ENEDAR

The ENEDAR project arises from the need to transform wastewater treatment plants (WWTPs) into energy-efficient and resilient infrastructures through the development of technologies that maximize the performance of anaerobic digestion (AD) of WWTP sludge, and obtain value-added products (energy and biofertilizers) in a profitable way, ensuring the sustainability of the water sector in a context of economic crisis and climate emergency.

The project includes a laboratory phase to determine the operating conditions that will later be implemented at a pilot scale. The processes ENEDAR focuses on are anaerobic digestion, biogas purification, and digestate treatment wetlands (DTW), developing and utilizing innovative materials and processes: Fe nanoparticles encapsulated in carbon (OPS), photoacoustic sensors for volatile fatty acids (VFAs) and CH₄, and cost-efficient physicochemical processes for biogas purification. Additionally, a cost-efficient cogeneration system will be implemented to utilize the energy from the produced biogas and biomethane.

The pilot will consist of:

• An anaerobic digester operated with OPS and a photoacoustic sensor for VFAs and CH₄ to control possible inhibitions due to VFA accumulation and CH₄ reduction in biogas in real time.
• A cost-efficient physicochemical biogas purification process for the simultaneous removal of CO₂ and H₂S, obtaining biomethane with a composition of CH₄ > 95%, CO₂ < 2%, and elemental sulfur as a byproduct.
• A nature-based solution for the stabilization (mineralization of volatile matter and dehydration) of AD digestate, consisting of a DTW to obtain a biosolid that is 50% mineralized and dehydrated.
• An energy utilization system for biogas and biomethane (85% efficiency) that contributes to improving the resilience and energy efficiency of the WWTP, reducing the normalized cost of electricity and heat production while offsetting biomethane generation.

In addition to the operation and optimization of the innovative pilot for WWTP sludge valorization, the ENEDAR project will develop a biofertilizer formulation protocol based on the biosolid obtained in the DTW, testing its agronomic potential.

Execution period: 2022-2025

Partners: FACSA, SMALLOPS, GENESAL, UVa, and AIMEN

Funding: Project CPP2021-008427 funded by MCIN/AEI /10.13039/501100011033 and the European Union NextGenerationEU/PRTR