Production Of Aviation Research Articles

Design considerations of an integrated thermochemical/biochemical route for aviation and maritime biofuel production

Abstract An integrated thermochemical-biochemical Biomass-to-Liquid (BtL) pathway for the production of aviation and maritime liquid fuels from biogenic residues is introduced. The presence of a semi-commercially proven technology like Dual Fluidized Bed Gasification (DFBG) ensures extended fuel flexibility, syngas of high quality, complete fuel conversion, and optimal heat integration while avoiding CAPEX (Capital Expenditure) intensive equipment like air separation unit. Then, a two-stage biochemical route is proposed: initially syngas fermentation (anaerobic) into acetate and subsequently acetate fermentation (aerobic) into targeted triglycerides (TAGs) that will be finally purified and hydrotreated to form the desired drop-in biofuels. The tolerance of the bacteria to syngas contaminants minimizes the gas cleaning requirements. Moreover, the low-pressure requirements (1–10 bar) along with the mild operating temperatures (30–60 °C) reduce drastically the capital and operational cost of the process. The biological process of syngas fermentation inherently has limited side products, a fact that reduces the risk of deactivation of hydrotreatment catalysts. Heat and mass balances are calculated for the proposed concept via full-scale process simulations in Aspen Plus™ assuming a thermal input of 200 MWth with crushed bark as feedstock. Three different operational scenarios are examined mainly through overall performance indicators such as carbon utilization (CU) and energetic fuel efficiency (EFE). Competitive performance compared to technologies that exploit similar feedstock (i.e., biogenic residues) was noticed, since values in the range of 22–27% and 31–37% were obtained for the CU and EFE, respectively. The aim of this study is to determine the appropriate key process specifications and assess the potential of the proposed concept compared to other competitive technologies.

Computational approach to thermal-stressed state modeling of tire based on the algorithm of its self-heating analysis . Part 1 – Theoretical basics of the approach

Elastomers and their composites are widely used in modern innovative technology: for the production of aviation and automobile tires, anti-vibration elements (rubber, rubber-metal springs), dampers, elastomeric bearings. Also they are used in shaft suspensions, as spacers between structural parts, supporting parts and fasteners. Elastomeric elements of structures have a high dynamic load, in particular of a cyclic nature, which is accompanied by the formation of hysteresis loops and, as a result, the occurrence of the phenomenon of self-heating. An increase in temperature in the middle of materials causes significant changes in their mechanical properties, reduces strength characteristics, accelerates aging and degradation processes, and has a significant impact on fatigue processes. In addition, an increase in temperature causes an additional thermal stress state, capable of significantly changing the qualitative picture of the structure's deformation characteristics' distribution. Thus, the purpose of this study is development of approach to assessing the thermal stress state of structures made of elastomeric materials for the possibility of further analysis of its influence on the structure work as a whole. The appropriate approach was built on the basis of numerical modeling of thermal and deformation processes which takes place into the structure during operation. The proposed approach includes several related calculations by using FEM and is based on the fundamental approaches of the theories of elasticity and viscoelasticity, thermal conductivity and thermo-elasticity. Thus, the article presents an approach to the analysis of the thermal stress state of structural elements under operating conditions. This approach was applied to determine the thermo-strain-stress characteristics of a pneumatic tire and corresponding pictures of its distribution were obtained.

Process integration of KOH/diatomite preparation and cyclopentanone self-condensation via ball-milling method

Cyclopentanone self-condensation is an attractive reaction for the production of sustainable aviation fuel. However, the catalysts used for this reaction are usually complex or time-consuming to prepare. The reaction also needs to be carried out at a high temperature and over a long reaction time. In this paper, an integrated process for catalyst preparation and self-condensation via the ball-milling method was proposed. Compared with the thermocatalytic method, this process can be implemented with higher product yield (98.6% vs. 85.0%), lower energy demand (0.43 kWh·g−1 vs. 1.31 kWh·g−1), less preparation and reaction time (3 h vs. 32 h) at room temperature. According to characterizations, the excellent catalytic activity of catalysts prepared by the ball-milling method can be attributed to two reasons: (i) Smaller particles are formed during the ball-milling process, which is more conducive to catalyst and reactant contact during the reaction; (ii) Less moisture is absorbed by the catalyst, which has a positive effect on catalytic activity.

Techno-economic assessment of jet fuel production using the Fischer-Tropsch process from steel mill gas

In order to reduce human-made global warming, the aviation industry is under pressure to reduce greenhouse gas (GHG) emissions. Production of sustainable aviation fuel (SAF) from steel mill gases could help reduce the emissions intensity of jet fuel. This study presents a simulation, techno-economic assessment, and GHG emissions assessment of a Fischer-Tropsch (FT) process using two steel mill gases (coke oven gas and blast furnace gas) as feedstock. The process was analysed both with and without carbon capture and storage (CCS) to reduce process emissions. The minimum viable selling price (MVSP) was determined to be 1,046 €/tonne for the standard scenario and 1,150 €/tonne for the CCS scenario, which is higher than the fossil-fuel-based benchmark (325–1,087 €/tonne since 2020), although similar to the lowest costs found for other SAF benchmarks. The GHG emissions intensity was found to be 49 gCO2-eq./MJ for the standard scenario and 21 gCO2-eq./MJ with CCS, far lower than the 88 gCO2-eq./MJ average for the conventional benchmark and in the mid-lower range of found emissions intensities for other SAF benchmarks. When a CO2 tax of 130 €/tonne is considered, the MVSP for the standard scenario increases to 1,320 €/tonne while the CCS scenario increases to 1,269 €/tonne, making them cost-competitive with the fossil-fuel benchmark (797–1,604 €/tonne). The studied process offers economically viable small-to-medium scale SAF plants (up to 50 kt/y SAF) at a CO2 tax of 190 €/tonne or higher for the CCS scenario and 290 €/tonne or higher for the standard scenario.

Production of aviation fuel with negative emissions via chemical looping gasification of biogenic residues: Full chain process modelling and techno-economic analysis

The second-generation bio aviation fuel production via Chemical Looping Gasification (CLG) of biomass combined with downstream Fischer-Tropsch (FT) synthesis is a possible way to decarbonize aviation sector. The CLG process has the advantage of producing undiluted syngas without the use of an air-separation unit (ASU) and improved syngas yield compared to the conventional gasification processes. This study is based on modelling the full chain process of biomass to liquid fuel (BtL) with LD-slag and Ilmenite as oxygen carriers using Aspen Plus software, validating the model results with experimental studies and carrying out a techno-economic analysis of the process. For the gasifier load of 80 MW based on LHV of fuel entering the gasifier, the optimal model predicts that the clean syngas has an energy content of 8.68 MJ/Nm3 with a cold-gas efficiency of 77.86%. The optimized model also estimates an aviation fuel production of around 340 bbl/day with 155 k-tonne of CO2 captured every year and conversion efficiency of biomass to FT-crude of 38.98%. The calculated Levelized Cost of Fuel (LCOF) is 35.19 $ per GJ of FT crude, with an annual plant profit (cash inflow) of 11.09 M$ and a payback period of 11.56 years for the initial investment.

Catalytic hydroprocessing of waste cooking oil for the production of drop-in aviation fuel and optimization for improving jet biofuel quality in a fixed bed reactor

Waste cooking oil (WCO) is a bio-waste with significant potential for developing improved transportation fuel, specifically for the aviation industry. This work investigates the catalytic hydrocracking of WCO over commercial hydrocracking catalyst (Ni-Mo/silica-alumina) in a continuous flow fixed bed reactor to produce jet range hydrocarbons (HCs). The aim was to convert WCO into sustainable aviation and automotive fuel to get the maximum benefit from waste oil with high selectivity towards paraffins, naphthenes, minimal aromatics, and high isomerization (isomer to normal (i/n) ratio) in a single-step process using a single catalyst composition. The higher i/n ratio boosts specific energy, thermal stability and provides a low freezing point to the fuel. The results show that WCO conversion of 96.6 % with 55.6 % selectivity of jet range HCs was obtained at 420 °C temperature, 1 h−1 LHSV, 10 MPa pressure, and 2200 NLgas/Lliquid H2/oil ratio. In addition, isomer yield of 82.9 %, i/n ratio of 4.8, and selectivity of kerosene range HCs based on paraffins (43.6 %), naphthenes (8.2 %), and aromatics (3.73 %) was obtained at optimum reaction conditions. After hydroprocessing, the major fraction of heteroatoms (N = 99.9 %, S = 94.3 %, O = 99.9 %) was removed from WCO. Finally, the time on stream (TOS) study showed no deactivation of the catalyst up to 590 h, indicating the long life and stability of the catalyst, which is one of the highest lifetimes reported so far. Bio-jet fuel properties were tested according to the ASTM D-1655 standard. This research will aid in developing novel catalysts for the selective conversion of WCO into jet range HCs in a single step process.

Computer aided-design of castor bean fruit-based biorefinery scheme to produce sustainable aviation fuel

In the aviation sector, the production and use of renewable aviation fuel is one of the most suitable alternatives to embrace its sustainable development. For this, the evaluation of different raw materials and processing schemes is required. In Mexico, the energy crop with more potential for the production of renewable aviation fuel is Higuerilla (Ricinus communis L.), also known as castor bean, which does not require fertilizers or pesticides. Thus, in this work, the conversion of the castor bean fruit through a biorefinery scheme to produce sustainable aviation fuel, other biofuels and value-added products is proposed. The biorefinery scheme, modelled in Aspen Plus, considers four main processing zones to generate platform and sale products. Results indicate that biojet fuel represents the 43% of total hydrocarbons produced, which is roughly 300 times higher than the actual demand of the 12 main Mexican airports. The biorefinery consumes 10.46% of generated power by turbines; thus, it is self-sufficient in terms of electricity requirements. Nevertheless, its invested energy by heating is 31.52 higher than the energy provided by the products and the MSP of biojet fuel is 22.93 times higher than its price in the market; thus, it is necessary to reduce the energy consumption for improving the profitability of the process.

Anaerobic environment as an efficient approach to improve the photostability of fatty acid photodecarboxylase

Fatty acid photodecarboxylase of Chlorella variabilis NC64A (CvFAP) is a novel photoenzyme with great potential in the treatment of waste lipids and production of sustainable aviation fuel. However, the fragile nature of CvFAP to blue light is an urgent challenge. Herein, we demonstrated anaerobic environment could significantly improve the photostability of CvFAP for the first time. The decarboxylation of palmitic acid by CvFAP for 3 h under anaerobic environment increased pentadecane yield by 44.7% as compared to that under aerobic environment. The residual activity of CvFAP after blue-light preillumination in the absence of palmitic acid for 0.5 h under anaerobic environment was 80.4%, which was 258.7 times higher than that under aerobic environment. Remarkable accumulation of superoxide radical and singlet oxygen in CvFAP under aerobic environment led to the poor photostability of CvFAP. Anaerobic environment helped to mitigate the production of superoxide radical and singlet oxygen in CvFAP, improving the photostability of CvFAP.

Fighting Climate Change with Synthetic Biology

Fighting Climate Change with Synthetic Biology

Catalytic hydrocracking of inedible palm stearin for the production of drop-in aviation fuel and comparison with other inedible oils

This work describes the use of palm stearin oil as a feed for the catalytic hydrocracking to produce the renewable aviation kerosene and diesel using the hydrocracking catalyst in a continuous flow fixed bed reactor. The efficacy of this method is evaluated using several reaction parameters, including hydrocracking temperature, hydrogen pressure, liquid hourly space velocity (LHSV), hydrogen to feed ratio (H2/feed) and time on stream (TOS). Higher temperatures and lower LHSVs are dominant to produce kerosene with maximum selectivity of 55.7%, while lower temperatures and LHSVs favoured the diesel production with maximum of 75.4% selectivity. The isomerization reactions were promoted by higher hydrocracking temperature due to the increase in iso-paraffins. The products consist of paraffins (96.9–99.3%), naphthenes (0.1–1.86%) and aromatics (0.2–1.59%). Aromatization reactions were also taking place in the process which is a considerable benefit of this method as aromatization reactions decrease hydrogen consumption. Moderate hydrogen pressure and H2/feed ratio favour the kerosene yield. The reaction mechanistic pathway was also proposed for converting palm stearin to biofuels. Furthermore, product yield, selectivity, heteroatom removal, and double bond saturation were also explored. The stability and activity of the catalyst were studied for 600 h without observable deactivation of the catalyst.

Screening of non-edible (second-generation) feedstocks for the production of sustainable aviation fuel

This paper examines the potential of suitable second-generation feedstocks for sustainable aviation fuel production, theoretically based on fatty acid-based fuel properties. The fatty acid composition of 38 s-generation feedstocks was collected from the literature. The fuel properties of these feedstocks were then calculated using empirical formula and assessed according to international fuel standards including American and European standards. The selected feedstocks were assessed and ranked using a multi-criteria decision analysis (MCDA) tool, i.e., PROMETHEE GAIA, to identify the suitability of the sources based on kinematic viscosity (KV), density (D), higher heating value (HHV), cetane number (CN), iodine value (IV), oxidation stability (OS), and cold filter plugging point (CFPP). It was found that 20 of the 38 feedstocks meet international fuel standards. The utilisation of the MCDA tool indicates that Ricinus communis is the highest-ranked feedstock for sustainable aviation fuel production, followed by the Azadirachta indicafeedstock, with Sterculia feotidaL. the lowest-ranked feedstock. The assessment of the properties of ranked feedstock against aviation fuel standards, including Jet A and Jet A1, reveals that the kinematic viscosity of all the feedstocks meets both these standards. However, fatty acid-based fuel properties could not satisfy the international aviation fuel standards for D, HHV, and freezing points. Further experimental work is recommended, including improvements in the processing and modification of biofuel produced from second-generation feedstocks. It is recommended that a comprehensive action plan is required to facilitate the introduction of sustainable biofuel from non-edible sources for the aviation industry, such as the adjustment of the current jet fuel standards.

Novel insights into the catalytic effect of hydrogen bonds on aldehyde groups generation during direct coal liquefaction

Direct coal liquefaction (DCL) is considered to be the effective method for production of aviation fuel and valuable chemicals, while low rank coal is appropriate feedstock because of high thermal reactivity. Original hydrogen bonds could promote low-temperature crosslinking reactions. liquefaction solvents could partially break original hydrogen bonds by forming new species. Impacts of hydrogen bonds formed by solvents on DCL reactions have rarely been studied. In order to figure out role of hydrogen bonds in DCL, a conjoint study of DCL experiments and density functional theory (DFT) calculations was carried out. More carboxyl groups were promoted to decompose. Meanwhile more aldehyde groups were found in solid products with increase of liquefaction temperature. As aldehyde groups are generated, hydrogen consumption increases. In terms of mechanism, effect of stronger hydrogen bonds on cleavage of covalent bonds were investigated by DFT-based potential energy surface scan. It turns out that cleavage of CO bonds in carboxyl groups could be enhanced, so that stabilization of free radicals results in consumption of extra hydrogen, which is provided by tetralin. Results of experimental methods are consistent with DFT calculations. The catalytic mechanism of hydrogen bonds upon conversion of carboxyl groups during DCL is proposed. Hydrogen bonds between coal and liquefaction solvents promote decomposition of carboxyl groups and consequently improve hydrogen transfer and thermal reactivity of solid products. Consequently, hydrogen bonds modulation should be taken into account during preparation of DCL solvents, for suppression of crosslinking reactions.

Production of renewable aviation fuel by waste cooking oil processing in a biorefinery scheme: Intensification of the purification zone

Renewable aviation fuel is the most promising alternative to achieve the sustainable recovery of aviation sector. The production of this biofuel is technically feasible, but its economic competitiveness is still a challenge in spite of the use of low-cost raw materials as well as strategies for energy reduction. In this context, the biorefineries are an alternative that improves the profitability. Thus, in this work the conversion of waste cooking oil (WCO) through a biorefinery scheme is proposed along with the intensification of the biojet fuel separation zone. The resulting biorefinery produce 306.4 kg/h of biojet fuel, and it is self-sufficient in electricity requirements. The intensified biorefinery reduces in 66.95% the energy consumption, respect to the conventional one, along with a reduction of 3.07% in CO2 emissions. The intensified biorefinery has a capital cost 11.74% higher than the conventional one, but 2.68% and 8.13% less operating costs for steam and cooling water, respectively. The intensified biorefinery scheme can be improved through energy integration and the intensification of the ethanol recovery train. Finally, the conversion of WCO through an intensified biorefinery allows generating biofuels, bioenergy, and value-added products, with the simultaneous revaluation of this hazardous residue.

Insight into the production of aviation fuel by aldol condensation of biomass-derived aldehydes and ketones followed by hydrogenation

Insight into the production of aviation fuel by aldol condensation of biomass-derived aldehydes and ketones followed by hydrogenation

Synthesis and intensification of a biorefinery to produce renewable aviation fuel, biofuels, bioenergy and chemical products from Jatropha Curcas fruit

The production of renewable aviation fuel has been explored in recent years considering different types of biomasses and several conversion pathways. The technical feasibility of the production of renewable aviation fuel has already been proved; however, the main challenge is to achieve economic and environmental sustainability regarding to its fossil counterparts. In this context, the integrated biorefineries are a potential strategy to address these challenges. Therefore, in this work it is presented the conversion of Jatropha curcas fruit through a biorefinery to produce renewable aviation fuel, biofuels, bioenergy and chemical products. The synthesis, modelling and simulation of each processing stage in the biorefinery is presented, along with its economic and environmental assessment. Moreover, the intensification of the purification zone is addressed. According to the results, biojet fuel, biodiesel, glycerol, fertilizer, green diesel, naphtha and electricity are produced through the biorefinery. In addition, less than 1% of energy savings were obtained due to intensified sequence to separate biojet fuel. Also, 90% of the total electricity consumption is covered by its generation in situ, improving the environmental sustainability of the production of renewable aviation fuel.

Electrifying the production of sustainable aviation fuel: the risks, economics, and environmental benefits of emerging pathways including CO2

Emerging CO2 to SAF pathways facilitates diversification of fuel production with the potential for a near carbon neutral footprint.

Thermal cyclodimerization of isoprene for the production of high-performance sustainable aviation fuel

Isoprene is converted to cycloalkanes by thermal dimerization followed by hydrogenation. The resulting blend exhibits outstanding jet fuel properties.

THEORETICAL AND PRACTICAL ASPECTS OF THE DEVELOPMENT OF HIGH-TECH PRODUCTION

This study is based on a comprehensive analysis of high-tech production as an economic phenomenon. The article on “Theoretical and practical aspects of high-tech production development” reveals the main approaches to the definition of a high-tech complex, a high-tech sector, a high-tech industry, and high-tech products. The article focuses on the allocation of industries according to the level of manufacturability, and describes the main development trends of the following high-tech sectors of the Russian economy: pharmaceuticals, power engineering, production of medical equipment, civil aviation and information technology sector. The key purpose of the study is to research theoretical and practical aspects of high-tech production development. To achieve the purpose, it is necessary: to consider the main approaches to the definition of high-tech production, to disclose the problem of determining the industries by the level of manufacturability, to describe the development of high-tech sectors in the Russian economy.The scientific novelty of the work lies in a number of unknown and little known facts, as well as in the development of theoretical provisions on the issue of defining high-tech production and selecting industries by the level of technology, and in the analysis of the development of key indicators of some high-tech industries. The research is based on the articles of foreign and Russian authors, various Internet resources, analytical materials prepared by the Higher School of Economics, as well as statistical compilations presented on the website of the Federal State Statistics Service.

A thermal-hydrodynamic model to evaluate the potential of different tray designs for production of renewable aviation fuel through reactive distillation

Reactive distillation is an intensified technology that has demonstrated interesting economical and operational advantages in the production of renewable aviation fuel. In tray distillation columns with heterogeneous catalyst, the arrangement of the latter determines flow characteristics that can influence the trays performance. This paper presents a CFD-based model for the simulation of a sieve tray with catalyst containers, which works under the operating conditions of a reactive distillation column used for production of renewable aviation fuel. Modeling of a non-isothermal liquid-vapor flow through the system was considered. The model was used to analyze the effect of geometric design of sieve trays and catalyst containers on important hydraulic parameters, mixing and heat transfer between phases. Profiles of clear liquid height and flow patterns estimated for different designs follow a similar behavior to that reported in available experimental studies. Additionally, the applied modeling approach makes possible the prediction of undesired phenomena, like downcomer flooding and excessive displacement of liquid phase. From these points, it is concluded that the model can serve as a basis for the development of a CFD modeling strategy to evaluate the performance of different tray designs with a similar catalyst configuration for production of renewable aviation fuel.

Synthesis of branched alkane fuel from biomass-derived methyl-ketones via self-aldol condensation and hydrodeoxygenation

Production of aviation fuel is promising but challenging in the field of biomass utilization. Here we proposed a route to produce highly branched alkanes by the self-aldol condensation of methyl isobutyl ketone (MIBK), followed by the one-step hydrodeoxygenation (HDO). The catalytic activities of magnesium-aluminum mixed oxides (MgAl-O) were carefully explored in the self-aldol condensation of MIBK using cyclohexane as the solvent. The basic sites with moderate and strong strength play a key role in the self-aldol condensation of methyl isobutyl ketone, which can capture α-H, promoting the aldol condensation. Under an optimal condition, the yield of condensation product C12 oxygenate is 70.3%. Furthermore, the regeneration ability of 500-MgAl-O catalyst is tested in the self-aldol condensation of MIBK. In addition, hydrodeoxygenation of condensation products was also conducted over 2 wt% Pd/HZSM-5 catalysts. These obtained HDO products are highly branched alkanes with low freezing point (<−60 °C).