1. What is Activity of Catalyst?

Definition: Activity of Catalyst refers to the ratio between the rate of reactions before and after adding catalyst pellets.

Purpose: It measures how effective a catalyst is in increasing the reaction rate compared to the reaction without the catalyst or with a fresh pellet.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( a \) — Activity of Catalyst (dimensionless)
• \( -r'_A \) — Rate at which pellet converts reactant A (mol/m³·s)
• \( -r'_{A0} \) — Rate of reaction of A with a fresh pellet (mol/m³·s)

Explanation: The negative signs indicate consumption rates of reactant A. The activity is calculated by dividing the current reaction rate by the fresh pellet reaction rate.

3. Importance of Catalyst Activity Calculation

Details: Calculating catalyst activity helps in monitoring catalyst performance, determining when regeneration or replacement is needed, and optimizing reaction conditions.

4. Using the Calculator

Tips: Enter both reaction rates in mol/m³·s. The rates should be measured under identical conditions except for the catalyst state.

5. Frequently Asked Questions (FAQ)

Q1: What does an activity value of 1 mean?
A: An activity of 1 means the catalyst is performing as well as a fresh pellet. Values less than 1 indicate deactivation.

Q2: Can the activity be greater than 1?
A: Typically no, unless the catalyst has been somehow enhanced. Normally activity decreases over time.

Q3: How often should I measure catalyst activity?
A: Frequency depends on the process, but regular monitoring helps identify deactivation trends.

Q4: What factors affect catalyst activity?
A: Temperature, pressure, feed composition, poisons, and mechanical damage can all affect activity.

Q5: When should I regenerate or replace the catalyst?
A: This depends on your process requirements, but typically when activity drops below 0.6-0.7.