Aviation Biofuels Research Articles

Progress and prospect of bio-jet fuels industry in domestic and overseas

We reviewed the progress of the bio-jet fuels industry in recent years and systematically analyzed the technical routes that have been approved or in the pipeline for approval by ASTM D7566. In addition, we highlighted a novel pathway to produce drop-in fuel by near-critical hydrolysis of waste cooking oils or algal oils followed by catalytic decarboxylation. Also, we introduced the source of oils and fats feedstock and the domestic bio-jet fuel industry status during the 12th Five-Year-Plan period. Based on our own research, we discussed the prospect of the bio-jet fuel industry and future research needs.

Derived Cetane Number, Distillation and Ignition Delay Properties of Diesel and Jet Fuels Containing Blended Synthetic Paraffinic Mixtures

Aviation turbine fuel and diesel fuel were blended with synthetic paraffins produced via two pathways and the combustion properties measured. Both aviation and diesel fuel containing synthetics produced from the fermentation of sugars, had a linear response to blending with decreasing ignition delay times from 5.05 - 3.52 ms for F-34 and 3.84 - 3.52 ms for F-76. For the same fuels blended with synthetics produced from the fermentation of alcohols, ignition delay times were increased out to 18.66 ms. The derived cetane number of the blends followed an inversely similar trend. Additionally, simulated distillation using ASTM D2887 at high synthetic paraffinic kerosene blend ratios resulted in the recovery temperatures being incorrectly reported. In this case, higher recovery volumes were at lower temperatures than earlier recovery points i.e. T90< T50, for SIP-SPK.

The adaptation of sustainable biojet fuels and its effect on aircraft engine maintenance

Aviation industries are looking into several resources for renewable and sustainable energy. Among those attention is focused in biojet fuel. This paper engages the issue of biojet fuel emissions that increase the environmental concern in the air transport sector. The paper presents the use of biojet fuel and its effect on aircraft engine maintenance through preliminary data collections, and a review of its development process in operations for time and goal. As conclusion, airlines management needs to adapt and adopt the transition to alternative fuels, especially given the global biofuel trend emerging due to the authority approval.

Hydrocracking of palm oil to jet biofuel over different zeolites

The aim of this study is to develop zeolite catalysts to produce jet biofuel from palm oil. Different Ni-loaded zeolites were tested as catalysts in the conversion of palm oil into jet biofuels with high alkane and low arene content. Five zeolite catalyst, were tested: Ni/SAPO-34, Ni/MCM-41, Ni/HY, Ni/SAPO-11 and Ni/Hbeta. Characterization was performed by X-ray diffraction, NH3-temperature-programmed desorption. The Ni/SAPO-34 catalyst exhibited the highest alkane selectivity (65%) and lowest arene selectivity (11%). The jet biofuel yield under catalysis increased from 21.1 to 42.0% when the reaction temperature was increased from 370 to 390 °C. The alkane content of the jet biofuel increased from 71 to 80% and the arene content decreased from 29 to 20%, when the weight ratio of Si/Al in the Ni/HY catalyst was reduced from 11 to 5, but the levels were almost unchanged as the nickel content was increased from 5 to 20%.

Techno‐economic assessment of biorefinery technologies for aviation biofuels supply chains in Brazil

AbstractProduction of aviation biofuels has been strongly encouraged by the volatility of oil prices and environmental concerns. Brazilian society, companies, and government are taking a step forward in the production of renewable jet fuel from biomass feedstocks largely available in the territory. This study evaluated the use of different feedstocks (sugar crops, oil crops, and lignocellulosic biomass) for co‐production of biojet fuel and higher value‐added products in a biorefinery platform. The co‐production of biofuels and biochemicals in a biorefinery context was demonstrated to be economically feasible. The main cost drivers of such a platform are feedstock biomass cost, selling price of the biochemicals, investment costs, and key process‐inherent parameters such as conversion yields, obtained fermentable sugars, or oil content in the feedstock. Sugarcane was the most promising feedstock for a biorefinery in the region of Minas Gerais, while soybean was the most promising feedstock for a biorefinery in the region of Rio Grande do Sul, despite its higher uncertainty. Succinic acid was the most promising chemical intermediate for biopolymers industry due to its relatively high market value, unique market opportunity as a substitute of conventional petrochemicals, and forecast for future growth. Ethanol‐to‐jet (ETJ) and hydro‐processed esters and fatty acids (HEFA) were the most attractive biojet fuel production routes in the present study. Scenarios for co‐production of biofuels and biochemicals in Brazil present large uncertainties and high financial risk, mainly due to the use of second‐generation feedstocks, and the introduction of new technologies and products. © 2016 Society of Chemical Industry and John Wiley &amp; Sons, Ltd

Aviation industry hopes to cut emissions with jet biofuel

This year, renewable jet fuel took off, graduating from demonstration and test flights to some regular commercial use. In January, some flights left the airport in Oslo, Norway, running on jet biofuel produced from an oilseed crop. In March, United Airlines became the first U.S. airline to use biofuel for regularly scheduled commercial flights leaving Los Angeles International Airport. Three months later, Alaska Airlines flew commercial flights using biofuel produced from renewable isobutyl alcohol. By 2050, the global aviation industry aims to combat climate change by reducing net carbon emissions by 50% compared with 2005 levels. That’s a commitment to cut one-tenth the emissions projected for 2050. Improved engine efficiency and aircraft aerodynamics will provide some reductions. But transitioning to fully renewable jet fuel is key to meeting the targets suggested by the International Air Transport Association (IATA). Alternative energy sources considered for cars and trucks—things such as batteries, fuel

Biojet fuel innovations to be key for meeting aviation industry's CO2 emissions target

Given how quickly the aviation sector is growing, it is crucial to find sustainable ways to supply the demand. Modern technological developments and the creation of alternative jet fuels are crucial elements that could help eliminate greenhouse gases (GHGs) like CO2 emissions. Traditional jet fuel produces a sizable amount of GHG emissions, which has raised concern on a global scale. Compared to conventional jet fuel, biofuel is thought to be more renewable and less polluting. Biojet fuels might work as an effective substitute. The varieties of bio jet fuel, manufacturing procedures (including alcohol-to-jet, oil-to-jet, syngas-to-jet, and sugar-to-jet ways), existing regulations, and the effects of bio jet fuels on the environment and the economy are all covered in length in this overview. These are the techniques that are most frequently used to create bio-jet fuel from both edible and inedible feedstock. The main conclusions of this review indicate that the most popular method for producing biofuel is hydrogenated esters and fatty acids (HEFA). The Fischer-Tropsch (FT) approaches cost more to install even though they produce fewer GHGs. Environmentally beneficial and technologically advanced, second-generation biofuels are a great choice. It has been revealed that jatropha is a crop that produces a lot of energy. The price of feedstock and the lack of bio-jet fuel are the two biggest obstacles to substituting conventional fuel. To increase the power and quality of energy, further in-depth research on optimal feedstocks is necessary. In order to address the needs of both commercial and military aircraft, biomass jet fuel has a lot of potential to replace conventional jet fuel. High yield should be one of the properties of the feedstock without affecting food production.

Hydrodeoxygenation catalyst

The cost, availability, and sustainability of feedstocks are key to successfully producing aviation biofuels. There are numerous routes to aviation fuels, and as such, it is likely that multiple feedstocks will be used globally to produce future aviation biofuels. In this chapter, a general overview of all the major feedstocks available, where they are regionally produced, the challenges inherent in increasing production to necessary levels, and key forecasts for bioenergy use ahead to 2050, will be presented and briefly discussed.

Development of a Bimetallic Pd-Ni/HZSM-5 Catalyst for the Tandem Limonene Dehydrogenation and Fatty Acid Deoxygenation to Alkanes and Arenes for Use as Biojet Fuel

A tandem process involving the dehydroaromatization of the terpene limonene and the hydrodeoxygenation of stearic acid has been found to be efficiently catalyzed by Pd-Ni/HZSM-5. The process involves the generation of p-cymene from terpene with concomitant formation of H2, which leads to the one-pot hydrodeoxygenation of stearic acid to C17 and C18 alkanes; these products can be used as kerosene additives for aviation fuel. Screening a wide range of catalysts, the bimetallic Pd-Ni/HZSM-5 catalyst is the most efficient, leading to quantitative conversion of stearic acid to alkanes in limonene at 280 °C at a H2 pressure of 2 bar after 120 min. It has been found that single Ni or Pd catalysts lead to a poor conversion of stearic acid in limonene at a H2 pressure of 2 bar. The combination of physically mixed Pd- and Ni-sites onto different supports (Pd/HZSM-5 or Pd/C, and Ni/HZSM-5, Ni/HY, or Ni/HBEA) leads to catalysts which show satisfactory conversion to p-cymene but generally have very low stearic acid co...

Aviation biofuel from integrated woody biomass in southern Australia

A synthesis of work on integrating short‐rotation biomass plantings into existing mixed crop and livestock farming regimes with the biomass being converted to biofuels, including aviation fuel, is provided. This agroforestry system, based on mallee eucalypt species native to Australia, provides broader environmental benefits, including biodiversity protection. These species are suited to the edaphic and climatic conditions of rainfed farming systems in southern Australia. The study focused on the Great Southern region of Western Australia, with an average annual rainfall of 400–600 mm. Compared to other locations in Australia, significantly more research and development has been conducted in this region, with a mallee biomass‐to‐jet fuel business case and farmer cooperation providing reliable data for assessing the viability and sustainability of commercial supply chain development. The limited capacity of Australian agricultural systems to produce biomass due to the relatively dry climate means that the available biomass resources should be directed to strategically important energy uses such as aviation fuel. Technical, economic, and environmental insights gained from these long‐term studies have demonstrated that it is feasible to integrate this new production system into the overall farming enterprise and indicate strong prospects for a biomass industry in this region should political and economic uncertainties currently facing the renewable energy industry in Australia be resolved. WIREs Energy Environ 2017, 6:e221. doi: 10.1002/wene.221This article is categorized under: Bioenergy &gt; Science and Materials Bioenergy &gt; Economics and Policy Bioenergy &gt; Systems and Infrastructure

Efficient selective breeding of live oil-rich Euglena gracilis with fluorescence-activated cell sorting.

Euglena gracilis, a microalgal species of unicellular flagellate protists, has attracted much attention in both the industrial and academic sectors due to recent advances in the mass cultivation of E. gracilis that have enabled the cost-effective production of nutritional food and cosmetic commodities. In addition, it is known to produce paramylon (β-1,3-glucan in a crystalline form) as reserve polysaccharide and convert it to wax ester in hypoxic and anaerobic conditions–a promising feedstock for biodiesel and aviation biofuel. However, there remain a number of technical challenges to be solved before it can be deployed in the competitive fuel market. Here we present a method for efficient selective breeding of live oil-rich E. gracilis with fluorescence-activated cell sorting (FACS). Specifically, the selective breeding method is a repetitive procedure for one-week heterotrophic cultivation, staining intracellular lipids with BODIPY505/515, and FACS-based isolation of top 0.5% lipid-rich E. gracilis cells with high viability, after inducing mutation with Fe-ion irradiation to the wild type (WT). Consequently, we acquire a live, stable, lipid-rich E. gracilis mutant strain, named B1ZFeL, with 40% more lipid content on average than the WT. Our method paves the way for rapid, cost-effective, energy-efficient production of biofuel.

IDENTIFICATION OF RISKS ARISING FROM THE USE OF TRADITIONAL AND ALTERNATIVE JET FUELS: AN ENVIRONMENTAL RISK

This work is devoted to the risk analysis of the use of traditional fuels and biofuels in aviation. An important step of risk analysis of the use of biofuels in aviation is the analysis of threats of environmental pollution. Also one of the aspects of the risk analysis is a new trend in research; identification of strengths and weaknesses; that is; the method of SWOT analysis.The analysis of factors influencing the threat of environmental pollution is to identify all sources of threats and assessment of their impact on the environment and humans. The article is identification of risks arising from the use of traditional and alternative fuels for jet aircraft. Discusses stages in the life cycle of fuel usage and the environmental impact of each stage. Also estimated emissions that occur during fuel combustion; thereby becoming relevant to the assessment of environmental risk for population health.

RESOURCE POTENTIAL OF CAMELINA TO PRODUCE COMPONENTS OF THE MODIFICATION OF THE COMPOSITION OF AVIATION FUEL

This article describes the main environmental problems associated with the use of conventional jet fuel. Considered currently available resources that can be used for biofuel production. Defines the requirements; which shall satisfy the alternative aviation fuels that are developed and used in the world today.The possibility of reducing the emissions of certain exhaust gases of aircraft on the example of aviation biofuels derived from vegetable fat-containing raw materials. Analyzes the current status and prospects for aviation biofuel production in Ukraine. Outlined the potential use of ginger as a raw material for producing alternative aviation fuels; added technological scheme of processing. To assess the prospects of using camelina as the raw material for the production of aviation fuel components was conducted SWOT-analysis.

Ectopic expression of Jatropha curcas APETALA1 (JcAP1) caused early flowering in Arabidopsis, but not in Jatropha.

Jatropha curcas is a promising feedstock for biofuel production because Jatropha oil is highly suitable for the production of biodiesel and bio-jet fuels. However, Jatropha exhibits a low seed yield as a result of unreliable and poor flowering. APETALA1 (AP1) is a floral meristem and organ identity gene in higher plants. The flower meristem identity genes of Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an AP1 homolog (JcAP1) was isolated from Jatropha. An amino acid sequence analysis of JcAP1 revealed a high similarity to the AP1 proteins of other perennial plants. JcAP1 was expressed in inflorescence buds, flower buds, sepals and petals. The highest expression level was observed during the early developmental stage of the flower buds. The overexpression of JcAP1 using the cauliflower mosaic virus (CaMV) 35S promoter resulted in extremely early flowering and abnormal flowers in transgenic Arabidopsis plants. Several flowering genes downstream of AP1 were up-regulated in the JcAP1-overexpressing transgenic plant lines. Furthermore, JcAP1 overexpression rescued the phenotype caused by the Arabidopsis AP1 loss-of-function mutant ap1-11. Therefore, JcAP1 is an ortholog of AtAP1, which plays a similar role in the regulation of flowering in Arabidopsis. However, the overexpression of JcAP1 in Jatropha using the same promoter resulted in little variation in the flowering time and floral organs, indicating that JcAP1 may be insufficient to regulate flowering by itself in Jatropha. This study helps to elucidate the function of JcAP1 and contributes to the understanding of the molecular mechanisms of flower development in Jatropha.

Biofuels in aviation: Fuel demand and CO2 emissions evolution in Europe toward 2030

This article presents the results of a scenario-based study carried out at the European Commission’s Joint Research Centre aimed at analyzing the future growth of aviation, the resulting fuel demand and the deployment of biofuels in the aviation sector in Europe. Three scenarios have been produced based on different input assumptions and leading to different underlying patterns of growth and resulting volumes of traffic. Data for aviation growth and hence fuel demand have been projected on a year by year basis up to 2030, using 2010 as the baseline. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, the type of aircrafts, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO2 emissions data. The target of the European Advanced Biofuels Flightpath to ensure the commercialization and consumption of 2milliontons of sustainably produced paraffinic biofuels in the aviation sector by 2020, has also been taken into account. Results regarding CO2 emission projections to 2030, reveal a steady annual increase in the order of 3%, 1% and 4% on average, for the three different scenarios, providing also a good correlation compared to the annual traffic growth rates that are indicated in the three corresponding scenarios. In absolute values, these ratios correspond to the central, the pessimistic and the optimistic scenarios respectively, corresponding to 360milliontonnes CO2 emissions in 2030, ranging from 271 to 401milliontonnes for the pessimistic and optimistic scenarios, respectively. This article also reports on the supply potential of aviation biofuels (clustered in HEFA/HVOs and biojet) based on the production capacity of facilities around the world and provides an insight on the current and future trends in aviation based on the European and national policies, innovations and state-of-the art technologies that will influence the future of sustainable fuels in aviation.

Efficient synthesis of high-density aviation biofuel via solvent-free aldol condensation of cyclic ketones and furanic aldehydes

Transferring lignocellulose-derived compounds to cyclic hydrocarbons via aldol condensation has great potential in synthesizing high-density biofuel. But current synthesis involves large amount of solvent that inevitably affects the production efficiency. Herein, we synthesized high-density biofuel efficiently using solvent-free condensation of cyclopentanone/cyclohexanone and furfural/5-hydroxymethylfurfural. It is found that the solvent-free reaction gives much higher conversion than the diluted one does, for example 86.7% vs 62.7% for cyclopentanone/furfural condensation, and the selectivity of condensed product is above 90.0%. The reaction rate slows down when the reactant is changed from cyclohexanone to cyclopentanone or from furfural to 5-hydroxymethylfurfural, but can be improved by simply increases the dosage of catalyst or reaction temperature. As a result, the yield over 85.0% is obtained for the condensation reactions. Subsequently, the condensed products were converted to branched cyclic hydrocarbons with selectivity of about 70–80%. Their density increases from 0.815g/ml to 0.826g/ml with the increase of carbon number, with the freezing point increasing from −24.6°C to −9.5°C. They have very low viscosity and can be used as liquid fuels alone or blended with other fuels.

Bio-Based Solvents for Green Extraction of Lipids from Oleaginous Yeast Biomass for Sustainable Aviation Biofuel.

Lipid-based oleaginous microorganisms are potential candidates and resources for the sustainable production of biofuels. This study was designed to evaluate the performance of several alternative bio-based solvents for extracting lipids from yeasts. We used experimental design and simulation with Hansen solubility simulations and the conductor-like screening model for realistic solvation (COSMO-RS) to simulate the solubilization of lipids in each of these solvents. Lipid extracts were analyzed by high performance thin-layer chromatography (HPTLC) to obtain the distribution of lipids classes and gas chromatography coupled with a flame ionization detector (GC/FID) to obtain fatty acid profiles. Our aim was to correlate simulation with experimentation for extraction and solvation of lipids with bio-based solvents in order to make a preliminary evaluation for the replacement of hexane to extract lipids from microorganisms. Differences between theory and practice were noted for several solvents, such as CPME, MeTHF and ethyl acetate, which appeared to be good candidates to replace hexane.

Toward an optimal formulation of alternative jet fuels: Enhanced oxidation and thermal stability by the addition of cyclic molecules

Oxidation and thermal stability (OTS) are key concerns for the development of alternative jet fuels, as they imply complex physical and chemical phenomena such as autoxidation, pyrolysis, cooxidation reactions and transfer-limitation. The OTS of an alternative aviation fuel was characterized using PetroOxy test from 120 to 160°C and JFTOT test at 325°C. The alternative jet fuel is a Synthetic Paraffinic Kerosene produced from Hydroprocessed Esters and Fatty Acids (HEFA-SPK). Results showed a high thermal stability of HEFA-SPK. However, a low oxidation stability was also observed. The oxidation stability of 8 model cyclic molecules was evaluated. Results allowed to estimate the influence of the molecular structure of cyclic molecules on liquid phase reactivity involving the number and the hydrogenation of the aromatic rings and the number and chain-length of the aromatic alkyl groups. The addition of several alkylbenzenes increased almost linearly the induction period of HEFA-SPK. Tetralin and decalin acted as inhibitors of the radical chain mechanism at low concentration, although having inherently low oxidation stability. Besides offering a better oxidation stability, the addition of specific low fractions of several alkylbenzenes, tetralin and decalin to HEFA-SPK allowed to achieve a good thermal stability as well. These molecules represent good candidates to improve OTS of HEFA-SPK. This work opens the way for the development of future fit-for-purpose formulations of alternative jet fuels with an increased fraction of renewables.

Intermediates for synthetic paraffinic kerosene from microalgae

Intermediates for synthetic paraffinic kerosene with structures of fatty acid methyl ester (FAME), were synthesized from algal oil extracted from Nannochloris sp. biomass. Microalgae were grown under mixotrophic conditions to improve biomass production, using glycerin as additional source of organic carbon, by-product in FAME obtaining process. Microalgae were supplementary stressed to increase the lipid productivity, by reducing the inorganic nitrogen and partially replacing it with organic nitrogen (hydrolyzed proteins from the same microalgae). Since algal oil has high free fatty acids (FFA) content, a two-step process for FAME synthesis was necessary. In the first step, FFA was esterified with methanol over SO42−/TiO2–La2O3 solid acid catalyst. The second step, i.e. methanolysis of pre-treated oil, was performed over Na2SiO3/Mg–Al-hydrotalcite (Na2SiO3/Mg–Al-HTC) heterogeneous base catalyst. The Na2SiO3/Mg–Al-HTC catalyst was synthesized and then characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), textural analysis (BET method), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence analysis (EDXRF) and Fourier transform infrared (FTIR) spectroscopy. The influences of catalyst loading and stability, methanol-to-oil molar ratio and the reaction time on the FAME yield were carefully studied. FAME producing technology was investigated first in batch and then in a continuous flow process.

Resilience Analytics of a Future Supply Chain for Aviation Biofuels

Capacity-building plans for transportation systems must be resilient to disruptions and erroneous assumptions to protect performance outcomes as well as schedule and cost. An example is the future supply chain of aviation biofuels for industry, government, and military applications. The challenges include balancing the aims and assumptions of diverse stakeholders, including regulators, agencies, manufacturers, airlines, fuel companies, and agricultural and husbandry producers. Resilience analytics of the strategic plans should characterize both the influential trends and stressors and the robust initiatives. This paper demonstrates resilience analytics to address varied, evolving, and potentially conflicting stakeholder preferences in the life cycle of supply chains for aviation biofuels. Heterogeneous feedstocks can be converted to aviation biofuel, although several are more attractive across technological, environmental, and economic criteria. The choice of feedstocks for conversion to biofuel depends on balancing desired outcomes, including life-cycle costs, availabilities, proximities, environmental impacts, and the like. Resilience analytics enables prioritization of feedstocks and other supply chain initiatives, with prioritization that varies by scenario. A technology road map for near- and midterm investment horizons to establish aviation biofuels is described. Poultry waste products are explored by using the above methods for a particular region in the mid-Atlantic area of the United States.