Onnu Green Hubs

The opportunity

It is impossible to overstate the damage caused to Wye Valley from phosphorous entering the waterways through run-off. A crucial contributor is the local intensive poultry farming, as the storage and land application of the poultry litter generated causes severe ecological damage through run-off. A well-loved UK river, this has affected local quality of life and the tourism industry, and a restriction on homebuilding due to nutrient neutrality rules is having a huge impact on the local economy. Poultry litter also produces toxic ammonia emissions and is associated with spread of disease.

The solution

In order to deliver the benefits of pyrolysis, Onnu has developed a unique, fit-for-purpose solution for poultry litter pyrolysis encompassing the highest standards of biosecurity, efficient integrated pyrolysis and drying equipment, together with the commercial, logistical and compliance know-how to make the process economically viable for widespread deployment across the UK poultry sector.  

Our proposed Green Hub located in Herefordshire will demonstrate to the industry and regulators that the pyrolysis of poultry litter is safe, effective and profitable, while quantifying the atmospheric carbon removal, biochar and energy production to demonstrate a strong business case for roll-out in the Wye Valley and nationwide.  

The localised nature of our plant minimizes transport-related costs and emissions, and we will establish a close relationship with Herefordshire's farming community, who will be paid for the litter, to ensure that the solution is deemed as attractive as less environmentally positive options. The poultry litter will then be dried in an integrated drying unit before it undergoes pyrolysis (heating under high temperature, inert conditions) which kills all pathogens and convert the poultry litter into biochar.

The result

Biochar is a low-density, porous carbon-rich material which when added to soil has high nutrient adsorption capacities that enable nutrients to stay within the soil and prevents leaching. In addition, biochar aids healthy microbial growth within the soil, and its high-water retention capacity ensures the soil remains moisture-rich for longer periods of time. This not only helps improve the soil quality but also increases crop yield.  

The project will also act as a centre of education, and we will share all information with the farming industry in terms of poultry litter processing, net zero impact, biochar applications and local energy usage to help improve farming practices, and so the substantial environmental and commercial benefits to the sector can be realized at scale.

Additionality

While delivering the outcomes seen with many biomass pyrolysis projects, the elimination of the catastrophic pollution caused by the feedstock’s current endpoint hugely increases the overall environmental impact of the project.

Farmers are paid for the litter, at a better-than-market rate, ensuring that the project is sustainable financially as well as environmentally.

A large percentage of project revenue comes from the sales of CORCs. Without carbon finance, the project would not be undertaken as the feedstock does not produce large amounts of excess energy to be sold, and the upfront cost of the pyrolysis equipment and biosecurity requirements means the plant would not be economically viable without carbon credits being produced and sold.