TY  - CONF
AU  - Jerome, Gbenga
AU  - Dam, An Phuc
AU  - Dirkes, Steffen
AU  - Selmert, Victor
AU  - Samsun, Remzi Can
AU  - Eichel, Rüdiger-A.
TI  - DryHy: Process analysis and optimization of high temperature solid oxide co-electrolysis coupled with direct air capture for sustainable air-derived methanol
M1  - FZJ-2025-05538
PY  - 2025
AB  - Addressing the increasing CO2 emissions contributing to global climate change requires more than the transition to the use of renewable electricity. As the chemical and heavy-duty transport sectors remain dependent on carbon-based inputs, alternative fossil-free production pathways are essential. Green methanol produced from renewable sources offers a promising pathway toward a carbon-neutral economy. This approach not only facilitates the storage of excess renewable power but also offers the potential of recycling carbon dioxide. Sustainable production of green methanol requires the availability of renewable resources, negative CO2 feedstock and hydrogen sources like water. However, the geographic mismatch between renewable electricity potential and freshwater availability poses a significant challenge for green methanol production. Regions around the subtropics, which include most of Africa, offer high solar potential but often face limited freshwater availability. Therefore, it is crucial to produce green methanol using processes that avoid competition with freshwater resources. In the “DryHy” project, a process technology is developed to overcome this challenge. By combining direct air capture, which extracts water and carbon dioxide from the atmosphere, with a Solid Oxide Electrolysis (SOE) system powered by renewably generated electricity, syngas can be produced as a key intermediate for methanol synthesis. To assess the performance of this process technology, a SOE system model capable of simulating operation in co-electrolysis mode has been developed and optimized in Aspen Plus. Two different system designs were investigated, each utilizing different strategies of avoiding undesired carbon deposition: a low utilization and a high utilization design. Four key objectives were considered in the multi-objective optimization study: stoichiometric number, carbon oxide ratio, inlet water-to-carbon dioxide ratio and energy efficiency related to syngas composition and the SOE system design. The trade-offs between these objectives are analyzed to optimize the operation and performance of SOE systems in co-electrolysis mode. A comparison of the two system designs reveals that the high utilization design consistently outperforms the low utilization design for the considered objectives. In addition, a significant difference is observed in the inlet water-to-carbon dioxide ratio required to achieve the stoichiometric number needed for methanol synthesis. Subsequently, the SOE system model will be integrated with mathematical models of the direct air capture system and the methanol reactor to assess the performance and efficiency of the overall system. The comprehensive analysis of the overall air-derived methanol process will provide insight into important relationships such as how variable product gas composition from the direct air capture system affects SOE system performance and subsequently methanol production. Moreover, insights will be gained into how different system configurations and heat integration strategies can further enhance the air-derived methanol process.
T2  - International Conference on Circular Economy, Renewable Energies and Green Hydrogen in Africa
CY  - 21 Oct 2025 - 25 Oct 2025, Windhoek (Namibia)
Y2  - 21 Oct 2025 - 25 Oct 2025
M2  - Windhoek, Namibia
LB  - PUB:(DE-HGF)6
UR  - https://juser.fz-juelich.de/record/1049754
ER  -