Examine individual changes

'<section begin="summary" /> [[File:Refuel EC-KNM Iberia (6218464950).jpg|thumb|Refueling an [[A320]] with [[biofuel]]]] '''Aviation biofuel''' or bio-jet-fuel<ref name=":1">{{Cite web|last=Universe|first=Investable|date=2020-12-04|title=Sustainable aviation fuel market demand drives new product launches|url=https://investableuniverse.com/2020/12/04/sustainable-aviation-fuel-argus-price-gunvor-group/|access-date=2020-12-11|website=Investable Universe|language=en-US}}</ref> or bio-aviation fuel (BAF)<ref name=":2" /> or sustainable aviation fuel (SAF) is [[biofuel]] used to power [[aircraft]]. The [[International Air Transport Association]] (IATA) considers it to be one of the key elements to reduce the [[carbon footprint]] within the [[environmental impact of aviation]].<ref>{{cite web |url= https://www.iata.org/en/programs/environment/sustainable-aviation-fuels/ |title= Developing Sustainable Aviation Fuel (SAF) |publisher= IATA}}</ref> <!--Environmental impact--> Biofuels are [[biomass]]-derived fuels, from plants or waste; they can lower CO₂ emissions by 50–80% compared to [[Jet A1|Jet-A1]].<!--ref name=AImar2009--> <!--Timeline--> The first test flight using blended biofuel was in 2008,<!--ref name=IEA18mar2019/--> and in 2011 blended fuels with 50% biofuels were allowed in commercial flights.<!--ref name=ASTMsep2011--> In 2019, the IATA was aiming for a 2% penetration by 2025. As current battery technologies limit [[electric aircraft]] to short ranges, aviation biofuel is a major possibility to [[Low-carbon economy|decarbonize]] medium- and long-haul air travel generating most emissions, and could extend the life of older aircraft types by lowering their carbon footprint.<!--ref name=IATAmay2019--> <!--Production--> Aviation biofuel can be produced from plant sources like [[Jatropha]], [[algae]], [[tallows]], waste oils, [[Babassu oil|Babassu]] and [[Camelina]] (bio-SPK); from solid [[biomass]] using [[pyrolysis]] processed with a [[Fischer–Tropsch process]] (FT-SPK); with an [[alcohol]]-to-jet (ATJ) process from waste fermentation; or from [[synthetic biology]] through a [[Chemical reactor|solar reactor]]. Small piston engines can be modified to burn [[ethanol]].<!--ref name=SDSU2016--> <!--Sustainable fuels--> [[Sustainable biofuel]]s do not compete with [[food crop]]s, prime [[agricultural land]] or fresh water. Sustainable aviation fuel are certified as being [[sustainable]] by a third-party organisation.<section end="summary" /> ==Environmental impact== {{further|Environmental impact of aviation|Biofuel#Greenhouse gas emissions}} Plants absorb [[Carbon Dioxide]] as they grow, offering large CO₂ emissions savings in their life-cycle: [[Jatropha oil]] used as a biofuel should lower CO₂ emissions by 50–80% compared to Jet-A1.<ref name=AImar2009>{{cite magazine |title= A Greener Future? |magazine= [[Aircraft Illustrated]] |date= March 2009}}</ref> Jatropha, used for [[biodiesel]], can thrive on [[marginal land]] where most cultures would produce low [[crop yield]]s.<ref>{{cite news |author= Ron Oxburgh |url= https://www.theguardian.com/commentisfree/2008/feb/28/alternativeenergy.biofuels |title= Through biofuels we can reap the fruits of our labours |newspaper= [[The Guardian]] |date= 28 February 2008}}</ref><ref>{{cite news |author= Patrick Barta |title= As Biofuels Catch On, Next Task Is to Deal With Environmental, Economic Impact |url= https://www.wsj.com/articles/SB120631198956758087 |newspaper= [[Wall Street Journal]] |date= 24 March 2008 |url-access= subscription}}</ref> A [[life cycle assessment]] by the Yale School of Forestry on [[jatropha]], one source of potential biofuels, estimated using it could reduce greenhouse gas emissions by up to 85% if former agro-pastoral land is used, or increase emissions by up to 60% if natural woodland is converted to use.<ref>{{Cite journal | last1 = Bailis | first1 = R. E. | last2 = Baka | first2 = J. E. | doi = 10.1021/es1019178 | title = Greenhouse Gas Emissions and Land Use Change fromJatropha Curcas-Based Jet Fuel in Brazil | journal = Environmental Science & Technology | volume = 44 | issue = 22 | pages = 8684–91 | year = 2010 | pmid = 20977266}}</ref> In addition, biofuels do not contain sulfur compounds and thus do not emit sulfur dioxide. NASA has determined that 50% aviation biofuel mixture can cut [[particulate emissions]] caused by air traffic by 50–70%.<ref>{{cite news |url= http://www.flyingmag.com/nasa-confirms-biofuels-reduce-jet-emissions |work= Flying Mag |title= NASA confirms biofuels reduce jet emissions |date= March 23, 2017}}</ref> ==Timeline== {{see also|Aviation biofuel demonstrations}} The first flight using blended [[biofuel]] took place in 2008.<ref name=IEA18mar2019/> [[Virgin Atlantic]] flew the first flight by a commercial airline to be powered partly by biofuel, while commercial biofuel flights were likely to use feedstocks such as [[algae]].<ref>{{cite news |url= http://news.bbc.co.uk/2/hi/7261214.stm |work=[[BBC News]]|title= First biofuel flight touches down |date= 24 February 2008}}</ref> By then, airlines representing more than 15% of the industry formed the Sustainable Aviation Fuel Users Group, with support from NGOs such as [[Natural Resources Defense Council]] and [[Sustainable biofuel#Roundtable on Sustainable Biofuels|The Roundtable For Sustainable Biofuels]]. They pledged to develop [[sustainable biofuels]] for aviation.<ref>{{cite news |url= https://www.boeing.com/aboutus/environment/environmental_report_09/_inc/3.4.3-Sustainable-Aviation-Fuel-Users-group.pdf |title= Our Commitment to Sustainable Options |publisher= Sustainable Aviation Fuel Users Group }}</ref> That year, Boeing was co-chair of the [[Algal Biomass Organization]], joined by air carriers and biofuel technology developer [[UOP LLC]] (Honeywell)..<ref>{{cite news |url= http://www.greencarcongress.com/2008/06/first-airlines.html |title= First Airlines and UOP Join Algal Biomass Organization |work= Green Car Congress |date= 19 June 2008}}</ref> In 2009, the IATA committed to achieve [[carbon-neutral]] growth by 2020, and to halve carbon emissions by 2050.<ref>{{cite press release |url= https://www.iata.org/en/pressroom/pr/2009-06-08-03/ |title= Carbon-Neutral Growth By 2020 |publisher= IATA |date= 8 June 2009}}</ref> In 2010, Boeing targeted of 1% of global aviation fuels by 2015.<ref>{{cite news |url= https://www.bloomberg.com/news/2010-07-22/commercial-airlines-may-get-1-of-fuel-from-biofuels-by-2015-boeing-says.html |title= Airlines May Get 1% of Fuel From Biofuels By 2015, Boeing Says |date=22 July 2010 |agency= Bloomberg}}</ref> [[File:US Navy 110921-N-ZZ999-002 An AV-8B Harrier assigned to Air Test and Evaluation Squadron (VX) 31 conducts the first test flight of a mix of 50-50 j.jpg|thumb|US Marine Corps [[AV-8B Harrier II]] test flight using a 50–50 biofuel blend in 2011]] By June 2011, the revised ''Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons'' ([[ASTM]] D7566) allowed commercial airlines to blend up to 50% biofuels with conventional jet fuel.<ref>{{cite news |url=http://www.renewableenergyworld.com/rea/news/article/2011/07/50-percent-biofuels-now-allowed-in-jet-fuel |title=50 Percent Biofuels Now Allowed in Jet Fuel |date=1 July 2011 |work= [[Renewable Energy World]] }}</ref> The safety and performance of jet fuel used in passenger flights is certified by [[ASTM International]].<ref name=ASTMsep2011>{{cite web |url= http://www.astm.org/SNEWS/SO_2011/enright_so11.html |title= Aviation Fuel Standard Takes Flight |quote= D7566 Revision Adds Bioderived Components |publisher= ASTM |date= September–October 2011}}</ref> Biofuels were approved for commercial use after a multi-year technical review from [[Aerospace manufacturer|aircraft maker]]s, [[List of turbofan manufacturers|engine manufacturer]]s and [[oil companies]].<ref>{{cite news |url= https://www.bloomberg.com/news/2011-07-01/airlines-win-approval-to-use-plant-based-biofuels-on-commercial-flights.html |title= Airlines Win Approval to Use Biofuels for Commercial Flights |date= 1 July 2011 |agency= Bloomberg}}</ref> Since then, some airlines have experimented with using biofuels on commercial flights.<ref>{{cite news |url= https://www.nytimes.com/2011/10/10/business/global/10iht-green10.html?_r=1 |title= Airlines Weigh the Advantages of Biofuels |newspaper= NY Times |date= 9 Oct 2011 |author= Bettina Wassener}}</ref> In December 2011, the [[FAA]] awarded US$7.7 million to eight companies to develop [[Substitute good|drop-in]] sustainable fuels, especially from [[alcohol]]s, [[sugar]]s, [[biomass]], and [[organic matter]] such as [[pyrolysis oil]]s, within its {{abbr|CAAFI|Commercial Aviation Alternative Fuel Initiative}} and {{abbr|CLEEN|Continuous Lower Emissions, Energy and Noise}} programs.<ref>{{cite news |url=http://www.renewableenergyworld.com/rea/news/article/2011/12/faa-awards-7-7-million-for-advancement-of-aviation-biofuels |title=FAA Awards $7.7 Million for Advancement of Aviation Biofuels |author= Meg Cichon |date= 2 December 2011 |work= [[Renewable Energy World]]}}</ref> From 2014, [[Solena]] planned to turn annually 500,000 tonnes of waste from the [[City of London]] that would normally go to [[landfill]] into biofuel to be used in the [[British Airways]] fleet.<ref>{{cite news |title= British Airways to buy jet fuel from city waste |date= 16 Feb 2010 |url= https://www.reuters.com/article/us-biofuel-britishairways-idUSTRE61F37520100216 |agency= Reuters}}</ref> By 2015, cultivation of [[fatty acid methyl ester]]s and [[alkenone]]s from the algae, ''Isochrysis'', was under research as a possible jet biofuel [[feedstock]].<ref>{{cite web|author1=Chris Reddy|author2=Greg O'Neil|title=Jet Fuel from Algae? Scientists probe fuel potential in common ocean plant |url= https://www.whoi.edu/oceanus/feature/jet-fuel-from-algae |date=28 January 2015 |work= Oceanus magazine |publisher= [[Woods Hole Oceanographic Institution]]}}</ref> By 2016, Thomas Brueck of [[Technical University of Munich|Munich TU]] was forecasting that [[algaculture]] could provide 3-5% of jetfuel needs by 2050.<ref>{{cite news|title=From green slime to jet fuel: algae offers airlines a cleaner future |url= https://reuters.com/article/idUSKCN0Z117F |agency= Reuters |date= 15 June 2016}}</ref> In Fall 2016, to achieve its emissions reductions goals, the ICAO planned multiple measures including the development and deployment of sustainable aviation fuels.<ref name=ICAOdec2018>{{Cite web |url= https://www.icao.int/environmental-protection/Documents/Sustainable%20Aviation%20Fuels%20Guide_100519.pdf |title= Sustainable Aviation Fuels Guide |publisher= ICAO |date= Dec 2018}}</ref> Dozens of companies received hundreds of millions in [[venture capital]] from 2005 to 2012 to extract fuel oil from algae, some promising competitively priced fuel by 2012 and a production of {{convert|1|e9USgal|e6m3|abbr=unit}} by 2012-2014.<ref name=Greentech19april2017/> By 2017, nor were achieved and most companies had disappeared or changed their [[business plan]]s to focus on [[cosmetics]] supplements, [[nutraceutical]]s, [[pet food]] additives, [[animal feed]], [[pigment]]s and speciality oils.<ref name=Greentech19april2017>{{cite web|last1=Wessof|first1=Eric|title=Hard Lessons From the Great Algae Biofuel Bubble|url=https://www.greentechmedia.com/articles/read/lessons-from-the-great-algae-biofuel-bubble#gs.5jG2khs|publisher=[[Greentech Media]]|date=19 April 2017}}</ref> In 2019, the [[International Air Transport Association]] (IATA) supports the adoption of Sustainable Aviation fuel, aiming in 2019 for a 2% penetration by 2025: {{convert|7|e6m3|e9USgal|abbr=unit}}.<ref name=IATAmay2019>{{cite web |url= https://www.iata.org/contentassets/ed476ad1a80f4ec7949204e0d9e34a7f/fact-sheet-alternative-fuels.pdf |title= Sustainable Aviation Fuels Fact sheet |publisher= IATA |date= May 2019}}</ref> By then, more than 150,000 flights have used biofuels and five airports have regular biofuel distribution: [[Bergen Airport|Bergen]], [[Brisbane Airport|Brisbane]], [[Los Angeles International Airport|Los Angeles]], [[Oslo Airport|Oslo]] and [[Stockholm Arlanda Airport|Stockholm]], with others offering occasional supply.<ref name=IEA18mar2019>{{cite news |url= https://www.iea.org/commentaries/are-aviation-biofuels-ready-for-take-off |title= Are aviation biofuels ready for take off? |author= Pharoah Le Feuvre |date= 18 March 2019 |publisher= [[International Energy Agency]]}}</ref> [[File:United Airlines - N851UA -Airbus A319 - San Francisco International Airport-0383.jpg|thumb|In 2019, [[United Airlines]] purchased up to {{convert|10|e6USgal|m3}} of SAF from [[World Energy (company)|World Energy]] over two years.<ref>{{cite press release |url= https://hub.united.com/united-biofuel-commitment-world-energy-2635867299.html |title= Expanding our commitment to powering more flights with biofuel |publisher= United Airlines |date= May 22, 2019}}</ref>]] That year, [[Virgin Australia]] had fueled more than 700 flights and flown more than one million kilometers, domestic and international, using [[Gevo Inc|Gevo]]'s alcohol-to-jet fuel.<ref>{{Cite press release |url= https://newsroom.virginaustralia.com/release/virgin-australia%E2%80%99s-sustainable-aviation-fuel-flies-one-million-kilometres|title=Virgin Australia's sustainable aviation fuel flies one million kilometres |publisher= Virgin Australia |date=17 June 2019}}</ref> Gevo is committed to going after the entire gallon of sustainable aviation fuel, potentially leading to a negative carbon footprint. [[Virgin Atlantic]] was working to regularly use fuel derived from the waste gases of [[steel mill]]s, with [[New Zealand Superannuation Fund#LanzaTech|LanzaTech]].<ref name=AvWeek26apr2019/> [[British Airways]] wanted to convert household [[Waste-to-energy|waste into jet fuel]] with [[Fischer–Tropsch process#Velocys|Velocys]].<ref name=AvWeek26apr2019/> [[United Airlines]] committed to {{convert|900|e6USgal|m3|abbr=unit}} of sustainable aviation fuel for 10 years from [[Fulcrum BioEnergy]] (to be compared to its {{convert|4.1|e9USgal|m3|abbr=unit}} fuel consumption in 2018), after its $30 million investment in 2015, and will develop up to five biofuel factories near its hubs.<ref name=AvWeek26apr2019/> From 2020, [[Qantas]] will start using a 50/50 blend of [[SG Preston]]’s biofuel on its Los Angeles-Australia flights, also providing fuel derived from non-food plant oils to [[JetBlue Airways]] during 10 years.<ref name=AvWeek26apr2019/> At its sites in [[Singapore]], [[Rotterdam]] and [[Porvoo]], Finland's [[Neste]] should improve its renewable fuel production capacity from {{convert|2.7 to 3.0|e6t|e9lb|abbr=unit}} a year by 2020, and is increasing its Singapore capacity by {{convert|1.3|e6t|e9lb|abbr=unit}} to reach {{convert|4.5|e6t|e9lb|abbr=unit}} in 2022 by investing €1.4 billion ($1.6 billion).<ref name=AvWeek26apr2019>{{cite news |url= https://aviationweek.com/commercial-aviation/biofuel-market-nearing-tipping-point |title= Biofuel Market Is Nearing A Tipping Point |date= Apr 26, 2019 |author= Kerry Reals |work= Aviation Week & Space Technology}}</ref> By 2020, [[International Airlines Group]] had invested $400 million to convert waste into sustainable aviation fuel with [[Fischer–Tropsch process#Velocys|Velocys]].<ref name=Flight3jan2020>{{cite news |url= https://www.flightglobal.com/ba-begins-offsetting-domestic-flight-emissions/135987.article |title= BA begins offsetting domestic flight emissions |date= 3 January 2020 |work= Flightglobal}}</ref> ==Production== [[Jet fuel]] is a mixture of a large number of different [[hydrocarbon]]s. The range of their sizes ([[molecular weight]]s or carbon numbers) is restricted by the requirements for the product, for example, [[freezing point]] or [[smoke point]]. Jet fuels are sometimes classified as [[Kerosene jet fuel|kerosene]] or [[naphtha]]-type. Kerosene-type fuels include Jet A, Jet A-1, JP-5 and JP-8. Naphtha-type jet fuels, sometimes referred to as "wide-cut" jet fuel, include Jet B and JP-4. "Drop-in" biofuels are biofuels that are completely interchangeable with conventional fuels. Deriving "drop-in" jet fuel from bio-based sources is [[ASTM]] approved via two routes. ASTM has also found it safe to blend in 50% SPK into regular jet fuels.<ref>[ https://www.astm.org/DATABASE.CART/HISTORICAL/D7566-11.htm Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons]</ref><ref>[https://www.greencarcongress.com/2008/07/astm-to-conside.html ASTM to Consider Adding 50% F-T Blend to Jet Fuel Specification: Work on Hydrotreated Fats and Oils Also Underway]</ref><ref>[https://www.autoblog.com/2011/07/11/astm-approves-use-of-50-renewable-biofuel-in-commercial-and-mil/ ASTM approves use of 50% renewable biofuel in commercial and military aircraft]</ref> Only tests have been done so far with blending in synthetic paraffinic kerosene (SPK) in considerably higher concentrations.<ref>[https://repository.tudelft.nl/islandora/object/uuid%3Aca415372-6ac0-4e7a-ab66-6e6dbf564e22 Evaluation of safety, performance and emissions of synthetic fuel blends in a Cessna Citation II]</ref> ; HEFA-SPK {{Expand section}} {{As of|2020|}} this is the only mature technology.<ref name=":0">{{Cite web|title=Are aviation biofuels ready for take off? – Analysis|url=https://www.iea.org/commentaries/are-aviation-biofuels-ready-for-take-off|access-date=2020-12-11|publisher=[[IEA]]}}</ref><ref name=":2">{{Cite journal|last=Doliente|first=Stephen S.|last2=Narayan|first2=Aravind|last3=Tapia|first3=John Frederick D.|last4=Samsatli|first4=Nouri J.|last5=Zhao|first5=Yingru|last6=Samsatli|first6=Sheila|date=2020|title=Bio-aviation Fuel: A Comprehensive Review and Analysis of the Supply Chain Components|url=https://www.frontiersin.org/articles/10.3389/fenrg.2020.00110/full|journal=Frontiers in Energy Research|language=English|volume=8|doi=10.3389/fenrg.2020.00110|issn=2296-598X}}</ref> It is a specific type of hydrotreated vegetable oil fuel used in aviation.<ref name=":2" /> ;Bio-SPK : This route involves using oil which is extracted from plant sources like [[Jatropha]], [[algae]], [[tallows]], other waste oils, [[Babassu oil|Babassu]] and [[Camelina]] to produce bio derived synthetic paraffinic kerosene (bio-SPK) by cracking and [[hydroprocessing]]. The growing of algae to make jet fuel is a promising but still [[emerging technology]]. Companies working on algae jet fuel are [[Solazyme]], Honeywell UOP, Solena, [[Sapphire Energy]], [[Imperium Renewables]], and [[Aquaflow Bionomic Corporation]]. Universities working on algae jet fuel are [[Arizona State University]] and [[Cranfield University]] Major investors for algae based SPK research are [[Boeing]], [[Honeywell]]/[[UOP LLC|UOP]], [[Air New Zealand]], [[Continental Airlines]], [[Japan Airlines]], and [[General Electric]]. {{See also|Algae fuel}} ; FT-SPK : The second route involves processing solid [[biomass]] using [[pyrolysis]] to produce [[pyrolysis oil]] or [[gasification]] to produce a [[syngas]] which is then processed into FT SPK ([[Fischer–Tropsch process|Fischer–Tropsch]] Synthetic Paraffinic Kerosene). ; ATJ-SPK : Research is also being done on the alcohol-to-jet (ATJ) pathway where alcohols such as [[ethanol]] or [[butanol]] are de-oxygenated and processed into jet fuels.<ref>[https://advancedbiofuelsusa.info/tag/atj-spk-alcohol-to-jet-synthetic-paraffinic-kerosene/ Alcohol to Jet Synthetic Paraffinic Kerosene]</ref> Some companies such as LanzaTech have already managed to create ATJ-SPK from CO2 in [[flue gas]]es.<ref>[http://www.lanzatech.com/jet-fuel-derived-ethanol-now-eligible-commercial-flights/Jet Fuel Derived from Ethanol Now Eligible for Commercial Flights]</ref> The ethanol is hereby produced from CO in the flue gases using microbes ([[clostridium]] autoethanogenum to be exact). LanzaTech has successfully demonstrated its technology at Pilot scale in NZ –using Industrial waste gases from the steel industry as a feedstock for its microbial fermentation.<ref>Voegele, E. November 2009. “Waste to ethanol projects move forward”, Ethanol Producer Magazine</ref><ref>[http://www.triplepundit.com/2013/05/lanzatech/ LanzaTech microbes]</ref><ref>[https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0638-3 Clostridium autoethanogenum being used by LanzaTech]</ref> ; Future production routes : Routes that use [[synthetic biology]] to directly create hydro-carbons are being researched. Also, the production of Fischer-Tropsch hydro-carbon fuels (i.e. FT-SPK, referred to as "solar kerosine" by the project) through the use of a [[Chemical reactor|solar reactor]] is being researched by the SUN-TO-LIQUID project.<ref>[http://www.solar-jet.aero/page/about-solar-jet/news-events.php SOLAR-JET project terminated and succeeded by SUN-TO-LIQUID project]</ref><ref>[http://europa.eu/rapid/press-release_IP-14-481_en.htm From sunlight to jet fuel]</ref><ref>[https://www.sun-to-liquid.eu/ SUN-TO-LIQUID project]</ref> ; Piston engines : Small piston engines can be modified to burn [[ethanol]] as a fuel.<ref name=SDSU2016>{{cite web |url= https://web.archive.org/web/20080515192245if_/http://www.age85.org/index.htm |title= AGE-85 (Aviation Grade Ethanol) |publisher= South Dakota State University |year = 2006 }}</ref> [[Swift Fuel]], a biofuel alternative to [[avgas]] under development, was approved as a test fuel by [[ASTM International]] in December 2009, aiming for a comparably priced, environmentally friendlier and more fuel-efficient general aviation fuel.<ref>{{cite press release |title=Indiana Airline Fuel Developer Moves Ahead With Testing |publisher=Purdue Research Park |date= December 14, 2009 |url= https://www.purdue.edu/uns/x/2009b/091214SwiftASTM.html }}</ref><ref>{{cite news |url= https://www.avweb.com/news/efforts-move-forward-to-produce-alternative-aviation-fuels/ |title= Efforts Move Forward To Produce Alternative Aviation Fuels |last= Grady |first= Mary |date= December 15, 2009}}</ref> ===Technical challenges=== [[Biodiesel]] that is stored for long periods of time is more likely to [[oxidize]], especially at low temperatures, causing it to gel. Some [[Gasoline additive|additive]]s improve the cold weather tolerance of biodiesel, but only by a few degrees.<ref name="one">{{cite web | title =Renewable and Alternative Energy Fact Sheet | work =Agricultural Research and Cooperative Extension | publisher =[[Penn State College of Agricultural Sciences]] | url =http://pubs.cas.psu.edu/FreePubs/pdfs/uc205.pdf | access-date =March 7, 2012 }}</ref> [[Nitrile]]-based rubber materials expand in the presence of aromatic compounds found in conventional petroleum fuel. Pure biofuels that aren't mixed with petroleum and don't contain paraffin-based additives may cause rubber seals and hoses to shrink.<ref>{{cite web | title =Technical Report: Near-Term Feasibility of Alternative Jet Fuels | publisher =Sponsored by the FAA. Authored by MIT staff. Published by RAND Corporation| url =http://web.mit.edu/aeroastro/partner/reports/proj17/altfuelfeasrpt.pdf | access-date =August 22, 2012 }}</ref> Manufacturers are starting to use a synthetic rubber substitute called [[Viton]] for seals and hoses. Viton isn't adversely affected by biofuels.<ref>{{cite web | title =Biodiesel FAQ | publisher =[[University of Kentucky College of Agriculture, Food, and Environment]] | year =2006 | url =http://www.ca.uky.edu/agc/pubs/aen/aen90/aen90.pdf | access-date =August 22, 2012 }}</ref> The [[United States Air Force]] has found harmful bacteria and fungi in their biofueled aircraft, and use [[pasteurization]] to disinfect them.<ref>http://www.af.mil/News/ArticleDisplay/tabid/223/Article/939659/afrl-discovering-whats-bugging-military-aircraft.aspx</ref> ==Economics== {{Expand section}} {{As of|2020|}} aviation biofuel is considerably more expensive than fossil jet kerosene,<ref name=":0" /><ref name=":1" /> considering [[aviation taxation and subsidies]] at that time.<ref>{{Cite web|last=|first=|date=|title=Sustainable Aviation Fuel: Review of Technical Pathways|url=https://www.energy.gov/sites/prod/files/2020/09/f78/beto-sust-aviation-fuel-sep-2020.pdf|url-status=live|archive-url=|archive-date=|access-date=|website=}}</ref> ==Sustainable fuels== [[File:Oslo Airport terminal night view.jpg|thumb|[[Oslo Airport]] was the first international airport to offer Sustainable aviation fuel as part of the fuel mix since 2016]] [[Sustainable biofuel]]s do not compete with [[food crop]]s, prime [[agricultural land]] or fresh water. Sustainable aviation fuel (SAF) are certified as being [[sustainable]] by a third-party like the [[Sustainable biofuel#Roundtable on Sustainable Biomaterials|Roundtable For Sustainable Biofuels]]. The sustainable aviation fuels certification and production pace seems insufficient to meet the [[International Air Transport Association]] target of halving the CO₂ emissions by 2050.<ref>{{cite news |url= http://aviationweek.com/commercial-aviation/glacial-pace-advancements-biofuel-threatens-emissions-targets |title= Glacial Pace Of Advancements In Biofuel Threatens Emissions Targets |date= Oct 10, 2017 |author= Kerry Reals |work=[[Aviation Week & Space Technology]]}}</ref> ===Certification=== A SAF sustainability certification verifies that the fuel product, mainly focussing on the biomass feedstock, has met criteria focussed around long-term global environmental, social and economic "[[triple-bottom-line]]" sustainability considerations. Under many carbon emission regulation schemes, such as the [[European Union Emissions Trading Scheme]], a certified SAF product may be granted an exemption from an associated carbon compliance liability cost.<ref>{{cite web|url=http://ec.europa.eu/energy/renewables/biofuels/sustainability_schemes_en.htm|title=Sustainability schemes for biofuels|work=European Commission/Energy/Renewable energy/Biofuels|access-date=1 April 2012}}</ref>&nbsp; This marginally improves the economic competitiveness of environmentally favourable SAF over traditional fossil-based jet fuel. However, in the near term there are several commercialisation and regulatory hurdles that are yet to be overcome through the collaboration of a variety of stakeholders for SAF products to meet price parity with traditional jet fuel and to enable widespread uptake.<ref>{{cite web|url=http://www.qantas.com.au/travel/airlines/sustainable-aviation-fuel/global/en#jump4 |title=Sustainable Aviation Fuel |publisher=Qantas |access-date=2013-10-24}}</ref> The first reputable body to launch a sustainable biofuel certification system applicable to SAF was the academic European-based Roundtable on Sustainable Biomaterials (RSB) NGO.<ref>{{cite web|url=http://rsb.epfl.ch/files/content/sites/rsb2/files/Biofuels/Documents%20and%20Resources/11-10-07_RSB_Fact_Sheet_EN.pdf |title=RSB Roundtable on Sustainable Biomaterials &#124; Roundtable on Sustainable Biomaterials |publisher=Rsb.epfl.ch |date=2013-10-17 |access-date=2013-10-24}}</ref> This multi-stakeholder organization set a global benchmark standard on which the sustainability integrity of advanced aviation biofuel types seeking to use the claim of being a Sustainable Aviation Fuel can be judged. Leading airlines in the aviation industry and other signatories to the Sustainable Aviation Fuel Users Group (SAFUG) pledge support the RSB as the preferred provider of SAF certification.<ref>{{cite web|url=http://www.safug.org/information/pledge/ |access-date=March 29, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120425051329/http://www.safug.org/information/pledge/ |archive-date=April 25, 2012 |title=Our Commitment to Sustainable Options}}</ref> These airlines believe it important for any proposed aviation biofuels have independently certified [[sustainable biofuel]] long term environmental benefits compared to the status quo in order to ensure their successful uptake and [[marketability]] <ref>{{cite web|url=http://www.safug.org/ |title=Sustainable Aviation Fuel Users Group – SAFUG |publisher=Safug.org |access-date=2013-10-24}}</ref> ====Sustainability Criteria==== ; EU RED II Recast (2018) : GHG reduction - Greenhouse gas emissions from aviation sustainable fuels must be lower than those from the fossil fuels they replace: at least 50% for production facilities prior to 5 October 2015, a mandatory reduction of 60% for production facilities after that date and 65% for sustainable fuels (SAF) produced in facilities starting operations after 2021. : Land use change - Carbon stocks and biodiversity: raw materials for sustainable fuel production cannot be sourced from land with high biodiversity or high carbon stocks (i.e. primary and protected forests, biodiversity-rich grasslands, wetlands and [[peatland]]<nowiki/>s). : Other sustainability issues are set out in the Governance Regulation and may be covered by certification schemes on a voluntary basis. ; ICAO ‘CORSIA’ : GHG Reduction - Criterion 1: Sustainable alternative fuel for reactors will generate net GHG reductions of at least 10% compared to fossil fuel for reactors, based on the life cycle. : Carbon Stock - Criterion 1: Sustainable alternative Fuel will not be produced from biomass obtained from land whose uses changed after 1st January 2008 and which has been from primeval forests, wetlands or peatlands, as all these lands have high carbon stocks. Criterion 2: In the case of a change in land use after 1st January 2008, as defined on the basis of the IPCC land categories, emissions from direct land use change (DLUC) shall be calculated. If the greenhouse gas emissions from a DLUC exceed the default value of the land use change induced (ILUC), the value of the DLUC will replace the default value of the ILUC. ===Global impact=== [[File:SENASA SAF.jpg|thumb|upright=1.4|Sustainable Aviation Fuel development in Europe. Source: SENASA (2020)]] As [[emissions trading schemes]] and other carbon compliance regimes are emerging globally, certain biofuels are likely to be exempted ("zero rated") by governments from having an associated carbon compliance liability due to their closed-emissions-loop renewable nature, if they can also prove their wider sustainability credentials. For example, in the [[European Union Emissions Trading Scheme]] it has been proposed by SAFUG that only aviation biofuels that have been certified as sustainable by the RSB or similar bodies would be zero rated.<ref>{{cite web|url=http://www.safug.org/assets/docs/SAFUG_Brochure.pdf |title=Sustainable Aviation Fuel Users Group : European Section |publisher=Safug.org |access-date=2013-10-24}}</ref> This proposal has been accepted.<ref>{{cite web|url=http://ec.europa.eu/taxation_customs/resources/documents/taxation/review_of_regulation_en.pdf |title=Revision of the EU Energy Tax Directive - technical press briefing |publisher=Ec.europa.eu |access-date=2013-10-24}}</ref> SAFUG was formed by a group of interested airlines in 2008 under the auspices of [[Boeing Commercial Airplanes]] and in cooperation with support from NGOs such as [[Natural Resources Defense Council]]. Member airlines represent more than 15% of the industry, and all member CEOs have signed a pledge to work on the development and use of Sustainable Aviation Fuel.<ref>{{cite web|url=http://www.boeing.com/newairplane/environment/#/SustainableAviationBiofuel/UsersGroup |title=Environment and Biofuels &#124; Boeing Commercial Airplanes |publisher=Boeing.com |access-date=2013-10-24}}</ref><ref>{{cite web|url=http://www.safug.org/safug-pledge/ |title= SAFUG Pledge; Boeing Commercial Airplanes |publisher=safug.org |access-date=2015-07-10}}</ref> In addition to SAF certification, the integrity of aviation biofuel producers and their product can be assessed by further means, such as by using [[Richard Branson]]'s Carbon War Room,<ref>{{cite web|url=http://www.carbonwarroom.com/sectors/transport/aviation/operation-renewablejetfuels#mission |title=Renewable Jet Fuels |publisher=Carbon War Room |access-date=2013-10-24}}</ref> or the Renewable Jet Fuels initiative.<ref>{{cite web|url=http://renewablejetfuels.org/ |title=Welcome |publisher=Renewable Jet Fuels |access-date=2013-10-24}}</ref> The latter currently cooperates with companies such as LanzaTech, SG Biofuels, AltAir, Solazyme, and Sapphire. A leading independent NGO focused on this issue is the Sustainable Sky Institute.<ref>{{cite web|url=http://www.sustainablesky.com |title=Sustainable Sky Institute |publisher=Sustainable Sky Institute |access-date=2016-04-26}}</ref> === Certified processes === {| class="wikitable" |- ! Abbreviation !! Conversion Process !! Possible Feedstocks !! Blending Ratio !! Commercialization Proposals / Projects |- | HEFA-SPK || Synthesized paraffinic kerosene produced from hydroprocessed esters and fatty acids || Bio-Oils, Animal Fat, Recycled Oils || 50% || World Energy, [[Universal Oil Products]], [[Neste]], Dynamic Fuels, EERC |- | FT-SPK || Fischer-Tropsch hydroprocessed synthesized paraffinic kerosene || Coal, Natural Gas, Biomass || 50% || Fulcrum Bioenergy, Red Rock Biofuels, SG Preston, [[Kaidi Finland]], [[Sasol]], [[Shell Oil Company]], [[Syntroleum]] |- | SIP-HFS || Synthesized kerosene isoparaffins produced from hydroprocessed fermented sugars || Biomass used for sugar production || 10% || [[Amyris (company)]], [[Total S.A.]] |- | SPK/A || Synthesized kerosene with aromatics derived by alkylation of light aromatics from non-petroleum sources || Coal, Natural Gas, Biomass || 50% || [[Sasol]] |- | ATJ-SPK || Alcohol-to-jet synthetic paraffinic kerosene || Biomass from ethanol or isobutanol production || 50% || [[Gevo]], Cobalt, [[Universal Oil Products]], Lanzatech, Swedish Biofuels, Byogy |} ==References== {{Reflist}} ==Further reading== * {{cite news |url= http://aviationweek.com/technology/opinion-biofuels-sustainable-essential-aviation-s-future |title= Opinion: Biofuels Sustainable, Essential To Aviation's Future |date= Oct 23, 2017 |author= Adam Klauber and Isaac Toussie ([[Rocky Mountain Institute]]), Steve Csonka ([[Commercial Aviation Alternative Fuels Initiative]]), Barbara Bramble ([[National Wildlife Federation]]) |work= Aviation Week & Space Technology}} * {{cite web |url= https://aim-builds.s3.amazonaws.com/gevo/Gevo+WP_aviation+fuel.pdf |title= Sustainable Aviation Fuel |quote= Alcohol-to-Jet Synthetic Paraffinic Kerosene Is a Proven Pathway to Deliver a Bio-Based, Low-Carbon Option to Travelers |publisher= [[Gevo]] |date= December 2019 }} ==External links== {{columns-list|colwidth=25em| * {{cite web |url= http://boeing.com/aboutus/environment/environment_report_10/3_biofuels_pg_2.html |publisher= Boeing |title= 2010 Environment report: Sustainable Biofuels}} * {{cite web |url= https://www.sustainablesky.com/ |title= Sustainable Sky Institute |quote= non-profit think tank/do tank focussed on [...] the market transformation of the world's air transport system towards a [...] sustainable long-term future}} * {{cite web |url= https://aviationbenefits.org/environmental-efficiency/climate-action |publisher= [[Air Transport Action Group]] |work= Aviation: Benefits Beyond Borders |title= Aviation industry reducing its environmental footprint}} * [[Appropedia:Air travel, climate change, and green consumerism|Air travel, climate change, and green consumerism]], [[Appropedia]] * {{cite web |url= http://www.cleancluster.dk/NISA |title= Nordic Initiative for Sustainable Aviation |quote= Nordic association working to promote and develop a more sustainable aviation industry, with a specific focus on alternative sustainable fuels}} * {{cite web |url= https://gevo.com/products/sustainable-aviation-fuel/ |title= Low-Carbon, Bio-Based Sustainable Aviation Fuel |publisher= [[Gevo]]}} * {{cite web |url= https://rsb.org/ |title= Roundtable on Sustainable Biofuels |quote= The RSB is supporting the development of a sustainable bioeconomy}} * {{cite web |url= https://www.qantas.com/fr/en/qantas-group/acting-responsibly/our-planet.html |title= Our planet |publisher= Qantas}} * {{cite web |url= http://www.inderscience.com/jhome.php?jcode=ijsa |title= International Journal of Sustainable Aviation |publisher= [[Inderscience Publishers]]}} * {{cite web |url= https://ec.europa.eu/energy/topics/renewable-energy/biofuels/biofuels-aviation_en |title= Biofuels for aviation |publisher= European Commission}} }} [[Category:Algae biofuels]] [[Category:Alternative fuels]] [[Category:Aviation and the environment]] [[Category:Aviation fuels]] [[Category:Biofuels]] [[Category:Renewable fuels]]'