissolving process by using aqueous alkaline or acidic solvent systems with amphiphilic additives instead of the traditional carbon disulfide-based viscose process. This parameter change enables cellulose dissolution without the harmful byproducts and high energy consumption associated with viscose, while maintaining production capability.
Solution Approach 2:
The patent implements a chemical recovery system that captures and recycles spent dissolving chemicals and delignification chemicals from the pulp mill process. This recovery system prevents harmful chemicals from being discarded into the environment and reduces the need for fresh chemical inputs, thereby reducing environmental burden while sustaining productivity.
2Productivity
If the viscose process is used for manufacturing regenerated cellulose fibers, then cellulose production is achieved, but energy consumption increases
Solution Approach 1:
The patent employs alternative solvent systems (aqueous alkaline or acidic with amphiphilic additives) that operate under different energy conditions compared to the viscose process. These parameter changes in the dissolving mechanism reduce the energy demand for cellulose dissolution and processing while maintaining production output.
Solution Approach 2:
The patent merges the cellulose dissolving process with the existing pulp mill chemical recovery cycle. By integrating the dissolving chemicals recovery into the pulp mill's existing recovery infrastructure, the process utilizes available energy and equipment resources more efficiently, reducing overall energy demand for cellulose production.
3Ease of manufacture
If traditional dissolving chemicals are used without recovery systems, then cellulose dissolution is achieved, but chemical waste increases
Solution Approach 1:
The patent implements a comprehensive chemical recovery system that captures spent dissolving chemicals and delignification chemicals from the pulp mill process. This recovery system prevents chemical waste by recycling these substances back into the process, thereby maintaining ease of manufacture while eliminating chemical loss to the environment.
Solution Approach 2:
The patent establishes a feedback loop where spent chemicals are recovered, processed, and returned to the dissolving and delignification processes. This feedback mechanism ensures continuous chemical availability and prevents waste accumulation, maintaining manufacturing efficiency while reducing substance loss.
4Adaptability or versatility
If the NMMO process is used for producing regenerated cellulose fibers, then an alternative to viscose is achieved, but solvent recovery becomes complicated and costly
Solution Approach 1:
The patent merges the dissolving chemicals recovery process with the existing pulp mill chemical recovery cycle. By combining these processes and utilizing the pulp mill's existing recovery infrastructure, the system achieves solvent recovery without the complicated and costly separate recovery systems required by the NMMO process.
Solution Approach 2:
The patent makes the pulp mill's chemical recovery system multi-functional by enabling it to handle both traditional pulping chemicals and cellulose dissolving chemicals. This universality allows a single recovery system to serve multiple purposes, reducing device complexity and cost while maintaining process versatility.
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 provides a low-capital-intensity, environmentally superior method for manufacturing cellulose dope suitable for shaping into new fibers, films, or derivatives, with improved chemical recovery and reduced environmental impact by recycling spent chemicals, thereby enhancing the efficiency and sustainability of cellulose production.
Implementation Method 1
amphiphilic additives with a capacity for breaking up the crystallinity of cellulose
Implementation Method 2
at least a part of the spent solvent and delignification chemicals are recovered and recycled within the pulp mill chemical recovery cycle
Data Source
AI summary
There is disclosed a process for the manufacturing of shaped cellulose materials from lignocellulose wherein a dissolving grade pulp is manufactured and dissolved in an aqueous alkaline or acidic solvent system forming a solution suitable for shaping new cellulose structures including fibers, films and cellulose derivatives. At least a part of the spent cellulose dissolving or cellulose shaping chemicals are recovered in one or more unit operations in a pulp mill chemical recovery cycle.