Sustainable Aviation Fuels

Aviation fuel demand is expected to continue to grow over the next decades and continue to rely heavily on kerosene fuel for use in jet engines. While efficiency and operational improvements are possible ways to reduce GHG emissions, decarbonisation will need to heavily rely on low carbon kerosene drop-in alternatives. Currently, alternative fuels make up a very small share of fuel used in aviation, but their commercialisation is making good progress. Hydrogen offers a longer term alternative fuel option but requires aircraft design and fuelling infrastructure changes. Electrification is emerging as an option for providing propulsion in aircraft, either in pure form in small aircraft or in hybrid mode in larger aircraft. This paper reviews the status, challenges and prospects of alternative fuels and electrification in aviation.

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Substantiation of the ratio of biofuel and kerosin in the mixture for its application as aviation fuel

Civil Aviation High TECHNOLOGIES ◽

10.26467/2079-0619-2020-23-3-17-28 ◽

2020 ◽

Vol 23 (3) ◽

pp. 17-28

Author(s):

V. M. Samoylenko ◽

K. I. Gryadunov ◽

A. N. Timoshenko ◽

S. Ardeshiri

Keyword(s):

Quality Indicators ◽

Alternative Fuels ◽

Raw Materials ◽

Alternative Fuel ◽

Economic Feasibility ◽

Point Of View ◽

Aviation Fuel ◽

Civil Aviation ◽

Negative Consequences ◽

Fuel Prices

Today, technologies for the production of alternative fuels and for the development of engines on different operating principles are actively developing, due to both the tightening of the environmental requirements of ICAO (International Civil Aviation Organization) for harmful emissions into the atmosphere and the depletion of non-renewable resources, and the interests of the oil importing countries. Strict requirements are imposed on the quality of aviation fuels related to ensuring the reliability of aviation technology and flight safety. Requirement toughening for quality indicators will inevitably lead to higher fuel prices, so today we can observe some concessions in domestic and foreign regulatory documents to certain quality indicators of aviation fuels, for example, to indicators of low-temperature properties. It follows that the use of petroleum fuels will sooner or later become inappropriate. Technologies to produce synthetic and biological fuels from various types of raw materials make it possible to obtain fuel with close quality indicators to traditional kerosene, but it has not yet been completely replaced. Therefore, today we are considering the use of alternative fuels in a mixture with petroleum kerosene in various proportions. The question remains open: in what proportion is it possible to use mixtures of alternative fuel with kerosene on the aircraft without any negative consequences for their operation. Based on the known dependencies, a mathematical model is proposed for calculating some operational indicators of fuel, engine and aircraft depending on the proportion of mixing alternative fuel and kerosene. In accordance with the calculations, the most rational ratio of petroleum kerosene and SPK fuel is substantiated both from the point of view of the necessary operational properties and from the point of view of economic feasibility.

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PTG-HEFA Hybrid Refinery as Example of a SynBioPTx Concept—Results of a Feasibility Analysis

Applied Sciences ◽

10.3390/app9194047 ◽

2019 ◽

Vol 9 (19) ◽

pp. 4047 ◽

Cited By ~ 1

Author(s):

Franziska Müller-Langer ◽

Katja Oehmichen ◽

Sebastian Dietrich ◽

Konstantin M. Zech ◽

Matthias Reichmuth ◽

...

Keyword(s):

Alternative Fuels ◽

Ghg Emissions ◽

Economic Assessment ◽

Production Costs ◽

Aviation Fuel ◽

Ghg Mitigation ◽

Important Conclusion ◽

Hydrogen Supply ◽

Alternative Scenarios ◽

Power To Gas

Limited alternative fuels for a CO2-neutral aviation sector have already been ASTM certified; synthetic paraffinic kerosene from hydrotreated esters and fatty acids (HEFA-SPK) is one of these—a sustainable aviation fuel. With the hypothesis to improve the greenhouse gas (GHG) balance of a HEFA plant by realizing the required hydrogen supply via electrolysis—power to gas (PTG)—an exemplary SynBioPTx approach is investigated in a comprehensive feasibility study, which is, regarding this comparatively new approach, a novelty in its extent. About 10 scenarios are analysed by technical, environmental, and economic aspects. Within the alternative scenarios on feedstocks, electricity supply, necessary hydrogen supply, and different main products are analysed. For different plant designs of the hybrid refinery, mass and energy balances are elaborated, along with the results of the technical assessment. As a result of this environmental assessment, the attainment of at least 50% GHG mitigation might be possible. GHG highly depends on the renewability grade of the hydrogen provision as well as on the used feedstock. One important conclusion of this economic assessment is that total fuel production costs of 1295 to 1800 EUR t−1 are much higher than current market prices for jet fuel. The scenario in which hydrogen is produced by steam reforming of internally produced naphtha proves to be the best combination of highly reduced GHG emissions and low HEFA-SPK production costs.

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Performance analysis of turbofan engine with additional combustion chamber fueled by alternative fuel

Combustion Engines ◽

10.19206/ce-2019-441 ◽

2019 ◽

Vol 179 (4) ◽

pp. 249-253

Author(s):

Natalia MARSZAŁEK

Keyword(s):

Performance Analysis ◽

Combustion Chamber ◽

Alternative Fuels ◽

Engine Performance ◽

Alternative Fuel ◽

Positive Influence ◽

Aviation Fuel ◽

Turbofan Engine ◽

Low Pressure Turbine ◽

Liquid Methane

Presented paper is focused on the performance analysis of turbofan engine with additional combustion chamber fueled by alternative fuel. Additional combustion chamber was situated between high pressure turbine and low pressure turbine. Such configuration is also know under the name inter turbine burner (ITB). As an alternative fuels burn in additional combustion chamber were selected cryogenics fuels: liquid hydrogen and liquid methane. The main combustion chamber was supplied by conventional aviation fuel - kerosene. Thermodynamic model of turbofan engine with ITB was implemented in MATLAB environment. The problem of modeling an additional combustion chamber was presented.Analysis was carried out for take-off conditions. Obtained results indicate that implementation of ITB exert a positive influence on engine performance result in thrust increase.

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The Use of Ethanol as an Alternative Fuel for Small Turbojet Engines

Sustainability ◽

10.3390/su13052541 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2541

Author(s):

Rudolf Andoga ◽

Ladislav Főző ◽

Martin Schrötter ◽

Stanislav Szabo

Keyword(s):

Alternative Fuels ◽

Alternative Fuel ◽

Jet Engines ◽

Gas Temperature ◽

Negative Effects ◽

Engine Exhaust ◽

Positive Effects ◽

Turbojet Engine ◽

Auxiliary Power ◽

Auxiliary Power Units

The use of alternative fuels to traditional kerosene-based ones in turbo-jet engines is currently being widely explored and researched. However, the application of alternative fuels in the area of small turbojet engines with thrust ratings up to 2 kilo-newtons, which are used as auxiliary power units or to propel small aircraft or drones, is not as well researched. This paper explores the use of ethanol as a sustainable fuel and its effects on the operation of a small turbojet engine under laboratory conditions. Several concentrations of ethanol and JET A-1 mixtures are explored to study the effects of this fuel on the basic parameters of a small turbojet engine. The influence of the different concentrations of the mixture on the start-up process, speed of the engine, exhaust gas temperature, and compressor pressure are evaluated. The measurements shown in the article represent a pilot study, the results of which show that ethanol can be reliably used as an alternative fuel only when its concentration in a mixture with traditional fuel is lower than 40%, yielding positive effects on the operating temperatures and small negative effects on the speed or thrust of the engine.

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Unpacking the ‘green’ recovery spending: an assessment of likely implications on greenhouse gas emissions towards 2030 for key emitters

10.21203/rs.3.rs-1024400/v1 ◽

2021 ◽

Author(s):

Frederic Hans ◽

Santiago Woollands ◽

Leonardo Nascimento ◽

Niklas Höhne ◽

Takeshi Kuramochi

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Ghg Emissions ◽

Transformational Change ◽

Low Carbon ◽

Gas Emissions ◽

Fiscal Stimulus ◽

The Status ◽

Over Time ◽

Fiscal Spending

Abstract This paper analyses how fiscal stimulus spending in response to the COVID-19 pandemic supports the low-carbon transition. We developed a new framework to categorize rescue and recovery spending measures according to their level of greenness and their type of expected impact on greenhouse gas emissions. This framework allows to better capture how measures’ emission impacts may unfold over time and to identify the share of fiscal spending missing robust conditions or incentives to be considered low-carbon. We assess nearly 2,500 measures announced by 26 emitters as of May 2021, representing around 65% of global GHG emissions in 2018. Our findings show that the largest share (35%) of spending with potential GHG emission implications went to measures that supported the status quo in the respective countries when there were low-carbon alternatives. Our assessment reveals the different magnitudes to which the emitters have missed the opportunity for a green recovery. While low-carbon spending is also significative in size (22%) across countries, almost two-thirds of it can be considered enabling or catalytic in nature and will rather unfold its impact over time. This fiscal spending will trigger transformational change over time but will not necessarily lead to direct emission reduction impacts before 2030.

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Costs and Benefits of the Transition to Low-carbon Economyin Russia: Perspectives up to 2050

Voprosy Ekonomiki ◽

10.32609/0042-8736-2014-8-70-91 ◽

2014 ◽

pp. 70-91 ◽

Cited By ~ 1

Author(s):

I. Bashmakov ◽

A. Myshak

Keyword(s):

Emission Reduction ◽

High Probability ◽

Ghg Emissions ◽

Mitigation Measures ◽

Low Carbon ◽

Costs And Benefits ◽

Ghg Emission ◽

Research Groups ◽

Emissions Mitigation ◽

Very High

This paper investigates costs and benefits associated with low-carbon economic development pathways realization to the mid XXI century. 30 scenarios covering practically all “visions of the future” were developed by several research groups based on scenario assumptions agreed upon in advance. It is shown that with a very high probability Russian energy-related GHG emissions will reach the peak before 2050, which will be at least 11% below the 1990 emission level. The height of the peak depends on portfolio of GHG emissions mitigation measures. Efforts to keep 2050 GHG emissions 25-30% below the 1990 level bring no GDP losses. GDP impact of deep GHG emission reduction - by 50% of the 1990 level - varies from plus 4% to minus 9%. Finally, very deep GHG emission reduction - by 80% - may bring GDP losses of over 10%.

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Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽

10.3390/en14134034 ◽

2021 ◽

Vol 14 (13) ◽

pp. 4034

Author(s):

Paolo Iodice ◽

Massimo Cardone

Keyword(s):

Physicochemical Properties ◽

Alternative Fuels ◽

Experimental Studies ◽

Alternative Fuel ◽

Exhaust Emissions ◽

Spark Ignition ◽

Operating Conditions ◽

Spark Ignition Engine ◽

Spark Ignition Engines ◽

The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

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Car Sharing as a Strategy to Address GHG Emissions in the Transport System: Evaluation of Effects of Car Sharing in Amsterdam

Sustainability ◽

10.3390/su13042418 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2418

Author(s):

Ana María Arbeláez Vélez ◽

Andrius Plepys

Keyword(s):

Ghg Emissions ◽

Transport Systems ◽

Car Ownership ◽

Low Carbon ◽

Car Sharing ◽

Shared Mobility ◽

Before And After ◽

Business To Consumer ◽

The City ◽

Carbon Transport

Shared mobility options, such as car sharing, are often claimed to be more sustainable, although evidence at an individual or city level may contradict these claims. This study aims to improve understanding of the effects of car sharing on transport-related emissions at an individual and city level. This is done by quantifying the greenhouse gas (GHG) emissions of the travel habits of individuals before and after engaging with car sharing. The analysis uses a well-to-wheel (WTW) approach, including both business-to-consumer (B2C) and peer-to-peer (P2P) car-sharing fleets. Changes in GHG emissions after engaging in car sharing vary among individuals. Transport-related GHG emissions caused by car-free individuals tend to increase after they engage in car sharing, while emissions caused by previous car owners tend to fall. At the city level, GHG emissions savings can be achieved by using more efficient cars in sharing systems and by implementing greener mobility policies. Changes in travel habits might help to reduce GHG emissions, providing individuals migrate to low-carbon transport modes. The findings can be used to support the development and implementation of transport policies that deter car ownership and support shared mobility solutions that are integrated in city transport systems.

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Is the service industry really low-carbon? Energy, jobs and realistic country GHG emissions reductions

Applied Energy ◽

10.1016/j.apenergy.2021.116878 ◽

2021 ◽

Vol 292 ◽

pp. 116878

Author(s):

Simon H. Roberts ◽

Barney D. Foran ◽

Colin J. Axon ◽

Alice V. Stamp

Keyword(s):

Service Industry ◽

Ghg Emissions ◽

Low Carbon ◽

Emissions Reductions ◽

Low Carbon Energy

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Does Revitalizing the Center of Mid-Sized French Cities Reduce GHG Emissions from Commuting?

Sustainability ◽

10.3390/su13041851 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1851

Author(s):

Alexis Poulhès ◽

Angèle Brachet

Keyword(s):

Land Use Planning ◽

Statistical Models ◽

Total Population ◽

Ghg Emissions ◽

Low Carbon ◽

Trip Distance ◽

Working People ◽

Shrinking City ◽

The Relationship ◽

Positive Effect

Mid-sized cities are usually considered in the literature to be shrinking cities. Some policies promote right-sizing and others promote revitalization. The relationship between land-use planning and mobility having been established, the present research issue is focused on whether a policy of revitalizing the centers of mid-sized cities is favorable to low-carbon mobility. Our study investigates commuting trips through two indicators: commuting trip distance and car modal share. The increase in total population, the increase in the number of jobs per resident, the decrease in the unemployment rate, the increase in the rate of executives, the increase in the rate of working people in the population and the decrease in the residential vacancy rate all come from the censuses of 2006 and 2016. Statistical models based on individuals in 113 mid-sized cities, in which sociodemographic variables are introduced, show that at the level of agglomerations, no indicator has a simultaneously positive effect in the center and in the urban periphery. No indicator is entirely positive or negative on GHG emissions from commuting trips. While the increase in GHG emissions from commuting trips between 2006 and 2016 is significant in mid-sized cities (18%), a shift toward shrinking city centers is insufficient to change this trajectory.

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