scholarly journals Towards greener aviation : a comparative study on the substitution of standard jet fuel with algal based second generation biofuels

Author(s):  
Mona Abdul Majid Haddad

The negative environmental impact of the aviation industry, related mainly to the gaseous emissions from turbine exhausts, is increasing with the increased demand on travel. In addition to the adverse environmental effects, the currently used aviation fuel is posing economic burdens on the air transport sector, with the increase in crude oil prices. Therefore, the aviation industry is investigating the potential of substituting the currently used aviation fuel with alternative fuels- mainly with those derived from second generation biofuels. Of all available sources of second generation biofuels, numerous studies indicate that those derived from algae seem to be the most promising, in terms of providing a viable and sustainable alternative to fossil fuels. This study explores the feasibility of microalgal jet fuel, taking into consideration technological, environmental and economic aspects. The results indicate that the viability and sustainability of microalgal jet fuel greatly depend on the technologies and inputs used during the different production stages of microalgal fuels. Provided certain conditions and characteristics are present, microalgal jet fuel has a realistic potential to provide the economic and environmental benefits needed to substitute conventional fuels.

2021 ◽  
Author(s):  
Mona Abdul Majid Haddad

The negative environmental impact of the aviation industry, related mainly to the gaseous emissions from turbine exhausts, is increasing with the increased demand on travel. In addition to the adverse environmental effects, the currently used aviation fuel is posing economic burdens on the air transport sector, with the increase in crude oil prices. Therefore, the aviation industry is investigating the potential of substituting the currently used aviation fuel with alternative fuels- mainly with those derived from second generation biofuels. Of all available sources of second generation biofuels, numerous studies indicate that those derived from algae seem to be the most promising, in terms of providing a viable and sustainable alternative to fossil fuels. This study explores the feasibility of microalgal jet fuel, taking into consideration technological, environmental and economic aspects. The results indicate that the viability and sustainability of microalgal jet fuel greatly depend on the technologies and inputs used during the different production stages of microalgal fuels. Provided certain conditions and characteristics are present, microalgal jet fuel has a realistic potential to provide the economic and environmental benefits needed to substitute conventional fuels.


Author(s):  
A. Alexiou ◽  
A. Tsalavoutas ◽  
B. Pons ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
...  

At present, nearly 100% of aviation fuel is derived from petroleum using conventional and well known refining technology. However, the fluctuations of the fuel price and the vulnerability of crude oil sources have increased the interest of aviation industry in alternate energy sources. The motivation of this interest is actually twofold: firstly alternative fuels will help to stabilize price fluctuations by relieving the world wide demand for conventional fuel. Secondly alternative fuels could provide environmental benefits including a substantial reduction of emitted CO2 over the fuel life cycle. Thus, the ideal alternative fuel will fulfil both requirements: relieve the demand for fuels derived from crude oil and significantly reduce CO2 emissions. In the present paper, the effects of various alternative fuels on the operation of a medium transport/utility helicopter are investigated using performance models of the helicopter and its associated turboshaft engine. These models are developed in an object-oriented simulation environment that allows a direct mechanical connection to be established between them in order to create an integrated model. Considering the case of a typical mission for the specific helicopter/engine combination, a comparative evaluation of conventional and alternative fuels is then carried out and performance results are presented at both engine and helicopter level.


2012 ◽  
Vol 134 (11) ◽  
Author(s):  
A. Alexiou ◽  
A. Tsalavoutas ◽  
B. Pons ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
...  

At present, nearly 100% of aviation fuel is derived from petroleum using conventional and well known refining technology. However, the fluctuations of the fuel price and the vulnerability of crude oil sources have increased the interest of the aviation industry in alternate energy sources. The motivation of this interest is actually twofold: firstly, alternative fuels will help to stabilize price fluctuations by relieving the worldwide demand for conventional fuel. Secondly, alternative fuels could provide environmental benefits including a substantial reduction of emitted CO2 over the fuel life cycle. Thus, the ideal alternative fuel will fulfill both requirements: relieve the demand for fuels derived from crude oil and significantly reduce CO2 emissions. In the present paper, the effects of various alternative fuels on the operation of a medium transport/utility helicopter are investigated using performance models of the helicopter and its associated turboshaft engine. These models are developed in an object-oriented simulation environment that allows a direct mechanical connection to be established between them in order to create an integrated model. Considering the case of a typical mission for the specific helicopter/engine combination, a comparative evaluation of conventional and alternative fuels is then carried out and performance results are presented at both engine and helicopter levels.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1538
Author(s):  
Felipe Andrade Torres ◽  
Omid Doustdar ◽  
Jose Martin Herreros ◽  
Runzhao Li ◽  
Robert Poku ◽  
...  

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.


Author(s):  
C. M. Benson ◽  
J. M. Ingram ◽  
P. N. Battersby ◽  
D. Mba ◽  
V. Sethi ◽  
...  

Abstract Over the next few decades air travel is predicted to grow, with international agencies, manufacturers and governments predicting a considerable increase in aviation use. However, based on current fuel type, International Civil Aviation Organization (ICAO) project emissions from aviation are estimated to be seven to ten times higher in 2050 than in 1990. These conflicting needs are problematic and have led to the EU Flightpath 2050 targeting dramatic emissions reductions for the sector (75% CO2, 90% NOX by 2050). One proposed solution, decreasing carbon emissions without stunting the increase in air travel, is hydrogen propulsion; a technology with clear environmental benefits. However, enabling the safe application of this fuel to aviation systems and industrial infrastructure would be a significant challenge. High-profile catastrophic incidents involving hydrogen, and the flammable and cryogenic nature of liquid hydrogen (LH2) have led to its reputation as a more dangerous substance than existing or alternative fuels. But, where they are used (in industry, transport, energy), with sufficient protocols, hydrogen can have a similar level of safety to other fuels. A knowledge of hazards, risks and the management of these becomes key to the integration of any new technology. Using assessments, and a gap analysis approach, this paper examines the civil aviation industry requirements, from a safety perspective, for the introduction of LH2 fuel use. Specific proposed technology assessments are used to analyze incident likelihood, consequence impact, and ease of remediation for hazards in LH2 systems, and a gap analysis approach is utilized to identify if existing data is sufficient for reliable technology safety assessment. Outstanding industry needs are exposed by both examining challenges that have been identified in transport and industrial areas, and by identifying the gaps in current knowledge that are preventing credible assessment, reliable comparison to other fuels and the development of engineering systems. This paper demonstrates that while hydrogen can be a safe and environmentally friendly fuel option, a significant amount of work is required for the implementation of LH2 technology from a mass market perspective.


Author(s):  
Nurul Musfirah Mazlan ◽  
Mark Savill ◽  
Timos Kipouros

Awareness of environmental and economic issues associated with fossil fuel has led to the exploration of alternative fuels for aviation. Analysis and measurements of alternative fuel using real aircraft engines are complex and costly. Thus, evaluation only through computation is an option at present. This paper presents an analysis of aircraft engine emissions, particularly NOx and CO, from the blend of bio-synthetic paraffinic kerosene (bio-SPK) fuel with kerosene using a simplified gas emission model. Three different fuels, namely, a conventional aviation fuel Jet-A, Jatropha bio-SPK and Camelina bio-SPK were tested as pure and as blends with Jet-A. Chemical properties of the tested fuels were introduced into HEPHAESTUS, an in-house gas emission software developed in Cranfield University. HEPHAESTUS was developed based on the physics-based approach by incorporating a number of stirred reactors to predict NOx, CO, UHC and soot. Gaseous emissions generated from kerosene were observed to follow the trends provided by the ICAO databank. The capability of HEPHAESTUS in predicting the NOx and CO level from biofuel is yet to be explored. The level of NOx and CO predicted in this study followed the trends shown in the literature, although they quantitatively differed. Compared to Jet-A, NOx decreased and CO increased as the percentage of Jatropha bio-SPK and Camelina bio-SPK in the mixture increased. NOx reduction was consistent with the reduction in flame temperature because NOx generation considered in the model was dominantly based on thermal NOx. In contrast, increases in CO were due to low flame temperature that led to incomplete combustion. The consistency of the results obtained showed that the computational work performed in this study as an initial step toward the prediction of emission level of biofuels was successful. However, further studies on the experimental work or computational fluid dynamic simulation is essential.


2020 ◽  
Vol 1008 ◽  
pp. 231-244
Author(s):  
Rehab M. El-Maghraby

Aviation industry is considered one of the contributors to atmospheric CO2emissions. It is forced to cut off carbon dioxide emission starting 2020. Current trends in bio-jet production involve mega projects with million dollars of investments. In this study, bio-jet fuel production by blending bio-diesel with traditional jet fuel at different concentrations of bio-diesel (5, 10, 15, 20 vol. %) was investigated. This blending technique will reduce bio-jet production cost compared to other bio-jet techniques. Bio-diesel was originally produced by the transesterification of non-edible vegetable oil (renewable sources), so, its blend with jet fuel will has a reduced carbon foot print. The blend was tested to ensure that the end product will meet the ASTM D1655 international specifications for Jet A-1 and Jet A and can be used in aircrafts.Available data on biodiesel blending with jet fuel in the literature is not consistent, there are many contradictory results. Hence, more investigations are required using locally available feedstocks. The main physicochemical properties for Jet A-1 and Jet A according to ASTM D1655 were tested to check if the blend will be compatible with existing turbojet engine systems. Different tests were conducted; vacuum distillation, smoke point, kinematic viscosity, density, flash point, total acidity and freezing point. In addition, heating value of the blend was calculated. The result was then compared with calculated value using blending indices available in the literature. Blending indices were able to predict the laboratory measured specifications for the studied blends.It was found that only 5% bio-diesel- 95% jet fuel blend (B5) meets ASTM standard for Jet A. Hence, biodiesel can be safely used as a blend with fossil-based jet for a concentration of up to 5% without any change in the ASTM specifications. Freezing point is the most important constrain for this blending technique. Higher blends of biodiesel will cause the bio-jet blend to fail ASTM specifications. In general, blending technique will reduce the cost impact that may have been incurred due to change in infrastructure when using other production techniques.


Author(s):  
Manoela Cabo ◽  
Elton Fernandes ◽  
Paulo Alonso ◽  
Ricardo Pacheco ◽  
Felipe Fagundes

Since World War I, the commercial aviation industry has seen many improvements that now allow people and goods to reach the other side of the world in few hours, consuming much less fuel than in recent decades. Improvements in cargo capacity and energy efficiency were significant and, in this scenario, commercial airlines were able to thrive and bring great benefits to world economy. However, this sector is facing environmental challenges due to the intensive use of aviation fuel. Brazil is one of the largest domestic air passenger markets in the world and still has great growth potential, considering its economic potential and territorial dimensions: roughly the same size as the US and twice the size of the European Union. This paper discusses partial productivity of jet fuel in Brazilian domestic aviation and proposes an econometric method to support public regulators and airlines decisions. The proposed model uses variables such as aircraft size, route characteristics and idle flight capacity in a panel data analysis. The results show that reducing idle capacity is one of the best ways to achieve better short-term fuel efficiency and therefore will reduce environmental impacts and have positive economic effects on commercial air transport activities.


Aviation industry is one of the main contributors and fastest-growing sectors in the world economy. Fuel consumption from this industry is one of the major issues that have drawn the attention of both professionals and researchers in recent years. The high dependency along with the high consumption of aviation fuel on petroleum plays a crucial role in environmental degradation due to increased carbon dioxide and other emissions, as well as in the increasing rate of fossil fuel depletion. Therefore, various potential technologies have been developed and further investigated to produce alternative aviation fuels, especially biofuels. In this article, principles, sustainability, and main concerns of different alternative aviation fuel processing technologies, with some focus on biofuels, are discussed in challenges and possible remedies. The major ecological problems connected with the application of conventional jet fuels in contrast to The advantages of biofuels implementation in the aviation industry are also highlighted. This work is aimed to show the state of the art of current alternative aviation fuels, their production technologies, and the potentiality of replacing the conventional jet fuel.


2019 ◽  
Vol 9 (18) ◽  
pp. 3720 ◽  
Author(s):  
Mohammed Kamil ◽  
Khalid Ramadan ◽  
Chaouki Ghenai ◽  
Abdul Ghani Olabi ◽  
Ibrahim T. Nazzal

Transportation is a vital necessity without which the entire world would come to a standstill. The fossil fuels used to power transportation are consumed at rates of approximately 100,000 times their rate of natural formation, and their consumption subjects the human environment and ecosystem to significant damage. As substitutes for fossil-based diesel, second-generation biodiesels can eliminate many of the challenges concerning first-generation biodiesels in terms of their high cost and the food versus fuel debate. The seeds of the date palm tree have significant oil content and are a promising prospective energy source. This study investigated the potential environmental benefits of this biofuel in terms of diesel tailpipe emission reduction. The various blends of palm date biodiesel were produced and matched to fuel standard requirements, resulting in four standard-compatible blends that were tested in a diesel engine at varying operating conditions for speed and load. Although the biodiesel emissions had lower concentrations of CO2, CO, and HC relative to fossil diesel, higher concentrations of NOx were detected. The results suggest that date-seed biodiesel could become a sustainable energy source for the transport sector, although further technical and economic investigations will be required before its wide deployment.


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