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SRU - Claus Process Tutorial


SRU - Claus Process Simulation

Envision Systems SRU Claus Process Tutorial


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

SRU - (Sulfur Recovery Unit) Claus Process Tutorial

The interactive SRU tutorial provides an overview, fundamental principles, control principles and operating principles for a Claus Process used in a sulfur recovery unit (SRU), using voice, video, animation and graphics. The topics covered are:


  • Introduction
  • Importance of SRU
  • Process Overview

SRU Components        

  • Amine Stripper
  • Sour Water Stripper
  • Thermal Reaction Furnace
  • Waste Heat Boiler
  • Sulfur Condensers
  • Catalytic Reactors

Principles of SRU     

  • Absorption/Regeneration of Amine
  • Claus Reactions
  • Ammonia Destruction
  • Sulfur Condensation

Key Controlled and Operating Variables     

  • Reboiler Steam to Feed Ratio
  • Amine Stripper Pressure
  • Amine Strength   
  • Sour Water Stripper Pressure
  • Sour Water Stripper Condenser Temperature
  • Air Flow Control
  • Claus Burner Temperature
  • Catalytic Reactor Temperature
  • Sulfur Condenser Temperature
  • Reheater Temperature

Startup Operation      

  • Introduction   
  • Pre-Startup Check
  • Purge and Warm-up of Claus Unit
  • Warm Up of Amine Unit
  • Introduction of Rich-Amine to Amine Unit
  • Introduction of Amine Acid Gas to Claus Unit
  • Warm up of Sour Water Stripping Unit
  • Introduction of Sour Water to Sour Water Stripping Unit
  • Introduction of Sour Water Gas to Claus Unit   

Shutdown Operation     

  • Introduction
  • Shutdown of Sour Water Stripping Unit
  • Shutdown of Amine Unit
  • Shutdown of Claus Unit


  • Hydrocarbons Carryover
  • Amine Stripper Flooding
  • Amine Losses    
  • Excessive Water in Gas to Claus Unit
  • Combustion Air Flow Problems
  • Degradation of Catalyst Activity
  • Plugged Sulfur Seal Legs
  • Sulfur Fires
Envision Systems SRU Simulation
Copyright © 2009 by EnVision Systems Inc. All rights reserved worldwide.

SRU - (Sulfur Recovery Unit) Claus Process Simulation

The SRU simulation is a rigorous and high-fidelity mathematical process model that provides a realistic dynamic response for a sulfur recover unit (Claus Process).

Process Overview:

The sulfur recovery unit converts hydrogen sulfide (H2S) contained in the acid and sour water gas streams into elemental sulfur. It also oxidizes ammonia present in the sour water gas.

Major Sections:

Amine Stripper/Regenerator Unit

  • Sour Water Stripping Unit
  • Claus Unit with Thermal and Catalytic Reactors
  • Tail Gas Treating Unit
  • Incinerator
  • Sulfur Storage and Shipping Facilities


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:

  • Amine Stripper Foaming and Tray Plugging
  • Sour Water Stripper Tray Plugging
  • Effect on Thermal Reaction
    • Temperature
    • Hydrogen Sulfide Loading
    • Tail Gas Recycle
  • Effect on Catalytic Reaction
    • Temperature
    • Sulfur Condensation
    • Hydrogen Sulfide Loading
    • Space Velocity
  • Tail Gas Air Demand (H2S - 2 x SO2) Control
  • Effect of Change in Catalyst Bed Activity
  • Effect of Plugging of Sulfur Seal Legs
  • Effect of Hydrocarbon in Feed
  • Effect of Ammonia in Feed
  • Sulfur Fire in Sulfur Pit
  • Sulfur Loading to Tankers
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