Source: Radio New Zealand
Matt’s kiln is fuelled with organic waste for biochar production RNZ/Sally Round
Just as he turns industrial waste back into good stuff for the earth, Matt Welton himself has come full circle.
The former prison officer and cartographer spent his first years out of school working in the scrap metal trade in London’s East End.
“Quite a lot of pressure on a young fella, going out knocking on doors to all these little scrap dealers and rag and bone men and whatever, with names like Jimmy Jighand and Pete Sparrowhawk.
“A good grounding, anyway, in how they sort of made a living out of nothing.”
Decades on from the early ’80s, he spends much of his time recycling waste and feeding it into a kiln in the heart of the rugged Akatarawa Valley, north of Wellington city.
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Welton collects the hops sludge left over from beer-making at Panhead Brewery in Upper Hutt, used wood pallets and forestry slash from his property to use as feedstock for the kiln, producing biochar.
Biochar is not unlike charcoal and is made from any sort of organic waste, and proponents say it improves the soil by helping it retain water and nutrients, sequestering carbon at the same time.
Matt on his weekly pick-up at Brewtown in Upper Hutt RNZ/Sally Round
Hops waste ready for fuelling the kiln RNZ/Sally Round
Welton has also partnered with the sustainability-focused fashion brand Kowtow, turning fabric from the cutting room floor into biochar, dubbed “black gold” by its devotees.
“[Kowtow] were looking at an alternative way of using their cutting room offcuts, rather than sending it to landfill, and so I said, ‘yeah, I’ll give it a go, we’ll try and make some biochar out of it’. It’s pure cotton. As long as it’s pure we should be able to turn it into char.”
He tests the char – produced via a technique known as pyrolysis – for impurities. Anything synthetic like elastic waistbands are a “no-no”, he said, as it can lead to higher readings of toxic elements like arsenic.
Welton took Country Life on a tour of his “biochar central”, a yard tucked into the side of a hill on his land, once covered in pine trees, which he is regenerating with wife Debbie into tracks and paddocks.
The couple has also placed 30 hectares of their block under a QEII Trust Covenant to protect the remaining native forest which escaped logging last century.
The Akatarawa Valley was a hive of sawmills and logging tracks up until the 1960s and remnants of the industry can be seen on Welton’s property.
They harvested the last of the pines when they arrived but mountains of slash were left behind by the foresters.
“They’ve taken the lengths they want, and then they just biff the rest over the side.”
A digger at work clearing slash from a former skid site on Matt and Debbie Welton’s Akatarawa Valley property RNZ/Sally Round
The forest waste sowed an idea to turn it into something useful, and Welton’s venture Biochar Carbon Options developed from there. He now sells the crumbly mix, charged with brews of seaweed and horse manure, and sells it to growers and farmers.
Welton said he’s had several “Heath Robinson” moments developing the process, including happening on the idea of petanque balls – their heaviness good for pulverising the lumpy pyrolised waste in an old concrete mixer – so that the biochar is the right consistency for sprinkling on the earth.
“It’s a bit of a number 8 wire system, but it works.”
Matt opens the door of the kiln to check the biochar production process RNZ/Sally Round
Matt found some petanque balls do a good job of crushing the biochar RNZ/Sally Round
Matt holds a bucket of biochar, ready for “charging” after it’s been sieved and crushed in an old cement mixer RNZ/Sally Round
Welton can see the potential for such a system at landfill sites, taking all the green waste, as well as at forestry blocks.
Forestry slash left over from the pine harvest which will be turned into biochar RNZ/Sally Round
“You could have mobile plants going up to forestry sites and converting [slash] into char, following the crews around. If you could talk to the crews and say, rather than throwing the waste to the left, can you throw it to the right, and then we can deal with it there.
“There’s so many different ways of utilising the product and utilising the waste, and, you know, getting involved with those communities that I just think it’s a no brainer, really.”
Learn more:
- Discover scientific research on biochar here
– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
