Conversion processes

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Annex 16 Vol IV defines a conversion process as "a type of technology used to convert a feedstock into aviation fuel".

As of October 2021, 9 conversion processes for SAF production have been approved  by the ASTM InternationalIn order to be used in commercial flights, a sustainable aviation fuel (SAF) has to comply with ASTM  D4054.

In order to be eligible for use within the ICAO Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), SAF must also meet a set of sustainability criteria. More information on CORSIA eligible fuels is available on the dedicated CORSIA Eligible Fuels webpage. 

Specific details on the conversion processes that already have CORSIA default Life Cycle Emission values (FT, HEFA, SIP and ATJ) are available in the CORSIA supporting document "LCA methodologies" 

ASTM reference
​Conversion process
​Possible Feedstocks
​Blending ratio by volume
​Commercialization proposals / Projects
​ASTM D7566 Annex​ 1
​Fischer-Tropsch hydroprocessed synthesized paraffinic kerosene
FT​Coal, natural gas, biomass​
50%​​Fulcrum Bioenergy, Red Rock Biofuels, SG Preston, Kaidi, Sasol, Shell, Syntroleum
ASTM D7566 Annex 2
Synthesized paraffinic kerosene from hydroprocessed esters and fatty acids​​HEFA
Bio-oils, animal fat, recycled oils​50%
World Energy, Honeywell UOP, Neste Oil, Dynamic Fuels, EERC​
ASTM D7566 Annex ​3
​Synthesized iso-paraffins from hydroprocessed fermented sugars
SIP​Biomass used for sugar production​10%​Amyris, Total​
ASTM D7566 Annex ​4
​Synthesized kerosene with aromatics derived by alkylation of light aromatics from non-petroleum sources
FT-SKA​Coal, natural gas, biomass​
ASTM D7566 Annex ​5
​Alcohol to jet synthetic paraffinic kerosene
ATJ-SPK​Biomass from ethanol or isobutanol production​​50%Gevo, Cobalt, Honeywell UOP, Lanzatech, Swedish Biofuels, Byogy​
ASTM D7566 Annex 6
​Catalytic hydrothermolysis jet fuel
​Triglycerides such as soybean oil, jatropha oil, camelina oil, carinata oil, and tung oil
​Applied Research Associates (ARA)
ASTM D7566 Annex 7
​Synthesized paraffinic kerosene from hydrocarbon-hydroprocessed esters and fatty acids
​IHI Corporation
​ASTM D1655
 Annex A1

co-hydroprocessing of esters and fatty acids in a conventional petroleum refinery

​co-processed HEFA
Fats, oils, and greases (FOG) co-processed with petroleum
ASTM D1655
 Annex A1

co-hydroprocessing of Fischer-Tropsch hydrocarbons in a conventional petroleum
​co-processed FT
Fischer-Tropsch hydrocarbons co-processed with petroleum

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