Refinery Process Fundamentals Curriculum

Module 4 - Hydroprocessing

Module from the Refinery Process Fundamentals Curriculum curriculum.

HYDROPROCESSING OVERVIEW · Learning Objectives · 1. Distinguish between hydrotreating and hydrocracking processes 2. Understand the role of hydrogen in upgrading petroleum fractions 3. Identify typical catalyst types and their applications 4. Describe key operating parameters: WABT, LHSV, H2 partial pressure, H2/oil ratio 5. Recognize the relationship between feed quality, operating severity, and product specifications · Hydrotreating vs Hydrocracking Comparison

Feature	Hydrotreating (HDT)	Mild Hydrocracking (MHC)	Conventional Hydrocracking (HCK)	Units	Notes
Primary Purpose	Remove S, N, metals, saturate olefins	Moderate conversion (20-40%) with desulfurization	Deep conversion (60-99%) to lighter products	—	Severity increases left to right
Typical Feed	Naphtha, diesel, VGO	VGO, heavy coker gas oil	VGO, DAO, heavy gas oils	—	Heavier feeds need more severe conditions
Operating Pressure	300-800 psig	800-1500 psig	1500-3000 psig	psig	Higher pressure = more H2 partial pressure
Operating Temperature	550-700°F	650-750°F	680-780°F	°F	WABT increases with catalyst age
LHSV	1.0-6.0	0.5-2.0	0.5-1.5	hr⁻¹	Lower LHSV = longer contact time
H2 Consumption	100-600 SCF/bbl	400-1000 SCF/bbl	1000-2500 SCF/bbl	SCF/bbl	Major operating cost driver
Catalyst Type	CoMo (desulfurization), NiMo (denitrification)	NiMo on alumina	NiMo or NiW on zeolite/amorphous	—	NiW for high aromatic saturation
Conversion	<10% (incidental)	20-40%	60-99%	vol%	Conversion of 700°F+ to lighter products
Products	Same boiling range, improved quality	Some naphtha + diesel, improved VGO	Naphtha + diesel/jet + lube base	—	HCK makes high-quality middle distillates
Common Hydroprocessing Catalyst Types
Catalyst	Active Metals	Support	Primary Application	Strength	Limitation
CoMo/Al2O3	Cobalt-Molybdenum	γ-Alumina	Desulfurization (HDS)	Best S removal activity/cost ratio	Limited N removal, low hydrogenation
NiMo/Al2O3	Nickel-Molybdenum	γ-Alumina	Denitrification (HDN), deep HDS	Best N removal, good aromatic saturation	Higher H2 consumption than CoMo
NiW/Al2O3	Nickel-Tungsten	γ-Alumina or Silica-Alumina	Aromatic saturation, lube hydrofinishing	Superior hydrogenation activity	Expensive, high H2 consumption
NiMo/Zeolite	Nickel-Molybdenum	USY Zeolite + Alumina	Hydrocracking (conversion)	High conversion activity, shape selectivity	Requires high H2 pressure, coke sensitive
CoMo/SiO2-Al2O3	Cobalt-Molybdenum	Amorphous Silica-Alumina	Mild hydrocracking	Moderate conversion with HDS	Less selective than zeolite catalyst
Grading Catalyst	Various (low activity)	Alumina (large pore)	Top bed guard — metals/particulate removal	Protects main catalyst bed	No significant treating activity
Source: FOS Chief Files — Module 06 (Hydrotreating), Module 09 (Hydrocracking), Hydroprocessing Design Manual, Example Calcs- Hydro

Source: Refinery_Process_Fundamentals_Curriculum_v1.xlsx · Sheet: Module 4 - Hydroprocessing

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