Land Conditioners from Bio-Energy Residues - AVAnD (Adding Value to Ash and Digestate)
Developing sustainable soil conditioners and plant fertilisers from the waste streams of anaerobic digestion and biomass thermal conversion
Lancaster Environment Centre, in partnership with Stopford Energy & Environment, is running a 3-year Natural Environmental Research Council (NERC) funded Resource Recovery from Waste project, seeking to optimise both the environmental and economic value of waste streams derived from biomass energy generation such as anaerobic digestion (AD) and thermal conversion technologies (incineration, gasification and pyrolysis). In doing so, the Defra supported project will also provide evidence relating to the impact of applying residues from bio-energy generation on ecosystem health.
Sustainable forms of energy generation using biomass are rapidly growing. The dominant disposal route for ash from gasification plants is to ash lagoons and landfill; whilst digestates, derived from AD, are typically disposed of to land at no cost. However, with rising pressures on environmental resources, rising landfill taxes and accompanying waste-minimisation legislation, alternative options for waste reuse are increasingly being sought.
It is hypothesised that a combination of ash and digestate may be regarded as comprehensive nutrient provider and soil conditioner. On this basis, our primary aim is to develop a suite of soil conditioners and fertilisers derived from mixtures of these waste streams for use within agriculture, with enhanced environmental value relative to presently available commercial products, while maintaining the same level of efficacy with regards to crop yield and health. The environmental benefits will be evaluated, not only from the formation of a closed-loop, circular economy, but also the holistic impact of such a product on broader ecosystems and the services they provide.
The project is being delivered in four main phases:
- Physical and chemical testing of individual ashes and digestates to enable formulation of blended products.
- Execution of glass-house trials to assess the performance of the blended products compared to that of conventional fertilizers on soil properties and crop growth
- Execution of pot trials to assess the performance of the blended products on crop yield and ecosystem health over two growing seasons
- Engagement with policy makers and regulators to determine the evidence required to permit the application of waste derived fertilizers to land
Further information relating to the background of this project can be found here: