KiwiNet Awards 2024: Rotorua finalist Cetogenix turns organic waste from ‘crap to cash’

Scion and Cetogenix team members (left to right) at Cetogenix in Rotorua: Kim Murrell, Tasman van der Woude, Sally Williams, Trevor Stuthridge, Donya Novin, Alex Stuthridge, Daniel Gapes, Martin Cooke-Willis, Rob Lei, Carla Cronje and Russell McKinley. Photo / Stephen Parker

Patience is key when you’re trying to shift human behaviour, Trevor Stuthridge says.

Stuthridge is chief executive of waste innovation start-up Cetogenix, which has been nominated alongside 17 other finalists at the KiwiNet Research Commercialisation Awards 2024. Cetogenix is nominated in the PwC breakthrough project category.

Cetogenix, based on the Scion campus in Rotorua, has been recognised for developing Ceto-Boost, a product that breaks down organic waste and tranforms it into biomethane, fertiliser and biomaterials by way of hydrothermal oxidation – a process that involves heat and pressure to generate chemical reactions.

“Think of it as a burning in water technology where we control the burn to make just what we need,” Stuthridge said.

Forests to Biobased Products general manager Dr Florian Graichen said the it was a significant achievement.

“These breakthrough projects demonstrate how research-driven ingenuity can unlock sustainable solutions to some of the world’s most pressing environmental challenges.

“Cetogenix is a prime example of how science can lead to real-world solutions with a positive impact on both the environment and the economy,” Graichen said.

“The ability to turn waste into renewable energy and useful byproducts is crucial for achieving global sustainability goals.”

Taking the risk took “courage” and achieving real-world solutions happened by accident, which Stuthridge called “strategic serendipity”.

“We were solving another problem, which is how we avoid landfill in Rotorua and the rest of the country.

Rotorua Lakes Council approved a proposal for Cetogenix to to build a pilot plant in 2012 to process biosolid wastes from Rotorua’s municipal wastewater treatment plant.

Stuthridge said the technology wasn’t used because the market wasn’t ready.

Cetogenix engineer George Estcourt with the Ceto-Boost prototype. Photo / Stephen Parker

“When I go back to some of those people and say this is what we’re now doing with the technology, they get incredibly excited,” he said.

“We said a number of times in our journey, we’re going to have to go out to come back in again.

“We used to say crap to cash, it costs a lot of money to treat sewage ... so we’ve got a double whammy,” Stuthridge said.

Accustomed to ruffling feathers, Stuthridge said he was prepared to make noise within industry again.

“It’ll disrupt the fertiliser value chain, the wastewater treatment value chain.

“The value is not just monetary, it’s economic, it’s environmental, it’s societal,” Stuthridge said.

“You’re always going to have sewage.

“It is a resource, it’s something that can be used, and sewage treatment plants are useful things to have.

Stuthridge said more and more supermarkets were requiring businesses to have “zero carbon” standards which increased local demand for sustainable solutions in commerce.

“Now the lights are going on, they’re going we need these technologies and that’s extremely heartening, but it’s taken 15 years for that to happen.”

Dr Daniel Gapes and Dr Donya Novin compare before (left) and after (right) samples from Cetogenix's proprietary Ceto-Boost system.

Stuthridge said he and co-founders Rob Daniel and Alex Stuthridge had “really nice jobs and great careers” before they developed Ceto-Boost.

“We’ve had to move through the bleeding obvious phase to the revelation phase,” Stuthridge said.

This year Cetogenix was commissioned alongside other international bioresource experts to drive sustainable alternatives to burning waste, which Stuthridge said was a success.

“In the last couple of years, the UK has woken up and said here’s the issue, we cannot put organic waste on to agricultural land.

“People do not want sewage to go on to land and so they’ve developed these bioresource strategies that go we need alternative solutions to not putting it on land.

Stuthridge said big supermarkets were helping to set consumer standards for zero carbon priorities.

“We need to live the zero-carbon thing a bit because our market is telling us, supermarkets are telling us your product better be zero-carbon or we won’t buy it.”