diagram of the Onunda process
03 January 2024 Type: Blog
Themes: Company news

How does the Onunda technology work?

Onunda is a sustainable wastewater management solution that eradicates land waste, removing microplastics and hazardous chemicals from wastewater, and transforming it into a sustainable source of clean energy and nutrient-rich fertiliser. 

Onunda technology integrates hydrothermal carbonization (HTC), drying and gasification processes to maximise the extraction of value from sewage and prevent the discharge of pollutants back to the environment.

What is the HTC process?

The HTC process uses waste heat and autogenous pressure to convert sewage and other organic wastes into their constituent elements: carbon-rich hydrochar and nutrient-rich liquor. This allows the recovery of valuable nutrients (N,P,K) by dissolving them in subcritical water while neutralising harmful micropollutants and pathogens. 

What is the gasification process? 

The Onunda process utilises our proven gasification technology to convert the carbon-rich hydrochar into high calorific value syngas. This syngas is used exclusively to power the Onunda plant and excess energy can be converted to electricity and exported to the national grid or used to supplement offsite heating demands.

What are the benefits of Onunda technology?

When Onunda technology is integrated with a traditional wastewater treatment plant the nutrient-rich liquor can be used to boost biogas output, the syngas can be used to supplement thermal hydrolysis heating, and the nutrient-rich residue can be used as an agricultural fertiliser. Furthermore, integration of Onunda technology can eliminate the need for land banks and stop the unmitigated release of sewage into our natural waterways.

In this way, sewage is transformed from a problem into a usable feedstock producing sustainable and environmentally friendly value streams.