SAF rules of thumb

As part of work on SAF projections, CAEP experts from Washington State University, supported by experts from Hasselt University developed a set of heuristics or "Rules of Thumb" for sustainable aviation fuel (SAF) that could be utilized to make order of magnitude estimations related to SAF costs, investment needs and production potential that could inform policymakers and project developers.

All of the information was calculated using U.S. costs and financial assumptions. The values will change based on regional variables. No incentives were included in the MSP values calculated. Contact ICAO to provide information that could be used to update the Rules of Thumb.

Four SAF manufacturing technologies were assessed: Gasification Fischer-Tropsch (GFT), alcohol to jet (ATJ), hydro-processed esters and fatty acids (HEFA), and pyrolysis. For each of the technologies, multiple feedstocks and two levels of technology maturity were assessed: nth plant and pioneer plant.

The Rules of Thumb provide the impact of feedstock cost, fuel yield, facility scale (total distillate and SAF), total capital investment (TCI) and minimum selling price (MSP) for nth plant and pioneer facility scales.

DISCLAIMER:

These SAF "Rules of Thumb" are intended to provide big picture trends for costs and processing technology/feedstock comparisons and could be utilized to make order of magnitude estimations. They do not provide precise cost or price information. As such, investment or policy decisions should be based on a dedicated analysis that captures specific details related to the investment or policy.

All of the information was calculated using U.S. costs and financial assumptions. The values will change based on regional variables. No incentives were included in the MSP values calculated.

The summary tables 1 an 2 below provide the most likely costs and facility scales based on the Techno Economic Assessment (TEA) models, existing literature values and expert opinion. Summary Table 3 provides estimates on CO2 abatement costs, obtained with the use of MSP information and the life cycle emission reductions associated with each fuel.

All of the TEA models are based on open-source information; costs that use proprietary technology may differ significantly.

Summary Table 1 - Feedstock Information

Technology, feedstock type and price, yield, total annual distillate scale, annual SAF production for both n^th and pioneer facilities.

Processing Technology	Feedstock	Yield (ton distillate/ton feedstock)	Feedstock Price	Total Capacity (million L/year)		SAF production (million L/year)
Processing Technology	Feedstock	Yield (ton distillate/ton feedstock)	Feedstock Price	n^th	pioneer	n^th	pioneer
FT*	MSW	0.31	$30/ton	500	100	200	40
FT*	forest residues	0.18	$125/ton	400	100	160	40
FT*	agricultural residues	0.14	$110/ton	300	100	120	40
ATJ	ethanol	0.60	$0.41/L	1000	100	700	70
ATJ	isobutanol-low	0.75	$0.89/L	1000	100	700	70
ATJ	isobutanol-high	0.75	$1.20/L	1000	100	700	70
HEFA	FOGs	0.83	$580/ton	1000	-	550	-
HEFA	soybean oil***	0.83	$809/ton	1000	-	550	-
FT	CO2 from Direct Air Capture (DAC) , H2	0.24	$300/t, $6/kg	1000	-	200	-
FT	waste CO_2,H₂	0.24	$300/t, $6/kg	1000	-	200	-
Pyrolysis**	forest residues	0.23	$125/ton	400	100	180	40
Pyrolysis**	agricultural residues	0.21	$110/ton	400	100	180	40

*feedstock price is for pre-processed feedstock

**pyrolysis ASTM approval is pending.

***2013-2019 average price of soybean and canola oils,

Summary Table 2 - SAF facilities information

Total capital investment (TCI), capital cost, and minimum selling price (MSP) for n^th and pioneer facilities for each pathway.

Processing Technology	Feedstock	TCI (million $)		Capital Cost ($/L total distillate)		MSP ($/L)
Processing Technology	Feedstock	n^th	pioneer	n^th	pioneer	n^th	pioneer
FT*	MSW	1428	813	2.9	8.1	0.9	2.1
FT*	forest residues	1618	1088	4.0	10.9	1.7	3.3
FT*	agricultural residues	1509	1267	5.0	12.7	2.0	3.8
ATJ	ethanol**	328	117	0.3	1.2	0.9	1.1
ATJ	ethanol, agricultural residues	581	170	0.6	1.7	2.2	2.5
ATJ	isobutanol-low**	332	94	0.3	0.9	1.3	1.5
ATJ	isobutanol-high**	410	110	0.4	1.1	1.7	1.9
HEFA	FOGs	448	-	0.4	-	0.8	-
HEFA	vegetable oil	456	-	0.5	-	1.0	-
FT	DAC CO_2,H₂	3366	-	3.4	-	4.4	-
FT	waste CO_2,H₂	3209	-	3.2	-	3.5	-
Pyrolysis***	forest residues	1038	594	2.6	5.9	1.3	2.1
Pyrolysis***	agricultural residues	1084	619	2.7	6.2	1.3	2.2

*feedstock price is for pre-processed feedstock,

**alcohol feedstock is corn-based,

***pyrolysis ASTM approval is pending.

Summary Table 3 - CO2 abatement costs

CO2 Abatement costs for n^th and pioneer facilities for each pathway (compared with the CORSIA baseline of 89 gCO2e/MJ).

Processing Technology	Feedstock	Life cycle emissions (gCO2e/MJ)*	Abatement Cost ($/tCO₂e)
Processing Technology	Feedstock	Life cycle emissions (gCO2e/MJ)*	n^th	pioneer
FT	MSW	32.5*	210	840
FT	forest residues	8.3*	420	990
FT	agricultural residue	7.7*	520	1170
ATJ	corn ethanol	90.8 , *	no CO2 abatement	no CO2 abatement
ATJ	agricultural residues ethanol, stand alone	39.7*	1020	1190
ATJ	agricultural residues ethanol, integrated	24.6*	780	910
ATJ	isobutanol - low, corn	77.9, *	2100	2510
ATJ	isobutanol - high, corn	77.9,*	3220	3680
ATJ	isobutanol - low, sugarcane	33.1,*	420	500
ATJ	isobutanol - high, sugarcane	33.1,*	640	730
HEFA	FOGs	18.2*	130	-
HEFA	soybean oil	64.9*	640	-
HEFA	brassica carinata	13.0*	160	-
FT	DAC CO2, green H2, wind electricity	7 ***	1390	-
FT	DAC CO2, green H2, solar electricity	25 ***	1780	-
FT	DAC CO2, green H2, grid electricity	279 ***	no CO2 abatement	-
FT	waste CO2, green H2, wind electricity	31 ***	1510	-
FT	waste CO2, green H2, solar electricity	49 ***	2190	-
Pyrolysis****	forest residues	25.7 ***	370	750
Pyrolysis****	agricultural residue	0.2 ***	270	550

* based on default life cycle emissions provided in the ICAO document "CORSIA Default Life Cycle Emissions Values for CORSIA Eligible Fuels".

** Includes ILUC values, which can be subtracted with the use of low LUC risk practices as defined in the ICAO document "CORSIA Methodology for Calculating Actual Life Cycle Emissions Values".

*** life cycle emissions obtained from external references; not CORSIA.

****pyrolysis ASTM approval is pending.