Rate Equation of Reactant A for Straight Mass Transfer for Gas Film using Volume of Contactor Calculator

Formula Used:

\[ r''''_A = -(k_{Ag} \times a \times (p_A - p_{Ai})) \]

Gas Phase MTC (k_Ag):

m/s

Interfacial Area using Contactor (a):

1/m

Partial Pressure of Reactant A (p_A):

Partial Pressure of Reactant A at Interface (p_Ai):

Overall Reaction Rate based on Volume of Contactor (r''''_A):

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1. What is the Rate Equation of Reactant A?

Definition: This equation calculates the overall reaction rate based on the volume of contactor for straight mass transfer through the gas film.

Purpose: It helps chemical engineers determine the reaction rate in gas-liquid systems where mass transfer is occurring.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ r''''_A = -(k_{Ag} \times a \times (p_A - p_{Ai})) \]

Where:

\( r''''_A \) — Overall reaction rate (mol/m³·s)
\( k_{Ag} \) — Gas phase mass transfer coefficient (m/s)
\( a \) — Interfacial area per unit volume (1/m)
\( p_A \) — Partial pressure of reactant A in bulk gas (Pa)
\( p_{Ai} \) — Partial pressure of reactant A at interface (Pa)

Explanation: The negative sign indicates the reactant is being consumed. The rate depends on the mass transfer coefficient, available interfacial area, and the driving force (partial pressure difference).

3. Importance of Reaction Rate Calculation

Details: Accurate reaction rate calculation is crucial for designing reactors, predicting conversion rates, and optimizing chemical processes.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. The gas phase MTC and interfacial area must be positive values.

5. Frequently Asked Questions (FAQ)

Q1: What does a negative reaction rate mean?
A: The negative sign indicates reactant consumption. The absolute value represents the rate of disappearance of reactant A.

Q2: How do I determine the gas phase MTC (k_Ag)?
A: It can be determined experimentally or estimated using correlations based on system properties and operating conditions.

Q3: What affects the interfacial area (a)?
A: It depends on the contactor design, gas-liquid flow rates, and physical properties of the fluids.

Q4: When would p_A equal p_Ai?
A: This occurs at equilibrium when there's no driving force for mass transfer, resulting in zero reaction rate.

Q5: Can this be used for liquid film control?
A: No, this equation specifically applies to gas film controlled systems. A different equation would be needed for liquid film control.