ACCIONA leads a project to produce biomethane using surplus renewable energy

• The BIOUP project aims at enriching the biogas produced in anaerobic digestion of sewage sludge by transforming it into biomethane through the use of green hydrogen from renewable energies

ACCIONA, in line with its commitment to sustainability and innovation, coordinates the BIOUP project, "Production of biomethane by integrating surplus renewable energies into WWTP".

The objective of this project is to develop and validate a technology that generates biomethane (95% CH₄) through the biological transformation of hydrogen (H₂) produced by surplus renewable energy and carbon dioxide (CO₂) contained in the biogas (60 % CH₄) that is produced in the anaerobic digestion of sewage sludge.

BIOUP technology will enable the enrichment of the biogas produced in the anaerobic digestion of sludge towards its transformation into biomethane, a gas with properties and characteristics similar to natural gas, which will increase the efficiency of cogeneration systems and may even be injected into the preexisting gas network.

In this biogas enrichment process, green hydrogen from renewable energies will be used, taking advantage of the surplus energy generated in certain time slots. This solution will make it possible to obtain a safe and manageable energy vector, overcoming the intermittency problems of these energy sources, which in this way can be used optimally.

Together with ACCIONA, project coordinator, the BIOUP consortium brings together the University of Valladolid and CIEMAT as strategic partners, in a project funded by the Ministry of Science and Innovation through NextGeneration funds.

TECHNOLOGY ADAPTED TO THE CHARACTERISTICS OF EACH WWTP

The BIOUP project pursues the generation of biomethane in one and two stages (in situ, in the digester itself, ex situ, in trickling biofilters, or through a combination of in situ and ex situ stages) for its integration into the gas network. The final objective is to obtain biomethane with a high calorific value that improves the energy yields of the wastewater treatment plant (WWTP), and can be injected into the natural gas network if the appropriate quality is achieved.

BIOUP technology is adapted to the needs of WWTPs, which have large volumes of anaerobic digestion and an important need to increase the energy efficiency of their operation. Furthermore, BIOUP technology shows high potential to be implemented in other sectors, such as the treatment of solid urban waste, also a crucial player in anaerobic digestion.

ACCIONA, a leading company providing end-to-end water services, contributes with this project to reinforcing its commitment to sustainability, innovation and the application of the latest technologies under the umbrella of circular economy principles and low carbon footprint activities.

This publication is part of the project "Production of biomethane through the integration in WWTP of surplus renewable energy - BIOUP”, project number CPP2021-009086, financed by MCIN/AEI/10.13039/501100011033 and by the European Union-NextGenerationEU/PRTR”.