Jet Fuel Research Articles

Carbon-Based Solid Acids for the Preparation of Renewable Jet Fuel and Diesel Range Alkanes

Carbon-Based Solid Acids for the Preparation of Renewable Jet Fuel and Diesel Range Alkanes

Scaling a bifunctional catalytic Fixed-Bed reactor for acetone-to-mesitylene Jet-Fuel additive production

De-fossilization of the aviation sector will require the use of renewable synthetic jet fuels and additives that comply with strict regulations. One such additive, mesitylene, can be produced using a novel sustainable process based on the fermentation of biomass waste to acetone, followed by the self-condensation of acetone to mesitylene. This study addresses the viability of gas-phase self-condensation of acetone, catalyzed by TiO2 and Al-MCM-41 acid catalysts, at a technological readiness level of TRL-4.The reactor used was a bench-scale fixed-bed reactor (28 mm diameter and 500 mm height) loaded with commercial-sized catalyst pellets (1/8″ diameter). It was equipped with a jacket for heat transfer using flowing thermal oil. The performance of commercial-scale reactors was approximated under conditions of 275 °C, 280 kPa, and a space velocity of 50–500 mol/kg·h.The catalyst pellets exhibited significant mass transfer resistances, which limited the reaction rate. This, in turn, reduced the deactivation rate caused by the adsorption of high-molecular-weight condensation products on the strongest acid sites. Additionally, the product distribution differed between pellet and powder forms of the catalysts, with higher yields of isophorone and mesitylene being observed on TiO2 and Al-MCM-41 pellets, respectively. A reaction and mass transfer model was proposed and fitted to the bench-scale data.The study also considered the combination of both catalyst pellets in the same reactor for the bench-scale unit. It was demonstrated that mesitylene yield could be improved, with the best configuration being two separate beds placed consecutively in the reactor with a catalyst ratio of 1:2 (TiO2:MCM-41).

Production of Jet Fuel Range Aromatics by Alkylation of Benzene with Olefins over Bifunctional Ga/ZSM-5 Catalyst.

Aromatic components of C8-C15 are playing indispensable roles in multi-functional properties of jet fuel. Here, we reported the controllable alkylation of benzene with mixed olefins of ethylene and propylene toward C8-C15 aromatic hydrocarbons for jet fuels over the bifunctional Ga/ZSM-5 catalyst. The resultant 2Ga/ZSM-5 exhibited a superior selectivity of 86.4% (yield of 55.5%) to C8-C15 range aromatics, at benzene conversion of 40.3%, ethylene and propylene conversion of 99.5% and 99.2%, respectively. The incorporation of Ga species could effectively weaken the strong acid sites of ZSM-5 and endow 2Ga/ZSM-5 catalyst with appropriate acidity, therefore facilitating the benzene alkylation process and suppressing the undesired hydrogen transfer or aromatization side reactions as well, thus improving the yield of desired C8-C15aromatics for jet fuels. This work provided insight into the development of promising bifunctional catalyst for the oriented transformation of biomass-derived chemicals to aviation fuels.

Hydroprocessing Microbial Oils for Advanced Road Transportation, Aviation, and Maritime Drop-In Fuels: Industrially Relevant Scale Validation

Triacylglycerides (TAGs) produced via the syngas fermentation of biogenic residues and wastes were evaluated as a potential feedstock for advanced road transportation, aviation, and maritime drop-in fuels via hydroprocessing technology. Due to the limited availability of TAGs, a simulated feedstock (SM TAGs) was utilized by blending various commercial oils, simulating the fatty acid composition of TAGs. At first, the simulated feedstock and the real TAGs were hydrotreated on a TRL 4 (technology readiness level) pilot plant to evaluate the potential of the SM feedstock to simulate the TAGs based on product quality. The hydrotreatment technology was evaluated and optimized on a TRL 4 plant. The research was further extended to a TRL 5 hydrotreatment plant with the optimum operating window for scaling up the technology. The resulting product was fractionated on a batch fractionation unit under vacuum to separate the jet and diesel fractions. The produced fuels were analyzed and evaluated based on the aviation Jet A1, EN590, EN15940, and marine diesel DMA specifications. The results show that the TAG composition was successfully simulated via a blend of vegetable oils. In addition, the hydrotreatment of the real TAGs and simulated feedstock resulted in similar-quality liquid products. The technology was successfully scaled up on a TRL 5 unit, leading to advanced, high-quality aviation and diesel drop-in fuels from TAGs, while the reaction pathways of hydrotreating can be controlled via the operating parameters of pressure, temperature, and H2/oil ratio. The hydrotreatment process’s optimum conditions were 13.8 MPa pressure, 643 K temperature, 1 h−1 liquid hourly space velocity (LHSV), and 5000 scfb hydrogen-to-oil ratio. Finally, a storage stability study of the hydrotreated liquid product showed that it can be stored for more than 6 months at ambient conditions without any noticeable changes to its properties.

Analyzing the influence of feedstock selection in pyrolysis on aviation gas turbine engines: A study on performance, combustion efficiency, and emission profiles

Commercial aviation is primarily reliant on fossil fuels, yet the depletion of these sources and the consequences of climate change necessitates the exploration of sustainable alternatives. The pyrolysis process offers a viable method for producing biofuels from various feedstocks. This research examines the combustion, emission, and performance characteristics of biofuels derived from agricultural residues, waste tyres, and plastics using pyrolysis. Pyrolysis oils derived from forestry or agricultural products exhibit high viscosity and moisture content, which impairs combustion efficiency and increases carbon monoxide (CO) from 70 % to 187 % and unburned hydrocarbon (UHC) emissions. Conversely, pyrolysis oils from plastics and waste tyres provide stable combustion with carbon monoxide and total hydrocarbon emissions (THC) comparable to those of commercial jet fuel. However, nitrogen oxide (NOX) emissions are significantly elevated from 57 % to 157 %. Engine performance tests demonstrated that forestry pyrolysis oils result in thrust loss due to their high viscosity value (14.3–113 mm2/s) and low calorific value (17.3–31.7 MJ/kg). In contrast, plastic and tyre pyrolysis oil perform similarly to commercial jet fuels but may potentially cause performance loss due to their high aromatic content (>47.67 %). Overall, upgrading the viscosity, moisture, and aromatic content of pyrolysis oils can enhance their suitability as alternative aviation fuels. These improvements could assist the aviation sector in achieving its carbon-neutral goals by making pyrolysis oils competitive with conventional jet fuels.

Diels–Alder Reaction of Biofuran Derivatives and Cycloolefin for Directional Synthesis of Fused Ring Hydrocarbon High Density Jet Fuel

Diels–Alder Reaction of Biofuran Derivatives and Cycloolefin for Directional Synthesis of Fused Ring Hydrocarbon High Density Jet Fuel

Exploring Impurity Effects and Catalyst Surface Features in Furfural Electroreduction for Jet Fuel Precursor Production: Experimental and Molecular Dynamics Insights

Exploring Impurity Effects and Catalyst Surface Features in Furfural Electroreduction for Jet Fuel Precursor Production: Experimental and Molecular Dynamics Insights

Spatially-explicit land use change emissions and carbon payback times of biofuels under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) requires airlines to offset their greenhouse gas (GHG) emissions above 2019 levels by either buying carbon offsets or using Sustainable Aviation Fuels (SAFs). These are drop-in jet fuels made from biomass or other renewable resources that reduce GHG emissions by at least 10 % compared to kerosene and meet certain sustainability criteria. This study assesses the direct land use change (DLUC) emissions of SAF, i.e., GHG emissions from on-site land conversion from previous uses (excluding primary forests, peatlands, wetlands, and protected and biodiversity-rich areas) into alternative feedstocks, considering spatial variability in global yields and land carbon stocks. The results provide DLUC values and carbon payback times at 0.5-degree resolution for six SAF pathways, with and without irrigation and a medium-input intensity, according to CORSIA sustainability criteria. When excluding CORSIA non-compliant areas, soybean SAF shows the highest mean DLUC factor (31.9 ± 20.7 gCO2/MJ), followed by reed canary grass and maize. Jatropha SAF shows the lowest mean DLUC factor (3.6 ± 31.4 gCO2/MJ), followed by miscanthus and switchgrass. The latter feedstocks show potential for reducing GHG emissions over large areas but with relatively greater variability. Country-average DLUC values are higher than accepted ILUC ones for all pathways except for maize. To ensure the GHG benefits of CORSIA, feedstocks must be produced in areas where not only carbon stocks are relatively low but also where attainable yields are sufficiently high. The results help identify locations where the combination of these two factors may be favourable for low-DLUC SAF production. Irrigated miscanthus offers the highest SAF production potential (2.75 EJ globally) if grown on CORSIA-compliant cropland and grassland areas, accounting for ∼1/5 of the total kerosene used in 2019. Quantifying other environmental impacts of SAFs is desirable to understand sustainability trade-offs and financial constraints that may further limit production potentials.

Computational modeling of the rectangular non-aligned multi-injector for efficient fuel mixing in a supersonic combustion chamber

The present investigation examines the usage of rectangular multi-injectors for fuel injection in a supersonic combustion chamber. To evaluate the fuel jet penetration and distribution, a computational method is applied to model the supersonic compressible flow with cross multi-fuel jets released from annular rectangular nozzles with different nozzle configurations. The main effort of this work is to evaluate the jet interactions in the existence of cross-supersonic flow. Fuel jet penetration and distribution are evaluated for three proposed injector arrangements to attain the more efficient option for better fuel mixing. Our results show that reducing injector space improves fuel mixing inside the combustor via creation of strong vortices. Beside, injection of air from internal nozzle increase fuel interactions and fuel mixing inside combustion chamber.

Integration of Deep Eutectic Solvents and Hydrotalcites for Biomass Conversion and Aldol Condensation: Toward Platform Chemicals and Jet Fuel Synthesis—A Review

AbstractThe abundance and renewability of lignocellulosic biomass have made it a suitable alternative to fossil fuels in the reduction of global warming. The complex nature of the cellulose–hemicellulose–lignin bonds in the biomass makes it difficult to directly obtain platform chemicals. Pretreatment of the biomass has become a solution to remove lignin and obtain cellulose and or hemicellulose to produce platform chemicals. Platform chemicals such as hydroxymethylfurfural, furfural, and levulinic acid are viable feedstocks for aldol condensation to produce C8–C15 fuels. This review reports on deep eutectic solvents and microwave‐assisted pretreatment as green techniques for the delignification and platform chemicals production. Emphasis is placed on the use of hydrotalcites (HTs) as catalysts in platform chemicals production and aldol condensation for C8–C15 alkane fuels. Additionally, the hydrogenation of furfural into cyclopentanone and successive conversion into C10 and C15 alkanes with HTs was reviewed.

Analysis of Aviation Fuel Performance

Aviation fuels are jet fuels produced from crude oil and has specific physical and chemical properties. Analysis experiments were conducted for different samples of aviation fuel such as gas chromatography, color test, smoke point freezing point, and flash point. The sample of aviation fuel produced from Khartoum refinery used as control sample and other three samples took from air force with different storage period. Results showed that there is no change in color test of all samples, while the components differed in the GC test, where the control sample consisted of 30 compounds, compared with storage sample, which has 40 compounds. The total acidity and the relative mass of sulfur decreased. Meanwhile, there was a slight change in the boiling range and freezing point due to the decrease in viscosity. The results from smoke point test showed that, the smoke point increased from 29.6? in control sample to 37.3? in the storage sample. The electrical conductivity greatly decreased from 256 S/m in the control sample to 110 S/m in the storage sample. These results proved that the effect of storage time in the properties of aviation fuel.

Electroreductive C–C Coupling of Furfural to Jet Fuel Precursors in Neutral Media via Synergistic Catalysis of the Polyoxotungstate and Cu Complex

Electroreductive C–C Coupling of Furfural to Jet Fuel Precursors in Neutral Media via Synergistic Catalysis of the Polyoxotungstate and Cu Complex

Exploring the first-stage ignition and model optimization in the comprehensive study of n-dodecane oxidation

n-Dodecane is commonly employed as a surrogate for investigating the combustion characteristics of jet and diesel fuels. Enhancing comprehension of its combustion behavior and developing accurate chemical kinetics models for simulating combustion is of paramount importance in engine development. This study focuses on a detailed exploration of n-dodecane oxidation kinetics under low-temperature conditions and presents a novel dataset concerning the first-stage ignition delay time. A broad spectrum of experimental conditions is investigated, encompassing a range of temperature (600 ∼ 1350 K), pressure (5 ∼ 20 atm), equivalence ratios (0.5 ∼ 1.0), and dilution gases (N2 and Ar). Additionally, combustion experiments in a pure oxygen environment are performed, contributing valuable data to existing research. To enhance the precision of the chemical reaction kinetics model of n-dodecane, this study integrates updated rate coefficients obtained from the latest theoretical calculations for specific reaction classes. The improved rate rule provides a more accurate reference for the construction of the chemical reaction kinetics model of long straight alkane. The resulting improved model excels in accurately predicting both the first-stage ignition delay time and the total ignition delay time under a wide range of operational conditions. Additionally, the model performance is rigorously evaluated through a comprehensive assessment against a diverse array of datasets gathered from various literature references. The results show that, in contrast to the previously proposed model, this enhanced model provides highly reliable predictions over a broad range of parameters.

Puffing/micro-explosion of two-liquid droplets: Effect of fuel shell composition

Theoretical research into the heat and mass transfer, hydrodynamic and physicochemical processes in combustion chambers of gas turbine engines usually implies that multi-component jet fuels are modeled using single-component liquids (saturated or cyclic hydrocarbons) and their substitutes. Due to an insoluble dispersed phase (e.g., water) in their composition, droplets consist of a noncombustible core and a liquid fuel shell. During heating, water droplets coalesce in fuel droplets to produce explosion-triggering volumes of liquid superheated to the boiling point. When heated, these heterogeneous droplets breakup in the micro-explosion and puffing modes. This study reports the numerical simulation results providing the temporal characteristics of heating and evaporation of heterogeneous droplets until puffing/micro-explosive breakup, when varying the composition of the fuel shell in the homologous series of saturated and cyclic (as illustrated by monocycloparaffins) hydrocarbons from C7 to C16. The conducted research has revealed that the variations in the breakup delay times in the homologous series of saturated and cyclic hydrocarbons are nonlinear. The breakup delay rates were found to increase substantially in the boundary points of the investigated series. Mechanisms to control droplet fragmentation delay time were identified for different initial and boundary conditions. A dimensionless complex reflecting the correlation between the critical conditions of composite liquid droplet breakup and the physicochemical properties of the fuel shell components was proposed.

Designing Novel Dual-Silane-Capped Boron Nanoparticles for Jet Fuels Targeting Simultaneous Enhancement in Combustion and Dispersion Stability

Designing Novel Dual-Silane-Capped Boron Nanoparticles for Jet Fuels Targeting Simultaneous Enhancement in Combustion and Dispersion Stability

Evaluating black wattle bark industrial residue as a new feedstock for bioenergy via pyrolysis and multicomponent kinetic modeling

This work presents an evaluation of the industrial residue from exhausted black wattle bark after the extraction of tannin for use as a new feedstock for biofuel production, without competing with food production. The physicochemical and thermodynamic properties, the influence of temperature on pyrolysis products and multicomponent kinetics were evaluated. Principal component analysis showed that sugars, carboxylic acids, ethers/esters, furans and aldehydes were formed as primary products of pyrolysis at 450 °C. At 550 °C, phenols and mainly ketones were favored, especially acetone and 2,3-butanedione. Pyrolysis at 650 °C favored the production of aldehydes, alcohols, and 1-alkene, polyene and alkane hydrocarbons. After an upgrade, the series of 1-alkenes produced, with carbons C7 to C16, could be suitable for a range of gasoline and jet fuels. Kinetic modeling was based on the deconvolution of the mass loss of three events of the pseudo-components: hemicellulose (DE-HC), cellulose (DE-CL) and lignin (DE-LG). The activation energy for kinetic models Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Starink presented average values of ∼141.4–149.4 for DE-HC, ∼190.5–200.9 for DE-CL and ∼237.2–252.3 kJ mol−1 for DE-LG. This study encourages using agro-industrial waste to produce second-generation drop-in biofuels and bio-based chemicals, aiming at industrial decarbonization.

A Simulation Study on Utilizing in Airbus380 fuel Tanks for Thrust and Fuel Efficiency

This paper explores the potential benefits of using nanofluids within the fuel system of an Airbus A380 to enhance engine thrust and reduce fuel consumption. By analyzing the Nusselt and Reynolds numbers, the study aims to understand the heat transfer and fluid dynamics that could lead to more efficient aircraft operation. The integration of nanotechnology in aviation fuel systems represents a promising frontier for improving aircraft performance. the nanoscale as a fluid whose particles are suspended between 1-100 nanometers and permanently in the particle. Adding nanoscale increases heat transfer. In this research used silicon carbide nanofluid (sic nanofluid) with a percentage of (1,2,3,4%) the base fluid (Jet A1) as well as thermal properties including Nusselt number and thermal conductivity coefficient and... It's been studied.

Comparison of Comprehensive Two-Dimensional Gas Chromatography with a Flame Ionization Detector and D2425 Methods in the Analysis of Different Hydrocarbon Types in Jet Fuel

Comparison of Comprehensive Two-Dimensional Gas Chromatography with a Flame Ionization Detector and D2425 Methods in the Analysis of Different Hydrocarbon Types in Jet Fuel

Life Cycle Economic and Environmental Assessment of Producing Synthetic Jet Fuel Using CO2/Biomass Feedstocks.

The aviation industry is responsible for over 2% of global CO2 emissions. Synthetic jet fuels generated from biogenic feedstocks could help reduce life cycle greenhouse gas (GHG) emissions compared to petroleum-based fuels. This study assesses three processes for producing synthetic jet fuel via the synthesis of methanol using water and atmospheric CO2 or biomass. A life cycle assessment and cost analysis are conducted to determine GHG emissions, energy demand, land occupation, water depletion, and the cost of producing synthetic jet fuel in Switzerland. The results reveal that the pathway that directly hydrogenates CO2 to methanol exhibits the largest reductions in terms of GHG emission (almost 50%) compared to conventional jet fuel and the lowest production cost (7.86 EUR kgJF-1); however, its production cost is currently around 7 times higher than the petroleum-based counterpart. Electrical energy was found to be crucial in capturing CO2 and converting water into hydrogen, with the sourcing and processing of the feedstocks contributing to 79% of the electric energy demand. Furthermore, significant variations in synthetic jet fuel cost and GHG emissions were shown when the electricity source varies, such as utilizing grid electricity pertaining to different countries with distinct electricity mixes. Thus, upscaling synthetic jet fuels requires energy-efficient supply chains, sufficient feedstock, large amounts of additional (very) low-carbon energy capacity, suitable climate policy, and comprehensive environmental analyses.

Pyrolysis mechanism of a highly branched bio-derived fuel and its blends with aviation kerosene (RP-3)

To address the environmental issues caused by traditional aviation fuels, the use of new alternative jet fuels (AJF) is emerging. C1 fuel, due to its excellent performance, is used as a blended fuel with traditional aviation kerosene. In this study, the pyrolysis pathways of C1 fuel are examined from molecular simulations. Furthermore, C1 fuel is blended with traditional aviation kerosene fuel RP-3 in a 1:4 vol ratio, and the potential coupling effects between two fuels are addressed under both pyrolysis and combustion conditions. In the process of fuel pyrolysis, it is observed that the composition of the fuel has a significant impact on the pyrolysis products. The decomposition process of C1 fuel is mainly dominated by branched-chain alkanes, while the pyrolysis of RP-3 primarily involves β-scission reactions of straight-chain alkanes. By comparing the combustion and pyrolysis processes of fuels, it is found that the combustion of fuel first involves the decomposition of fuel molecules, followed by the oxidation of pyrolysis products. Moreover, it is found that the reaction kinetics of blended fuel can be approximated using the additivity of two neat fuels, indicating a minor chemical coupling. Based on the proportion of C1 and RP-3 in the blended fuel, the mass fractions of key hydrocarbon products, including CH4, C2H2, C2H4, C2H6, C3H6, C4H6, C6H6, and C7H8, can be computed from the simulations of neat fuels. From a molecular perspective, the additivity of the HyChem model in describing the combustion behavior of blended fuels is verified.