Extending Naphtha Hydrotreater Run Lengths
An interactive guide to understanding and mitigating feed/effluent exchanger fouling when processing coker naphtha.
3-6 Months
Typical TBC (Unmitigated)
Run length with coker naphtha and no robust mitigation strategy.
11-18 Months
Typical TBC (With Mitigation)
Achieved with basic operational controls or chemical treatment.
2+ Years
Refinery Goal TBC
Aligns cleaning with catalyst life, requiring advanced solutions.
The Anatomy of Fouling
Coker naphtha introduces a perfect storm of contaminants. Click on a mechanism below to understand the primary drivers of exchanger fouling and how they interact.
Polymerization & Coking
The most aggressive mechanism.
Inorganic Particulates
Corrosion and solid debris.
Salt Deposition
Ammonium salt crystallization.
Chemical Reaction Fouling
This is the primary challenge with coker naphtha. Highly reactive diolefins, initiated by dissolved oxygen and catalyzed by iron, undergo a chain reaction to form long-chain polymers (gums). At high temperatures (>177°C), these gums precipitate and "bake" onto hot tube surfaces, forming a hard, insulating layer of coke. This process is self-accelerating: as the foulant layer insulates the tube, the surface temperature increases, which in turn speeds up the coking reaction rate.
Interactive Fouling Map: 8-Bundle Exchanger
Fouling is not uniform. The temperature profile across the exchanger train dictates where specific mechanisms dominate. Use the controls to visualize the most probable fouling zones.
Display Fouling Risk:
Select a fouling risk to see where it impacts the exchanger train and read an explanation here.
A Tiered Framework for Mitigation
A successful strategy involves a multi-layered approach, from low-cost operational changes to capital-intensive hardware upgrades. Explore the options below.
Tier 1: Operational Discipline
Low-cost, immediate actions using existing assets. This is the foundation of any fouling mitigation program.
- ● Rigorous Oxygen Exclusion
- ● High-Efficiency Feed Filtration
- ● Maintain High Fluid Velocity
- ● Inject "Soaker" Hydrogen
Tier 2: Chemical Treatment
A high-ROI intervention using specialized additives to disrupt the fouling process at a chemical level.
- ● Antipolymerants (Radical Scavengers)
- ● Dispersants
- ● Metal Deactivators
- ● Online Cleaning Chemistries
Tier 3: Capital Solutions
Permanent hardware solutions for chronic, severe fouling that provide the highest level of reliability.
- ● Diolefin Saturation Reactor (DSR)
- ● Welded Plate Heat Exchangers
- ● Helixchanger™ Technology
- ● Advanced Offline Cleaning (Ultrasonic)
Benchmarking Performance: Case Studies
This chart visualizes the impact of mitigation strategies from real-world case studies, showing the achievable extension in Time Between Cleanings (TBC).