1 Department of Environmental Science - Emission modeling & enviromental geography, Department of Environmental Science, Science and Technology, Aarhus University2 IRSTEA – National Research Institute of Science and Technology for Environment and Agriculture3 Department of Environmental Science - Emission modeling & enviromental geography, Department of Environmental Science, Science and Technology, Aarhus University
Anaerobic digestion (AD) of organic waste from agriculture and others sectors is a widely used technology which shows increasing implementation due to its capacity to produce renewable energy and also to reduce greenhouse gas emissions from waste management. The development of AD is also an opportunity to improve nutrient recycling from organic waste through the development of an eco-effi cient post-treatment system. In this context, LCA was applied to evaluate the sustainability of diff erent raw digestate post-treatment technologies regarding recycling of nutrients from agricultural and organic waste to agricultural soils for decreased resource depletion and climate mitigation. Substitution of the use of N and P mineral fertilizers with recycled soil health improver or organic fertilizers products as function of fi ve diff erent post-treatment technologies and raw digestate characteristics was evaluated. A particular attention was carried to (1) the gaseous emissions (NH3 and N2O) from process (post-treatment) but also after land spreading and (2) the carbon cycle considering the CO2 carbon costs of fertiliser production and the soil carbon sequestration benefit.
LCA; digestate; post treatment; nutrient recycling; biogas plants; eco-efficiency; recycling