Space Time Formula:
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Definition: Space time is the time required to process one reactor volume of feed at entrance conditions for a second-order reaction in plug flow.
Purpose: It helps chemical engineers determine the residence time needed for a given conversion in a plug flow reactor.
The calculator uses the formula:
Where:
Explanation: The formula accounts for the reaction kinetics, volume change due to reaction, and desired conversion level.
Details: Accurate space time calculation ensures proper reactor sizing and optimal conversion rates in chemical processes.
Tips: Enter the rate constant, initial concentration, fractional volume change (0 if no volume change), and desired conversion (between 0 and 1).
Q1: What is fractional volume change (ε)?
A: It's the ratio of volume change to initial volume (ΔV/V₀) caused by the reaction.
Q2: What are typical values for second-order rate constants?
A: They vary widely but often range from 10⁻⁶ to 10 m³/mol·s depending on the reaction.
Q3: Why does the formula become undefined at X_A = 1?
A: Complete conversion (100%) would require infinite time in a plug flow reactor.
Q4: How does volume change affect space time?
A: Volume expansion (ε > 0) increases space time needed for same conversion compared to no volume change.
Q5: Can this be used for first-order reactions?
A: No, a simpler formula exists for first-order reactions in plug flow reactors.