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Hydrogen (H 2) aircraft have been proposed for the "Fly Net Zero" target. The combination of jet fuel and H 2 was offered to successfully operate the jet engine with H 2 without further combustor modification. The current work used hydro-processed renewable jet fuel (HRJ) and experimentally investigated its combustion properties and H 2 addition in the constant volume combustion chamber (CVCC). Experiments were performed at the initial temperature (T i n i) from 600 K to 818 K, initial pressure (P i n i) 10, 15 bar and equivalence ratio (φ) = 0.5. Normal spray ignition (SPI) and direct injection spark ignition (DISI) were studied. Overall, HRJ has a shorter ignition delay (ID) for SPI. At 600 K, adding 10% and 20% H 2 to HRJ increased ID to 12.68% and 38.46%, respectively. As T i n i rose to 725 K, increment in ID was shortened to 5.96% and 20.47% with 10% and 20% H 2 addition, respectively. For DISI, at 600 K, adding 10% and 20% H 2 to HRJ shortens ID to 3.56% and 4.92%, respectively. When comparing the ID of DISI with the SPI, ID was shortened to 84.64% and 91.77% for 10% and 20% H 2 addition, respectively. Emission results showed that adding H 2 reduced CO 2 , while NOx emissions were increased. Ansys Chemkin-Pro was used to run numerical simulations of a zero-dimensional (0-D) closed homogeneous batch reactor model (CHBR). An existing HRJ mechanism was adopted, and H 2 elementary reaction rate constant factors were updated for better model predictions. The updated model was under prediction with the experimental ID periods. The simulation results showed that the reaction H 2 +OH = H + H 2 O is the primary cause for consuming OH radicals with H 2 addition, leading to an increase in fuel ID. At higher temperatures, two major reactions (HO 2 + H 2 = H 2 O 2 + H, and HO 2 +HO 2 = H 2 O 2 + O 2) followed by H 2 O 2 = OH + OH are accountable for reproducing OH radicals. Thus, the fuel ID was shorter. • The ignition performance is examined for H2-additive HRJ. • Both spray ignition and direct injection spark ignition were studied. • The addition of H2 reduced CO2, while NOx emissions were higher. [ABSTRACT FROM AUTHOR]

Summary: The role of single‐metal‐loaded on SAPO‐11‐based hydro‐processing catalyst to produce renewable jet fuel was investigated in this work. First, three metals, nickel, cobalt, and molybdenum, were selected to be loaded on SAPO‐11 separately and their activities were tested over the model feedstock, n‐hexadecane. Among the three catalysts, nickel SAPO‐11 shows the highest conversion of 70%. Second, the performance of Ni/SAPO‐11, synthesized with (Ni/SAPO‐11(CA)), and without (Ni/SAPO‐11) citric acid was investigated with the hydro‐processed alkanes derived from palm oil for the production of hydro‐processed renewable jet fuel (HRJ). Catalyst metal particle size, structure, textural properties, acidity, and reduction degree were detected through transmission electron microscope (TEM), X‐ray diffraction (XRD), N2 adsorption/desorption, pyridine‐adsorbed infrared spectroscopy (Py‐IR), and temperature programmed reduction (TPR). The product compositions over the Ni/SAPO‐11(CA) catalyst show higher selectivity toward the carbon chain length of jet fuel (C8‐C14) for 48% compared to the Ni/SAPO‐11. Through the Taguchi method, the optimal operating conditions were found to be: temperature of 380°C, pressure of 52 bar, liquid hourly space velocity of 0.5 h−1, and H2‐to‐feedstock ratio of 1250, which yielded in 73% conversion to HRJ with 6.1 isomer‐to‐normal (I‐to‐N) alkane ratio. The derived cetane number (DCN) and the flash point of HRJ were also obtained to be 56 and 56°C to confirm the compatibility of HRJ with conventional jet fuel. [ABSTRACT FROM AUTHOR]

In this study, process simulation and techno‐economic analysis (TEA) were conducted to evaluate the production of renewable jet fuel (RJF) through the pyrolysis‐to‐RJF process. The process model was developed based on experimental results for the renewable jet fuel production process using the fast pyrolysis of rice husk, hydro‐processing of pyrolytic oil, and hydro‐cracking / isomerization of hydro‐processed oil. The mass and energy flows were input into the TEA model, which was established based on local conditions in Taiwan. The study included three parts: (1) the mass, energy and carbon balances – the major product, RJF, gave an energy yield of 26.8%, a mass yield of 9%, and a carbon yield of 21%; (2) an economic analysis – the MJSP of RJF for the pyrolysis‐to‐RJF process was $3.21/L, based on the plant capacity of 600 tonnes per day; (3) a sensitivity analysis: the impacts of the feedstock cost, catalyst life, co‐product selling price, catalyst cost, hydrogen cost, and plant capacity were discussed. This study demonstrated the economic potential of locally developing a pyrolysis‐to‐RJF process to produce RJF from solid biomass. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

• The pyrolytic oil derived from waste SBR is considered to be used in aviation. • With addition of SBR, CO2, NOx and unburned HC emissions are reduced. • The measured ID and NTC were replicated using a reduced mechanism. Owing to the similar carbon range in components, the pyrolytic oil derived from waste styrene–butadiene rubber (SBR) is preferred in aviation, for achieving waste-to-energy and fly net zero missions. The present study investigated the combustion and emission characteristics of SBR using a constant volume combustion chamber (CVCC) spray at 673–873 K initial temperature (T ini), 10 and 15 bar initial pressure (P ini), and 0.5 equivalence ratio (φ). SBR combustion properties were benchmarked with conventional jet propellant 5 (JP-5), and JP-5 and SBR were blended at a 50% volume ratio (JP-5-SBR-50). SBR has a shorter ignition delay (ID) and combustion delay (CD) at 15 bar Pini, compared to 10 bar. SBR exhibits negative temperature coefficient (NTC) behavior starting from T ini = 773–823 K, which was more significant at 10 bar. In the NTC region, at T ini = 723 and 823 K, the ID nearly has a 3-fold variation between 10 and 15 bar, and CD has 4- and 1.7-fold variations at T ini = 723 and 823 K, respectively. Finally, τ has a 3- and 1.5-fold variation at T ini = 723 and 823 K. JP-5 has a shorter ID and CD, followed by JP-5-SBR-50 and SBR. At T ini = 673 K, the addition of JP-5 to SBR significantly shortened ID and CD by nearly 24% and 17.5%. JP-5 has higher CO 2 , thermal NOx, and unburned HC emissions, whereas those were reduced with SBR addition to JP-5. Moreover, CO emissions at the SBR NTC region (773–823 K) gradually increased more than at any other tested T ini. Meanwhile, the measured ID periods and NTC characteristics for SBR were replicated using a reduced mechanism of 106 species and 2,162 reactions. The reduced mechanism also predicted the measured SBR inhibition effect on the ID periods for JP-5. [ABSTRACT FROM AUTHOR]

This study considered the techno-economic evaluations for the economic feasibility of jatropha derived hydro-processed renewable jet (HRJ) fuel, starting from the farming processes to the refinery (fruit-to-fuel) processes, based on the situations in Taiwan. The farming processes included plantation, growing and harvesting. The fruit-to-fuel processes included fruit dehulling, shell combustion, oil extraction, pyrolysis of press cake, oil refinery and product separation. In addition, the calculated minimum jet fuel selling price (MJSP) was compared to the cases from two different countries (Thailand and Cambodia) and to the scenario without cultivation. The MJSP of the Taiwan case, $6.25/L jet fuel, was higher than the cases of Thailand and Cambodia as well as the without-cultivation scenario. Moreover, according to the annual aviation fuel consumption from one of the aviation companies in Taiwan, the MJSPs of various blending fractions were calculated and compared with the cases of Thailand and Cambodia. [ABSTRACT FROM AUTHOR]

The feedstock has been the most significant issue for promoting a sustainable and economical renewable aviation fuel in Taiwan. In this study, the potential feedstocks available for producing hydro-processed renewable jet (HRJ) fuel locally in Taiwan were evaluated economically through the process simulation and techno-economic analysis. The productivities, H 2 consumptions, product distributions and properties of the produced fuel, which strongly depend on the fatty acid content within the oil/fat feedstocks, were demonstrated and discussed. The baseline economics, sensitivity analyses and pioneer plant analyses were also conducted in accordance with the simulation results. The minimum aviation fuel selling prices (MAFPs) of all feedstocks were calculated ranging from $0.91/L∼ $2.74/L. The feedstock costs, prices of hydrogen, prices of hydro-processing catalyst and plant capacities have influences on the selling prices of renewable aviation fuel by 54%, 18%, 12% and 11%, respectively. Furthermore, although the greases have the most economical benefits among the selected feedstocks, the feedstock pretreatment processes lead to the complexity of the production and result in higher pioneer plant costs compared to the ones of plant oils. This study provides the suggestions for the government to locally select an appropriate HRJ feedstock. Image 1 • The process simulation and TEA were conducted to evaluate HRJs from 12 feedstocks. • The MAFPs of all feedstocks were calculated as $0.91/L∼ $2.74/L. • Greases obtain high productivity but have relatively high pioneer plant costs. [ABSTRACT FROM AUTHOR]

Abstract Renewable aviation fuel produced from hydro-processing has been a commercially available technique currently. Studies conducted recently were toward finding an appropriate catalysts to produce the jet fuel range products with high normal alkanes and low aromatics. This study focused on hydro-processing of waste cooking oil (WCO) into straight alkanes, which can serve as the blendstock for aviation fuel after further cracking and isomerizing, over two different catalysts, pre-sulfurized NiMo/γ-Al 2 O 3 and Pd/C, under various experimental conditions such as reaction temperature, pressure, liquid hourly space velocity (LHSV) and H 2 -to-oil ratio. The resulting liquid and gas products from the two catalysts were analyzed through GC-MS/FID and GC-TCD for judging the performances of hydro-deoxygenation (HDO) as well as decarboxylation (DCO2)/decarbonylation (DCO). The fresh and spent catalysts were examined through XRD, FTIR, TGA and SEM to characterize the catalysts before and after hydro-processing. The performance of Pd/C, based on the concentrations of produced C 15 ∼C 18 normal alkanes, was higher than NiMo/γ-Al 2 O 3 with low reaction temperature, low hydrogen pressure, low LHSV, low H 2 -to-oil ratio and short time-on-stream. Highlights • Fresh and spent NiMo/γ-Al 2 O 3 and Pd/C were examined by XRD, FTIR, TGA and SEM. • HDO/decarbonylation/decarboxylation were studied with various reaction conditions. • Pd/C was found to be better than NiMo/γ-Al 2 O 3 for producing C 15 -C 18 alkanes. [ABSTRACT FROM AUTHOR]

HRJ (Hydro-processed Renewable Jet) conversion technology has been recently used to produce renewable jet fuel for commercial or military flights. In this study, a techno-economic analysis is carried out for evaluating the production of jatropha-derived HRJ fuel through a bio-refinery process. Each component of the chosen feedstock jatropha can be converted into valuable products. The bio-refinery process is split into 6 parts: (1) Fruit Dehulling; (2) Shell Combustion; (3) Oil Extraction; (4) Press Cake Pyrolysis; (5) Oil Upgrading; (6) Product Separation. The minimum jet fuel selling price (MJSP) from this fruit scenario is calculated to be $5.42/gal based on the plant capacity of 2400 metric tonne of feedstock per day. The co-products obtained from the process not only significantly deduct the production cost but make the entire process energy self-sustainable. We also discuss the oil scenario, which oil is the starting material and the process begins from Oil Upgrading section. The oil scenario offers the MJSP of $5.74/gal with lower capital but higher operating costs. The differences of MJSPs for fruit and oil scenarios are due to feedstock cost, refinery capital cost, co-product credits and energy cost. Based on the sensitivity analysis, the feedstock price, oil content, plant capacity, reactor construction and catalyst usage are important parameters that control the price of the produced fuel. [ABSTRACT FROM AUTHOR]

Ozone (O 3) addition combustion is a trending technique to enhance the ignition characteristics of hydrocarbon fuel. In this study, the spray ignition characteristics of jet fuel along with hydrogen (H 2) and O 3 seeding were experimentally investigated and numerically simulated with an updated chemical kinetic model. The ignition delay (ID) period of jet propellant 5 (JP-5) with H 2 /O 3 addition was measured using a constant volume combustion chamber (CVCC) at 600 K to 818 k, the pressure of 15 bar, equivalence ratio of 0.5. The intake manifold was added with air, H 2 (10%, and 20% volume fraction), and 2000 ppm ozone (O 3). In general, pure JP-5 has a shorter ID than those obtained with H 2 addition. At 600 K, with 10% and 20% H 2 to JP-5, the ID was increased by 18.49%, and 35.12% respectively. When O 3 was added, the ID of JP-5 was shortened by 10%, while for 10% and 20% H 2 addition, the ID was shortened by 19.25% and 22.5%, respectively. An existing jet fuel mechanism was chosen and validated with the previous and the present study experimental ID. The model was in agreement with the practical ID. The H 2 -mechanism rate constants were updated with the recently optimized values available in the literature to reflect the newly obtained experimental data at low temperatures. An existing sub-mechanism of O 3 was adopted and combined with the JP-5 model. The updated model was validated with the present study ID data. Good predictions were noticed between the model and JP-5 experimental ID. However, a small deviation of 5.01% and 0.71% was found for 10%, and 20% H 2 ID at 600 K. The reaction H 2 + OH = H 2 O + H and HO 2 + HO 2 = H 2 O 2 + O 2 were found to be the critical reactions responsible to reduce the systems reactivity and makes the fuels ID to become longer. The O-atom from O 3 was decomposed through the reaction O 3 + N 2 = O 2 + O + N 2 , and O 3 + O 2 = O 2 + O + O 2 at an early stage of combustion. Due to H 2 addition to O 3 and air, the early formation of OH radicals is due to O 3 + H = O 2 + OH, which further accelerates the oxidation of the fuel, resulting in a shorter ID. [ABSTRACT FROM AUTHOR]

• An RCM is developed to study jet fuel ignitions at low-to-intermediate temperature. • High H/C and low cyclic molecules improve the fuel reactivity. • Double compression pressure shortens the ignition delay by 59 % The combustion characteristics of jet fuels, including conventional (Jet-A1 and JP-5) and renewable (hydro-processed renewable jet, HRJ) jet fuels at low-to-intermediate temperatures were studied in a rapid compression machine (RCM). Compression pressures were varied at 10, 15, and 20 bar under a low temperature combustion regime (626 K-874 K). Fuel/oxidizer mixture conditions were created in order to investigate the auto-ignition delays responding to various equivalence ratios of 0.25 and 0.5. Longer auto-ignition delays were observed with a leaner fuel/oxidizer mixture (ϕ = 0.25) by as much as 79.2% as compared to the richer mixture condition (ϕ = 0.5). Doubling the compression pressures from 10 to 20 bar led to the reduction of the auto-ignition delays by as much as 58.8%. The negative temperature coefficient (NTC) regime was found to be strongly related to the changes in the equivalence ratio, where the NTC formation is clearly observed at lower equivalence ratio of 0.25 for all the tested fuels. In addition, the renewable jet fuel exhibited a shorter auto-ignition delay by as much as 54.5% as compared to Jet-A1 and JP-5 at equivalence ratio of 0.5. The higher hydrogen-to-carbon (H/C) ratio and lower concentration of cyclic molecules in the HRJ were among the reasons for the reactivity improvement compared to the petroleum jet fuels. [ABSTRACT FROM AUTHOR]

The commercial production of jet fuel from camelina oil via hydrolysis, decarboxylation, and reforming was simulated. The refinery was modeled as being close to the farms for reduced camelina transport cost. A refinery with annual nameplate capacity of 76,000 cubic meters hydrocarbons was modeled. Assuming average camelina production conditions and oil extraction modeling from the literature, the cost of oil was 0.31 $ kg −1 . To accommodate one harvest per year, a refinery with 1 year oil storage capacity was designed, with the total refinery costing 283 million dollars in 2014 USD. Assuming co-products are sold at predicted values, the jet fuel break-even selling price was 0.80 $ kg −1 . The model presents baseline technoeconomic data that can be used for more comprehensive financial and risk modeling of camelina jet fuel production. Decarboxylation was compared to the commercially proven hydrotreating process. The model illustrated the importance of refinery location relative to farms and hydrogen production site. [ABSTRACT FROM AUTHOR]

Abstract: Fuel spray and atomization characteristics play an important role in the performance of internal combustion engines. As the reserves of petroleum fuel are expected to be depleted within a few decades, finding alternative fuels that are economically viable and sustainable to replace the petroleum fuel has attracted much research attention. In this work, the spray and atomization characteristics were investigated for commercial No. 2 diesel fuel, biodiesel (FAME) derived from waste cooking oil (B100), 20% biodiesel blended diesel fuel (B20), renewable diesel fuel produced in house, and civil aircraft jet fuel (Jet-A). Droplet diameters and particle size distributions were measured by a laser diffraction particle analyzing system and the spray tip penetrations and cone angles were acquired using a high speed imaging technique. All experiments were conducted by employing a common-rail high-pressure fuel injection system with a single-hole nozzle under room temperature and pressure. The experimental results showed that biodiesel and jet fuel had different features compared with diesel. Longer spray tip penetration and larger droplet diameters were observed for B100. The smaller droplet size of the Jet-A were believed to be caused by its relatively lower viscosity and surface tension. B20 showed similar characteristics to diesel but with slightly larger droplet sizes and shorter tip penetration. Renewable diesel fuel showed closer droplet size and spray penetration to Jet-A with both smaller than diesel. As a result, optimizing the trade-off between spray volume and droplet size for different fuels remains a great challenge. However, high-pressure injection helps to optimize the trade-off of spray volume and droplet sizes. Furthermore, it was observed that the smallest droplets were within a region near the injector nozzle tip and grew larger along the axial and radial direction. The variation of droplet diameters became smaller with increasing injection pressure. [Copyright &y& Elsevier]

• Ignition delays were dependent on chamber pressures, temperatures, and the global equivalence ratio. • HRJ fuel exhibited a shorter ignition delay compared to petroleum jet fuels. • Cyclo-alkanes and aromatics affect the fuel reactivity and ignition acceleration. In this study, the spray ignition characteristics of conventional aviation fuels (JP-5 and Jet-A1) and hydro-processed renewable jet fuel (HRJ) were investigated in a constant volume combustion chamber at chamber pressures of 10, 15, and 20 bar and temperatures ranging from 600 K to 818 K. It was found that all the ignition delays profile were shortened exponentially with increases in the chamber temperature. The HRJ fuel was found to obtain a shorter ignition delay as compared to JP-5 and Jet-A1 by as much as 74% and 67%, respectively. In addition, the first stage ignition delay for HRJ fuel was 50% shorter than that for the petroleum jet fuels. The reactivity of the fuels increased with increases in the chamber pressure. The HRJ fuel was 1 ms and 2 ms earlier than Jet-A1 and JP-5, respectively, in terms of achieving a combustible mixture at low and intermediate chamber pressures. The chamber pressure was also found to be sensitive to the formation of the NTC zone for all of the tested fuels. [ABSTRACT FROM AUTHOR]

Hydro-conversion of triglyceride to renewable jet fuel (HRJ) plays an important role in drop-in aviation fuels and has drawn the attention of scholars because of its potential to reduce aircraft pollution and mitigate greenhouse gas emissions. A direct one-step conversion of glyceride-based oil into HRJ over NiAg supported on SAPO-11 zeolite was investigated in this paper. Also, the properties of the catalysts were characterized using XRD, TEM, N 2 adsorption-desorption, TG and Py-FTIR. The NiAg/SAPO-11 catalyst showed good performance in terms of hydro-processing, hydro-cracking, and hydro-isomerization reactions with the assistance of citric acid (CA) and phosphotungstic acid hydrate (HPW). The key to high conversion, high selectivity, and high iso-alkane content depended mostly on the reaction temperature, metal dispersion, acid content and the pore structures of the zeolite. Furthermore, the fuel properties were tested in a GC-MS/FID and flash point tester to ensure to meet the ASTM D7655 specifications. Under the optimal reaction conditions, a conversion of 100%, selectivity of 84%, an I-to-N ratio of 2.1, a yield of 72%, an aromatics content of 7%, and a flash point of 58 °C were obtained. The mass, carbon and energy yield for both one-step and two-step processes were also determined. This study provides a novel technique for producing renewable jet fuel with higher production yield. Image 1 • One-step conversion of glyceride-based oil into HRJ over NiAg/SAPO-11 was studied. • Under the optimal conditions, a 100% conversion and 84% selectivity were obtained. • An 2.1 I-to-N ratio, 72% yield and 7% aromatics content were obtained. [ABSTRACT FROM AUTHOR]

In this study, the surrogates of long chain paraffins produced from waste cooking oil through hydro-processing was hydro-cracked and hydro-isomerized for studying the process for producing renewable aviation fuel, through carrying out the experiments with varying reaction temperature, pressure, H 2 -to-alkane ratio and weight hourly space velocity (WHSV) over the home-made NiAg/SAPO(silicoaluminophosphate)-11catalyst. The data of conversion, selectivity, isomer yield and isomer-to-normal (I-to-N) alkane ratio were determined for evaluating the performance of the catalyst. The catalyst characterizations of the fresh and spent catalysts were examined through the technologies of Scanning Electron Microscopy (SEM), powder X-ray diffraction (XRD), thermo-gravimetric analysis (TGA) and fourier-transform infrared (FTIR) spectroscopy. It was found that the rearrangement of vapor-liquid equilibrium and increase in residence time by adjusting the operating conditions improved the performance of hydro-cracking/isomerization. In addition, based on the results of catalyst characterizations, the unreacted feed was dispersed onto the surface of the catalyst, expected to deactivate the catalyst. • Surrogate of hydro-processed alkanes was converted by max. 71% over NiAg/SAPO-11. • The selectivity of jet fuel, I-to-N alkane ratio reached 88% and 1.5 respectively. • Catalyst activity would be reduced due to the blockage of pore by unreacted feed. [ABSTRACT FROM AUTHOR]

The application of renewable jet fuel is an eco-friendly technique that can reduce greenhouse gas emissions. Based on existing commercial processes, this study aimed to evaluate the hydro-conversion processes for producing renewable jet fuel. Three process scenarios were compared, in which the feedstock used cooking oil (UCO) is converted to hydroprocessed renewable jet fuel (HRJ) and its byproducts. Then, the investment feasibility of the three processes was evaluated through an economic analysis and predicted by an uncertainty analysis. The results show that if the main product (HRJ) is the profit target, one-step conversion is the best choice. However, if we consider the overall economic benefits, the three-step conversion method is more suitable with an average more 11.94% chance of profiting than the one-stage under uncertain analysis, which means it is a considerably competitive approach with lower risk and only 0.31 $/L of minimum selling price of jet fuel (MJSP), because it has the advantages of a wider range application and higher value of byproducts which reduce the risk of a single factor contribution. From the sensitivity analysis, jet fuel price is the key factor which contributes 75–82% for one- and two-stage processes, but UCO price in three-stage process reach nearly 50%. In addition, due to the economic scale, scaling up the plant capacity will lead higher economic benefits. Therefore, an efficient UCO recovery system and three-stage process are the keys for the industrial development aspect through the value-chain analysis under uncertainty. Image 1 • One-, Two- and three-step processes for producing renewable jet fuel are compared. • Three-stage process will have an average more 11.94% chance of profiting. • Jet fuel price contributes 75–82% for one and two-stage processes. • UCO recovery system is important due to the benefits from scaling up the capacity. • Three-step process is the most suitable one for overall economic benefits. [ABSTRACT FROM AUTHOR]

Producing renewable jet fuels from solid waste contributes greatly on circular economy with respect to the energy, environment and economics. The feedstock sources are resolved, the solid wastes are re-used, the pollution from aircrafts are reduced and the air energy is renewed. In this study, the rice husk biomass, which has been a headache agriculture waste in Taiwan, was turned into products similar to traditional jet fuel through fluidized bed fast pyrolysis, hydro-processing and hydro-cracking/isomerization, in which significant increases in normal alkanes, iso-alkanes and cycloalkanes were found. The final product from hydro-cracking/isomerization contained appropriate amount of normal, iso-, and cyclo-alkanes, which made it suitable to be the replacement for jet fuel. • Renewable jet fuel was produced from local agriculture wastes. • Process includes fast pyrolysis, hydro-processing and hydro-isomerization/cracking. • Final fuel contains proper amount of normal, iso- and cyclo-alkanes similar to JP5. [ABSTRACT FROM AUTHOR]

Bio-jet fuel currently represents one of the solutions for reducing the emissions from aircraft without engine modifications. This study mainly focused on producing the jet fuel blendstock from glyceride-based oil through hydro-processing and hydro-cracking/isomerization. The palm oil was selected as the glyceride-based feedstock and was first converted into hydro-processed alkanes within the diesel range through hydro-processing, which has been reported in the authors' previous work. The hydro-processed alkanes, in this paper, were turned into jet fuel range products through hydro-cracking/isomerization over the nickel-silver (NiAg) supported on silico-aluminio-phosphates (SAPO-11) catalyst. Catalyst characterizations were first performed through XRD for the fresh and used catalysts for understanding the performance of the catalyst during the reaction. The effects of the reaction parameters such as temperature, pressure, and liquid hourly space velocity (LHSV) on the carbon distributions, isomer-to-normal (I-to-N) alkane ratios and aromatics contents were investigated to find the proper conditions for producing bio-jet fuel over the NiAg/SAPO-11 catalyst. [ABSTRACT FROM AUTHOR]

• Soot formation of HRJ and petroleum jet fuels have been studied. • The soot particle morphology of the fuels was characterized using TEM. • The order of soot volume fraction: JP-5 > Jet-A1 > HRJ. • The fuel with higher H/C ratio has lower soot volume fraction. In this study, the soot formation behavior of hydro-processed renewable jet and petroleum jet fuels (Jet-A1, and JP-5) was investigated using a laminar counter-flow diffusion flame. Laser-induced incandescence was utilized to measure the soot volume fraction. The soot particle morphology of the fuels was characterized using transmission electron microscopy (TEM). It was found that the highest soot volume fraction was obtained in the following order: JP-5 > Jet-A1 > HRJ. Modifications to the reactant concentrations were observed to strongly influence the soot volume fraction by as much as 81%, 60%, and 64% for HRJ, JP-5, and Jet A1, respectively, and led to an increase in the soot particle diameter by as much as 26%, 15% and 10% for HRJ, JP-5, and Jet-A1, respectively. Both petroleum jet fuels reported soot particle diameters that were double those of the HRJ fuels. The fuel with higher H/C ratio (i.e. HRJ) had the lowest soot volume fraction. The smoke point results were found to have a positive correlation with the soot volume fraction for all of the tested fuels. [ABSTRACT FROM AUTHOR]