Association commentary from Dr Ranya Simons, CSIRO group leader
Our world is facing a materials crisis. Global demand for raw materials has skyrocketed to 100 billion tonnes each year and is projected to hit a staggering 160-180 billion tonnes by 2060. This insatiable appetite is putting immense strain on our planet’s resources, leading to depletion, pollution and waste.
The future holds incredible potential, but first we need to rethink our relationship with materials. The traditional linear model of material use – often described as ‘take, make, dispose’ – must be replaced with a circular approach that emphasises keeping resources in use for as long as possible.
Australia’s current circularity rate is only around 4 per cent according to a recent CSIRO report. This means we use a mere 4 per cent of materials in a closed loop, with the rest ending up as waste. We need a fundamental shift.
The good news is that some innovative solutions are emerging in the field of materials science. Here at CSIRO, we’re at the forefront of developing sustainable materials for a circular economy.
As leader of the Hybrid Materials Group at the national science organisation, I’ve been incredibly proud to be part of this journey. We’re tackling the challenge from two key angles: downstream recycling and deconstruction of waste created from current materials, and upstream redesign of materials for circularity.
Giving waste a second life
Mechanical recycling reprocesses waste streams without altering them chemically. While it’s often the simplest and cheapest method, there is usually a limit to how many times a material, especially plastic, can be mechanically recycled due to degradation.
It can also be difficult, or even impossible, to mechanically recycle mixtures, hybrid or composite materials. Downstream deconstruction, also known as advanced recycling, goes beyond simple mechanical recycling. It focuses on uncovering hidden potential within complex waste materials, transforming them into valuable resources.
At our MUSE (Materials Upcycling and Sustainability Exploration) labs, we’re pioneering advanced recycling techniques. Take waste expanded polystyrene (EPS), which is currently difficult to recycle. Being mostly air, it is expensive, inefficient and cost prohibitive to transport it for recycling.
We’re developing a portable reactor that returns it to styrene monomer – the essential building block for many products like food packaging, insulation materials, and even car parts. This mobile reactor will eliminate bulky waste transportation.
Used cooking oil gets a new lease on life, too. Our research explores using special catalysts to convert it into useful products like biodiesel fuel and industrial chemicals, which can then be used in everything from powering vehicles to creating everyday cleaning products. This not only diverts waste from landfills but also reduces reliance on virgin resources.
But deconstruction isn’t limited to single materials. We’re developing a new method that uses a special solution to dissolve PVC from mixed waste streams, like old electrical cable covers. This recovered PVC is then purified to be as good as virgin PVC, allowing it to be seamlessly reintroduced into the production cycle.
CSIRO is also investigating other advanced plastic recycling techniques. This includes chemical depolymerisation, which breaks down waste plastics to their original building blocks, or transforms them into valuable chemicals.
The idea is to create entirely new materials from what was once destined for landfill. Importantly, chemical depolymerisation does not have a limit on how many times a material can be recycled, unlike traditional mechanical recycling.
However, recycling isn’t a one-size-fits-all solution. Sometimes, the most sustainable, lowest energy option involves combining waste streams to make brand new materials with useful properties, known as ‘upcycling’.
At CSIRO we have worked with industry to create new composites from mixed waste streams for a range of applications such as footwear, furniture, sporting goods, in the construction space, and for the food industry.
An example is our collaboration with Worn Up. We helped them test and refine their innovative process for creating high-quality furniture from 100 per cent recycled composite material made from discarded uniforms. This gives used textiles a valuable second life while reducing demand for virgin resources in furniture production.
Metals aren’t left out either. CSIRO is exploring the development of high entropy alloys, formed by combining multiple recycled metal powders in unique proportions. The resulting alloys possess exceptional properties that could revolutionise various industries.
Another CSIRO initiative, for ‘TiWi’ or titanium wire, tackles the challenge of transforming recycled titanium – a valuable but often underutilised metal – into a roll of continuous wire for additive manufacturing.
This can then be used for a range of applications in everything from medical implants to high-performance sporting equipment.
We’re also investigating the use of recycled titanium powders to create protective coatings for steel structures in acidic environments. Imagine extending the lifespan of bridges and buildings by essentially giving steel a suit of armour made from recycled materials!
Engineering sustainability from scratch
Recycling is crucial, but wouldn’t it be better to create materials that are inherently sustainable? This is where upstream design comes in. This involves re-engineering materials from the ground up, with features like recyclability and biodegradability built in.
CSIRO is at the forefront of this approach. We’re working on innovative creations like 100 per cent biodegradable shipping pallets, bioplastic composites and coatings, bioderived polymers from microalgae, and home-compostable materials made from food and agricultural waste.
These biomaterial solutions offer a game-changing alternative to traditional plastics, as they reduce the strain on resources and ease the burden of waste management.
Some materials do not currently have sustainable pathways for waste disposal and can only go to landfill or be incinerated at their end of life.
Thermoset polymers are an example of difficult-to-recycle materials because they contain irreversible bonds, which means they cannot be thermally processed or mechanically recycled like traditional plastics.
That’s why we’re developing “recyclable-by-design” polymers, which will have a significant impact in reducing such wastes. These innovative materials are essentially pre-programmed for efficient recycling, compostability, or re-use at the end of their lifespan.
We’re developing innovative coatings, composites, sealants and adhesives. This includes creating special reversible chemical groups for epoxies and polyurethanes to allow end of (first) life reprocessing.
We are even redesigning synthetic polymers so that they can be digested by insects at their end of life.
In another exciting project we’re developing a sprayable, biodegradable mulch film for broadacre agriculture. Traditional plastic mulch films used on farms create a major microplastics issue.
Our solution offers a sustainable alternative that helps farmers retain soil moisture, increase crop yield, and suppress weeds while minimising environmental impact.
Supporting Australian manufacturers on the road to sustainability
Transitioning to a circular economy offers significant environmental and financial benefits to Australian manufacturers. But navigating this shift can be a complex challenge.
We’ve collaborated with numerous Australian companies, helping them implement circular economy principles and often realising substantial cost savings.
Whether you’re looking to integrate recycled materials, explore bio-based alternatives, develop advanced or modular and portable recycling technologies, or design products with efficient end-of-life solutions in mind, our world-class scientists can partner with you on the journey.
If you’re looking to reduce your environmental impact and create a more sustainable future for your company, get in touch.
