Utility transforms food waste to power in circular economy initiative

A new partnership will see Queensland’s Urban Utilities add organic food waste from the region’s supermarkets to the materials it uses to produce renewable energy.

The five-year agreement with waste management company Cleanaway follows an 18-month trial in which Urban Utilities used its existing facilities to process fat, oil and grease waste that Cleanaway delivered from local restaurants.

“What we were able to do was demonstrate that we're able to generate the green energy efficiently from those fats, oils and greases, and also understand some of the handling issues,” said Urban Utilities Water Ventures General Manager Matthew Magee.

“Learning to do that was really important, and that's led us to a point where we've been able to design and are now building a dedicated receival point so we can also efficiently treat a wider variety of organic food waste and use it to generate renewable power.”

Although Urban Utilities already produces biogas from wastewater, which it then converts into electricity, adjustments need to be made to its Luggage Point Resource Recovery Centre so that it is capable of handling food waste. That involves acclimating its anaerobic bacteria so that they can thrive in the higher temperature needed to handle that waste.

“We've got significant expertise around processing different types of material — we've been doing that for a long time,” Magee said.

“Those bugs like particular conditions, and as we introduce new materials, it takes a while for us to be able to adjust those bugs so they're happy treating a broader range of organic waste. So the process itself is fundamentally the same, but we change some of the chemistry and biology in order to be able to bring these different materials in.”

Magee said Urban Utilities saw it as important to its circular economy strategy to maximise the value of its waste recycling and most efficiently produce energy.

“That's really the key thing for our customers and partners in that we're providing those higher value outcomes from the material,” he said. “Just processing it into a low-value outcome isn't enough. We need to be able to maximise the value from that. If you think about the highest and best use that can possibly be done, that's central to the circular economy.

“We've got to a point now that our approach going forward is to continue to improve that year on year. We can always do better, and we need to do better next year than we did this year and so on.”

Adapting facilities

Urban Utilities will take 12 months to prepare its facilities so that they can handle the company’s target processing rate of 30 to 32 million litres of food waste and fat, oil and grease waste per year.

“The receival point upgrade at Luggage Point is currently under construction and we're taking some of those materials on an interim basis through a sort of temporary receivable point,” Magee said.

“Adding the new receivable point into the mix helps us to further improve the safety and efficiency of that process and really make sure that we're integrating well with what is a world class asset at Luggage Point.

“And also bringing the digital systems to bear that help us to track that end to end so that we can account for the types of material we've got coming through and really provide that confidence to our customers that the outcome that's being generated is linked to the materials that we're processing.”

A natural extension

Steven Trajceski, Cleanaway’s South East Queensland Liquids Collection Branch Manager, said food waste was one of the most under-recycled waste streams.

“Food waste is becoming an increasingly important challenge to address, particularly as our population grows, and we want to avoid organics ending up in landfill wherever we can,” Trajceski said.

“Through our new partnership with Urban Utilities, we’ve found a cleaner, greener way to beneficially reuse both organic food waste and fat, oil and grease waste.”

Magee said the partnership builds progressively on Urban Utilities’ long history of organic waste management

“This is a natural extension for us now to continue to play a stronger role as customers are demanding higher and higher value [environmental and social governance] outcomes,” Magee said.

“We've got a decade of experience and capability and capacity in terms of being able to bring those solutions to bear, and a strategy and an intent to continue to develop that year on year. That's all underpinned by a very strong investment the businesses made over the last decade and continuing in innovation and research and development.”