Hydrotreater Corrosion Prevention

Hydrotreating units operate under conditions that would destroy ordinary equipment: temperatures above several hundred degrees Celsius, high hydrogen partial pressure and corrosive media. Hydrotreater corrosion prevention is therefore not an optional add-on but the core of a reliable design, because a single day of unplanned downtime can erase weeks of margin.

High-Temperature Sulfidic Attack

In the hot section, organic sulphur reacts with hydrogen to form hydrogen sulphide, which attacks carbon and low-alloy steel to create an iron sulphide scale. That scale is loose and easily stripped by flowing fluid, exposing fresh metal to continuous thinning of heater tubes, reactor shells and hot effluent lines. Selecting the correct alloy and controlling temperature are the first lines of defence.

Ammonium Chloride Deposition

Downstream of the reactor, where streams cool below the water dew point, ammonia and hydrogen chloride combine into solid ammonium chloride salts. These hygroscopic deposits wick moisture into a concentrated, acidic chloride environment that causes pitting corrosion under the scale, far more aggressive than the uniform thinning seen up top. Managing this narrow temperature window is what protects reactor effluent air coolers and cold separators.

Process Mitigation

Operational controls matter as much as materials. Continuous injection of deoxygenated wash water dissolves ammonium salts before they crystallize, real-time wall-temperature monitoring keeps metal above the salt dew point, and upstream desalting reduces the chloride load entering the unit in the first place. Together these measures target the corrosion driver at its source rather than compensating for it later.

Material Selection and Cladding

The most durable solutions combine a chromium-molybdenum pressure shell with a metallurgically bonded corrosion-resistant lining. Cladding with stainless or nickel-based alloys provides an H2S- and chloride-resistant barrier at a fraction of the cost of fabricating the entire vessel from the exotic alloy. This is where engineering value is highest: strong substrate, engineered surface, and a cost that stays controlled.

Learn More:

• Feasibility Studies for Waste-to-Value Projects
• Turn-Key EPC Delivery
• Plant Design & Engineering
• Facility Efficiency Upgrades
• Resource Recovery Projects

Design Corrosion Out, Not Around It

Reliability in a hydrotreater is built into the alloys and controls before the first run.

Klean Industries engineers corrosion-resistant hydrotreating systems that protect uptime and safety.

Considering a hydrotreater corrosion prevention project?

Contact Klean Industries about hydrotreater corrosion prevention » GO.