In the oil refining industry, efficiency and longevity of equipment are crucial to ensuring operational success. The selection of materials for equipment depends on service conditions, which include factors such as temperature, pressure, and corrosive conditions affected by sulfur, chlorides, and acids. One of the most critical areas where performance must be optimized is in crude distillation units (CDUs) overhead condensers, where corrosion is a common yet challenging issue.
At Alleima, we are driving value for refineries worldwide with our materials technology innovations.
The challenges in CDU Overhead Condensers
Corrosion is an ever-present risk in CDUs, particularly in the overhead condensers, where the sever corrosive environment can lead to significant material degradation. Some overhead systems experience severe corrosion and fouling that increase the atmospheric column operating pressure, reduce the distillate yield, or require tube bundle changes at intervals shorter than the usual 4-6-year turnarounds. High salt content, acids, and chloride compounds present in the process stream can lead to frequent maintenance, production losses, and costly equipment replacements.
Below is a clear example of corrosion found in a carbon steel tube bundle after just three years of service in a CDU overhead condenser:
Image 1: Carbon steel tube bundle with heavy corrosion after three years of service
Image 2: Duplex steel has a good surface in comparison with corroded carbon steel tie-rod (red colour tube at bottom) in overhead condenser after seven years of service.
Traditional materials like carbon steel and copper alloys often fall short under the pressure of modern refining processes, leading to corrosion and fouling. These issues can cause refineries to experience unplanned shutdowns, increased maintenance costs, and even safety risks.
Our material solutions
Over the years, Alleima has developed high-performance alloys designed to meet the most demanding industrial conditions. Our latest solution for addressing corrosion in CDU overhead condensers is the award-winning, Sanicro® 35.
Sanicro® 35 represents a breakthrough in alloy design, combining the best properties of stainless steels and nickel alloys. It provides excellent resistance to a wide range of corrosion, including pitting, stress corrosion cracking, and general acid corrosion. Due to its unique properties, it is particularly well-suited for applications in which traditional materials have struggled.
Key benefits of Sanicro® 35:
- Exceptional resistance to general corrosion in both acidic and caustic environments
- High mechanical strength for demanding operating conditions
- Superior resistance to pitting and crevice corrosion, even in seawater applications
Download the datasheet here
Proven performance in corrosive environments
Setting Sanicro® 35 apart is its proven track record in resisting some of the most aggressive forms of corrosion. Tests have shown that it outperforms traditional alloys in environments where hydrochloric acid is present, a common byproduct in crude processing. Additionally, it has demonstrated excellent performance in seawater environments, making it a versatile solution for a variety of industrial applications. This image highlights pitting corrosion, one of the key challenges that Sanicro® 35 is designed to overcome:
Image 3: Example of pitting corrosion on carbon steel
Advancing industries with materials technology
For over 160 years, Alleima has been advancing industries through materials technology. Our commitment to innovation continues with Sanicro® 35, a solution that drives refineries to optimize their CDU operations by reducing corrosion-related risks. By investing in the right materials, you can improve efficiency, reduce maintenance costs, and ensure the longevity of your critical assets.
Our 900+ advanced steels and alloys help reduce your carbon footprint and energy consumption while increasing efficiency. Our production processes use 83% recycled steel and 96% fossil-free energy worldwide.