###### Abstract  
The hydrogen economy has received resurging interest in recent years, as more countries commit to net-zero CO\({}_{2}\) emissions around the mid-century. \"Blue\" hydrogen from natural gas with CO\({}_{2}\) capture and storage (CCS) is one promising sustainable hydrogen supply option. Although conventional CO\({}_{2}\) capture imposes a large energy penalty, advanced process concepts using the chemical looping principle can produce blue hydrogen at efficiencies even exceeding the conventional steam methane reforming (SMR) process without CCS. One such configuration is gas switching reforming (GSR), which uses a Ni-based oxygen carrier material to catalyze the SMR reaction and efficiently supply the required process heat by combusting an off-gas fuel with integrated CO\({}_{2}\) capture. The present study investigates the potential of advanced La-Fe-based oxygen carrier materials to further increase this advantage using a gas switching partial oxidation (GSPOX) process. These materials can overcome the equilibrium limitations facing conventional catalytic SMR and achieve direct hydrogen production using a water-splitting reaction. Results showed that the GSPOX process can achieve mild efficiency improvements relative to GSR in the range of 0.6-4.1%-points, with the upper bound only achievable by large power and H\({}_{2}\) co-production plants employing a highly efficient power cycle. These performance gains and the avoidance of toxicity challenges posed by Ni-based oxygen carriers create a solid case for the further development of these advanced materials. If successful, results from this work indicate that GSPOX blue hydrogen plants can outperform an SMR benchmark with conventional CO\({}_{2}\) capture by more than 10%-points, both in terms of efficiency and CO\({}_{2}\) avoidance. H\({}_{2}\)-power cogeneration; gas switching partial oxidation; gas switching reforming; CO\({}_{2}\) capture and storage; steam methane reforming; blue hydrogen +
Footnote †: journal: Applied Sciences
Using an excess of renewable energy to produce H2 from water electrolysis (\"green hydrogen\") is a promising pathway avoiding CO2 emissions, as suggested by [PERSON] et al. [6]. [PERSON] et al. carried out a techno-economic assessment of an electrolyzer with direct renewable electricity supply achieving a minimum cost of 4.33 \(\upxi\)/kg of H2 when powered with the onshore wind [7]. However, 95% of the total H2 produced is currently originated from fossil fuels and the traditional pathway through natural gas reforming with steam (SMR), is responsible for approximately 50% of the total H2 production. Furthermore, it will remain more cost-effective when integrating CCS technologies (\"blue hydrogen\") in several world regions [2]. For example, natural gas exporting regions like Norway can achieve an approximately 1 \(\upxi\)/kg lower-levelized cost of H2 with CCS than electrolysis [8]. In addition, this comparison does not account for the cost of intermittent hydrogen production from electrolyzers powered by wind and solar power, which adds substantial further costs, increasing the gap between blue and green hydrogen even for natural gas importers like Germany, as assessed by [PERSON] et al. [9]. If significant fossil fuel-based electricity generation is still on the grid, certification of green hydrogen production can be challenging. Some studies indicate the low development prospects of green hydrogen in the short term [10]. Nonetheless, blue hydrogen faces a relatively high energy penalty compared to the unabated process that results in large CO2 avoidance costs (100 \(\upxi\)/ton), well above the actual emissions tax, as reported by [PERSON] et al. [11]. [PERSON] et al. revealed that SMR with shifted syngas CO2 absorption is the most cost-effective pathway for CO2 abatement in H2 production processes from natural gas with currently deployable technology [12].