Northshore CC827494: Crude decalcification

The refinery processed a slate of high-calcium offshore crudes with calcium content varying by blend. Its report linked the incoming calcium problem to increased desalter electrical load and trips, as well as calcium carried into heavier streams feeding the downstream FCC operation. The plant wanted calcium removal that could work within the existing desalter equipment.

The downstream concern extended to catalyst condition. The refinery reported high calcium on equilibrium catalyst, elevated fresh-catalyst demand and difficulties in FCC operation. The project therefore followed both desalter performance and selected downstream indicators. That wider scope allowed the customer to evaluate whether improved upstream removal was accompanied by changes that mattered to the rest of the refinery.

Northshore CC827494 is Cestoil's water-soluble calcium-removal agent. The treatment was designed to transfer calcium associated with oil-soluble compounds into the desalter water phase, allowing it to leave with the brine. In this application, chemical removal supplemented the existing desalting process rather than relying on wash water alone to address the calcium burden.

The program used injection ahead of the wash-water mixers in a three-stage desalter train, supported by a pretreatment aid at the crude charge pump. The full treatment arrangement matters when assessing the result: the reported performance belongs to this coordinated application, with its mixing, stage distribution and operating follow-up.

Treatment began after the crude unit returned from turnaround. Early in the program, the refinery's existing metering pumps did not provide the required dosing control. The source describes equipment-related difficulties and excessive chemical delivery as issues that needed correction while the team followed the separation results and effluent quality.

Cestoil installed dedicated metering pumps and the team revised the stage-by-stage application. Treatment was then adjusted while calcium and iron, desalter currents, effluent pH and chemical oxygen demand were monitored. The case demonstrates why feed equipment and service follow-up belong in a chemical-performance account: reliable metering made it possible to evaluate and optimize the program more meaningfully.

The refinery reported approximately 80% lower calcium on equilibrium catalyst and reduced fresh-catalyst consumption in the downstream comparison. Catalyst activity and product-yield indicators also improved. These records give the case commercial relevance beyond the desalter, since the customer was investigating a contaminant that affected subsequent processing.

The comparison also coincided with FCC equipment upgrades and changes in throughput. The refinery attributed much of the improvement to calcium removal while acknowledging a contribution from the upgrades. The observed catalyst and yield changes should therefore be reviewed with that context. They are not an isolated measurement of the chemical's contribution to every downstream performance indicator.

The full report includes the refinery's historical estimate of catalyst-cost savings and its estimate of decalcifier-program cost. Those figures use different throughput bases: FCC feed for the catalyst calculation and crude throughput for the treatment calculation. Reviewing those assumptions is necessary before drawing a conclusion about net value.

For another refinery, timely calcium data on incoming crude receipts is a practical starting point. The original plant identified delayed knowledge of feed calcium as a difficulty in adapting treatment. A new evaluation should also connect crude-slate changes, metering records and desalter samples with equilibrium-catalyst metals, catalyst addition and yields. Tracking those indicators across an appropriate operating period helps distinguish a sustained improvement from a short-term or concurrent process change.