Process Technology Quick Reference Cards

Renewable Fuels

Chapter from the Process Technology Quick Reference Cards.

RENEWABLE FUELS (HVO / HEFA / CO-PROCESSING)

Process Objective

Produce renewable diesel and sustainable aviation fuel (SAF) by hydrotreating bio-based fats, oils, and greases (FOG).

Key Operating Variables

Variable	Typical Range	Effect / Notes
WABT	550-700°F	Higher T → more deoxygenation but faster deactivation
Pressure	500-1,500 psig	Higher P → HDO pathway dominant, better catalyst stability
LHSV	0.5-2.0 hr⁻¹	Lower LHSV → complete deoxygenation
H2/Oil Ratio	2,000-6,000 SCF/BBL	Higher H2 demand than petroleum HDT (2-3×)
Feed FFA	<5%	High FFA → corrosion, catalyst issues, requires pretreatment

Process Configurations

Co-processing: 5-20% renewable blend in existing HDT (lowest capital, fastest path)
Standalone HVO: 100% renewable feed, dedicated unit (full CI credit)
Converted refinery: repurposed conventional HDT for renewables
Two-stage (HDO + isomerization): for SAF production — isomerization improves cold flow

Products & Yields

Renewable diesel (HVO/HEFA): cetane 75-90, <1 ppm sulfur, ~0% aromatics
Renewable naphtha: C5-C9 paraffins (steam cracker or gasoline blend)
Renewable jet (SAF): per ASTM D7566 Annex A2 — up to 50% blend
Propane: co-product from glycerol backbone cracking
Water: 10-15 wt% of feed — manage in separation system

Common Troubleshooting

Catalyst deactivation: feed metals (Na, K, Ca, P) — improve pretreatment
Corrosion: FFA + water at temperature — verify metallurgy, monitor corrosion
High H2 consumption: inherent to HDO pathway — ensure H2 capacity
Water management: large water make — sour water system capacity
CO/CO2 in recycle gas: decarboxylation products — purge or PSA recovery

Source: Process_Tech_Quick_Reference_Cards_v1.xlsx · sheet “Renewable Fuels”

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