Refinery Process Fundamentals Curriculum

Module 5 - FCC

Module from the Refinery Process Fundamentals Curriculum curriculum.

FLUID CATALYTIC CRACKING · Learning Objectives · 1. Explain the FCC process: riser cracking, catalyst regeneration, product fractionation 2. Describe FCC catalyst (zeolite) function and deactivation by metals/coke 3. Identify key operating variables: riser outlet temperature, cat/oil ratio, feed preheat 4. Interpret FCC yield structure: LPG, gasoline, LCO, HCO, coke 5. Understand FCC contributions to the refinery product slate and economics · FCC Process — Key Operating Parameters

Parameter	Typical Range	Effect of Increase	Effect of Decrease	Primary Control	Units
Riser Outlet Temperature	960-1020°F	Higher conversion, more gasoline + LPG, more coke	Lower conversion, more LCO/HCO	Catalyst circulation rate	°F
Cat/Oil Ratio	5-8 wt/wt	Higher conversion, more gasoline	Lower conversion	Slide valve position	lb cat/lb oil
Feed Preheat Temperature	400-700°F	Lower cat/oil ratio for same conversion, lower regen temp	Higher cat/oil required	Feed preheat exchanger/furnace	°F
Feed Rate	20,000-100,000 BPD	Higher throughput, lower residence time per pound	Lower throughput	Feed pump speed	BPD
Reactor Pressure	15-30 psig	Higher coke yield, lower gasoline selectivity	Better selectivity, limited by blower	Reactor/regen pressure balance	psig
Regenerator Temperature	1250-1350°F	Better coke burn, catalyst deactivation risk >1400°F	Incomplete burn, CO in flue gas	Coke on catalyst, air rate	°F
Catalyst Activity (MAT)	65-75%	Higher conversion, more gasoline	Lower conversion	Fresh catalyst addition rate	% (microactivity test)
Residue in Feed (CCR)	0.1-3.0 wt%	More coke, higher regen temp, metals deposition	Cleaner operation, lower conversion	Feed selection, pretreating	wt%
FCC Yield Structure — Typical VGO Feed
Product	Yield (vol%)	Yield (wt%)	Disposition	Key Quality	Value Driver
Fuel Gas (C1-C2)	3-5 (wt%)	3-5	Refinery fuel gas system	BTU content	Offsets purchased fuel
LPG (C3-C4)	12-18	10-15	Alkylation feed, propylene sales, LPG sales	Propylene/propane split, C4 olefin content	Propylene premium ($0.30-0.50/gal over propane)
FCC Gasoline (C5-430°F)	48-58	42-50	Gasoline blending pool	RON 91-93, olefins 20-35%, sulfur	Largest volume product, octane contribution
Light Cycle Oil (430-650°F)	15-25	16-26	Diesel blending (limited), ULSD hydrotreater feed	High aromatics (60-80%), low cetane (20-28)	Low value — poor diesel quality
Heavy Cycle Oil (650°F+)	3-8	4-10	Recycle to FCC, fuel oil blending, coker feed	High aromatics, high density	Low value product
Coke	4-6 (wt%)	4-6	Burned in regenerator (provides process heat)	Heat of combustion ~14,000 BTU/lb	Fuel for the process — not a product
Source: FOS Chief Files — Module 08 (FCC), FCC Learning folder, Examples-FCC, Cracking Catalyst Activity reference

Source: Refinery_Process_Fundamentals_Curriculum_v1.xlsx · Sheet: Module 5 - FCC

© 2026 Inflection Point Engineering, LLC. All rights reserved. The content of this page — including calculation methods, reference data, written analysis, interactive tools, and source code — is the intellectual property of Inflection Point Engineering, LLC and is protected under applicable copyright, trademark, and trade secret laws. Unauthorized reproduction, redistribution, modification, or derivative use in whole or in part is prohibited without prior written consent.

Disclaimer. This material is provided for informational and educational purposes only and does not constitute professional engineering advice. Calculations, reference data, and methodologies are based on published standards and accepted engineering practice but are not a substitute for engineering judgment, site-specific analysis, or review by a licensed Professional Engineer. Inflection Point Engineering, LLC makes no warranties, express or implied, regarding the accuracy, completeness, or fitness for a particular purpose of any content presented here, and shall not be liable for any direct, indirect, incidental, or consequential damages arising from its use. Users assume all risk associated with applying this content to real-world design, operations, or decisions.