Veena Sahajwalla of the Sustainable Materials Research and Techology (SMaRT) Centre at UNSW Sydney with the products of microrecycling.
Veena Sahajwalla of the Sustainable Materials Research and Techology (SMaRT) Centre at UNSW Sydney with the products of microrecycling.
Coffee tables fabricated by SMaRT Microfactories.
Coffee tables fabricated by SMaRT Microfactories.

Microrecycling and MICROfactorie® technologies offer a way forward

Australia’s governments have agreed to ban the exporting of glass, plastic, paper, and rubber tyres from January 2021, so we need to start treating these waste items as the ‘renewable resources’ they really are.

And since COVID-19 has disrupted global supply chains, the limitations of Australia’s manufacturing capability has come under sharp focus.

This issue of countries like Australia ‘standing on our own two feet’ by not having to rely on unreliable global supply chains for certain materials and goods has sparked political debate about how countries can produce the goods they need.

One crucial area that is now being appreciated is the concept of microfactories, which can reform waste into value-added materials for re-use and re-manufacturing.

This decentralized model, which merges recycling with manufacturing, is the brainchild of Professor Veena Sahajwalla and her team at the Sustainable Materials Research and Techology (SMaRT) Centre at UNSW Sydney.

UNSW SMaRT MICROfactories® are an innovation designed to transform problematic waste materials, such as glass, textiles and plastics, into new value-added materials and products such as green ceramic tiles for the built environment and filament as feedstock and 3D printing. Many of these innovations have progressed as a result of funding from the Australian Research Council (ARC), which resulted in the formation of the ARC Green Manufacturing Hub hosted by the SMaRT Centre.

Through her collaboration with manufacturing and waste recycling industries, Sahajwalla and her team have developed new manufacturing and recycling solutions that address urgent problems and deficiencies around waste and recycling, while at the same time addressing the need for more sovereign manufacturing capability and job creation, let alone the enormous environmental benefits.

These microrecycling and MICROfactorie® processes reduce waste going to landfill, reduce the loss of valuable resources to the Australian economy, generate local employment, and create products that are highly sustainable compared to most comparable products in the built environment and associated sectors.

Sahajwalla comments: “We now have an incredible opportunity to solve for numerous existential problems at once: we can collectively address waste and recycling issues and lower our carbon footprint, while also enhancing our manufacturing capability, thus creating jobs and new supply chains to enhance our sovereign capability."

“In fact, we have the ability to do this now, but not at scale. COVID has unearthed the weaknesses in our current way forward to meet these challenges but we can start a whole new ‘green materials’ movement where we use waste as renewable resources for manufacturing to supercharge our economy which is going into the biggest recession and depression since the 1930s.”

SMaRT@UNSW has been working on projects to synthesize hybrid materials and products from recycled waste.  The aim was to create compact, modular MICROfactories® that could stimulate the circular economy by transforming problem waste streams into value-added products close to the source of waste.

The project was developed to address the ever-increasing volume of waste streams. For instance, hundreds of thousands of tonnes of glass were being stockpiled or landfilled instead of recycled because of contamination and cost issues. It was cheaper to import new glass bottles than to recycle used ones, while another obstacle was difficulties in recycling contaminated waste glass.

The project established pilot scale facilities at UNSW to manufacture hybrid products containing glass and textiles. In 2019, the process was revised and adjusted to speed up the production rate and were upscaled to industrial sized products. In December 2019, the MICROfactorie® project secured NSW government funding to assist with scaling and commercializing the technology to manufacture hybrid products.

The evolution of producing green ceramics from lab to industrial scale – and the current commercialization efforts – are an example of an innovative project that has the potential to set new benchmarks in innovation, efficiency, and sustainability for the built environment sector.  

The SMaRT Centre has also developed MICROfactorie® techniques to recover valuable metals and plastic from electronic waste (e-waste). The project can reform plastic into highly valuable filament as feedstock for 3D printing. Most filament is imported to Australia, yet we can now reform our own e-waste plastic that is not currently recycled into a new, valuable material for manufacturing.

Manufacturing challenges are expected to increase in coming decades, due to global material and energy constraints, as well as growing environmental issues caused by increasing worldwide generation of waste. To address these problems, coupling recycling with manufacturing while developing energy efficient techniques is required.

For example, conventional recycling of e-waste, i.e. recycling of printed circuit boards, is at present employed at a very high-energy intensive operating temperature of 1250°C with several steps of processing to recover the metal via pyrometallurgy process.

In contrast, SMaRT Centre researchers have showed that selective recycling at a smaller scale (i.e. microrecycling) can capture different valuable elements at different steps, which is beneficial not only for the environment but also for the economy in terms of resource efficiency.

An example of this is the step-by-step recovery of tin-based alloys at 500°C and copper-based alloys at 1000 °C from waste PCBs, which cannot be done conventionally. Another example is green steel technology, or PIT, which uses waste tyres as an alternative to coal and coke in steel making and delivers more energy efficient outcomes.

MICROfactories® have been built at the UNSW SMaRT Centre at both lab and industry scale for testing and production. Those small modules could be deployed at local and regional locations near waste sources.

This is in contrast to conventional, centralized recycling and reprocessing facilities, which are often located at large factory sites and require waste to be transported long distances. MICROfactories® could provide communities with the technology to establish local reprocessing of their discarded waste, creating local jobs enhancing social and economic outcomes – not just for local communities but for the whole nation.

Laureate Professor Sahajwalla says: “Doing onshore and more sophisticated processing of recycling coupled with manufacturing can change the game for Australia, and all countries around the world, particularly given the current waste, recycling and manufacturing challenges."

“What we have come to realize is that in all of the debate about supply chains and resource management, within the context of the desirability for broader sustainability, that the capability to achieve much of this is already with us."

“We are partnering with various businesses and sectors, including various small-scale firms in regional settings, to unleash this technology to create local manufacturing capability and supply chains. These businesses are motivated by focusing on sustainably developing quality-based goods; they are not looking only to compete on price.”

Microfactorie® technologies reduce the need for centralization and a lot of transportation, while creating localized supply chains, jobs, and addressing some of our urgent waste and recycling challenges.

Sahajwalla adds: “We need to embrace the opportunity to adopt and replicate our existing capabilities and pockets of excellence already operating around the nation. Sovereign capability of material resource management and manufacturing is within our reach."

“The link between R&D and industry has never been stronger, and it is time to capitalize on the productive partnerships between researchers and business to accelerate our world-leading innovations. Now is the time to act on working together to address these challenges around waste, recycling and manufacturing.”