PROJECT DESCRIPTION
BACKGROUND
Energy generation is the main contributor to greenhouse gas emissions. For that reason, renewable energies, such as biomass, must play a fundamental role in climate change mitigation.
At the same time, improving waste management in order to achieve a completely circular economy remains another EU priority. The agri-food industries produce substantial volumes of waste, mainly organic, derived from the processing and packaging of products, and also from the cleaning of agri-food facilities. These wastes have to be treated, in most cases, at the location where they are produced or by an authorised waste manager. In some cases, the wastes enter the sewage system as a result of accidental leaks. These wastes commonly have a high water content, which increases their freight costs and makes their treatment difficult.
One alternative for treating this kind of waste is its co-digestion with wastewater treatment plant (WWTP) sludge, which neutralises the waste while producing biogas.
Spain has an available potential of 49.7 million tonnes/year of agri-food industry waste that could be used to generate 2 600 million m3/year of biogas, equivalent to 4.2% of Spain's annual natural gas production.
OBJECTIVES
The LIFE ECOdigestion project would generate biogas by streamlining the co-digestion of agri-food industry waste and wastewater in a WWTP. The project would deploy in the WWTP an innovative waste dosage control technology applied in anaerobic digesters.
This new technology would also allow continuous measurement of the quantity and composition of the biogas that is generated, yielding better results through optimised digestion of both waste and sludge. Onsite energy production would also minimise freight costs.
The project will design and install two prototypes: one with the new dosage and measuring technology; and one with conventional technology. In this way the new technology can be compared to the conventional approach.
RESULTS
The LIFE ECOdigestion project team demonstrated the feasibility of the co-digestion of wastewater treatment plant (WWTP) sludge and agrifood wastes, by increasing the amount of biogas produced. Moreover, thanks to the ECOdigestion software developed, the production of biogas can be adapted to the energy demand curve of the WWTP.
Taking into account the additional costs for the operation of the system, the software maintenance and the savings from the natural gas purchase, it was calculated that the overall balance of the ECOdigestion system shows a benefit of €50 675 per year.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
