Number of Stripping Stages by Kremser Equation Calculator

Kremser Equation Formula:

\[ N = \frac{\log_{10}\left(\frac{(X_0 - (Y_{N+1}/\alpha))}{(X_N - (Y_{N+1}/\alpha))} \times (1 - \frac{1}{S}) + \frac{1}{S}\right)}{\log_{10}(S)} \]

Solute Free Mole Fraction of Liquid in Stripping Inlet (X₀):

Solute Free Mole Fraction of Gas in Stripping Inlet (Y_N+1):

Equilibrium Constant for Mass Transfer (α):

Solute Free Mole Fraction of Liquid in Stripping Outlet (X_N):

Stripping Factor (S):

Number of Stages (N):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Kremser Equation Calculator?

Definition: This calculator determines the number of theoretical stages required for stripping operations using the Kremser equation.

Purpose: It helps chemical engineers design and optimize stripping columns for separation processes.

2. How Does the Calculator Work?

The calculator uses the Kremser equation:

\[ N = \frac{\log_{10}\left(\frac{(X_0 - (Y_{N+1}/\alpha))}{(X_N - (Y_{N+1}/\alpha))} \times (1 - \frac{1}{S}) + \frac{1}{S}\right)}{\log_{10}(S)} \]

Where:

\( N \) — Number of theoretical stages
\( X_0 \) — Solute mole fraction in liquid inlet (solute-free basis)
\( Y_{N+1} \) — Solute mole fraction in gas inlet (solute-free basis)
\( \alpha \) — Equilibrium constant for mass transfer
\( X_N \) — Solute mole fraction in liquid outlet (solute-free basis)
\( S \) — Stripping factor (ratio of operating line to equilibrium line slope)

Explanation: The equation calculates the stages needed to achieve the desired separation based on material balances and equilibrium relationships.

3. Importance of Stripping Stage Calculation

Details: Accurate stage calculation ensures efficient separation, optimal column design, and cost-effective operation in processes like gas purification and wastewater treatment.

4. Using the Calculator

Tips: Enter all required parameters. Typical values are provided as defaults. All values must be ≥ 0 except X₀ and α which must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the stripping factor (S)?
A: It's the ratio of the slope of the operating line to the equilibrium line in the stripping section. S > 1 indicates effective stripping.

Q2: How is the equilibrium constant (α) determined?
A: α is typically determined experimentally or from vapor-liquid equilibrium data for the specific system.

Q3: What if I get a fractional number of stages?
A: Fractional stages are common in calculations. In practice, you would round up to the next whole number.

Q4: Can this be used for absorption calculations?
A: Yes, with appropriate modifications to the equation (using absorption factor A instead of stripping factor S).

Q5: What assumptions does the Kremser equation make?
A: It assumes constant flow rates, equilibrium at each stage, and a linear equilibrium relationship.