The Situation
A Gulf Coast Refiner was incurring costs of $2.5M in equipment, labor, and lost production due to salt deposition and fouling of their overhead heat exchangers. To mitigate the threats, mechanical changes, such as installing a continuous water wash, were considered but discounted due to the disadvantages.
3D TRASAR for Crude Overhead Systems controlled the caustic more efficiently at the moment of demand.
The Solution
The problems with the variability of the process are exacerbated by the low frequency of measurement of key corrosion control variables like pH, chlorides and iron levels. The refinery implemented the Nalco Water 3D TRASARTM Technology for Crude Overhead Systems (3DTCOS) to improve the chloride control with the goal of linking chemical addition directly to the demands of the overhead system.
The Results
Starting in Monitoring Mode, the increased sampling frequency showed the chloride KPI performance, thought to be 90% within the specification limit of 20ppm, was in fact only 80% compliant with a high degree of variability.
Progressing to Control Mode significantly improved KPI compliance to 97% and reduced the high degree of variability on the chloride results, achieved with a reduction in the amount of caustic injected. This in turn substantially reduced the risk of salt formation, and demonstrated the value of the real-time analysis.
