H2NEXUS

Integration of Renewable Hydrogen, Biogas and E-Fuels

H2NEXUS explores the integration of green hydrogen and CO₂ contained in biogas, assessing different technologies for the production of synthetic fuels and intermediate molecules.

The main technological pathways under investigation include the production of methanol, olefins and ethanol through processes powered by renewable energy.

Each solution is assessed in terms of technological performance, energy efficiency, costs and environmental impact, with the aim of identifying potential pathways for the industrialisation and valorisation of existing biogas plants.

Technical Description

H2NEXUS investigates an integrated energy value chain based on the combined valorisation of renewable hydrogen and CO₂ contained in biogas generated through waste treatment.

Hydrogen is produced through water electrolysis powered by renewable electricity and is subsequently used as a reactant in synthesis processes. At the same time, the CO₂ present in biogas is considered a carbon resource to be recovered and valorised for the production of new energy carriers.

The project investigates three main technological pathways:

• production of methanol from CO₂ and green hydrogen

• production of olefins from CO₂ and hydrogen or through biogas reforming integrated with H₂

• electrochemical production of ethanol from CO₂ and water using renewable electricity directly

The different configurations are assessed through modelling, feasibility studies and comparative analysis without the construction of a physical demonstration plant. The aim is to identify technically feasible and potentially industrialisable solutions with particular focus on the potential conversion and valorisation of existing biogas plants.

Considering the entire process chain, the project analyses a flexible operating model capable of using renewable electricity during periods of higher availability or lower cost to power electrolysers and electrochemical systems while relying on biogas-based cogeneration under different operating conditions.

The research activities also include the study of selective membranes for water removal in methanol and olefin synthesis processes with the aim of improving reaction conditions and increasing conversion yields.

The H2NEXUS approach therefore enables the assessment not only of individual technologies but of the entire H₂–CO₂–e-fuel value chain, identifying the most promising configurations from a technical, energy, economic and environmental perspective.

The expected outcome is the development of a technical and scientific basis and an industrialisation roadmap aimed at developing more flexible, efficient and integrated energy systems capable of simultaneously valorising renewable energy sources, biogas and CO₂ within new circular economy models.