1. Biomass fractionation - chemical pulping refineries and novel fractionation processes:
We investigate radically new energy and resource efficient production technologiesfor chemical pulping, e.g. Kraft-Oxygen Delignification (KrOxy) process and new dissolving pulp technologies.In addition, our research group develops novel biomass fractionation processes based on the utilization of Biomass valorisationsupercritical water and green solvents, e.g. gamma-valerolactone (GVL).
- Investigation of novel fractionation technologies such supercritical water, and Organosolv fractionation methods simultaneously with the optimization of the conventional kraft pulping process;
- Pulp characterizations, bleaching, purification (hemicellulose removal) and the adjustment of pulp properties.
2. Biomass valorisation:
Cellulose: We study conversion of cellulose e.g. into man-made cellulose fibers and all-cellulose composites.
Hemicelluloses: Our research topics include the valorisation of xylan from alkaline extractions, production of xylo-oligosaccharides and catalytic conversion of biomass-derived sugars into furans.
Lignin: Lignin is an interesting biomass component which can be converted into valuable products such as bio-oil. Lignin-cellulose blends can be used e.g. as precursor fibers for carbon fibers, or as natural dye in textiles.
- Dissolving pulp production according to existing and new protocols
- Production of man-made cellulose fibers from virgin cellulose pulp and cellulosic textile wastes by the Lyocell spinning process with emphasis on the Ioncell® fiber process
- Chemical modification of regenerated cellulose fibers
- Production of furanic-based platform chemicals from biomass-extracted hemicellulose
- Production of bio-oil and monoaromatic compounds from various lignin sources by catalyzed and uncatalyzed hydrothermolysis.
Our versatile reactor portfolio enables flexible pulping experiments from small lab-scale (30 mL) to pilot scale (10 L), including both traditional (prehydrolysis) kraft and novel Organosolv processes. Elemental-Chlorine-Free (ECF) and Total-Chlorine-Free (TCF) bleaching techniques are readily available.
Our flagship research in biomass valorization is the production of novel man-made cellulose fibers for the circular economy by the dry-jet-wet spinning Ioncell® process, which convert cellulose from virgin wood pulp or cellulosic textile waste into high-quality, high-strength textile fibers. In addition, our research group is equipped with fiber characterization equipment and yarn spinning machinery. We also investigate in the conversion of extracted hemicelluloses and lignin to high value products such as furanic platform chemicals, monoaromatic compounds and bio-oil. Our lab developed advanced chromatography methods (HPLC, CE, IC, GPC) for comprehensive analysis of complex product mixtures.
ALL-CELL: From ultra-light to ultra-strong all-cellulose composites via green processing
Finland Distinguished Professor grant awarded to Prof. Tatiana Budtova (Center for Materials Forming of MINES ParisTech, France). The goal of the 4-year project (started 2016) is to imagine, prepare and characterize new fully bio-based materials, all-cellulose composites.
Ioncell-F is a technology that turns used textiles, pulp or even old newspapers into new textile fibers sustainably and without harmful chemicals. The process converts cellulose into fibers which in turn can be made into long-lasting fabrics.
Read more about the Ioncell process and our projects at ioncell.fi!
Mrs. Jenni Haukio’s gala dress in the Independence Day Reception 6.12.2018; photo: Vesa Moilanen, Lehtikuva. Textile design: Helmi Liikanen (ARTS), dress design: Emma Saarnio (ARTS)
A scarf made of Ioncell® fibers from recycled waste cotton and given to president Macron
Marimekko’s Unikko dress. It was produced form Ioncell®/Tencel™ blend woven fabric. Photo: Sebastian Johansson, dress design: Riikka Buri, Marimekko
The Ioncell dress group
γ-valerolactone pulping is a novel organic solvent fractionation process developed by Professor Herbert Sixta’s Biorefineries research group.
Herbert Sixta, head of the research group
We urge not only for investment in pulping research, but also for the commitment of young researchers.Together we make pulping great again!
The textile industry needs sustainable fibers produced from renewable or recycled sources, which can be recycled at the end of their life and which do not produce micro-plastics. The demand for textile fibers is growing due to population growth and living standards. Currently, most textile fibers are synthetic, e.g. polyester, and are made from non-renewable sources. Cotton cultivation causes environmental problems due to the high consumption of irrigation water, pesticides and fertilizers. When textiles made of synthetic fibres are washed and worn, small fragments are released, causing microplastic contamination.
Aalto University offers the opportunity to study the raw material chemistry and process engineering necessary for the development of a sustainable textile industry, thereby combining materials research with textile and fashion design.
Production of commodities from biomass is the most viable option in the foreseeable future to mitigate the climate changes.
The raw materials of novel man-made cellulose fibers that we are developing in our research group are virgin pulp and recycled cotton waste. Cellulose pulp is made from smaller trees, and thinning stimulates the growth of remaining trees, thereby increasing carbons storage. When pulp is used for long-lasting products like textiles, the carbon is stored in the product. The recycling of cellulosic textiles even prolongs the carbon sink
Professor Emeritus Herbert Sixta: “The most important task of a professor is to educate young people, to help them build their career”
After an extensive career in academia and the forest-based industries, Professor Herbert Sixta has retired. Having worked in Austria for 25 years, Sixta arrived to Aalto in 2007, where his research in biorefineries helped create, among other things, the Ioncell process, a technology that turns used textiles, pulp, and paper into new textile fibres sustainably and without chemicals.
Biorefineries research group annual seminar presented the latest developments in forest-based, sustainable refineries and analytical tools.
The tensile strength of fibres created with the Ioncell method is up to 2.5 times more than that of cotton, while an Ioncell knitted fabric made from recycled hemp withstands abrasion for twice as long as normal hemp fabric.
We need systemic and fundamental changes in the textile and fashion industry’s business model, including a deceleration of manufacturing and the introduction of sustainable practices throughout the supply chain; decreasing clothing purchases and increasing garment lifetimes.
An Aalto University-designed and -produced dress made of birch trees shows how one day we will all look—and feel—good in sustainable fabrics
Jenni Haukio to wear gown made of sustainable Ioncell material at December’s Independence Day reception
Ioncell is a new technology that creates high-quality textile fibres from wood or recycled materials.
The sustainable textile process was introduced to the President during his visit to Aalto University on 30 August 2018.
Professor Herbert Sixta donated an Ioncell scarf to Sirpa Välimaa, Product Manager Dissolving Pulp, Stora Enso Oyj, in PulPaper Conference on 31 May in Helsinki.
Increasing consumption requires new ways to recycle waste. In Aalto University old newspapers were converted to textile.
Aalto’s Ioncell team presents their work at a meeting of the American Chemical Society.
Trash textiles are a valuable resource that should not be left untapped. Aalto and VTT are participating in an EU project called Trash-2-Cash.
A greener textile industry requires expertise in chemistry, design and economy, stresses Herbert Sixta who leads the development of Ioncell-F.
The Ioncell-F™ process adapted for the conversion of waste-cotton into new textile was awarded as one of five winners among 2,700 proposals.
Prize-winning spinning method can reduce the environmental hazards of textile production.