Transforming agri-waste into low-carbon materials

Working within the space of circular economy technologies for sustainable energy and waste management, UNSW Associate Professor Jason Scott develops technology that converts or manages traditional waste streams into new products. This has come to life through a number of projects, including a successful endeavour to combine waste streams from salt mining with carbon dioxide to create sustainable, low-carbon building materials. 

Working alongside Australian chemical company, EcoMag Ltd, A/Prof. Scott and his team are recycling industrial agri-waste into eco-friendly plasterboard – thereby helping Australia’s construction sector to reduce its carbon footprint.

Across a period of four years, the partnership is transforming the products of three separate waste streams – magnesium from solar salt bitterns in Western Australia, agri-waste (straw and wood) and carbon dioxide into low-carbon plasterboard, internal dry wall or external cladding. “EcoMag developed the process, which allows them to produce kilogram volumes of its hydrated magnesium product, but they saw UNSW as a resource to help develop these new products, technologies and ideas,” explains A/Prof. Scott. “We’re working with them in finding more applications of their products, as well as making their process more sustainable.”

The process for this new technology starts with the integration of carbon dioxide capture and utilisation. “Their process requires a carbonate, and what we can do is now use CO2 to form that carbonate and then form the final product,” explains A/Prof. Scott. “If we have a CO2 emitter, we capture that CO2, pass it into their process, lock it up in the carbonates in the product and you can then form it into your drywall or cladding,” he adds. 

In partnership with Ecomag, UNSW engineers have developed a process to produce low-carbon plasterboard made from carbon, magnesium and agri-waste such as straw and wood.

By capturing the CO2 into a new product, the team have been able to further develop EcoMag’s magnesium product by seeing how it can be used as an alternative to current plasterboard. It’s also allowed them to consider whether this material has comparable properties to what’s currently on the market, including flame resistance, tolerance to moisture, strength and flexibility.

The project, which has been funded through the Future Food Systems CRC, has been highly collaborative and multi-disciplinary in its approach, and has seen the team work closely with the technical-scientific team at EcoMag – in particular Chief Technology Officer, Dr. Tam Tran. “The team has now established a process which can capture and store CO2, with the produced hydrated magnesium carbonate material also a fire retardant capable of slowing down the flaming of construction materials.”

With growing demand for construction materials made through circular economy frameworks, the creation of this new material has a number of potential outcomes. “This idea has real-world, commercial potential,” adds A/Prof. Scott.