Researchers use ancient Amazonian tech to turn waste into battery gold

How can biochar be used?

Biochar isn't a single product but a name given to products that have certain physical and chemical properties. These products can be made from various biological products ranging from plant residues to wood chips, manure, or even agricultural waste products.

The technology dates back thousands of years and was also reported to be used by the indigenous people in the Amazon basin. Back then, the material was used to improve the fertility of soil and improve crop yields, the webpage of the US Department of Agriculture states.

Along with this application, biochar has also been found to be useful in making carbon electrodes for batteries and other energy storage devices, prompting an increased adoption of the method in recent years.

Where is PYROCO at?

Researchers at RMIT have teamed up with South East Water, Intelligent Water Networks (IWN), and Greater Western Water to make PYROCO a reality. In 2021, the collaboration carried out its first trials and turned biosolids into biochar after removing all pathogens, Per-and Polyfluoroalkyl Substances (PFAS), and microplastics, which can harm humans and the environment.

More recently, the team carried out further trials at a pilot plant commissioned and installed at the Melton Water Recycling Plant, where wastes from other streams were used, and safety features, along with automation, were demonstrated. This included food and garden organic waste along with canola straw that was co-mingled with other biosolids.

"The trials we've just completed are an exciting step towards scaling up this innovative pyrolysis technology to prove the findings and operationalize it – this represents a real step-change in the field," said Kalpit Shah, associate professor in Chemical Engineering at RMIT in a press release.

The team is now proceeding toward commercialization of its approach and hopeful that it will provide solutions to the water industry's challenge of treating biosolids disposal.

"We believe that this exciting technology has the potential to transform by-products of the wastewater process into a valuable resource in a way that is the most carbon-efficient while maximizing the quality of the biochar," said Daniel Sullivan, General Manager of Research, Innovation, and Commercialisation at South East Water.