AD is a natural process where plant and/or animal materials (feedstock biomass) are broken down by micro-organisms in the absence of oxygen. AD is widely used as a source of renewable energy.
The AD process produces biogas and a residue known as digestate, from waste biodegradable materials, such as agricultural manure and slurry, food waste and sewage sludge. The micro-organisms mainly release methane which can be used to generate renewable heat and power; this helps cut fossil fuel use and reduce greenhouse gas emissions.
Digestate is made from left over indigestible material and dead micro-organisms. It is mainly in liquid form (typically 80% liquid) and contains valuable plant nutrients like phosphate, nitrogen and potassium. It can be used as a fertiliser and the solid fraction as a soil conditioner.
Below is a figure demonstrating where the ADFerTech device sits (right) with photos of liquid digestate (top left) and resultant granules (bottom left). Grey shaded AD process is shown producing biogas and digestate. Liquid digestate is processed (blue shading) and the result is solid fertiliser and wastewater minus nutrients.