1. What is Murphree Efficiency of Distillation Column?

Definition: Murphree Efficiency of Distillation Column is defined for each tray according to the separation achieved on each tray based on either the liquid phase or the vapor phase.

Purpose: It helps chemical engineers evaluate the performance of individual trays in a distillation column by comparing actual separation to equilibrium separation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E_{Murphree} \) — Murphree Efficiency (%)
• \( y_n \) — Average mole fraction of vapour on nth plate
• \( y_{n+1} \) — Average mole fraction of vapour at n+1 plate
• \( y_n^* \) — Average mole fraction at equilibrium on nth plate

Explanation: The formula compares the actual change in vapor composition between trays to the change that would occur if equilibrium were achieved.

3. Importance of Murphree Efficiency

Details: Understanding tray efficiency helps in designing distillation columns, troubleshooting operational issues, and optimizing separation processes.

4. Using the Calculator

Tips: Enter the mole fractions for vapor on the nth plate, n+1 plate, and equilibrium value. All values must be between 0 and 1, and y_n* cannot equal y_n+1.

5. Frequently Asked Questions (FAQ)

Q1: What does 100% Murphree Efficiency mean?
A: 100% efficiency means the tray achieves equilibrium between the liquid and vapor phases.

Q2: What are typical Murphree Efficiency values?
A: Typical values range from 50% to 90% depending on tray design and operating conditions.

Q3: How is this different from overall column efficiency?
A: Murphree Efficiency applies to individual trays, while overall efficiency describes the entire column.

Q4: What factors affect Murphree Efficiency?
A: Factors include vapor velocity, tray design, liquid distribution, and system properties.

Q5: Can efficiency exceed 100%?
A: In rare cases, yes, due to mixing effects or measurement errors, but typically not.