Developing a suite of novel land conditioners and plant fertilisers from the waste streams of biomass energy generation

The use of different forms of biomass is becoming more important in the production of sustainable forms of energy; important examples include gasification and anaerobic digestion (AD)AD alone has the potential to deliver over 40TWh of renewable energy, equivalent to over 10% of the UK's domestic gas demand. As such, waste from energy generation, including ashes and digestate, are being produced in large volumes and this is likely to grow. The dominant disposal route for ash from gasification plants is to ash lagoons and landfill; whilst digestates, derived from anaerobic digestion, are typically disposed of to land at no cost. However, in the face of rising pressures on environmental resources, rising landfill taxes and accompanying waste-minimisation legislation, alternative options for waste reuse are increasingly being sought.

Previous studies have demonstrated that biomass-ash and digestate can be useful nutrient sources for crop plants in nutrient limited conditions. Although virtually nitrogen free, ash is rich in many micro- and macro-nutrients. Whilst, anaerobic digestate is a rich source of trace metals and nitrogen, as well as relatively stable forms of C, which may improve soil structure and enhance C-sequestration within soil. Therefore, if combined, it is hypothesised that the mixtures of ash and digestate may be regarded as comprehensive nutrient providers and soil conditioners.

This project seeks to develop a suite of novel soil conditioners and plant fertilisers from ash and digestate waste streams originating from biomass energy generation. Commercial scale energy generation from biomass, using anaerobic digestion and gasification technology is a rapidly growing sector and is forecast to generate 15% of the UK's energy demand by 2020. This proposal supports a radical change in the way that biomass energy producers can support a circular economy and facilitates new ways to mesh commercial ideas with positive environmental benefits. It would support a scopingstudy that would define an integrated pathway for multi-stakeholder research that underpins effective implementation and uptake of a new waste stream for soil conditioning.

The following groups will be interested in and benefit from the ultimate outputs of this research:
1. Academics working in this area in their research: soil science, nutrient dynamics, soil microbiology, soil ecology, crop/plant physiology and climate change
2. Those working in various aspects of this industry including sustainable energy producers, waste disposers, farmers, alternative fertiliser developers, wastewater treatment industry.
3. Clearly this has implications for generation and production of energy fromwaste and therefore will be of interest to policy makers and regulators working in this area.

Commercial scale energy generation from biomass, using anaerobic digestion (AD) and gasification technology is a rapidly growing sector, underpinned by government policy (Renewable Obligation Order 2009 and Renewable Heat Incentive 2011). AD alone has the potential to deliver over 40TWh of renewable energy, equivalent to over 10% of the UK's domestic gas demand. As such waste from energy generation, including ashes and digestate, are being produced in large volumes and this is likely to grow. The dominant disposal route for ash from gasification plants is in ash lagoons and landfill, whilst digestates derived from anaerobic digestion are typically disposed of to land at no cost. However, in the face of rising pressures on environmental resources, rising landfill taxes and accompanying waste-minimisation legislation, alternative options for waste reuse are increasingly being sought. Creating new and environmentally sound materials from the digestates and wastes from these processes is our project ambition. Eco-innovation - the development of new business opportunities that support positive environmental benefits - underpins our approach and our integrated multi-stakeholder development team.
Successful innovation in this area will lead to the development of products and processes of global impact, whereby a "whole systems approach" can be adopted when assessing the viability of recovering nutrients from industrial waste streams. Furthermore, in executing this study it is the intention of the consortium to "eco-innovate" a land conditioning product, through resource recovery from waste, which in turn will result in the diversion of waste from landfill, provide a sustainable alternative to conventional resource intensive fertilizers and improve food security in areas where agriculture is suffering the consequences of rising fertilizer costs. It has been well documented that nutrient resource scarcity is an increasing threat to future economic development.
Widespread adoption of this technology could result in a sustainable substitute for conventional chemical fertilizers, so significantly reducing the environmental impact of the agrochemical industry. Furthermore, utilising the growing waste stream of biomass by-products to promote the growth of crops, including energy crops, will close the production loop for biomass to energy generation enabling a 'cradle to cradle' approach. Given the increasing demand for inorganic mineral reserves (e.g. phosphorus) globally and regional restrictions on nitrogen inputs, the demand for alternative sustainable land conditioning products is vast. Therefore significant research to develop new agrochemical products from industrial waste streams is required. The research has local application but a truly global reach as society moves towards greater reliance on efficient resource recovery based on sound 'eco-innovative' principles.