1. What is Rate Constant for Second Order Reaction in Mixed Flow?

Definition: This calculator determines the rate constant for a second-order reaction occurring in a mixed flow reactor based on reactant conversion, space time, and initial concentration.

Purpose: It helps chemical engineers and researchers quantify reaction kinetics in continuous stirred-tank reactors (CSTRs).

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( k_{mixed} \) — Rate constant (m³/mol·s)
• \( X_{mfr} \) — Reactant conversion (0 to 1)
• \( \tau_{mixed} \) — Space time (seconds)
• \( C_0 \) — Initial reactant concentration (mol/m³)

Explanation: The formula relates the reaction rate constant to measurable parameters in a mixed flow reactor system.

3. Importance of Rate Constant Calculation

Details: Accurate rate constants are essential for reactor design, process optimization, and scaling up chemical reactions.

4. Using the Calculator

Tips: Enter the reactant conversion (as decimal), space time in seconds, and initial concentration in mol/m³. All values must be positive, with conversion between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical range for second-order rate constants?
A: They typically range from 10⁻⁶ to 10³ m³/mol·s depending on the reaction.

Q2: How does mixed flow differ from plug flow reactors?
A: Mixed flow reactors (CSTRs) have uniform composition throughout, while plug flow reactors have concentration gradients along the length.

Q3: What if my conversion is 100% (X=1)?
A: The formula becomes undefined at X=1 since denominator becomes zero. In practice, complete conversion is rarely achieved.

Q4: How do I determine space time?
A: Space time is reactor volume divided by volumetric flow rate at inlet conditions.

Q5: Does temperature affect the rate constant?
A: Yes, rate constants are temperature dependent (Arrhenius equation). This calculator assumes isothermal conditions.