Periodic Reporting for period 1 - DARE2X (Decentralised Ammonia production from Renewable Energy utilising novel sorption-enhanced plasma-catalytic Power-to-X technology)
Okres sprawozdawczy: 2022-10-01 do 2024-03-31
The main challenges for realising European green NH3 production is to transition away from fossil fuel-based, centralised Haber-Bosch facilities, to decentralised, dynamic systems that can be coupled directly to renewable electricity generators at or near the point of use. This does, however, require significant developments. DARE2X will overcome these barriers through the following game-changing solutions: (i) reactors utilising non-thermal plasma to drive NH3 synthesis; (ii) novel, more active catalysts using low-CRM materials, iii) stable and efficient NH3 sorption materials for in-situ NH3 separation. These innovations will be integrated into a single sorption-enhanced plasma-catalytic device that will be validated at TRL4. The economic, environmental and social feasibility will be assessed through LCA, LCC and a social acceptance study.
The DARE2X main objectives are listed below:
MAIN OBJECTIVE 1: Development of highly efficient catalysts and sorption materials, to provide means of converting renewable H2 into NH3 at ambient conditions, and effectively col-lect/separate NH3 while promoting a higher system efficiency, respectively.
MAIN OBJECTIVE 2: Development of a novel sorption-enhanced reactor using plasma-catalytic technology, with a scalable design. The integration of sorption materials will allow the im-mediate separation of the produced NH3. This single stage configuration will be evaluat-ed in comparison with the competitive efficiency levels of the industrial Haber-Bosch process. NH3 synthesis will have target operation conditions of 30 °C and 1-3 bar, powered directly by an electricity supply, and therefore compatible with green renewable sources.
The technical development in the project of catalyst, sorption materials and plasma reactors, are complemented by environmental, economical and social acceptance assessments. These assessments feed back into the technical development to take environmental, economic and social considerations into account when developing the technology.
Several catalysts have been synthesized and tested in the plasma reactor. Based on the computational screening and literature, catalyst materials based on Ru, Ni, Co, Pt, Cu was synthesized on different supports and tested in the plasma reactor. Ni and Co based catalyst showed the highest activity, but the effect of the support turned out to be more significant than the active metal for the catalyst activity. Catalyst supported on zeolites had much higher activities than catalyst supported on alumina and carbon. Our catalyst KPI was reached with a catalyst activity of >2100 μmolNH3·gcat.-1·h-1, in a lab-scale reactor system (1 bar, 30 °C, 16 W, 20 ml*min-1).
Different zeolites were tested for ammonia adsorption and characterized for physisorption and chemisorption. For this application the physisorption capacity is more important as we aim for a material that can adsorb/desorb without large temperature swings. The goal is to develop sorption materials that can be integrated into the reactor bed and also sorption material for a separate sorption unit that can separate the ammonia without condensation. For this purpose, the best performing sorption materials have been tested for both pressure and temperature swing adsorption where pressure swing would be the optional as the plasma reactor works at ambient conditions.
Plasma technology: A scalable coaxial dielectric barrier discharge (DBD) reactor was built for plasma-catalytic ammonia production. This was used for testing the catalytic materials developed in the project. Using the best catalyst it was possible to reach an NH3 yield of 2.4% at ambient conditions.
The identification of the most effective sorption materials in the low-temperature region <100 °C is an improvement upon state-of-the-art in the field. Furthermore, considerations about how these sorption materials could be implemented in the prototype system were started, with the aim to identify the most efficient NH3 separation approach at low temperature and pressure. The impact of the sorption material development in DARE2X is to enable efficient NH3 separation also at lower concentrations and pressures, where state-of-the-art condensation would be far too inefficient. This is key for efficient NH3 plasma-catalytic synthesis.
A key DARE2X innovation beyond state-of-the-art is the combination of plasma catalysts and sorption materials into the same overall material. By sorbing produced NH3 already inside the plasma reactor, the reverse reaction of plasma-induced decomposition will be mitigated. As elaborated in the above points, supporting the active catalyst on sorption material results in the best steady-state activity. The dynamic operation of combined catalyst/sorption materials also including the sorption/desorption of NH3 is a key focus point for the second half of the project, and is expected to yield further performance enhancements.
The novel plasma reactor designed for NH3 synthesis described above goes beyond state-of-the-art, along with optimisation of operating parameters and reactor configuration. This work will continue throughout the integration and prototyping stage in the second half of the project.