What Is the Extractive Distillation Solvent Relative Volatility Calculator?
Extractive distillation introduces a miscible, high-boiling solvent that selectively alters component activity coefficients to widen relative volatility.
How Does the Extractive Distillation Solvent Relative Volatility Calculator Work?
Evaluates modified volatility alpha_12 = (gamma1 * P1_sat) / (gamma2 * P2_sat); values significantly above 1.2 allow practical fractionation.
Extractive Distillation Solvent Relative Volatility Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
alpha_{12} = rac{gamma_1 P_1^{ ext{sat}}}{gamma_2 P_2^{ ext{sat}}}, quad alpha_{ ext{ideal}} = rac{P_1^{ ext{sat}}}{P_2^{ ext{sat}}}
Modified relative volatility in non-ideal extractive distillation systems.
How to Use the Extractive Distillation Solvent Relative Volatility Calculator
- Input pure saturation vapor pressures in kPa and liquid-phase activity coefficients gamma in the presence of the solvent.
Step-by-Step Example Calculation
Ethanol-Water Azeotrope Breaking with Ethylene Glycol
Input Values:
vaporPressure1Kpa:101.3
vaporPressure2Kpa:96.5
activityCoeff1:1.85
activityCoeff2:1.05
Worked Steps: Ideal volatility = 1.05 (Azeotropic pinch), Modified volatility = 1.85 (Azeotrope broken, clean separation feasible).
Understanding Your Result
Shows modified relative volatility, ideal baseline volatility, solvent enhancement ratio, and whether the azeotrope is successfully broken.
Factors That Affect the Result
- Solvent-to-feed ratio and polar/hydrogen-bonding interactions govern activity coefficient selectivity.
When Should You Use This Calculator?
- Separating ethanol-water, cyclohexane-benzene, and close-boiling alkane-alkene petrochemical cuts.
Assumptions & Limitations
- Assumes ideal gas vapor phase under low-to-moderate operating pressures.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard chemical thermodynamics VLE formulation.