Interfacial Reaction Rate Calculator

Calculator Inputs

Temperature

Temperature unit

Interfacial area

Area unit

Reactant A concentration

Reactant B concentration

Equilibrium concentration of A

Concentration unit

Pre-exponential factor

Activation energy

Activation energy unit

Order with respect to A

Order with respect to B

Interfacial efficiency factor

Mass-transfer coefficient

Mass-transfer unit

Product molecular weight (g/mol)

Reaction time (s)

Example Data Table

Case	T (K)	Area (m²)	C_A (mol/L)	C_B (mol/L)	k_m (m/s)	E_a (kJ/mol)	Overall Rate (mol/s)
Base slurry system	298.15	1.20	0.85	1.10	0.0020	45	0.0189
Heated interface	318.15	1.20	0.85	1.10	0.0020	45	0.0387
Lower mixing	298.15	1.20	0.85	1.10	0.0006	45	0.0062
High area emulsion	298.15	2.80	0.85	1.10	0.0020	45	0.0442

Formula Used

Arrhenius intrinsic constant: k = A₀ × exp(-Eₐ / RT)

Intrinsic interfacial flux: J_int = η × k × C_A^m × C_Bⁿ

Mass-transfer-limited flux: J_mt = k_m × (C_A - C_eq)

Overall coupled flux: 1 / J = 1 / J_int + 1 / J_mt

Overall reaction rate: Rate = J × Interfacial Area

This approach treats chemical reaction and transport as serial resistances. It works well for liquid-liquid, gas-liquid, and solid-liquid interface estimates when surface kinetics and diffusion both matter.

How to Use This Calculator

Enter temperature and choose the matching temperature unit.
Provide total interfacial area exposed to reaction.
Input bulk concentrations for both reacting species.
Set equilibrium concentration to define the transport driving force.
Enter pre-exponential factor, activation energy, and reaction orders.
Add an interfacial efficiency factor between 0 and 1.
Enter the mass-transfer coefficient and the product molecular weight.
Choose a reaction time, then press Calculate Rate.
Review intrinsic flux, transport flux, overall rate, control regime, and produced mass.
Use the CSV or PDF buttons to save your computed results.

Frequently Asked Questions

1. What does interfacial reaction rate mean?

It is the rate of reaction occurring at the boundary between phases, such as liquid-liquid, gas-liquid, or solid-liquid interfaces. It depends on chemistry, transport, and available surface area.

2. Why include both intrinsic and mass-transfer flux?

Many real systems are not controlled by chemistry alone. Diffusion or mixing can restrict reactant delivery to the interface, so the observed rate becomes lower than the intrinsic kinetic rate.

3. What does the efficiency factor represent?

It captures nonideal behavior at the interface, such as imperfect contact, partial coverage, catalyst wetting losses, or blocked reactive sites. A value of 1 means ideal effectiveness.

4. How should I choose the reaction orders?

Use orders from experiments, literature fits, or mechanistic studies. If no data exists, start with first-order assumptions and compare predictions with measured conversion or flux data.

5. What does the Damköhler number show here?

It compares the intrinsic interfacial reaction tendency with transport capacity. Very high values suggest chemistry dominates. Very low values indicate strong mass-transfer limitation.

6. Can this calculator be used for catalytic interfaces?

Yes, for screening estimates. It is useful when catalytic activity occurs at a phase boundary and both surface kinetics and external transport resistances influence the measured rate.

7. Why does increasing area raise the overall rate?

The model calculates flux per unit area, then multiplies by interfacial area. Larger area exposes more active boundary, which increases the total reaction rate when other factors remain unchanged.

8. Is this suitable for final plant design?

It is better for scoping, comparison, and educational analysis. Final design should use validated kinetics, detailed transport models, pilot data, and safety margins specific to the process.