A technology firm believes it can prevent phosphorous run-off from broiler farms and turn the problem into a revenue stream for producers.
Greentech firm Onnu has announced a plan to build the first of 16 pyrolysis hubs in the Wye Valley on the English/Welsh border as one of the UK’s largest carbon removal projects.
The company has purchased a site for its first hub at Madley, Herefordshire, and is set to buy waste from poultry farmers to turn into biochar. Biochar is a black, solid substance that bears a strong resemblance to charcoal that is produced during pyrolysis – burning at high temperature (300°C) without oxygen – of biomass.
The River Wye has been at the heart of a major row over the role and extent of broiler producers in affecting the water quality. In the catchment area, 24 million chickens are farmed, and their waste is spread as fertiliser, but during heavy rainfall, it can leach into the river. Natural England downgraded the status of the River Wye in May due to the pollution.
Onnu says that once all the 16 hubs are completed, they will annually sequester more than 500,000 tonnes of carbon, which would otherwise be released into the atmosphere.
Giles Welch, Onnu CEO, said the disposal of poultry litter had become problematic and expensive due to the public outcry over the impact of phosphorus run-off on local ecosystems and stricter regulatory controls on land spreading.
“By using this waste biomass as a pyrolysis feedstock, we turn a problem into a revenue stream for local farmers. The resulting biochar will be used as a safe and transportable organic fertiliser, forming part of a circular economy in UK agriculture,” said Welch.
Onnu plans to build the 16 hubs across Herefordshire, Shropshire, and Powys by 2027. They will be strategically located a few minutes’ drive from several dozen local poultry farmers to minimise traffic to and from the site. Each hub will be able to process 10,000 tonnes of waste biomass each year. Once all 16 are up and running, 1.6 million tonnes of waste biomass will be processed annually – sufficient to account for all the poultry litter produced in the Wye Valley catchment area.
Meanwhile, a research team at Aston University’s Energy and Bioproducts Research Institute also believe the muck could be valuable if used in the right way. They have received a grant totalling nearly £2 million to see how biochar can be used commercially.
“We are pulling together a lot of science to make it work for communities and the economy. We are taking the material, such as chicken muck, processing it and then producing a range of new material which can then be developed into new products,” said spokesman Tim Miller.
Biochar has already been used as compose for plants used in Birmingham’s gold medal-winning Chelsea Flower Show entry, and the team are also working on matting for chicken sheds to soak up ammonia and to help prevent farm spillages.
Poultry firm Avara Foods, which processes two million birds at its factory in Hereford, confirmed they had been in talks with Onnu.