“The urine has got enough energy within it to power this process on its own,” says Freguia.
The energy is used to push the urine through membranes that filter out the desired nitrogen, phosphate and potassium. The result is a liquified fertiliser ready for use and the recouped urea could also be used to manufacture AdBlue, a crucial diesel additive that’s increasingly expensive and scarce.
“In four years we’ll get to commercial readiness. And after that, it will be a long journey of transition to bring these technologies into new buildings.”
Freguia and his team will focus on rolling the technology out to council parks and gardens and small-scale urban horticulture projects before scaling up in step with the hub’s 20 industry partners.
All the traditional kind of fertiliser that’s put into the ground is, by nature, very inefficient because of the soil chemistry.
Ken Hancock, managing director of RFL AgTech
Another early-stage startup with its eyes on wastewater is Australian Hydrothermal, based in Adelaide. Director Dr Benjamin Keiller is focused on the potential of hydrothermal carbonisation technology (HTC). The process sees waste, such as sewage or food scraps, placed in water that’s heated beyond 200 degrees but pressurised, so it doesn’t boil.
“Basically, we are accelerating the coalification process that occurs deep beneath the earth, but instead of doing it over millions of years, we’re able to do it in like, an hour,” says Keiller.
The result is a solid “char” that can be burnt as a low-ash alternative to coal, buried as a method of carbon sequestration or treated as “biochar” and crumbled into soil, which “dramatically improves” soil quality.
The leftover liquid is rich in nitrogen and can be used as a liquid fertiliser.
Keiller and his team are in talks with SoMax, an American HTC company, with a view to get reactors installed in South Australian wastewater facilities in the next five years.
Meanwhile, other agtech companies are focused on the efficient use of fertiliser. Between 60 and 70 per cent of nitrogen is never taken up by the target plants.
“A lot of [fertiliser delivery] technology hasn’t changed greatly in the last 80 to 100 years,” says Ken Hancock, managing director of RLF AgTech, which supplies technology that precisely delivers fertiliser and micronutrients to crops. “All the traditional kind of fertiliser that’s put into the ground is, by nature, very inefficient because of the soil chemistry.
“We bypass the soil and deliver the nutrient directly into the seed and the foliage of the crop. That allows us to reduce the soil-applied fertiliser by about 20 per cent. That, on a macro level, allows growers to reduce their input costs and boost their yields.”
RLF AgTech listed on the ASX 200 in mid-April after an $8.5 million initial public offering. Hancock said globally rising fertiliser prices meant growers were having a “good hard look” at their use of urea and other additives.
“They do need to take up technology to make their programs more efficient and keep them profitable because fertiliser is the most significant input cost to their program.”
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