Neuling, UlfUlfNeulingBullerdiek, NilsNilsBullerdiek2025-01-142025-01-142025In: Powerfuels : Status and Prospects / edited by Nils Bullerdiek, Ulf Neuling, Martin Kaltschmitt. - 1st ed. 2025. - Cham : Springer Nature Switzerland ; Cham : Imprint: Springer, 2025978-3-031-62411-7https://tore.tuhh.de/handle/11420/53218The fight against climate change to limit global warming is one of the biggest challenges of mankind. Therefore, strict decarbonization efforts within all areas of our society are necessary. This is also seen by international governments, resulting in strict national and international climate protection policies. Besides the energy sector, the transport sector is responsible for the second largest share of global emissions. Today, transport accounts for around 30% of the annual greenhouse gas emissions in the EU-27, of which road transport accounts for more than two-thirds (about 72%). A vast consensus within politics, science, and industry sees direct electrification as the most efficient and cheapest solution to reduce emissions. However, in hard-to-abate sectors like aviation or maritime transport, where direct decarbonization is difficult, reducing greenhouse gas emissions is particularly challenging. Partly, this is due to the reliance on energy-dense fuels and long operational lifetimes of aircraft and vessels. For these transport modes, a defossilization based on renewable electricity is only possible indirectly via synthetic fuels, so-called Power-to-X (PtX) fuels. Against this background, feasible areas of application as well as general technical aspects of PtX fuels are described in this article. A subsequent classification of Power-to-X products based on the hydrogen rainbow and potential carbon sources is presented. According to this, the combination of biogenic or atmospheric CO2 with green hydrogen shows the highest climate mitigation potential. However, other CO2 and low-carbon hydrogen sources may be a short-term option that is required for a timely ramp-up of PtX production capacities if strict sustainability and environmental protection measures are taken.enCarbon Sources | Efficiency | Hydrogen Sources | Powerfuels | SustainabilitySocial Sciences::333: Economics of Land and Energy::333.7: Natural Resources, Energy and EnvironmentBook part10.1007/978-3-031-62411-7_18Other