# Techno-Economic Potential of Plasma-Based CO\({}_{2}\) Splitting in Power-to-Liquid Plants
## 4 Results
### Sensitivity Analysis
If the optimized GDE current densities of S2050 (\(i\big{(}x_{O_{2}}=21\%\big{)}=200\) mA/cm\({}^{2}\)) are already used in the 2018/20 scenario, the \(NPCs\) decrease from EUR 8.5/L to EUR 5.5/L. This results from a decrease in GDE \(CAPEX\) from >900 Mio EUR to <200 Mio EUR. On the other hand, if in the 2050 scenario the GDE performance is not optimized as assumed and is according to the performance of S2018/20, the NPC increase from EUR 3.8/L to EUR 6.8/L, resulting from an increase of the GDE \(CAPEX\) from 200 Mio EUR to 1300 Mio EUR. The recycle streams were also varied. In Table 9, the main parts of the \(NPC\) as well as the process efficiency of scenarios 2018/20 and 2050 are shown without the use of recycle streams. The \(NPC\) are 1.7 times bigger than the scenario values with recycle streams. \begin{table}
\begin{tabular}{l l l} \hline \hline  & **S2018/20 without Recycle** & **S2050 without Recycle** \\ \hline \(NPC_{ACC}\) in EUR/L & 5.04 & 1.08 \\ \(NPC_{OPER,dir}\) in EUR /L & 6.53 & 4.70 \\ \(NPC_{OPER,ind}\) in EUR /L & 3.03 & 0.68 \\ \(NPC_{ALC}\) in EUR /L & 0.05 & 0.04 \\ \(NPC\) in EUR /L & **14.65** & **6.50** \\ \(\eta_{process}\) & 11\% & 16.4\% \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Results (net production costs \(NPC\) and process efficiency) using no recycle streams. Figure 12: Development of power distribution by increasing the energy efficiency of the plasma-based CO\({}_{2}\) splitting (300 MW total). The reduced yield decreases the process efficiency and increases the costs significantly. This results mainly from the recirculation around the FTS reactor, which is why a rate of 0.9 was also chosen in all scenarios. Recirculation around the plasma increases the absolute conversion of CO\({}_{2}\) to CO, but the capital costs increase significantly. Since CO\({}_{2}\) behaves inerth in the FTS reactor, the present ratio between CO\({}_{2}\) and CO has no major influence. In further sensitivity analyses, different plant sizes were compared. In Figure 13, for scenario 2018/30 and scenario 2050, the parts of the \(NPC\) are shown for a 300 MW and a 3 MW plant. It is obvious that the \(NPC_{ACC}\) are rising because of the used cost functions and the lost of economy of scale. Based on the hourly share of renewable energy and the corresponding average price per MWh in the European Union, a correlation between these factors could be identified [45]. A high share of renewable energy sources, such as wind and PV, reduces the cost of electrical energy significantly. In the study of ICCT from the year 2020, different scenarios for electricity prices from renewable energies in future were defined [52]. They differ in terms of the generation and transmission of energy. The scenario in which just the generation is observed, so that the user is directly connected to the renewable energy plant, results in electricity costs of \(c_{e}=\) EUR 25/kWh. Because of the flexible operating of plasma-based processes, the reactors could fit with these scenarios. The BEniVer also conducted research and defined scenarios with different electricity prices. The values are shown in Table 10. All mentioned electricity costs are marked in the diagrams shown in Figure 14. Due to the higher process efficiency, the gradients in the diagram for the GA plant are significantly lower. \begin{table}
\begin{tabular}{l c c} \hline \hline  & **Minimum Value \(\epsilon_{e,min}\)** & **Maximum Value \(\epsilon_{e,max}\)** \\ \hline S2018/20 & EUR 55.7/MWh & EUR 86.6/MWh \\ S2030 & EUR 66.3/MWh & EUR 106.7/MWh \\ S2050 & EUR 40.9/MWh & EUR 81.3/MWh \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Specific electricity cost minimum and maximum values for the different scenarios, set by BEniVer. Figure 13: Comparison of net production costs (NPC) of different plant sizes for S2018/20 and S2050.