# Techno-Economic Potential of Plasma-Based CO\({}_{2}\) Splitting in Power-to-Liquid Plants
## 5 Discussion--Techno-Economic Potential  
The results of the individual scenarios show that the plasma-based CO\({}_{2}\) splitting does not quite reach the values of the Concawe study on the PTL plants with RWGS. In order to get an overview of which combinations of efficiency and conversions go into which cost areas of \(NPC\), the diagrams shown in Figures 15 and 16 were created. The figure shows the \(NPC\) over the conversion \(\chi_{CO_{2}}\) as well as the efficiency \(\eta_{CO_{2}}\) of plasma-based CO\({}_{2}\) splitting. For the diagram in Figure 15, other boundary conditions are taken from the 2050 scenario that are important for the overall efficiency are, e.g., \(\eta_{EL}=90\%\) and a higher-performing GDE in terms of current density. Figure 14: Net production costs (NPC) by varying the electricity cost. The solid vertical line shows the assumption made in the results of the scenarios. The dotted vertical line that of the ICCT scenario described in the text. Figure 15: Net production costs (NPC) as a function of CO\({}_{2}\) conversion and energy efficiency; \(\eta_{EL}=90\%\), high-performing GDE. At low values of both \(\eta_{CO_{2}}\) and \(\chi_{CO_{2}}\), unilateral optimization does not have a large impact on the overall performance and, thus, on the NPC. Until the line highlighted in orange at EUR 5/L, there is a high slope of the cost development. This limit can be undercut when reaching \(\eta_{CO_{2}}=\chi_{CO_{2}}=25\%\). To reach the value of the fuel costs determined in the Concave study, conversions and efficiencies must be developed to a level above the red line shown [10]. To get below this cost, efficiencies of at least 45% and revenues of at least 40% must be achieved. By optimizing the GDE and using more efficient compressors and pumps, the efficiency can theoretically be further increased and, thus, \(NPC<\) EUR 2.4/L can also be achieved. If the efficiencies of the compressors, turbines, and pumps increase from 80% to 85%, the process efficiency increases by \(\Delta l_{process}=0.1\%\), which enables an \(NPC\) minimum of EUR 2.2/L. Further cost savings are only feasible through more energy-efficient oxygen separation. As already shown in the sensitivity analysis, a larger plant capacity leads to a decrease in fuel costs. The PTL plant considered in the Concave study delivers 1 million tons of product per year (here considered case: <50,000 t), based on the boundary conditions mentioned in the appendix, which leads to the conclusion that the input capacity is significantly larger. As a result, further NPC decreases can be expected if the dimensions are adjusted. With the supposed development potential of the DBD reactor of \(\chi_{CO_{2}}=\eta_{CO_{2}}=40\%\), we get between the two lines shown, thus, a value of EUR 3.8/L can be reached with assumed boundary conditions and electricity costs. For the GA reactor, we suppose a development potential to \(\chi_{CO_{2}}=45\%\) and \(\eta_{CO_{2}}=50\%\), thus coming closer to the red line with \(NPC=\) EUR 3.5/L. Both reactors reach an equal range of NPC under the scenario assumptions made. Looking at the current state of the research, the values are more in favor of using GA plasma in CO\({}_{2}\)-only splitting, as all high-performing DBD reactors do not get above the orange line. The additional capital costs that arise are not considered or offset as in the scenarios via better heat utilization. If other boundary conditions are set to those of scenario 2018/20, the result shown in Figure 16 is achieved. Thus, it is assumed that the electrolysis, as well as the GDE, do not receive any further development. The minimum \(NPC=\) EUR 5.5/L can be seen in the figure as a worst case. Considering the change in power distribution to the main processes plasma and electrolysis and  
Figure 16: Net production costs (NPC) as a function of CO\({}_{2}\) conversion and energy efficiency; \(\eta_{EL}=75\%\), bad-performing GDE.