CARMA-H2 will enable highly attractive hydrogen production from biogas through demonstration of a protonic membrane reformer (bioPMR) that integrates steam methane reforming and water-gas shift reactions, hydrogen separation, heat management, CO2 capture and hydrogen compression in a single stage. The realization of 6 process steps in a single reactor allows to achieve unprecedented energy efficiency with a project target to demonstrate >85% (HHV) at the bioPMR level.
The bioPMR technology enables direct delivery of purified and pressurized H2 (30 bar). BioPMR will be coupled with CO2 liquefaction to enable direct production of food-grade CO2. Coupling the liquefaction unit allows for higher hydrogen recovery and liquid CO2 production as the off-gas from the liquefaction process will be recycled back to the bioPMR unit. CARMA-H2 will demonstrate the bioPMR technology integrated with CO2 liquefaction at the existing Arazuri wastewater treatment plant in the region of Navarra in Spain. The demonstration plant will be operated for at least 4000 h, and produce 500 kg/day of hydrogen and above 4000 kg/day of food-grade CO2.
To facilitate the demonstration CARMA-H2 will install
- a pre-treatment system for biogas compression and removal of sulphur and other impurities,
- two bioPMR modules which will operate directly on biogas (CO2 > 40 vol.%), and
- an integrated CO2 liquefaction unit.
The demonstration plant will be located in Ebro Valley Hydrogen Corridor, and the project aims to secure off-take of the produced hydrogen and liquid CO2 during operation. The overall system will be controlled and analysed by an advanced control system and an associated digital twin that will be developed in the project. The wastewater plant is currently operating a biogas production plant of >4 MW from which the biogas is utilized for power generation.
The achievements in CARMA-H2 will be an important proof of technological feasibility advancing the technology from TRL5 to TRL7.
SINTEF’s role in the project is to evaluate the durability of the hydrogen membrane towards impurities present in biogas, with particular focus on H2S.
