Researchers at Kaunas University of Technology (KTU) are developing innovative methods to convert textile waste into energy and high-performance cement materials, offering more sustainable solutions for two resource-heavy industries: textiles and construction.
Image Credit: Bykfa/Shutterstock.com
Waste is no longer just a disposal issue; it’s increasingly seen as a valuable resource. Scientists at KTU in Lithuania are investigating how discarded textiles can be transformed into energy or repurposed as components in cement and concrete production. These approaches aim to reduce environmental impact, support circular economy principles, and create new industrial opportunities.
Each year, the European Union (EU) produces billions of tonnes of waste. In response, the EU is revising its waste management policies to promote a circular economy, an approach that prioritizes reuse, repair, and recycling over the traditional linear model of use and disposal.
Textiles and construction are two sectors under particular scrutiny due to their large environmental footprints. Circular strategies in these industries are essential to reducing resource consumption and waste generation at scale.
The Problem with Textile Waste
Despite growing awareness, managing textile waste remains a major global challenge. Most used garments are still either incinerated or sent to landfills. In Europe, the separate collection of post-consumer textiles is limited, and only a small portion of used clothing is recycled into new products. Fibre-to-fibre recycling is still an emerging field.
When textiles are recycled, they’re typically turned into low-value materials like cleaning cloths, insulation, or padding. Recycling synthetic fabrics is even more complex as additives and chemical treatments make processing difficult, and blended fibres are hard to separate. Additionally, microplastics are released during washing and thermal treatments. These complications mean incineration and landfill remain the norm, despite their significant environmental downsides.
A Higher-Value Use: Concrete
One promising direction for textile reuse is in the production of concrete and cement - industries that are both resource-intensive and heavily polluting.
The cement industry, especially clinker firing processes in rotary kilns, contributes significantly to environmental pollution. This is why researchers are actively seeking ways to reduce the amount of conventional cement in cement-based mixtures by replacing it with alternative binders or fillers.
Dr. Raimonda Kubiliute, Faculty of Chemical Technology, Kaunas University of Technology
Across the sector, there's a growing effort to develop concrete mixtures that rely less on ordinary Portland cement without compromising performance. In some cases, alternative additives have been found to even improve material strength and durability.
For instance, recent studies show that calcined smectitic clay waste can partially replace Portland cement in LC3-type binders while maintaining high compressive strength. This points to the broader potential of using industrial waste as supplementary material in construction.
At KTU, early tests show that adding just 1.5 % of recycled polyester fibres sourced from used clothing can increase concrete strength by 15–20 %. These fibres also enhance freeze–thaw resistance, an important factor for concrete used in colder climates.
Turning Ash into Added Strength
Another approach involves converting textile waste into fuel.
When textiles are thermally treated at 300 °C in an oxygen-free environment, they produce carbon-rich granules with high energy value. These could reduce dependence on fossil fuels, but combustion also creates ash, which is often discarded.
KTU researchers have been analyzing this byproduct. They found that replacing up to 7.5 % of conventional cement with ash from textile waste can actually increase compressive strength by up to 16 % under standard curing conditions.
This technological solution not only reduces CO2 emissions during cement production but also provides an innovative and environmentally friendly approach to textile waste management.
Dr. Raimonda Kubiliute, Faculty of Chemical Technology, Kaunas University of Technology
While the use of textile-derived fuels is still in early stages both in Lithuania and abroad, the potential benefits are becoming more widely recognized.