Gas Phase Mass Transfer Coefficient By Two Film Theory Calculator

Two Film Theory Equation:

\[ K_y = \frac{1}{\left(\frac{1}{k_y}\right) + \left(\frac{H}{k_x}\right)} \]

Gas Phase Mass Transfer Coefficient (k_y):

mol/(s·m²)

Henry's Constant (H):

Liquid Phase Mass Transfer Coefficient (k_x):

mol/(s·m²)

Overall Gas Phase Mass Transfer Coefficient (K_y):

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1. What is the Two Film Theory?

The Two Film Theory is a fundamental concept in mass transfer that describes the transfer of a component between two phases (gas and liquid) through two stagnant films at the interface. It provides a simplified model for calculating overall mass transfer coefficients.

2. How Does the Calculator Work?

The calculator uses the Two Film Theory equation:

\[ K_y = \frac{1}{\left(\frac{1}{k_y}\right) + \left(\frac{H}{k_x}\right)} \]

Where:

\( K_y \) — Overall Gas Phase Mass Transfer Coefficient (mol/(s·m²))
\( k_y \) — Gas Phase Mass Transfer Coefficient (mol/(s·m²))
\( H \) — Henry's Constant (-)
\( k_x \) — Liquid Phase Mass Transfer Coefficient (mol/(s·m²))

Explanation: The equation accounts for the resistance to mass transfer in both gas and liquid phases, with Henry's constant relating the equilibrium concentrations between phases.

3. Importance of Mass Transfer Coefficients

Details: Mass transfer coefficients are crucial for designing and optimizing separation processes such as absorption, distillation, and extraction. They help determine the efficiency and size of mass transfer equipment.

4. Using the Calculator

Tips: Enter gas phase mass transfer coefficient, Henry's constant, and liquid phase mass transfer coefficient. All values must be positive numbers. The calculator will compute the overall gas phase mass transfer coefficient.

5. Frequently Asked Questions (FAQ)

Q1: What is Henry's Constant?
A: Henry's Constant is a measure of the solubility of a gas in a liquid. It represents the ratio of the partial pressure of the gas above the liquid to the concentration of the gas in the liquid at equilibrium.

Q2: When is the Two Film Theory applicable?
A: The Two Film Theory is applicable when the mass transfer resistance is concentrated in thin films at the interface and when the interface is at equilibrium, which is valid for many industrial mass transfer operations.

Q3: What are typical units for mass transfer coefficients?
A: Mass transfer coefficients are typically expressed in mol/(s·m²) or similar units representing moles transferred per unit time per unit area per unit driving force.

Q4: What are the limitations of the Two Film Theory?
A: The theory assumes stagnant films, constant physical properties, and equilibrium at the interface. It may not accurately represent systems with high turbulence or complex interfacial phenomena.

Q5: How are mass transfer coefficients determined experimentally?
A: Mass transfer coefficients are typically determined through laboratory experiments using well-defined equipment such as wetted-wall columns, packed columns, or stirred cells under controlled conditions.