In an electrical desalter used for crude oil, what are the typical operating pressure and temperature maintained for effective salt and water removal?

Introduction:Electrical desalters remove salts and entrained water from crude before atmospheric distillation, protecting heat exchangers, furnaces, and catalysts from corrosion and fouling.

Given Data / Assumptions:

• Device: crude electrical desalter.
• We seek representative operating pressure and temperature.

Concept / Approach:Desalting efficiency improves with proper mixing, dilution water addition, and emulsion coalescence under an electric field. Moderate pressure and elevated temperature reduce viscosity and enhance separation without excessive vaporization.

Step-by-Step Solution:1) Select a pressure high enough to suppress flashing across heaters and maintain stable operation (about 10 kg/cm2 is common).2) Choose a temperature that lowers crude viscosity and interfacial tension (about 110–150 C is typical; 120 C is representative).3) Match to the closest option provided.

Verification / Alternative check:Typical operating windows published by licensors and refiners indicate ~7–15 kg/cm2 and ~110–150 C; the 10 kg/cm2 and 120 C pair falls squarely within practice.

Why Other Options Are Wrong:1 kg/cm2 and 200 C: Too low in pressure for safe operation at that temperature.50 kg/cm2 and 250 C: Unnecessarily high; energy-intensive and atypical.10 kg/cm2 and 300 C: Excessively hot for desalting step.5 kg/cm2 and 90 C: Too cool for good viscosity reduction and separation.

Common Pitfalls:Confusing upstream heater conditions with desalter internals; over-heating can worsen emulsions or risk flashing, while too low temperature reduces coalescence efficiency.

Final Answer:10 kg/cm2 and 120 C