# Techno-Economic Potential of Plasma-Based CO\({}_{2}\) Splitting in Power-to-Liquid Plants
## 3 Methodology
### Boundary Conditions  
For the modeling and techno-economic analysis, different boundary conditions were assumed. Some of the parameters are varied within the chosen scenarios and sensitivity analyses. In Table 2, general plant parameters are shown first. These were selected in the PlasmaFuel joint project in consultation with BEniVer and were also included in the current model. In Table 3, important technical parameters are listed, which were chosen in the modeling. In some cases, technical parameters were varied. This was due to the differentiation of various scenarios. The current state of the art is represented by the 2018/20 scenario, and the 2030 and 2050 scenarios were defined for an outlook. Assumptions were made for the outlook of the performance of the dielectric barrier discharge (DBD) and gliding arc (GA) plasma technologies. Information on temperature and pressure levels has already been given in the modeling text sections, so the table values are mainly about efficiencies. Other important technical boundary conditions related to the recycle streams. The parameters regarding recycle streams were chosen the same in all scenarios. A mass fraction of 0.9 was selected for the return of the residual gas to the FTS. For the return after the GDE back to the plasma reactor inlet, a mass fraction of 0.5 was selected. \begin{table}
\begin{tabular}{l l} \hline \hline
**Plant Parameter** & **Value** \\ \hline Electric power input & 300 MW \\ Plant location & Germany \\ Plant lifetime & 20 years \\ load & 8000 h/year \\ Interest rate & 5\% \\ Labor cost & EUR 41/h \\ workforce & 2 + 4/2 (300 MW), \\ \multicolumn{2}{l}{1/3 (3 MW)} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Plant parameters. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Component** & **Parameter** & **Value** & **Reference** \\ \hline \multirow{2}{*}{Electolysis} & \multirow{2}{*}{efficiency} & 75\% (S2018/20), 80\% (S2030) & [45] \\  & & 90\% (S2050) & \\ \hline \multirow{4}{*}{DBD-plasma-reactor} & \multirow{2}{*}{CO\({}_{2}\) conversion} & 26\% (S2018/20), 30\% (S2030) & [38], assumptions \\  & & 40\% (S2050) & \\ \cline{2-3}  & & 23 (S2018/20), 30 (S2030) & [38], assumptions \\ \cline{2-3}  & & 40 (S2050) & \\ \hline \multirow{4}{*}{GA-plasma-reactor} & \multirow{2}{*}{CO\({}_{2}\) conversion} & 27 (S2018/20), 35 (S2030) & [41], assumptions \\  & & 45 (S2050) & \\ \cline{2-3}  & & 43 (S2018/20), 45 (S2030) & [41], assumptions \\ \hline \multirow{2}{*}{GDE} & \multirow{2}{*}{Current density at 21\% oxygen} & 25 mA/cm\({}^{2}\) (S2018/20) & \\  & & 100 mA/cm\({}^{2}\) (S2030) & Experimental, assumptions \\  & & 200 mA/cm\({}^{2}\) (S2050) & \\ \hline FTS reactor & CO conversion & 50\% & PlasmaFuel \\ \hline Compressors & Isentropic efficiency & 80\% & PlasmaFuel \\ \hline Turbines & Isentropic efficiency & 80\% & PlasmaFuel \\ \hline Pumps & Isentropic efficiency & 80\% & PlasmaFuel \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Important technical parameters of the modeled components. In addition to the technical parameters, economic boundary conditions must also be set. Table 4 shows cost functions applied in the model and factors used for adjustment via \(CEPCI\) and for calculating fixed costs. For this purpose, a factor \(F_{FCI}=FCI/EC\) was defined, which was calculated from the factors \(F_{j}\). The factors were selected based on [PERSON] et al. and [PERSON] et al. and adjusted for the plasma reactors, electrolysis, and GDE [12; 47]. This adjustment was carried out within the framework of the accompanying study BEniVer and applied in the joint project PlasmaFuel. In addition to the Factors shown in the Table, material and pressure factors were considered for a few of the components. For pumps and compressors, a material factor of 2.4 for stainless steel was applied; for heat exchangers in the high-pressure section, a pressure factor of 1.16 was applied; and for a turbine located at the purge expansion, a material factor of 5.1 for Ni-coating was applied.