3 minute read
OVERCOMING THE BOTTLENECKS OF THE WOOD-TO-TEXTILE VALUE CHAIN
Today, the textile industry is one of the most polluting industries globally, and the demand for textile fibres is estimated to nearly double by 2030 due to population growth.
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A way to minimise the environmental footprint of the current textile value chain is to reconsider the raw materials used in the first place: man-made fibres based on natural polymers are a valuable alternative to fossil-based synthetic fibres and controversially sourced natural fibres. Accessing wood pulp, especially paper-grade pulp as a raw material for man-made cellulosic fibres may open up the current bottlenecks and enable a sustainable textile industry.
Pulp manufacturing is already a highly competitive and sustainable bio-based industry that can be found both, in the North and the South of Europe. Combining novel cellulose-based textile manufacturing with such a solid platform is a key element in re-introducing extensive European man-made cellulosic fibre production.
The GRETE technologies enlarge the product portfolio and business opportunities for advanced biorefineries that source their biomass sustainably, prospecting to increase economic growth and employment by developing sustainable and competitive bio-based industries in Europe.
201905
PRE-TREATMENTS
Unique Pulp Modifications
Nowadays the textile industry uses dissolving pulp to produce man-made cellulosic textile fibres. Replacing this high-grade cellulose pulp with a paper-grade Kraft pulp decreases environmental impact and production expenses.
In GRETE chemical modification and enzymatic pre-treatments of the wood pulp prior to dissolution were carried out, both at high and low pulp consistency, and have enabled the successful spinning of regenerated fibres from hardwood and softwood Kraft pulp. In particular, chemical modifications targeting improved technical properties of the regenerated fibres have been performed, while novel hydrolytic and oxidative enzymes for targeted studies on pulp modification have been developed and used to prepare samples for dissolution studies.
Finally, dissolution and regeneration of proteins have been studied to examine their potential use in cellulosic fibres.
DISSOLUTION
Novel Solvent System
Man-made cellulosic fibres are regenerated from natural polymers via chemical transformation processes. Today two processes are used commercially, and both use toxic, unstable or explosive solvents.
In GRETE novel superbase ionic liquids have been developed: a system of sustainable and recyclable solvents for cellulose dissolution and fibre regeneration, responding to demanding process- and market requirements. The developed superbase ionic liquids have been produced on a kg scale and found to be harmless, as demonstrated by preliminary toxicity and sustainability assessments.
Essential for the economic viability of the process is the recovery and purification of the superbase ionic liquids from the spinning bath. The GRETE research demonstrated reaching the desired ionic liquid concentration using distillation and reducing the energy demand for diluted solutions with membrane filtration.
202304
SCALE-UP
Industrial Exploitation
By the end of the project, a family of novel solvents for cellulose dissolution will be available for industrial scale-up. These novel solvents are chemically stable, recyclable and non-toxic allowing environmentally benign and economically viable pathways for cellulose processing to textile fibres. New information concerning the enzymatic modification of Kraft pulp and recycling of the superbase ionic liquids have been obtained and models to assess technical, economic and environmental aspects of the GRETE concept were defined, paving the way for industrial exploitation of the technologies.
The impact of the achieved results is expected to be seen on industrial level and consumer markets throughout the next decade.
Regeneration
Successful Fibre Spinning
With the GRETE technologies, regenerated cellulose fibres have been successfully spun from two enzymatically and chemically modified pulps - hardwood and softwood Kraft pulp - using the novel superbase ionic liquids.
The chemical modifications have been stable during dissolution and regeneration, and an analysis method to determine the amount of residual ionic liquids in the regenerated fibres has been developed. In particular, characterization of impurities from the dissolution and regeneration process and degradation products of superbase ionic liquids have been analysed using sophisticated analytical tools.
POST-TREATMENTS
HIGH-QUALITY FUNCTIONAL FIBRES
Chemical modification carried out either before or after dissolution and regeneration of wood pulp will bring chemical functionalities to fibres. In GRETE the pulp pre-treatments and the post-modifications of regenerated fibres have been successful to introduce fire-retardant and improved dyeing properties to the fibres, allowing to significantly reduce the use of freshwater in the textile finishing processes.
In view of the GRETE achievements, regenerated wood pulp fibres from the pulp and paper industry can potentially be utilised as textile fibres with good dye uptake capacity that may possibly provide an alternative for dyeing treatments.
2020-08
«Enzymatic treatment of softwood kraft pulp at high and low consistency»
2020-10
«Modelling of Lyocell fibre production and technical analysis of solvent recovery concepts»
2021-09
«Spinning of cellulose fibres from ionic liquid solution»
2022-05
«Physico-chemical characterization of aqueous solutions of superbase ionic liquids with cellulose dissolution capability»
2022-09
«Preconcentration of superbase ionic liquid from aqueous solution by membrane filtration»
2022-09
«From regenerated wood pulp fibers to cationic cellulose: preparation, characterization and dyeing properties»
