Pyreg installs its largest plant to date for Sydney Water

German sludge carbonisation specialist Pyreg has announced it will install a new system at a Sydney Water wastewater treatment plant, the company's largest project to date.

[Source: Pyreg]

Pyreg's first installation in Australia

The system is the company's first carbonisation installation in Australia and is set to produce over 400kg of biochar at maximum production. The site will house two Pyreg systems, which are due to be shipped in late 2025.

Australian general contractor John Holland will be responsible for the construction of the project, alongside Stantec and KBR who will be the design and engineering consultants.

The system is due to process all of the biosolids from the Riverstone Wastewater Treatment Plant – on average 10.5 tonnes of dry solids per day – with the potential to treat sludge imported from other plants in the future, as part of a centralisation plan for biosolids management in the region.

Australia puts focuses on sludge pollutants

The project adds to Australia's growing list of advanced thermal conversion projects, as the country puts a focus on pollutants in the sludge going to land. According to the Australian and New Zealand Biosolids Partnership, nearly 300,000 tonnes of dry solids were sent to land in the country in 2023. 

Although there is no ban on PFAS in biosolids, national and state-level guidelines for the levels of PFAS in land-applied sludge have been introduced. "The number of enquiries from Australia and New Zealand have increased tenfold [because of the changes to guidelines]," outlined Pyreg chief sales officer Robert Kovach.

The company also anticipates increased interest from the US and UK in the future as PFAS in sludge becomes a hotter topic.

No pyrolytic oils or tars

Elsewhere in Australia, South East Water in Victoria started scaling up the country's first sludge pyrolysis project in 2023, after testing the technology previously and seeing successful destruction of micropollutants. Furthermore, Logan City in Queensland installed a full-scale permanent gasification plant in 2022, using Pyrocal's technology. The installation saved Logan Water $1.8M AUD per year in trucking and disposal costs for its sludge.

Pyreg now has around 60 installations worldwide, and its process differs from traditional pyrolysis by not producing pyrolytic oils and tars. "We don't allow our syngas to ever condense, which is what ends up creating an oil or tar residue – a waste product. The energy from these gases keeps the process autothermal, and the customers can use the energy to dry the wet sludge," commented Kovach.

The company also commented that its process creates the correct internal conditions to preserve plant-available phosphorus, making its biochar desirable for agriculture where this is permitted. Pyreg has also seen interest from the construction industry to embed the biochar into concrete, with the Sydney Water plant seeing some interest for this application.

Provided by content partner, GWI. For further stories about the circular economy in water, visit: https://www.globalwaterintel.com/technologies/resource-recovery