1. What is Internal Reflux Ratio?

Definition: The Internal Reflux Ratio is the ratio of the liquid flowrate from the reflux drum back to the distillation column to the flowrate of distillate taken as product.

Purpose: It's a crucial parameter in distillation column design and operation, affecting separation efficiency and energy consumption.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R_{Internal} \) — Internal Reflux Ratio (dimensionless)
• \( L \) — Internal Reflux Flowrate to Distillation Column (mol/s)
• \( D \) — Distillate Flowrate from Distillation Column (mol/s)

Explanation: The ratio compares the amount of liquid returned to the column versus the amount withdrawn as product.

3. Importance of Internal Reflux Ratio

Details: Proper reflux ratio ensures optimal separation of components, affects column diameter and height requirements, and impacts energy costs.

4. Using the Calculator

Tips: Enter both flowrates in moles per second. The reflux flowrate should typically be greater than the distillate flowrate.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical internal reflux ratio value?
A: Common values range from 1.5 to 10, depending on the separation difficulty and energy considerations.

Q2: How does reflux ratio affect column operation?
A: Higher ratios improve separation but increase energy costs and may require larger column diameters.

Q3: What's the difference between internal and external reflux ratio?
A: Internal ratio uses the actual liquid flow inside the column, while external ratio uses the reflux drum flow.

Q4: When would I use a very high reflux ratio?
A: For difficult separations where components have similar boiling points.

Q5: Can the reflux ratio be less than 1?
A: Yes, but this indicates more product is being taken than liquid is being returned, which may compromise separation quality.