Anita Esa RanikaIqbal AbdurrahmanVera MarsellaProduced @2010

Liquid-liquid extraction is a method to separate compounds based on their relative solubilities

in two different immiscible liquids, usually water and an organic solvent.

Liquid-liquid extraction is based on the transfer of a solute substance from one liquid phase into another liquid phase according to the solubility. Extraction becomes a very useful tool if you choose a suitable extraction solvent.You can use extraction to separate a substance selectively from a mixture, or to remove unwanted impurities from a solution. In the practical use, usually one phase is a water or water-based (aqueous) solution and the other an organic solvent which is immiscible with water.

(1) The components of the solution is sensitive to warming even if it is used in vacuum distillation(2) The boiling point components in a mixture of adjacent(3) Ease evaporate (volatility) is almost the same components.

1. Selectivity (separation factor = β)

mass fraction of solute in extract / diluent mass fraction in the extractmass fraction of solute in rafinate / mass fraction of diluent in rafinate

For the extraction process can take place, the price of β must be greater than one. If the value of β = 1 means the two components are inseparable.

ß=

(2) distribution coefficient

concentration of solute in extract phase ysolute concentration in phase rafinat x

Should be selected large distribution coefficient, so that the number of solventit takes a little more.

K=

(3) Recoverability (ability to be purified)Separation of solutes from the solvent is usually done by distillation, so thatexpected price "relative volatility" of the mixture is quite high.(4) DensityPhase density difference solvent and diluent phase should be large enough to be easily separated.This density difference is changed during the extraction process and affect the rate ofmass transfer.

(5) Voltage interface (interfasia tension)Large interfacial tension causes the merging (coalescence) are easierbut complicates the process of dispersing. Ease of integration is more emphasisso that the selected solvent which has a large interfacial tension.(6) Chemical reactivitySolvents are compounds that are stable and inert towards the components insystems and materials (construction materials).(7) The viscosity, vapor pressure and low freezing point is recommended to facilitatehandling and storage.(8) solvents are not toxic and not flammable.

In this experiment determining the distribution coefficient for the system of tri chloro ethylene-acidacetate-water, and showed its dependence on concentration. In the third mixtureThis substance is considered that the phase is in equilibrium. At low concentrations, the coefficientdistribution depends on the concentration, so that Y = KXY = concentration of solutes in the extract phaseX = concentration of solutes in the phase rafinatK = distribution coefficient

In this experiment demonstrates how the behavior of the mass balance onextraction column and measure the mass transfer coefficient and its variation with flow ratewith water as a medium continuous phase. Symbol and formulas used incalculation is shown as follows. For the system water-ethylene tri-chloro acetic acid,Vw = water flow rate (L / s)Vo = TCE flow rate (L / s)X = concentration of acetic acid in organic phase (kg / L)Y = concentration of acetic acid in aqueous phase (kg / L)Index 1: on top of the columnIndex 2: at the base of the column

1. Mass BalanceAcetic acid is extracted from organic phase (rafinat) = Vo (X1-X2)Acetic acid is extracted from the aqueous phase (extract) = Vw (Y1-0)Then: Vo (X1-X2) = Vw (Y1-0)

2. Extraction EfficiencyKoef mass transfer = mass transfer rate / (volume packing thrust X average)Log average thrust = (ΔX1 - ΔX2) / ln (ΔX1/ΔX2)ΔX1: thrust on top of the column = X2 - 0ΔX2: Thrust at the base of the column = X1 - X1 *X1 *: concentration of acid in the organic phase with a concentration berkesetimbanganY1 in the water phase. This equilibrium price is obtained from the curve coefficientdistribution (in experiment 1)

Separatory Funnel Extraction Procedure

Separatory funnels are designed to facilitate the mixing of immiscible liquids

Separatory Funnel Extraction Procedure

1. Support the separatory funnel in a ring on a ringstand. Make sure stopcock is closed

2. Pour in liquid to be extracted

3. Add extraction solvent

4. Add ground glassStopper (well greased)

Separatory Funnel Extraction Procedure

Pick up the separatory funnel with the stopper in palce and the stopcock closed, and rock it once gently.

Then, point the stem up and slowly open the stopcock to release excess pressure. Close the stopcock. Repeat this procedure until only a small amount of pressure is released when it is vented

Shake the separatory funnel.

Separatory Funnel Extraction Procedure

Shake the separatory funnel vigorously.

Now, shake the funnel vigorously for a few seconds. Release the pressure, then again shake vigorously. About 30 sec total vigorous shaking is usually sufficient to allow solutes to come to equilibrium between the two solvents.

Vent frequently to prevent pressure buildup, which can cause the stopcock and perhaps hazardous chemicals from blowing out. Take special care when washing acidic solutions with bicarbonate or carbonate since this produces a large volume of CO2 gas

Separatory Funnel Extraction Procedure

Separate the layers.

Let the funnel rest undisturbed until the layers are clearly separated

While waiting, remove the stopper and place a beaker or flask under the sep funnel.

Carefully open the stopcock and allow the lower layer to drain into the flask. Drain just to the point that the upper liquid barely reaches the stopcock

Liquid-liquid extraction Unit

The Armfield UOP5 unit demonstrates this process in the laboratory so that students may gain a thorough understanding of this industrial technique.

UOP5: Schematic diagram1: Liquid/liquid extraction column (glass)2: Condenser3: Distillation column4: Distillation column boiler5: Receiver vessel (stainless steel)6: Condensate tank, solvent (stainless steel)7: Solvent supply tank (stainless steel)8: Column supply tank, water9: Column collection tank, water10: Water supply pump11: Solvent metering pump

SERVICES REQUIREDElectrical supply:UOP5-A: 220-240V/1ph/50HzUOP5-B: 120V/1ph/60HzUOP5-G: 220V/1ph/60HzCold water supply: mains

pressureVapour extraction systemOVERALL DIMENSIONSHeight: 2.5mLength: 1.30mDepth: 0.75mSPECIFICATIONVolume: 3.3m3Gross weight: 380kg

1 INJURY THROUGH MISUSE 2 INJURY FROM ELECTRIC SHOCK 3 INJURY FROM INCORRECT HANDLING 4 POISONING FROM TOXIC MATERIALS 5 INJURY FROM CORROSIVE LIQUIDS 6 RISK OF INFECTION THROUGH LACK OF

CLEANLINESS 7 DAMAGE TO CLOTHING

8 adequate air ventilation9 Use of nasal mask to prevent inhalation of TCE vapor10 High water in the tub is always above the water pipes go into rorameter11 organic tank can not be empty (if blank will cause the pump organic substancesrapid wear and ultimately destroyed)12 Clean the packing in the column after the experiment