Crude desalting performance: After electrical desalting, the residual salt (as NaCl) content in crude oil is typically reduced to approximately what level, expressed in ptb (pounds per thousand barrels)?

Introduction / Context:
Salt removal is critical before crude distillation to prevent corrosion, fouling, and catalyst poisoning downstream. Electrical desalting (with wash water and electrostatic coalescence) reduces salts to low levels specified by refinery practice.

Given Data / Assumptions:

• Salt content is reported as ptb (pounds NaCl per thousand barrels).
• Standard single/two-stage desalters with adequate wash ratios.
• Target is typical, not absolute best-case.

Concept / Approach:
Typical refinery acceptance targets for desalted crude are in the low single digits of ptb, often near ~3–5 ptb, depending on crude and unit limits. Hence, the closest standard value is about 3 ptb.

Step-by-Step Solution:

Verification / Alternative check:
Desalter design and operating manuals commonly quote product salt specs around 3–5 ptb for crude fed to atmospheric distillation.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing ppm in water with ptb in crude; they are different measures.

Final Answer:
3