# Techno-Economic Potential of Plasma-Based CO\({}_{2}\) Splitting in Power-to-Liquid Plants
## 1 Introduction  
Mitigating climate change requires the development of technologies that combine energy and transport sectors. One of them is the production of sustainable fuels from electricity and carbon dioxide via power-to-liquid (PtL) processes. As one option of splitting CO\({}_{2}\), plasma-based processes promise a high potential due to their flexibility, scalability, and theoretically high efficiencies. The use of renewable energies to operate the traffic and transport sector plays an important role due to the high energy requirements and the large part of global CO\({}_{2}\) emissions (20%) [1]. Driven by economic and political interests, renewable energies are set to become the dominant source of electricity worldwide. Based on announced pledges by governments, the global share of electricity in total final energy consumption will rise from 20 percent in 2021 to 24 percent in 2030 and up to 39 percent in 2050 [2]. According to reports of the European government, the share of renewable energy in Europe has more than doubled between 2004 and 2021 [3]. In Germany, for example, the installed electrical capacity of renewable energies was expanded from 4.4 MW in 1990 to 139 GW (46% wind, 42% photovoltaics) in 2021 [4]. New acceleration plans were also published at the beginning of 2023 to further accelerate the expansion. One target is the expansion of offshore wind power plants from 8 GW (2022) to 30 GW (2030) and then to 70 GW (2045) [5]. The goal of the expansion of renewable energies is not only the conversion of the power supply but also the electrification of various sectors, especially the transport segment andthe chemical industry. In addition to accelerating the expansion of renewable energies, the German government published a power-to-liquid (PtL) roadmap in 2021 [6]. The roadmap defines measures to enable CO\({}_{2}\)-neutral and sustainable flying. As the electrification of air traffic is hardly possible according to the current state of knowledge, this transport sector will have to rely on liquid fuels (hydrocarbons) in the long term. In the PtL roadmap, the annual use of 200,000 t of synthetic PtL kerosene is formulated as a target by 2030. This corresponds to approximately 2% of the kerosene refueled annually in Germany (as of 2019). The PtL roadmap identifies alternative syngas production as an important step toward achieving the defined targets. The consumption share of syngas for the production of chemicals is around 80%. The demand for syngas is estimated to grow approximately 5% per year with a value of \(4.21\times 10^{11}\) m\({}^{3}\) (normal cubic meters) in 2022, leading to high CO\({}_{2}\) emissions in conventional production. The main source of syngas production is coal, with a share of 50%, followed by natural gas at around 15%. Sixty percent of the production and half the consumption of syngas take place in China [7]. Since fossil fuels are finite and recent crises have shown us how quickly the price of natural gas can rise (500% percent price rise in Germany from mid-2021 to mid-2022 [8]), defossilization is a necessary step alongside electrification and decarbonization. Due to the high demand for syngas and the desire for defossilization, the question of the best-performing PtL processes is huge. In addition to the further development of individual process steps, system integration and the interaction of individual process components take on an important role. Gas separation processes for coupling, in particular, play an important role in system integration. Economically, these process steps have had a major impact, which has been investigated, for example, in the study by [PERSON] et al. on the use of selective membranes for hydrogen [9]. For better planning and further development of PtL plants, process engineering modeling and coupled analyses are indispensable. In the report \"E-Fuels: a techno-economic assessment of European domestic production and imports towards 2050\", published in 2022 by Concave [10], individual power-to-liquid plants were considered techno-economically.