Scion’s Distributed Biomass Conversion programme focuses on developing technology that could lead to mini factories that could be deployed in the forest to utilise wood waste, including forest slash.
“Scion has built up a good level of knowledge and research around turning wood into chemical building blocks for other products, and there is also a large body of work there built up at Scion around how to turn waste resources into bioproducts ranging from biofuels to high-value biochemicals,” Marc Gaugler, Scion’s lead of distributed and circular manufacturing, says.
Scion’s research programme also aims to examine tech already in existence internationally, and how it could be adopted to suit New Zealand applications. A project in Central North Island is due to road-test the technology in coming months.
Solid biofuel in the form of pelletised wood may well be one of the first outcomes from what is described as a “distributed manufacturing” model, where containerised processing plants could be placed on forestry skid sites to process slash in situ.
However, the Scion technology could also prove to be invaluable in turning bulky slash on site into a liquidised intermediatory raw material, suitable for further processing at a regional bio-processing centre.
As a zero-value waste product, companies are loath to want to cart slash any distance over tough terrain – meaning offering a plant close by has strong appeal.
“But there is also a lot of work to be done around the equipment’s power demand and water needs and the infrastructure it requires – you do not typically have a lot of room on such sites, so space and risk have to be considered too.”
There is a circular appeal in having technology that could create bio-diesel suitable for fuelling the big machines working on the slash-generating sites. But Gaugler says this is challenging, given the high level of refining even diesel demands, its fundamental properties, and safety issues on storing liquid fuels on site.
The feed stock supply for successfully commissioned plants are huge, with estimates that NZ forests generate 4-5 million tonnes a year of slash waste.
“And then there are a lot of lower value logs that earn little. If you could develop technology capable of producing a product of greater value, they too could be included as feedstock,” Gaugler says.
There is also a scalable appeal to the containerised plant model.
“The smaller, commercially viable plant helps de-risk this sort of new technology. It would provide a good base from which you could scale up with additional plants, matching to supply growth in one area.”
This may hold more appeal to some investors than investing millions into a single, centralised processing site that requires large tonnages from the get-go to be commercially viable.
As more economies work to move from hydrocarbon reliance, there are greater efforts in exploring bio-sourced alternatives for chemicals. The global biochemical market size was estimated at US$80.81 billion (about $1127.7b) in 2022 and is projected to hit around US$148.6b by 2030.
The technology does not have to be limited to forest waste alone.
The Irish have trialled a modular bio-refining process that converts freshly harvested grass into cattle feed fibre, and essentially removes the surplus protein from it that livestock usually excrete as environmentally problematic nitrates.
The result is a higher feed-value grass, and surplus protein turned into a feed suitable for pigs and poultry and a liquid fraction suitable for fertiliser.
A joint research project between Scion and AgResearch is also looking at the feasibility of turning “paunch grass”, the semi-digested grass in the guts of slaughtered animals, into usable gas.
This project is in conjunction with the newly commissioned EcoGas plant near Reporoa, which collects organic household waste for gas production.
“Primary industry in NZ is well positioned to take advantage of biorefinery technology. With forestry and pasture, we know how to grow both quite quickly and efficiently. This is just another step in the process that solves some other big issues along the way,” Gaugler says.
