Invasive weeds eyed as new biomass source

Invasive weeds from the outskirts of Brisbane in Australia could soon help power homes and businesses, thanks to new research from the University of Queensland.

Scientists from UQ’s Queensland Alliance for Agriculture and Food Innovation (QAAFI) have discovered that several problematic weed species can be converted into high-quality biomass pellets - a solid, renewable fuel source.

The study examined 15 invasive plant species collected near Ipswich in South-East Queensland. Lead researcher Dr Bruno de Almeida Moreira said two species in particular - Brazilian Nightshade and Climbing Asparagus - stood out for their potential.

“Historically, the international pellet market has relied on forest biomass,” Dr Moreira said. “But in Australia, wood pellets are not classified as renewable. So we’re investigating alternative sources of biomass that can produce pellets of the same quality.

“These weeds have a lignin content of about 25 per cent, which is competitive with wood. That’s a crucial component in making durable, market-grade pellets.”

The research was conducted in collaboration with Ipswich-based startup WorkEco, supported by a seed grant from the Australian Government’s Strategic University Reform Fund (SURF).

Co-author Associate Professor Sudhir Yadav, head of UQ’s AgriSustain lab, said the aim is to support sustainability in the agricultural sector while reducing environmental impacts.

“Agencies like the Australian Renewable Energy Agency have forecast that bioenergy could supply 20 per cent of Australia’s energy needs by 2050,” Dr Yadav said. “That’s an ambitious target, but with the right research, it’s achievable.”

Dr Yadav said the team is also exploring the use of other low-value biomass sources - including crop residues, straw, wood chips, animal manure and even council-collected green waste.

“This work has the potential to generate income for startups, solve waste problems for local governments, and, importantly, reduce environmental burdens,” he said.

The researchers noted that supply from invasive weeds may eventually be limited, highlighting the need to expand the search for other biomass sources, including broadacre crops like sorghum.

The findings were published in the journal *Sustainable Energy Technologies and Assessments*.