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CRU - Fixed-Bed

Reformer Fixed-Bed Tutorial


Reformer Fixed-Bed Simulation

Envision Systems CRU Tutorial


Copyright © 2009 by EnVision Systems Inc. All rights reserved worldwide.


Reformer Fixed-Bed Tutorial

The interactive CRU tutorial provides an overview, fundamental principles, control principles and operating principles for a fixed-bed semi-regenerative catalytic reforming unit, using voice, video, animation and graphics.
The principles taught for the fixed-bed semi-regenerative CRU are also applicable for a fixed-bed cyclical CRU.

The topics covered are:


  • Introduction
  • The Importance of the Reformer in Refineries
  • The Importance of Reformer in Petrochemical Plants
  • Feedstock Types    
  • Process Overview
  • Classifications of Reformer Units

Reformer Components   

  • Feed Preparation and Preheat System
  • Reactor and Furnace System    
  • Reactor Effluent Cooling and Separation System
  • Product Stabilization and Fractionation System

Principles of Reformer

  • Reforming Catalysts    
  • Catalytic Reforming Reactions
  • Reactor Conversion and Reformate Yield
  • Catalyst Deactivation
  • Catalyst Regeneration    

Key Controlled and Operating Variables

  • Reactor Inlet and Differential Temperatures    
  • Weighted Average Inlet Temperature (WAIT)
  • Weighted Average Bed Temperature (WABT)
  • Reactor Pressure
  • Hydrogen to Hydrocarbon Ratio and Recycle Rate    
  • Feed Rate or Space Velocity
  • Feedstock Properties
  • Chloride and Water Injection

Safeguard System

  • Introduction    
  • Emergency Unit Shutdown (ESD)
  • Naphtha Feed Shutdown
  • Reactor Furnace Shutdown
  • Recycle Gas Compressor Protection
  • Product Separator Low Level Protection
  • Stabilizer Reboiler Furnace Shutdown    

Startup Operation

  • Pre-Startup Check
  • Nitrogen Purge
  • Hydrogen Circulation
  • Waste Heat Boiler Commissioning
  • Reactor Furnace Commissioning and Warm-up
  • Waste Heat Boiler Pressurization
  • Stabilizer Commissioning
  • Naphtha Feed Cut-in
  • Stabilizing the Reformer Unit

Shutdown Operation

  • Reduce Naphtha Feed Flow    
  • Reactor Furnace Shutdown
  • Waste Heat Boiler Shutdown
  • Depressurizing and Purging the Reactors
  • Stabilizer Shutdown


  • Loss of Naphtha Feed    
  • Loss of Recycle Gas
  • Loss of Reactor Furnace
  • Loss of Cooling
  • Loss of Stabilizer Reboiler
  • Sulfur Catalyst Poisoning
Envision Systems Reformer Fixed-Bed Simulation
Copyright © 2009 by EnVision Systems Inc. All rights reserved worldwide.

Reformer Fixed-Bed Simulation

The CRU simulation is a rigorous and high-fidelity mathematical process model that provides a realistic dynamic response for a fixed-bed semi-regenerative catalytic reforming unit.

Process Overview:

The catalytic reforming unit dehydrogenates paraffins and naphthenes in naphtha feed stream to aromatics. The resulting product is a high octane, high aromatics stream that can be used as a gasoline blending component or can be further processed for aromatics recovery. By-product streams include a hydrogen-rich make-gas and a liquefied petroleum gas (LPG) stream.

Major Sections:

  • Feed and Reactor Section
  • Furnace and Waste Heat Recovery Section
  • Product Separator and Recycle Gas Compressor Section
  • Stabilizer Section


Major Operations for Trainee Practice:

  • Startup and Shutdown Operations
  • Normal Operations
  • Emergency Shutdown Operations
  • Troubleshooting Equipment, Instrument and Control Valve Malfunctions
  • Malfunction Recovery Actions


Simulation Features:

  • Effect on Reforming Products
    • Reactor Inlet Temperatures
    • Reactor Pressure
    • Naphtha Feed Rate and Feedstock Quality
    • Recycle Gas H2 to Oil Ratio
    • Catalyst Coking or Bed Ageing
    • Chloride and Alcohol Injection
    • Sulfur inhibition of Catalyst Activity
    • Water in feed
  • Effect on Coking
    • Reactor Inlet Temperatures
    • Reactor Pressure
    • Recycle Gas H2 to Oil Ratio
  • Waste Heat Steam production
  • Interlock/Safeguard System
  • Product Properties Calculation such as:
    • Reformate Reid Vapor Pressure and Octane Number
    • LPG C5+ and Benzene Volume %
    • Hydrogen Make-Gas Composition
    • Light Hydrocarbon Offgas Composition
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