Throughout the project, significant advancements were made. A comprehensive evaluation of new composite electrolytes integrating various proton conducting and oxide ion conducting phases was made generating knowledge on stability, conductivity and hydration properties of these compounds. Electrode materials were optimised to operate at T ≤ 450ºC by adjusting their composition and microstructure. Hybrid catalysts for direct CO2 reduction to jet fuel hydrocarbons via the reverse water gas shift and Fischer-Tropsch synthesis route were successfully developed for operation at 400ºC. A two-step process was also validated to match the operation of the catalysts and the electrochemical cell, coupling direct CO2 reduction with an oligomerization step to produce jet fuel with higher yields and adjusted aromatics content.
The project expanded know-how on producing tubular cells with various BZCY-based electrolyte compositions and tubular cells integrating oxide ion electrolytes. Microwave sintering protocols were also developed to densify BZCY based electrolytes.
The validation phase focused on demonstrating operation of electrochemical reactors in pressurized operation up to 30 bar, using single tubular cells. This resulted in the successful electrochemical validation of complete cells with different electrolyte stoichiometries, demonstrating methanation and the co-electrolysis reaction to produce syngas under targeted conditions. The prototype testing phase involved adapting a multi-tube reactor for operation under eCOCO2 conditions, emphasising automation and safety aspects. Successful commissioning of the reactor and tests using protonic tubular cells were conducted.
Concurrently, processes within targeted industries were identified and defined in specific scenarios within the process engineering phase. Detailed CO2/steam feed flow characterization, flow diagrams, and potential integration assumptions for eCOCO2 technology were developed. The screening methodology identified key cost drivers for CAPEX and OPEX, indicating that further technology developments could enhance economic viability. Life Cycle Assessment indicated climate change reductions when using renewable electricity in the studied industrial scenarios. The societal perception studies conducted indicated a growing acceptance of CO2-based aviation fuel, positive attitudes towards innovative solutions for addressing climate change, and a preference for CO2-based fuels over conventional alternatives.
It is also worth highlighting the high participation in the project's communication channels, over 100 communications at events, 8 scientific publications, training activities, and academic initiatives. Finally, the results of eCOCO2 underline the viability and strategic significance of the proposed technological scale-up, emphasizing modular design, continuous reactor operation, thermal integration and strategic process integration as key elements for achieving efficient CO2 emission reduction in industrial sectors.
