Jet Fuel Range Research Articles

Response optimisation of TiO2-supported bimetallic NiCo catalyst for the cracking and deoxygenation of waste cooking oil into jet-fuel range hydrocarbon fuels under non-hydrogen environment

Waste cooking oil is a sustainable feedstock that can be utilised to produce biojet fuel via the hydrodeoxygenation process. However, the need for hydrogen for the hydrodeoxygenation process incurs high cost. In the present work, a type of bimetallic catalyst that can deoxygenate and selectively crack free fatty acids under hydrogen-free conditions was developed. The NiCo/TiO2 catalyst was prepared via the impregnation of varying amounts of Ni and Co salts onto TiO2. Optimisation of the production conditions was performed via response surface methodology based on the Box-Behnken experimental design to maximise the deoxygenation and biojet fuel yield. A maximum deoxygenation yield of 83.13 % with 44.5 % biojet fuel selectivity was obtained from the experiment and optimisation based on Box-Behnken design (R2 > 0.9). Incorporation of Ni and Co onto TiO2 reduced the surface area of the catalyst, but active metal dispersion significantly improved the deoxygenation performance and biojet fuel selectivity. The viscosity, flash point, freezing point and net heat of combustion value of the liquid product were within the jet fuel standard specifications. Overall, the study shows the potential of bimetallic NiCo/TiO2 catalyst in waste cooking oil deoxygenation for biojet fuel production.

Performance of Hydrothermally Prepared NiMo Dispersed on Sulfated Zirconia Nano-Catalyst in The Conversion of Used Palm Cooking Oil into Jet Fuel Range Bio-Hydrocarbons

Human efforts to overcome environmental problems from using fossil fuels continue, such as hydroconversion of biomass into bio-jet fuel. Research on producing a jet fuel range of bio-hydrocarbons from used palm cooking oil catalyzed by sulfated zirconia impregnated with nickel-molybdenum bimetal has been successfully conducted. The hydrothermal method synthesized the nano-catalyst material in the sulfation and impregnation processes. The hydroconversion process was carried out at atmospheric pressure and a temperature of 300–600 °C for 2 h with a hydrogen gas flow rate of 20 mL/min and a catalyst-to-feed ratio of 1:100 (wt%). Compared with zirconia and sulfated zirconia, NiMo-impregnated sulfated zirconia showed the best activity and selectivity in bio-jet fuel production with liquid product and selectivity of 61.07% and 43.49%, respectively. This catalyst also performed well in three consecutive runs, with bio-jet fuel selectivity in the second and third runs of 51.68% and 30.86%, respectively. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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.

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.

Sustainable synthesis of bio-diesel and jet-fuel range hydrocarbons from poisonous Abrus Precatorius seed oil over MoO3-HPW/Ga-KIT-6

Energy problems and environmental deterioration can be combated by renewable biodiesel production from poisonous, waste, and non-edible oil seeds. Molybdenum oxide and phosphotungstic acid were impregnated into gallium-incorporated KIT-6 mesoporous silica employing a hydrothermal technique, to construct MoO3-HPW/Ga-KIT-6 catalyst. Abrus precatorius (Rosary Pea) seeds were utilized to extract non-edible oil, which was then submitted to a catalytic reaction with freshly prepared MoO3-HPW/Ga-KIT-6 for the synthesis of eco-friendly bio-diesel. An optimal biodiesel yield of 100% was reached from Abrus precatorius oil using MoO3(5)-HPW(10)/Ga (20)-KIT-6 catalyst at 6:1 methanol to oil molar ratio, 100 °C and 3 h reaction time. Oleic, linolenic, eicosapentaenoic, arachidic, and behenic acids were esterified under ideal conditions, and the 1H NMR spectroscopy revealed the result was an isolated methyl ester. Additionally, MoO3(5)-HPW(10)/Ga(20)-KIT-6 catalyst have been effectively produced C16–C18 range jet fuels from Abrus precatorius seed oil (APSO) and Abrus oil methyl ester (AOME) through the hydrodeoxygenation route at 400 °C, WHSV 2.7 h−1, 40 bar H2 pressure (62% of C18H38) and 400 °C, WHSV 1.8 h−1, 30 bar H2 pressure (67% of C18H38) respectively. The high dispersion of molybdenum and HPW on the Ga/KIT-6 catalyst and the more acidic centers, which promote the selectivity of the biodiesel and jet-fuel range hydrocarbons (JFRH), are credited with the good catalytic performance; this was demonstrated by HR-TEM and NH3-TPD (341 μmol/g) analyses.

Direct Synthesis of a Jet Fuel Range Dicycloalkane from Polycarbonate Waste at a High Concentration

Direct Synthesis of a Jet Fuel Range Dicycloalkane from Polycarbonate Waste at a High Concentration

High-Density Jet-Fuel Hydrocarbons from Biomass-derived Cyclic Ketones via Vapor Phase Hydrodeoxygenation over Ru-Ni2P/Al (10)-KIT-6

Jet-fuel range hydrocarbons such as 97.2% bi-cyclohexane, 94.1% di-cyclohexyl methane, and 95.6% trans-decalin have been produced selectively from biomass-derived cyclic ketones, namely, phenyl cyclohexanone (PCHO), benzyl cyclohexanone (BCHO), and α-tetralone (TLO), by vapor phase hydrodeoxygenation (VP-HDO). In this work, a mesoporous Ru-Ni2P bimetallic Al/KIT-6 catalyst was prepared hydrothermally with Si/Al = 10. Vapor phase hydrodeoxygenation over Ru-Ni2P/Al (10)-KIT-6 with hydrogen pressure of 50 mL/min, 300–450 °C of reaction temperature, and 2–10 h of time was carried out and attained the highest selectivity and conversion. Under optimal reaction circumstances (400 °C, 8 h, H2 = 50 mL/min), PCHO, BCHO, and TLO conversion over Ru (2.0)-Ni2P(4.0)/Al(10)-KIT-6 is 94.8, 96.2, and 92.7%, respectively. Ru particles on Ni2P promote C–O bond cleavage and complete ketone reduction, resulting in a synergistic interaction between Ru and Ni2P in VP-HDO catalysis. Jet-fuel hydrocarbon invention demonstrated the elimination of oxygen from BDK.

Upcycling waste polycarbonate plastics into jet fuels over NiCo/C by catalytic tandem hydropyrolysis/hydrodeoxygenation

Chemical upcycling of waste polycarbonate (PC) into jet fuels through catalytic tandem hydropyrolysis/hydrodeoxygenation (THH) is a practical strategy to generate value from polymer wastes. A process which combining hydropyrolysis with vapor phase hydrodeoxygenation (HDO) was proposed in a two-stage pressurized fixed-bed reactor. A cobalt-based Metal-Organic Framework (MOF) derived material supported with nickel was designed for the vapor-phase HDO of phenolic compounds derived from PC hydropyrolysis. The product distribution could be regulated by optimizing reaction pressure in the reactor and catalyst to PC mass ratio. Experimental results showed that the products are all phenolic compounds in the absence of catalysts, while a high yield of jet-fuel range cycloalkanes (100%) was obtained under optimized conditions (7 bar H2 pressure and 5:1 catalyst to PC mass ratio) over NiCo/C. The high HDO activity of NiCo/C depends on the synergistic effect of nickel and cobalt atoms, which facilitates the elimination of phenolic hydroxyl group and hydrogenation of benzene ring. This work puts forward an efficient approach for upcycling PC waste into jet fuels with MOF-derived NiCo/C as a catalyst.

Synthesis of high density and low freezing point jet fuels range cycloalkanes with cyclopentanone and lignin-derived vanillins

In this work, a “cyclopentanone-vanillin” strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation (HDO). Ethanolamine lactate ionic liquid (LAIL) exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin. Desired mono-condensation and bi-condensation products were obtained with yield of 95.2% at 100 °C. It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation. The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb2O5 catalyst. The density of the obtained HDO products is 0.89 g/cm3 and the freezing point is lower than −60 °C. These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels.

Potassium-modified bifunctional MgAl-SBA-15 for aldol condensation of furfural and acetone

Potassium modified acid–base bifunctionalized MgAl-SBA-15 for mild aldol condensation of furfural and acetone to high-quality jet-fuel range or chemical intermediates.

Converting polyisoprene rubbers into bio-jet fuels via a cascade hydropyrolysis and vapor-phase hydrogenation process

Producing alternative drop-in bio-jet fuels from biomass provides a promising approach to achieve carbon neutrality. To upcycle biomass-based polyisoprene rubbers into jet-fuel range C10 cycloalkane, we proposed a cascade hydropyrolysis and vapor-phase hydrogenation process in a flow-through two-stage pressurized fixed-bed reactor. The hydropyrolysis temperature in the first stage is of vital importance for the formation of primary limonene intermediate in the non-catalytic degradation of polyisoprene rubbers, and a reaction temperature of 460 °C maximized limonene yield to 588.6 mg/g for natural rubber and 546.2 mg/g for Eucommia rubber. Over a Pt/C catalyst loaded in the second stage, the limonene intermediate produced from the first-stage reactor can be completely hydrogenated, giving a 642.7 mg/g yield of jet-fuel range C10 cycloalkane with 83.6% selectivity. The depolymerization mechanism of polyisoprene rubbers was thoroughly studied, and a competitive reaction between limonene hydrogenation and limonene dehydrogenation was observed. This is the first report on producing C10 cycloalkane from natural rubbers via a cascade hydropyrolysis and hydrogenation process, providing a promising strategy to upcycle polyisoprene rubbers into bio-jet fuels.

Blend Prediction Model for the Freeze Point of Jet Fuel Range Hydrocarbons

Blend Prediction Model for the Freeze Point of Jet Fuel Range Hydrocarbons

Production of jet-fuel-range olefins via catalytic conversion of pentene and hexene over mesoporous Al-SBA-15 catalyst

The oligomerization of biomass-derived light olefins offers a promising potential for the synthesis of sustainable jet-fuels, which mostly comprise C10-C18 hydrocarbons. However, the selectivity control of oligomerization reaction remains a challenge. In this contribution, oligomerization of pentene and hexene mixtures was studied over acidic mesoporous Al–SBA–15 catalyst in continuous operation, and the impact of different process parameters on conversion and selectivity is thoroughly evaluated. Kinetics evaluation showed that the reactivity of pentene is higher than that of hexene. Selectivity to jet-fuel range products > 98 % were achievable at low-to-moderate conversions (<50 %), while higher conversions (ca. 90 %) resulted in selectivities of ca. 75 %. Notably, the product distribution at iso-conversion was unaffected by temperature, pressure, and weight hourly space velocity, implicating that adjusting the conversion is the primary way to tune the selectivity of the Al-SBA-15 catalyst. This understanding of the oligomerization process opens the door for the research devoted on the oligomerization of complex olefin mixtures, mimicking the process stream of olefins production units, in order to achieve “biomass to jet-fuel” transformation.

Production of jet-fuel range precursors from carbonyl model compounds in aqueous-phase pyrolysis oil of wood over La-based mixed oxides

Medium-chain oxygenates as jet-fuel range precursors were produced from carbonyl model compounds in aqueous phase pyrolysis oil via aldol-condensation reaction on La-based mixed oxides. LaCeOx with high medium-strength basic site density related to the tight metal‑oxygen pairs of mixed oxides produced a larger amount of adducts as compared with commercial MgO and LaOx. Water in the reactant appears to have a positive effect on LaCeOx catalyst having tight Lewis acid-base pairs with carbon balance up to 100%. Acetic acid in the solution affected the furfural conversion and the amount of adduct due to competitive adsorptions on active sites.

Polyethylene upcycling to fuels: Narrowing the carbon number distribution in n-alkanes by tandem hydropyrolysis/hydrocracking

The extensive use of plastics in modern life has resulted in a global waste crisis to the environment. Polyethylene (PE) is one of the most popular and hardest plastics to recycle because of its strong C(sp3)-C(sp3) bonds. In this report, a tandem conversion process, i.e., hydropyrolysis and subsequent vapor-phase hydrocracking of primary intermediates (Cn>5 alkenes and long-chain alkanes), was conducted via a two-step pressurized flow-through fixed-bed reactor over a CoAl2O4 spinel-derived catalyst. The product distribution could be flexibly tuned by regulating operating parameters in the cascade fixed-bed reactor and Co/Al molar ratio in CoAl2O4 spinel catalysts. Under optimal reaction conditions (0.2 MPa H2, 550 °C for hydropyrolysis in the 1st reactor, 300–325 °C for hydrocracking in the 2nd reactor, 20 s−1 of gas hourly space velocity), the maximum single-pass yields of gasoline (C5-C12) and jet-fuel (C8-C16) range n-alkanes reached 86.0 wt% and 68.1 wt%, respectively. The CoAl2O4 spinel catalysts also gained high activity in degrading realistic post-consumer plastics such as linear low-, low-, and high-density PE, and a ∼ 73.1 wt% gasoline yield and a ∼ 54.7 wt% C8-C16 yield were retained even after 3 cycles in-situ regeneration of deactivated CoAl2O4 catalysts. This work provides an efficient and tunable approach to upcycle PE wastes into liquid fuels with an ideal carbon length.

Experimental study on the impact of alternative jet fuel properties and derived cetane number on lean blowout limit

AbstractThe impact of alternative aviation jet fuels and their properties on lean blowout (LBO) limits has recently raised several questions in the jet fuel area. There is a need for a detailed investigation of the impact of fuel properties on the LBO limit involving actual engine hardware. This study investigates the impact of a range of alternative aviation jet fuels with notable differences in physical and chemical properties and derived cetane number (DCN) on the LBO limit and their effects on key performance indicators. LBO performance results for ten different alternative fuels using a Rolls-Royce single-can Tay combustor are presented in this study. The study also assesses impact of different equivalence ratios and flow rates on LBO, with the aim of determining the impact of a certain range of operating conditions. The results are further analysed to determine the influence of fuel chemical and physical properties on the LBO limit. Finally, based on results in the above experiments, individual fuel properties are adjusted for subsequent experimental analysis of blended fuels. With this approach, 25 additional fuel blends are evaluated and presented, with an emphasis on varying the DCN. This study provides effective data and results to facilitate future fuel optimisation and reduce the risk of a negative performance of new fuels in gas turbines.

Understanding the Compositional Effects of SAFs on Combustion Intermediates

This work analyses, experimentally and numerically, the combustion behavior of three aviation fuels: a standard Jet A-1, a high aromatic content fuel, and an isoparaffinic Alcohol to Jet (ATJ) fuel. The goal is to demonstrate the ability of a chemical kinetic model to capture the chemistry underlying the combustion behavior of a wide range of jet fuels, starting from compositional information. Real fuels containing up to hundreds of components are modeled as surrogates containing less than 10 components, which represent the chemical functionalities of the real fuel. By using an in-house numerical optimizer, the fuel components and their relative quantities are selected, and a semi-detailed kinetic model (containing about 450 species) is used to simulate the formation of the main oxidation products and reaction intermediates. Calculations are compared with species profiles measured in a laminar flow reactor to validate the model and provide insights into the reactivity of the fuels. Finally, starting from the results, general observations on the strengths and limits of the approach are provided, highlighting areas where further investigations are required.

Ni-based metal–organic frameworks prepared with terephthalic acid hydroxylation converted methyl palmitate into jet-fuel range hydrocarbons in CO2 atmosphere

To promote selectivity of jet fuel products in deoxygenation and cracking of microalgal biodiesel in CO2 atmosphere, terephthalic acid (BDC) was hydroxylated to prepare Ni-based metal–organic frameworks (Ni-MOFs) as efficient bifunctional catalysts to convert methyl palmitate into jet-fuel range hydrocarbons. The strong acid concentration of Ni-MOF catalyst increased from 0 to 0.75 mmol/g and active nickel atom content increased from 5.05 to 5.70% after BDC hydroxylation, due to enhanced coordinative unsaturated properties of nickel metal center. The Brunauer-Emmett- Teller surface area of Ni-MOFs catalyst increased from 57.6 to 901 m2/g after BDC hydroxylation. The deoxygenation occurred more readily than bond cracking of methyl palmitate, while C = C bond migration and lactonization were key steps in cycloalkane formation. The selectivity of jet-fuel range hydrocarbons products over BDC-hydroxylated MOF (Ni-DOBDC) catalyst increased from 68 to 82 %.

Production of Jet Fuel Range Alkanes by Oriented Synthesis of Single Aldol Condensation Product and Subsequent Hydrodeoxygenation

Production of Jet Fuel Range Alkanes by Oriented Synthesis of Single Aldol Condensation Product and Subsequent Hydrodeoxygenation

On the Role of Zr to Facilitate the Synthesis of Diesel and Jet Fuel Range Intermediates from Biomass-Derived Carboxides Over Aluminum Phosphate

On the Role of Zr to Facilitate the Synthesis of Diesel and Jet Fuel Range Intermediates from Biomass-Derived Carboxides Over Aluminum Phosphate