Technology Strategy forSAF (Sustainable Aviation Fuel)in NEDONew Energy and Industrial Technology Development Organization (NEDO)
Technology Strategy Center (TSC)
Sustainable energy unit
Hiroshi ENOMOTO
Innovation for Cool Earth Forum, Tokyo
October 5, 2023

Future of SAF (sustainable aviation fuel)
TSC Sustainable Energy Unit

In 2050
 Global SAF demand is from 294 M-m3 to 425 M-m3.
 In Japan, 23 M-m3 is necessary.
In 2030
 In Japan, 2.0 M-m3 is necessary.
In 2020
 Global SAF supply is 0.063 M-m3, 0.03% of aviation fuel supply.
 SAF production cost is from 2.0 USD/L to 16.0 USD/L.
 Conventional aviation fuel cost is almost 1.0 USD/L.

Definitions
SAF = a fuel loaded in air plain.
neat SAF (nSAF) = An aviation fuel produced from non-fossil fuel.
Normally, SAF is a mixture of nSAF and conventional Jet fuel (e.g. Jet A from crude oil) with 1:1 in weight ratio.
As nSAF amount is not enough, a Jet fuel mixed with few percent of nSAF is called SAF in the market.
第1回 持続可能な航空燃料（SAF）の導入促進に向けた官民協議会, ANRE (2022) 2History of the technology strategy in NEDOTSC Sustainable Energy Unit

 13 technologies were selected in 2017.
 The three technologies, 1) Alcohol to Jet (ATJ), 2) Gasification＋
Fischer-Tropsch (G+FT), 3) Microalgae+Hydroprocess (MA+H),
were selected in 2019.
2017Classified with source(4) Wastecooking oil(3) MSW,
Waste gas(2) Microalgae(1) Biomass (Cellulose)

Saccharification

Gasification

Saccharide

Synthesis gas

2019Classified with process

Fermentation

Alcohol

Alcohol fermentation to jet

Polymerintermediate

Saccharides fermentation to jet

FTOil from FT

Gasification + FT(wood/grass)

FermentationAlcohol

Gasification + alcohol fermentation(wood/grass)

Polymerintermediate

Gasification + saccharides fermentation(wood/grass)

Rapid thermal
decomposition

Bio crude

Hydroprocess

Entracting

Fats

Esterifying

HTL hydrothermal liquefaction(wood/grass)
Bio-diesel(FAME)

Microalgae(oil)

Entracting

Crude oil

Reforming

Microalgae(hydrocarbon)

HTL

Bio crude

Reforming

HTL(microalgae)

Gasification

Esterifying
Hydroprocess

Synthesis gas

Bio-diesel(FAME)

Gasification +FT(G+FT)FTOil from FT

Gasification + FT(residue)

Fermentation

Alcohol

Gasification + alcohol fermentation(residue)

Polymerintermediate

Gasification + saccharides to jet(residue)

Hydroprocess

Alcohol to jet(ATJ)HEFA
Hydroprocessed ester and fatty acids

Microalgae +hydroprocess(MA+H)NEDO TSC Foresight (2017) 21 3

How to find the pros in the price?
TSC Sustainable Energy Unit

For “carbon neutral” production and enough supply, the followings areapproximated to find the dominant cost.
 The production rate [m3-nSAF/plant/year] is varied from 1,000 (1k)to 1,000,000 (1M).
 Any utility (electricity and steam) in the plant is from the raw
material.
 Number of labor is calculated with Japanese standard.
The index are as follows.
1. CAPEX of 30 years plant lifetime
2. OPEX (labor): Japanese standard in 2023
3. OPEX (utility)
4. Raw material cost
Pros in general
ATJ
Alcohol (ethanol) has the conventional market.
Alcohol from cellulose (future technology) won’t compete against food demand.
G+FT
Conventional plant technology is enough.
Any place could be used for the plant.
MA+H
Higher growth rate could be achieved.
“Reasonable” CO2 usage is possible.
NEDO TSC (2023) 4

ATJ (alcohol to Jet)
TSC Sustainable Energy Unit

 In large scale, raw material cost is dominant. This means that
alcohol should be from cellulose (or waste).
 In small scale, labor OPEX is dominant. This means that “fullautomatic” plant could be adapt in local usage.
ATJ
1

0.5

0
1,000
CAPEX

10,000OPEX (labor, tax)

100,000
OPEX (utility)

1,000,000
raw material

m3-nSAF/year
NEDO TSC (2023) 5

Gasification+Fischer-Tropsch (G+FT)TSC Sustainable Energy Unit

 In large scale, raw material cost and CAPEX are dominant. Thismeans that the plant should be placed at the raw material
production area and that low price gasifier is necessary.
 In small scale, labor OPEX is dominant. This means that “fullautomatic” plant could be adaptG+FTin local usage.
10.5

01,000
CAPEX

10,000OPEX (labor, tax)

100,000
OPEX (utility)

1,000,000
raw material

m3-nSAF/year
NEDO TSC (2023) 6

Microalgae+hydroprocess, (MA+H)
TSC Sustainable Energy Unit

 10 times of wood growth rate could be achieved.
 Gene recombination is not necessary.
 “Effective” CO2 supply technology is necessary for ultimate usage ofphotosynthesis.

Effective land use evaluated with the growth rate
• Wood in Japan
5 ton-dry/ha/year• Wood in tropical region
30 ton-dry/ha/year• Sugarcane in Brazil
80 ton-dry/ha/year• Microalgae in tropical region
100 ton-dry/ha/year(target of NEDO project)

Theoretical maximum of photosynthesis efficiency is 0.124.
Higher heating value (HHV) of microalgae is 22 MJ-HHV/kg-dry.
Solar energy for photosynthesis around equator is 60 TJ/ha/year.
From these approximations, the maximum energy by photosynthesis is 60×0.124 = 7.44 TJ/ha/year.
The maximum microalgae growth rate is 7440/22 = 338 ton-dry/ha/year.
For 400 M-m3-nSAF, almost 8 M-ha (only 0.2% of Moon surface area) is necessary with the ideal microalgae.
Discussion with T. Hoshino from C4, CHITOSE 7

How much area can we use for biomass?
TSC Sustainable Energy Unit

 The forest around Pacific ocean (Asia and Oceania) can supply 30% of
global nSAF demand from wood.
 Microalgae in NEDO project can supply 100% of global nSAF demand fromthese forest.

1.0% of production forest in Asia = 1.1 M-ha = 5.5 M-m3-nSAF = 2 %50% of unknown forest in Asia = 12.5 M-ha = 62.5 M-m3-nSAF = 20 %50% of unknown forest in Oceania = 19.5 M-ha = 97.5 M-m3-nSAF = 30 %10 ton-dry/ha/year (wood) is approximated.
0.5 m3-nSAF/ton-dry = 5 m3-nSAF/ha/year
FAO, Global Forest Resources Assessment 2020: Main report (2020). 8

Conclusion
TSC Sustainable Energy Unit The three technologies as follows are evaluated.
1. Alcohol to Jet (ATJ) will be a solution with low price alcohol.
2. Gasification and Fischer-Tropsch (G+FT) could be constructed with small
capacity in any place.
3. Microalgae and hydroprocess with carbon neutral CO2 (MA+H) has thelargest growth rate.
 In case of 1.0 M-m3/year production rate, as the ratio of raw material costis large, the plant should be places at the raw material production area.
 Hydrogen and water are also important raw materials in any case. The
carbon intensity of them should be evaluated.
 As the plant or the place for the place should be designed to make thecarbon intensity [kg-CO2/kg-nSAF] minimum, the supply chain design isimportant.

NEDO TSC (2023) 9