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Item type:Publication, Access status: with files , Kerosene production from power-based syngas : a technical comparison of the Fischer-Tropsch and methanol pathwayTo achieve long-term greenhouse gas (GHG) neutrality within the aviation sector, substituting fossil aviation fuels with Sustainable Aviation Fuels (SAF) derived from renewable energy sources is essential. Among the synthetic SAF options produced through Power-to-Liquid (PtL) processes, the Fischer-Tropsch (FT) and methanol pathway are of significant interest. However, to assess and compare these pathways, detailed technical process analyses are required to provide a sound basis for economic and environmental assessments. Thus, this research paper investigates and compares both SAF production pathways starting from power-derived syngas within an in-depth technical analysis, providing novel insights into overall process characteristics and efficiencies. Carbon and energy flows are derived from steady-state flowsheet simulations. A variation of technical parameters (FT pathway: FT chain growth probability and hydrocracking behavior, Methanol pathway: Dehydration olefin-selectivity and oligomerization product distribution) is carried out to assess impacts on carbon and energy efficiency, indicating uncertainties and parameter ranges for optimized kerosene production. The results show a very high carbon efficiency of the FT pathway (98 to 99%) regarding the total liquid products, while the carbon efficiency regarding kerosene lies between 60 and 77%. For the methanol pathway, a higher kerosene carbon efficiency can be achieved (60 to 90%); however, the total product efficiency (74 to 92%) is notably lower. The energy efficiencies of both pathways behave similarly to carbon efficiency, with the methanol pathway benefiting from thermodynamic advantages, leading to higher energy efficiency at equal carbon efficiency. Within the FT pathway, kerosene efficiency increases at high chain growth probabilities, while a high olefin-selectivity is crucial for efficient kerosene production within the methanol pathway. The analysis results provide comprehensive insights into the technical behavior of the overall processes which contributes to an improved understanding of the production pathways.Publicationtype: Journal ArticleScopus© Citations 2 91 237 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Hydroprocessing of fossil fuel-based aviation kerosene : technology options and climate impact mitigation potentials(Elsevier, 2024-04-01); ; ; ; Aviation contributes about 4 % of global anthropogenic climate forcing primarily by contrails, CO2 and NOx emissions. Renewably sourced aviation kerosene can help to reduce the climate impact from CO2 and from contrails, but so far, its production capacities are very small. Hence, the climate impact of using fossil fuel-based kerosene with a hydrogen content increased by hydroprocessing as short term mitigation measure is studied here. Therefore, the change in net energy forcing (ΔEFnet) in 2019 is calculated as the sum of the change in contrail energy forcing (ΔEFcontrail) and additional CO2 emissions (ΔEFhydroprocessing) from aviation kerosene hydroprocessing (ΔEFnet = ΔEFcontrail + ΔEFhydroprocessing). The results show that hydroprocessed aviation kerosene can reduce the net energy forcing EFnet by about 33 % with ΔEFhydroprocessing penalty of 5 %-points. Increasing the hydroprocessing severity increases the relative climate benefit, which is only slightly affected by the emissions factor for hydroprocessing or the choice of the time horizon. Data limitations about fuel composition and its effect on contrails and climate cause considerable uncertainties and the fuel's compliance with specification standards needs consideration. This study on the climate effect of hydroprocessed fossil kerosene can help to assess near-term measures to reduce the climate impact from aviation.Publicationtype: Journal Article31 120 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , CO₂ Transport and Storage OptionsSince the onset of industrialization, humanity has been releasing increasing amounts of carbon dioxide (CO2) into the atmosphere due to the use of fossil fuels. CO2 is a greenhouse gas that significantly impacts the global climate when concentrated in the atmosphere. To limit global warming to below 2°C compared to pre-industrial levels, as outlined in the 2015 Paris Climate Agreement, greenhouse gas emissions—especially CO2 from fossil fuels—must be drastically reduced. In addition to replacing fossil fuels with renewable energy sources, strategies like carbon capture and storage (CCS) or carbon capture and utilization (CCU), collectively known as CCUS, offer ways to mitigate CO2 emissions. As new applications for CO2 are expected to emerge, and as the volume and transport distance of CO2 will likely increase in the future, there is an urgent need to further develop the global CO2 infrastructure. A suitable infrastructure must be designed to handle the specific characteristics of CO2, including transportation methods and facilities for conditioning and intermediate storage. Therefore, first the key properties of CO2 are presented and then the current state and future advancements in CO2 conditioning, storage, and transportation are reviewed. Finally, scenarios are created to compare different CO2 logistics chains, evaluated from a techno-economic perspective, followed by an outlook on future developments and concluding remarks.Publicationtype: Book part45 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Power-to-Chemicals: Defossilization of the Chemical Industry via PtXThe chemical industry predominantly relies on fossil fuel-based feedstocks for both material and energetic uses, leading to significant CO2 emissions. Power-to-Chemicals (PtC) offers a promising solution to defossilize material uses by producing primary chemicals through electricity-derived synthesis gas and various downstream conversion technologies. This chapter provides an overview of the current status of fossil fuel use in the chemical sector and explains various defossilization options for the different requirements. Key PtC pathways, including the production of ammonia, methanol, olefins, and BTX aromatics, are outlined and discussed. The chapter also discusses the synergies and challenges in deploying PtC technologies alongside PtX-based fuel production, emphasizing the need for a collaborative cross-sectoral approach to scale-up and market adoption.Publicationtype: Book part127 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Chain-of-Custody Models for Renewable Fuels: A Comparison of Basic CharacteristicsPowerfuels are expected to play a crucial role in meeting global climate targets, particularly in hard-to-abate sectors like aviation, shipping, or heavy-duty road transportation. Ensuring compliance with established sustainability criteria across the entire value chain and implementing processes to allocate and forward the associated environmental benefits, such as greenhouse gas (GHG) emissions reductions, to end-users is crucial for the large-scale use of powerfuels. This is where so-called chain-of-custody models play a key role. Thus, this chapter provides an overview of the general significance of chain-of-custody models for powerfuels and presents the different available models as well as their specific characteristics. While these chain-of-custody models are not limited to specific sectors or fuel options, they are discussed in the context of the aviation sector and for the use of renewable aviation fuels, including kerosene-type powerfuels.Publicationtype: Book part46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 69 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Carbon—Classification, Sources, and PotentialsCarbon is a vital element in the biosphere due to its abundance in living organisms. It exists in both pure and chemically bound forms and has the capacity to form a wide range of complex compounds, making it integral to industrial society. Since the Industrial Revolution, carbon-based fuels (e.g., coal, oil, natural gas) have been the primary sources of energy, but their combustion releases CO2, contributing significantly to anthropogenic climate change. Despite the need to limit fossil fuels, hydrocarbons will remain crucial for sectors like chemicals and transportation, where alternative energy sources are challenging to implement. Sustainable synthetic or biologically produced hydrocarbons may offer alternatives for hard-to-decarbonize sectors. This chapter examines carbon availability, focusing on CO2 provision options, categorizes carbon sources (fossil, biogenic, mixed), and assesses their potential in transitioning toward a defossilised energy and economic system.Publicationtype: Book part30 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Classification of Power-to-Gas (PtG) and Power-to-Liquid (PtL) ProcessesThe 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.Publicationtype: Book part46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Blending of Aviation PowerfuelsAs the global energy landscape evolves in response to anthropogenic climate change, there is an increasing focus on using sustainable alternatives to conventional fossil-based fuels. In aviation such an alternative is provided by drop-in synthetic fuels which can blended with fossil kerosene to produce a blend that is virtually indistinguishable from conventional kerosene and is fully compatible with existing infrastructure. However, for most of these fuels blending is a crucial part of the process as the fuels are not fully drop-in on their own. This topic is discussed in the following chapter, with a focus on powerfuels.Publicationtype: Book part21 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , IntroductionAs in recent decades, global population and average living standards are expected to continue to grow substantially in the years and decades to come. The consequence is that, even despite increasing exploitation of existing energy efficiency potentials and a continued shift toward more efficiently usable energy carrier (e.g., electrical energy), a significant increase of the global energy demand is expected in the coming decades. In this context, the transformation of the global energy system towards a more sustainable and climate-friendly energy supply is becoming imperative.Publicationtype: Book part12