1. What is Mass Transfer Coefficient by Surface Renewal Theory?

Definition: This calculator determines the convective mass transfer coefficient based on the surface renewal theory, which models mass transfer at fluid interfaces.

Purpose: It helps chemical engineers and researchers estimate mass transfer rates in processes like absorption, distillation, and extraction.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( k_L \) — Convective mass transfer coefficient (m/s)
• \( D_{AB} \) — Diffusion coefficient (m²/s)
• \( s \) — Surface renewal rate (1/s)

Explanation: The mass transfer coefficient is calculated as the square root of the product of the diffusion coefficient and surface renewal rate.

3. Importance of Mass Transfer Coefficient Calculation

Details: Accurate estimation of mass transfer coefficients is crucial for designing efficient separation processes and reactors in chemical engineering.

4. Using the Calculator

Tips: Enter the diffusion coefficient in m²/s and surface renewal rate in 1/s. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is surface renewal theory?
A: It's a model that assumes fluid elements at the interface are periodically replaced by fresh elements from the bulk fluid.

Q2: How do I determine the diffusion coefficient?
A: Diffusion coefficients can be found in chemical engineering handbooks or estimated using empirical correlations.

Q3: What factors affect surface renewal rate?
A: Fluid turbulence, interfacial velocity gradients, and system geometry influence the renewal rate.

Q4: What are typical values for k_L?
A: Values typically range from 10^-5 to 10^-3 m/s depending on the system and conditions.

Q5: Can this be used for gas-liquid systems?
A: Yes, the surface renewal theory applies to both liquid-liquid and gas-liquid interfaces.