Estimate product slate when shifting from RD to SAF via hydroisomerization (not hydrocracking). Branching n-paraffins lowers boiling points into the jet range without breaking C-C bonds — preserving carbon yield and energy density. Adjust severity, feedstock, and cracking leakage below.
⚙️ Parameters
Presets:
NoneMaximum
0% (perfect catalyst)30% (poor selectivity)
C14 (palm kernel)C18 (soybean/tallow)
270°C (tight)310°C (relaxed)
5% (HDO only)18% (HDO+DCO)
Isomerization severity controls how much branching occurs. Higher branching → lower boiling points → more product falls in jet range. Cracking leakage is the fraction of feed that unavoidably cracks to naphtha/gas during isomerization (catalyst-dependent; SAPO-11 ≈ 3–8%, amorphous SiO₂-Al₂O₃ ≈ 15–30%).
📊 Estimated Product Slate
SAF
55%
55.0%
Ren. Diesel
24%
24.0%
Naphtha
3.0%
LPG / Gas
2.0%
Propane
4.0%
Water+CO₂
12.0%
88%
Jet + Diesel Selectivity
3.3%
Naphtha Penalty
84%
Total Liquid Yield
33
H₂ (kg/t oil)
📐 Comparison: If this were done by cracking instead
SAF yield
—
RD yield
—
Naphtha
—
Jet+Diesel selectivity
—
Naphtha penalty vs isomerization
—
Model basis: Isomerization shifts n-paraffin boiling points by introducing methyl branches. The boiling point depression per branch is modeled as ~15–25°C depending on carbon number and branch position (based on NIST data for C16–C18 isomers). At maximum severity, multi-branched iso-C18 (bp ~260–280°C) falls well within the jet spec FBP of 300°C. Cracking leakage represents the fraction of feed that undergoes C-C bond scission during isomerization — a function of catalyst acid strength (SAPO-11: mild → low cracking; amorphous SiO₂-Al₂O₃: strong → high cracking). HDO losses include water, CO₂, and propane from deoxygenation of triglyceride backbone. The cracking comparison uses the central estimate from Pearlson (2013) and Zech (2018) interpolated to the same SAF yield.
Patent references:
(1) Frey, S.J.; Wang, H.; Bozzano, A.G. "Process for Producing Jet Fuel from Isomerizing a Biorenewable Feed." U.S. Patent App. Pub. No. US 2025/0026990 A1, Jan. 23, 2025. Assignee: UOP LLC (Honeywell).
(2) Zink, S.F.; Lesch, D.A.; Pan, W.; Kozlowski, J.T.; Prabhakar, S.; Sanchez, S. "Selective Hydroisomerization Catalyst." U.S. Patent No. 11,697,111, Jul. 11, 2023. Assignee: UOP LLC (Honeywell).
Data calibrated against: Neste NEXBTL campaign (Ketjen/ERTC 2024: 74 wt% SAF, >90% L/L yield, cloud point −46°C); UOP Patent US 2025/0026990 (>70–80% jet yield with ≥14 wt% C18+ retention); Pearlson et al., Biofuels Bioprod. Bioref. 7:89–96 (2013); Zech et al., Applied Energy 231:997–1006 (2018); Robota et al., Energy Fuels 27:985–996 (2013). Boiling point depression from NIST WebBook n-/iso-alkane data.