## 4 Summary and Conclusions  
This study investigated the potential of a novel La-Fe-based oxygen carrier with thermodynamic properties that enable the partial oxidation of natural gas with integrated CO\({}_{2}\) capture. Such an oxygen carrier can avoid the equilibrium limitations restricting conventional catalytic methane reforming and facilitates direct hydrogen production via the water-splitting reaction. In addition, it can alleviate safety concerns related to the toxicity of Ni-based reforming catalysts. The benefits facilitated by these features were quantified and compared to three benchmarks: conventional steam methane reforming (SMR), SMR with conventional CO\({}_{2}\) capture (pre-combustion MDEA absorption), and the gas switching reforming (GSR) process using a Ni-based oxygen carrier. In terms of equivalent H\({}_{2}\) production efficiencies, it was shown that the novel gas switching partial oxidization (GSPOX) process achieved mild benefits relative to the GSR concept (of around 0.6%-points for the case with reactor operating pressure of 32.7 bar). Even though GSPOX could convert methane with a much lower steam requirement, a similar amount of steam as in GSR is needed in the subsequent water-gas shift reactors to maximize hydrogen production. Next, the possibility of designing the GSPOX plant for H\({}_{2}\) and power co-production was investigated. A semi-pure H\({}_{2}\) fuel stream can be produced for extra firing; to heat the depleted air stream from the GSPOX oxidation step outlet temperature to the gas turbine firing temperature for high-efficiency power production. Thus, the cluster was integrated into combined power cycles with two different firing temperatures, representative of two GT technology levels. In terms of equivalent H\({}_{2}\) efficiencies, the Current and Advanced GT configurations were 4.5 and 0.9%-points below the unabated SMR benchmark, respectively, but both plants achieved equivalent CO\({}_{2}\) avoidance of 140% because of considerable low-carbon electricity exports. When an NGCC plant with CO\({}_{2}\) capture was taken as reference for imported/exported electricity, CO\({}_{2}\) avoidance was approximately 100% with equivalent H\({}_{2}\) production efficiencies 0.7 and 4.8%-points higher than the SMR benchmark. Figure 17: Equivalent CO\({}_{2}\) emissions and SPECCA indexes of the H\({}_{2}\)-power production processes for electricity generation reference plants with and without CO\({}_{2}\) capture. In comparison to the GSR technology with Ni-based oxygen carriers, the GSPOX process in H2 mode shows mild improvements that increase with pressure. When operated at 40 bar, the GSPOX-H2 plant achieves 1.5%-points higher equivalent H2 production efficiency than GSR with similar CO2 avoidance. The combined power and H2 GSPOX configuration with the Advanced gas turbine can increase this benefit to 4.1%-points when exported electricity is assumed to displace NGCC power production with CO2 capture. However, such an efficient power cycle requires a large gas turbine that will lead to a plant with a very high hydrogen output, which will only be feasible when a large hydrogen market is established. When a smaller and less efficient gas turbine is used, the GSPOX co-production plant offers no efficiency benefits relative to GSR. However, such a smaller plant will be a good option for independent clean power and hydrogen supply to an industrial cluster. To conclude, the successful development of a GSPOX oxygen carrier can further increase the efficiency gains promised by GSR, producing clean \"blue\" hydrogen at a higher efficiency than carbon-intensive \"grey\" hydrogen from steam methane reforming. These gains increase when the system can be operated at very high pressures or market conditions allow for the construction of large, combined power and hydrogen plants. When factoring in the avoidance of toxicity concerns related to Ni-based oxygen carriers needed in GSR to catalyze the reforming reaction, further development of these novel oxygen carriers can be safely recommended.