Reducing Overhead Corrosion through continuous analysis & online control

A European Refiner is aggressive in their crude selection, which poses a high degree of difficulty in controlling the overhead corrosion. This challenge demands constant attention, but due to the high degree of variability, corrosion control often struggled historically with frequent low pH excursions (pH less than 5). In response the refinery was considering upgrading the metallurgy of the overheads to address the corrosion concerns.

Historically, the crude unit overheads were sampled daily for pH, chlorides, iron and ammonia. To improve corrosion performance, the refinery was interested in the 3D TRASAR™ Technology for Crude Overhead Systems (3DTCOS). If successful, the refinery could avoid a capital project worth $5M to upgrade the system to a more corrosion resistant metallurgy.

Starting in Monitor Mode, the "learning phase" was catching potential upsets as changes were made manually to improve performance. Progressing to Control Mode tightened corrosion performance further. The improvements realized on pH and Fe (controlling neutralizer), grew our data collection to over 17,500 points a year. The performance gain continued with chemical control.

This step-change in performance increased unit reliability and system assurance, while real-time analysis and chemistry control enhanced crude flexibility. With a higher confidence to catch upsets, the $5M metallurgy upgrade project could be avoided.