3. Wood-based glycols: Cutting out oil from textiles
Glycols have long been a cornerstone of the chemical industry, and especially when it comes to generating the softness and flexibility we have come to expect in our clothes. But traditional glycols have a dirty secret: they are derived from fossil resources, predominantly crude oil and coal.
One day soon clothing manufacturers will have no excuse but to say goodbye to fossil-based glycols for good. Next generation biochemicals to replace fossil-based components in polyester will be manufactured at UPM’s Leuna biorefinery soon.
Not only is the renewable glycol derived purely from locally-sourced beech trees, the process boasts optimised CO2 emissions and provides a seamless replacement for manufacturers.
Laboratory manager (R&D) for UPM Biochemicals, Sebastian Funtan oversees the development of new applications for sugars and glycols derived from wood at the Leuna biorefinery in Germany.
For the textiles industry, change is often quite slow, he says.
“Changing to new products means brands and manufacturers have to do research and work to see how they can adapt their processes to retain product quality. It's a unique selling point therefore for them to be able to just switch directly from fossil-based glycols to the bio-based ones without having to change anything in their processing.”
As of this year, the biorefinery enables the mass production of biochemicals including renewable glycols for the first time.
It’s early days for the refinery, but Funtan hopes the research taking place there will one day soon expand to develop other uses for glycols, too:
“There is a lot of interest in this from manufacturers who all want to make their brands more sustainable.”
The biggest challenge is meeting demand: Leuna refinery will produce 220,000 tons of product including glycols each year. According to Funtan, the global demand for this type of glycols is currently at 35 million tons per year – that’s the same weight as 163,487 commercial aircrafts.
“The good news is the beechwood we use is a renewable resource, unlike fossil-based oil. We can only be one part of the solution, but I am hopeful for the future of sustainable textiles.”
Why recycling textiles alone is not the answer?
One of the biggest challenges in making clothing more sustainable, is that textiles are not easy to recycle fully. We can swap and share items, sell and buy second-hand, but to break down the fibres of the fabrics themselves to fully recycle their parts? It’s a challenge.
Globally, it’s estimated that just 12 per cent of the material used for clothing ends up being recycled. The biggest reason for this is that clothes are often made from a complex combination of fibres, dyes and fixtures: they are rarely homogeneous in their components. Even that favourite cotton shirt is likely to contain some elastane, plastic buttons and a polyester label.
According to Laboratory manager (R&D) for UPM Biochemicals, Sebastian Funtan one of the biggest problems comes with polyethylene terephthalate (PET), which is one of the main polymers for synthetic fibres of textiles and clothing.
“We see a lot of companies selling clothing where they specify that a certain amount of it is from recycled PET. Unfortunately that PET is mostly derived from bottle waste, which means they are not solving the textile PET problem.”
And there’s another major reason why recycling alone is only a finite solution:
“Recycling always means that you lose some properties of the item. For example with PET the molecular weight gets lower and at some point it cannot be reused anymore.”
Looking to the future, manufacturers should think about two things, Funtan says: the properties of the synthetic fibre but also the role it has to fill – the longevity of the product.
"The brands should also design new textiles with End of Life in mind. Of course, usage and recycling of the product as much as possible is very important. But once unusable, the product should not be deposited on landfills or incinerated since this is removing the carbon from the loop."
Equally, consumer understanding of where products come from, and the limitations of recycling has a key role to play, he concludes.