## 3 Results and Findings from the Existing Literature
### Techno-Economic Analysis (TEA)
The study revealed promising results, particularly with the modelled Fischer-Tropsch process achieving a 99% carbon conversion rate through the recycling of CO\({}_{2}\) and oxycombustion, with a process energy efficiency of 70%. MFSP values were calculated at 0.95 USD/L, 0.74 USD/L, and 0.70 USD/L of FT fuel mix for nuclear power plant capacities of 100, 400, and 1000 MWe, respectively. The study revealed a high sensitivity of SAF costs to electricity and DAC expenses. A TEA was conducted by [PERSON] et al. [56], who utilised thermodynamic and economic analysis methods. The focus was on biogas-to-methanol conversion, where biogas was purified using water washing. Hydrogen was produced from a PEM electrolyser powered by solar PV. A hybrid system was then employed to produce methanol. The study concluded that the power required for methanol production was 2923 kW, predominantly sourced from the PEM system. Daily methanol production was found to be 1674 kg, with the associated costs for electricity, hydrogen, and methanol being 0.043 USD kWh\({}^{-1}\), 3.156 USD kg\({}^{-1}\), and 0.693 USD kg\({}^{-1}\), respectively. The process was found to have feasible methanol production costs with reasonable investment prospects. An analysis of the future context of e-fuels in Europe was conducted by [PERSON] and [PERSON] [28] with respect to their safety, environmental implications, societal acceptance, and regulatory barriers. The institutional economics theory was used to analyse the environmental governance system framework around the implementation of carbon capture and utilisation (CCU) and e-fuels. The economic assessment highlighted the potential economic benefits and challenges associated with H\({}_{2}\)-based e-fuel production methodologies. A comprehensive techno-economic assessment was carried out by [PERSON], [PERSON] [57] for a power-to-fuel plant designed to produce e-methanol from green hydrogen and captured CO\({}_{2}\). The study served as a pre-feasibility analysis for a facility aiming to produce 500 kg/h of renewable methanol. The resultant levelised cost of methanol (LCoM) was found to be 960 USD/t (about 175 USD/MWh). Although currently not economically competitive, prospects indicate potential economic viability due to shifting European policies. The PESTEL analysis, which concentrated on diverse economic, technological, and environmental factors, emphasised the potential of blue hydrogen as an economically viable short-term solution. Insights revealed the influential variables on synthetic fuel pricing and their intertwined relationships [58]. A technical and economic analysis focused on the potential of waste-to-methanol and power-to-methanol processes, conducted by [PERSON], [PERSON] [59]. The feasibility study highlighted the innovation of combining the power-to-methanol process with MSW (municipal solid waste) gasification as aligning with energy transition and circular economy principles. The anticipation of an increase in renewable power soon could render the hybrid method more economically appealing. In 2020, [PERSON], [PERSON] [60] presented key techno-economic indicators for the production of power-to-liquid (PtL) kerosene. They employed DAC and electrolysis methodologies using CO\({}_{2}\) and water as feedstock. The study emphasised the significant impact of local CO\({}_{2}\) sources on PtL. There is a projection of a need for an additional 48-745 TWh of renewable electricity for scenarios spanning 2030-2050. Notably, the average fuel production costs are expected to range from 2.3 to 3.3 USD/kg in 2030, decreasing to 1.8-3.1 USD/kg by 2050. The research highlighted the importance of sustainable CO\({}_{2}\) sources and the achievement of renewable electricity development targets. Furthermore, in 2023, Italy underwent a comprehensive technical and economic analysis of producing synthetic kerosene from green H\({}_{2}\) and DAC CO\({}_{2}\) by [PERSON], [PERSON] [61]. Their methodology combined hydrogen derived from water electrolysis, CO\({}_{2}\) capture, RWGS, and FT synthesis.