ENGINEERING – CHEMICAL ENGINEERING CALCULATOR
Extraction Distribution
A precise tool.
What is the Extraction Distribution & How does it work?
Liquid‑liquid extraction relies on the preferential solubility of a solute in one liquid phase over another. The distribution coefficient, (K_D), quantifies this preference and is defined as the ratio of equilibrium concentrations of the solute in the solvent and feed phases.
When a feed stream contacts a fresh solvent, mass transfer drives the system toward equilibrium. The amount of solute transferred depends on (K_D), the initial concentration in the feed, and the relative volumes of the two phases. Engineers use these relationships to size extraction columns and select solvent volumes.
The basic equilibrium relationship can be expressed mathematically, allowing rapid calculation of the solute concentration in the solvent phase and the total amount extracted. This forms the foundation for more complex stage‑wise or continuous extraction designs.
K_D = frac{C_s}{C_f}
K_D = distribution coefficient
Parameters
Result
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Frequently Asked Questions
What is the distribution coefficient in liquid-liquid extraction?
The distribution coefficient, (K_D), is the ratio of the equilibrium concentrations of a solute in the solvent and feed phases.
How does the initial concentration of the solute affect mass transfer in liquid-liquid extraction?
Higher initial concentrations lead to more significant mass transfer as there’s more solute available to move between phases.
What factors determine the amount of solute transferred during liquid-liquid extraction?
The amount of solute transferred depends on the distribution coefficient, initial concentration in the feed, and relative volumes of the solvent and feed.
Can you explain how equilibrium is reached in a liquid-liquid extraction process?
Equilibrium is reached when mass transfer drives the system such that the concentrations of the solute in both phases become stable.
What role does the solvent play in liquid-liquid extraction?
The solvent acts as the phase into which the solute preferentially dissolves, driving the separation process.
How is the distribution coefficient calculated in practice?
The distribution coefficient is calculated by dividing the equilibrium concentration of the solute in the solvent by its concentration in the feed phase.
What are some common applications of liquid-liquid extraction?
Common applications include purification, separation of components in chemical processes, and recovery of valuable substances from waste streams.
Results are for informational purposes only and do not constitute professional advice.