liquid-liquid extraction

Telephone: (201) 267-8670www.modularprocess.com

LIQUID-LIQUID EXTRACTION

An Introduction

4 5 E i se n h o w er D r i v e , S u i te 35 0 , P ara m u s , N J 0 76 52 | Te l : (2 01 ) 26 7 - 86 70 | F a x : ( 20 1 ) 3 68 -8 98 9 | w ww. m o d u l ar p ro c es s . c o m

2

WHO IS ?

Koch Modular Process Systems (KMPS) is a joint venture with Koch-Glitsch LP, one of the world's most prominent suppliers of mass transfer equipment. Koch-Glitsch's parent company is Koch Industries, one of the largest privately held corporations in the United States.

For over 20 years KMPS has successfully designed and constructed mass transfer systems for the worldwide Chemical Processing Industry. Our customer’s rely upon KMPS for our quality products and technical expertise.

M O D U L A R P R O C E S S S Y S T E M S | D I S T I L L A T I O N | L I Q U I D E X T R A C T I O N | E N G I N E E R I N G | P I L O T T E S T I N G

3 Telephone: (201) 267-8670www.modularprocess.com

Hierarchy of Separation Technologies



Typical Applications

When is it prudent to use extraction?

When you want to:• Remove products and pollutants from dilute aqueous streams• Wash polar compounds or acids/bases from organic streams• Separate heat sensitive products• Purify non-volatile materials• Process azeotropic and close boiling mixtures• Avoid a high cost distillation solution



Industries Using Extraction Technology

Chemical •Washing of acids/bases, polar compounds from organics•Recovery of valuable chemicals from aqueous solutions

Biochemical Processing • Recovery of carboxylic acid from fermentation broths• Recovery of valuable “oil” from algae broths

Effluent Treatment • Recovery of phenol, DMF, DMAC• Recovery of acetic acid from dilute solutions

Pharmaceuticals • Recovery of active materials from fermentation broths• Purification of vitamin products

Polymer Processing • Recovery of caprolactam for nylon manufacture• Separation of catalyst from reaction products



Industries Using Extraction Technology

Petroleum • Lube oil quality improvement• Separation of aromatics/aliphatics (BTX)

Food • Decaffeination of coffee and tea• Separation of essential oils (flavors and fragrances)

Metals • Copper production• Recovery of rare earth elements

Inorganic Chemicals • Purification of phosphoric acid

Nuclear • Purification of uranium



Removal of Organics From Water:Distillation vs. Extraction

Organic Compound BP [°C] Water Solu.

[%]Azeotrope

B.P. [°C]AzeotropeWater [%]

Typical Reduction Level

Methylene Chloride 40 2.0 38.1 1.5 < 50 ppb

Acetone 56.2 Infinite Non Azeotropic < 50 ppb

Methanol 64.5 Infinite Non Azeotropic < 50 ppb

Benzene 80.1 0.18 69.4 8.9 < 50 ppb

Toluene 110.8 0.05 85.0 20.2 < 50 ppb

Formaldehyde -21 Infinite Non Azeotropic < 1,000 ppm

Formic Acid 100.8 Infinite 107.1 22.5 < 500 ppm

Acetic Acid 118.0 Infinite Non Azeotropic < 500 ppm

Pyridine 115.5 57 92.6 43 < 10 ppm

Aniline 181.4 3.60 99.0 80.8 < 10 ppm

Phenol 181.4 8.20 99.5 90.8 < 10 ppm

Nitrobenzene 210.9 0.04 98.6 88.0 < 10 ppm

Dimethyl Acetamide 166.1 Infinite Non Azeotropic < 10 ppm

n-Methylpyrrolidone 202.0 Infinite Non Azeotropic < 10 ppm

Disti

llatio

nEx

trac

tion



Simple Extraction Single Stage

8

4.07.929950MF

SE

7.9299

0.250

0.8

RaffinateinSoluteConc.ExtractinSoluteConc.M

0.21.00.2

FeedinSoluteRaffinateinSoluteU

Fraction Unextracted

Distribution Coefficient

Extraction Factor

A – 99

B – 0

C – 1

100

Feed (F)

A – 0

B – 50

C – 0

50

Solvent (S)

A – 0

B – 50

C – 0.8

50.8

Extract (E)

A – 99.0

B – 0

C – 0.2

99.2Raffinate (R)



Cross Flow Extraction

LEGEND

A, B Components in feed

C Component in solvent

Rx Raffinate from stage x

Ex Extract (made up of components B & C)

Mx Composition of two phase mixture R1R2R3

R4

E1 E2 E3E4

M1M2M3M4

B

A C

F

C C C CA + B

Feed

E1 E2 E3 E4

F + S = M1 R1 + S = M2 R2 + S = M3 R3 + S = M4

R1 R2 R3 R4

Solvent Solvent Solvent Solvent



Countercurrent Flow Extraction

F + S = ME1 + R4 = MF + S = E1 + R4

F – E1 = R4 – S = Δ

Equations

NOTE: Extract is made up of components B and C

A

CE1

E2

E3

E4

A + B

Feed R1 R2 R3 R4

Solvent

C

R1

R2R3

R4

E1

B

A

F

ΔM E2

E3E4



B + C

A

C

A + BFeed (F)

Solvent (S)

Extract (E):Solute Rich Stream

Raffinate (R):Solute Lean Stream

Primary Interface

Continuous Phase

Dispersed Phase

Countercurrent Extraction



Bench Scale Test Apparatus

Variable Speed Drive

ThermometerBaffle

Tempered Water In

Drain

1 – Liter Flask

Tempered Water Out



Simple Extraction

Solute Free Basis

𝑋𝐵𝐹=𝑋 𝐵𝐹

𝑋 𝐴𝐹

𝑌 𝐵𝐸=𝑦𝐵𝐸

𝑦 𝐴𝑅+𝑦𝐶𝐸

𝑋𝐵𝑅=𝑥𝐵𝑅

𝑥𝐴𝑅+𝑥𝐶𝑅𝑌 𝐵𝑆=

𝑦𝐵𝐹

𝑦𝐴𝑆+𝑦𝐶𝑆R’

E’

F’

S’

XBF

Graphical Solution

Y

X

YBE

YBS

XBR

Equilibriu

m Curve ->

Slope = m

Operating Line ->

Slope = F’/S’

𝑚=𝑌 𝐵❑

∗

𝑋 𝐵❑∗(Distribution Coefficienton Solute Free Basis )



Typical LLE Equilibrium Curve

0.000 0.005 0.010 0.015 0.0200.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

Raffinate Composition (Wt. Frac., Solute Free)

Extr

act C

omp.

(Wt.

Frac

., So

lute

Fre

e)



Graphical Determination of Theoretical Stages95% Solute Extraction, S/F = 1.0 mass basis

0.000 0.020 0.040 0.060 0.080 0.100 0.1200.00

0.02

0.04

0.06

0.08

0.10

0.12

Raffinate Composition (Wt Frac., Solute Free)

Extr

act C

omp

(Wt F

rac.

, Sol

ute

Free

)

1

23

(0.136, 0.114)



Graphical Determination of Theoretical Stages98% Solute Extraction, S/F = 1.0 mass basis

0.000 0.020 0.040 0.060 0.080 0.100 0.1200.00

0.02

0.04

0.06

0.08

0.10

0.12

Raffinate Composition (Wt Frac., Solute Free)

Extr

act C

omp

(Wt F

rac.

, Sol

ute

Free

)

23

456

(0.136, 0.118)

1



Kremser Equation

Where: n = Number of theoretical stages requiredxf = Conc. of solute in feed on solute free basisxn = Conc. of solute in raffinate on solute free basisys = Conc. of solute in solvent on solute free basism = Distribution coefficientE = Extraction factor = (m)(S/F)

ELOG

E1

E11

msy

nxm

syfx

LOG

n


18

Engineering CalculationsKremser Type Plot

1.00.80.6

0.40.3

0.2

0.10.080.06

0.040.03

0.02

0.010.0080.006

0.0040.003

0.002

0.0010.00080.00060.0005

1 2 3 4 5 6 7 8 10 15 20Number of Ideal Stages

X BR/X

BF =

Fra

ction

Une

xtra

cted

E = 0.3

E = 20

E = 1.3

R’

E’

F’

S’

XB

YBS

XBF

YBE

E: Extraction FactorE = m (S’/F’)


19

Typical Extraction System

(A+B)

FeedA+B

C

A+(B+C)

B+C+(A)

A (B+C) B (C)

C(A)

C(A+B)

Extraction

Raffinate

Stripping

Solvent Recovery

Solvent


Removal of Phenol from Wastewater

ppb Phenol

Extraction

Raffinate

Stripping

Solvent Recovery

Wastewater Feed

0.1 – 8 % Phenol

Raffinate

RecycledSolvent

Extract

PhenolBiological Treatment

Or

Carbon Adsorption

< 1 ppm Phenol

Steam


21

Recovery of Acetic Acid from WaterUsing a Low Boiling Solvent

Aqueous Feed

1 - 30 % Acetic Acid

Typical Solvents:Ethyl Acetate

MTBEExtraction

Raffinate

Stripping

Solvent Recovery

Raffinate

RecycledSolvent

Extract

Acetic Acid

Aqueous Raffinate

Steam



Neutralization/Washing of Acid or Baseor Polar Compounds from Organic Stream

Extraction

Water

Water + Salts

Organic

Caustic (Mild)**

Feed (Organic + Acid) **

**Organic Feed could contain caustic. Mid-Feed would be mild acid.



Series Extraction

Extractor #1

Extractor #2

Feed

A + B

Extract

B + C

Solvent 1

C Solvent 2

D

ProductB + D

RaffinateA

Extractor 1 & 2 May Differ In:• Temperature• pH• Solvent


24

Recovery of Caprolactam

Feed From

ReactionSection

Lactam O

il Ext.

AQ Waste to Discharge

Am. Sulphate Ext.

Am. Sulph. Waste to Discharge

Re-Extraction

Lactam Oil to Recovery

WaterLactam Oil Phase65 – 70% Caprolactam

Ammonium Sulphate Phase2 – 3% Caprolactam

Extract

RaffinateSolvent


25

Phosphoric Acid Extraction

Extraction

Raffinate to Disposal

Scrub Extraction

Re-Extraction

Phosphoric Acid to Recovery

Water

Solvent

Phosphate Rock DigesterHCL

Feed

Recycle

Scrub Solv.



Organo-Metallic Catalyst Recovery

Water Effluent(1 ppm Cobalt)

Extraction

Feed

Makeup Organic

CatalystPreparation

Reactor

SeparatorWater Effluent

(200 ppm Cobalt)

Cobalt

Organo-MetallicCatalyst

Product

Slipstream

Organic



Fractional ExtractionProcess Scheme

NR

NS

XAS2,XBS2

XAF,XBF

XAS1,XBS1

YAE,YBE

XAR,XBR

I2S

I1F

I1S

IE

IR(B-Rich)

(A-Rich)



Extraction of Flavors and Aromas

Oil

Essential Extract

Extraction

Solvent 1 Distillation

Aqueous AlcoholSolvent 2

Distillation

Essential Oil

Hydrocarbon

Typical Products: Orange OilLemon Oil

Peppermint OilCinnamon Oil



Fractional LLE – Mixed Polymer Feed



Major Types of Extraction Equipment

Used primarily in the metals industry due to:- Large flows- Intense mixing- Long Residence time- Corrosive fluids- History

Used primarily in thepharmaceutical industry due to:- Low Volume- Short Residence time- Handles Small Gravity Diff.- History

Static Agitated

Spray Packed Tray Pulsed Rotary Reciprocating

Rarely usedUsed in:- Refining- Petrochemicals

Example:- Random- Structured- SMVPTM

Used in:- Refining- Petrochemicals

Example:- Sieve

Used in:- Nuclear- Inorganics- Chemicals

Example:- Packed- Tray- Disc & Donut Example:

- RDC- SCHEIBEL®

Example:- KARR®

Used in:- Chemicals- Petrochemicals- Refining- Pharmaceutical

KARR® and SCHEIBEL® are registered trademarks of Koch-Glitsch, LP.

Mixer Settlers Column Contactors Centrifugal



Mix / Decant Tank

Characteristics• Mix – Settle – Phase separate in

a single tank• Batch Processing only• Requires multiple solvent

additions for more than one stage (crossflow operation)

• Typically used for small capacity operations or intermittent processing

Feed Inlet

Outlet

Sight Glass



Mixer / Settlers

Characteristics• Handle very high flowrates• Good for processes with

relatively slow reactions (residence time required)

• Provide intense mixing to promote mass transfer

• Require large amount of floor space

• Suitable when few theoretical stages required

• Large solvent inventory (and losses)

Light Phase In

Heavy Phase Out



Centrifugal Extractor

Characteristics• Countercurrent flow via centrifugal

force• Low residence time ideally suited for

some pharmaceutical applications• Handles low density difference

between phases• Provide up to several theoretical

stages per unit• High speed device requires

maintenance• Susceptible to fouling and plugging

due to small clearances



Packed Column

Feed (F)

Solvent (S)

Extract (E)

Raffinate (R)

Characteristics• High capacity:

20-30 M3/M2-hr (Random) 500-750 gal/ft2-hr (Random) 40-80 M3/M2-hr (Structured) 1,000-2,000 gal/ft2-hr (Structured)

• Poor efficiency due to backmixing and wetting

• Limited turndown flexibility• Affected by changes in wetting

characteristics• Limited as to which phase can be dispersed• Requires low interfacial tension for

economic usefulness• Not good for fouling service



Sieve Tray Column

Feed (F)

Solvent (S)

Extract (E)

PrimaryInterface

Raffinate (R)

Characteristics• High capacity: 30-50 M3/M2-hr

750-1,250 gal/ft2-hr • Good efficiency due to minimum back-

mixing• Multiple interfaces can be a problem• Limited turndown flexibility• Affected by changes in wetting

characteristics• Limited as to which phase can be dispersed• Not effective for high interfacial tension



RDC Extractor

VesselWalls

Shaft

Stators RotorsLightPhase In

HeavyPhase In

LightPhase Out

HeavyPhase Out

Drive Motor

Gearbox

InterfaceControl

Interface

Characteristics• Reasonable capacity:

20-30 M3/M2-hr• Limited efficiency due to

axial backmixing• Suitable for viscous

materials• Suitable for fouling

materials• Sensitive to emulsions due

to high shear mixing• Reasonable turndown

(40%)



SCHEIBEL® Column

Characteristics• Reasonable capacity:

15-25 M3/M2-hr 350-600 gal/ft2-hr

• High efficiency due to internal baffling

• Good turndown capability (4:1) and high flexibility

• Best suited when many stages are required

• Not recommended for highly fouling systems or systems that tend to emulsify

LightPhase In

HeavyPhase In

LightPhase Out

HeavyPhase Out

Variable SpeedDrive

InterfaceControl

Interface

VesselWalls

RotatingShaft

TurbineImpeller

HorizontalInner Baffle

HorizontalOuter Baffle




SCHEIBEL® Column Internal Assembly




KARR® Reciprocating Column

Characteristics• Highest capacity:

30-60 M3/M2-hr 750-1,500 gal/ft2-hr

• Good efficiency• Good turndown capability (4:1)• Uniform shear mixing• Best suited for systems that emulsify

LightPhase Inlet

Sparger

HeavyPhase Inlet

Sparger

LightPhase Out

Interface

Baffle Plate

Tie Rods& SpacersPerforated

Plate

DriveAssembly

InterfaceControl

HeavyPhase Out




KARR® Column Plate Stack Assembly




Comparing Commercial Extractors

1 2 4 6 10 20 40 60 1000.2

0.4.06

1

2

4

6

10

20SCHEIBEL

KARR

RDC

GraesserKuhni

RZE

PFKPSE

FK

MS SE

Effic

ienc

y / S

tage

s pe

r M

eter

Capacity M3/(M2 HR)

Graesser = Raining BucketMS = Mixer SettlerSE = Sieve PlateFK = Random PackedPFK = Pulsed PackedPSE = Pulsed Sieve PlateRDC = Rotating Disc ContactorRZE = Agitated CellKARR = KARR® Recipr. PlateKuhni = Kuhni ColumnSCHEIBEL = SCHEIBEL® Col.

Key




Column Selection CriteriaStatic Column

A static column design may be appropriate when:

• Interfacial tension is low to medium: up to 10-15 dynes/cm

• Only a few theoretical stages are required, and reduction in S/F is not an economic benefit

• No operational flexibility required

• There is a large difference in solvent to feed rates



Column Selection CriteriaAgitated Column

Agitated columns are generally more economical when:

• More than 2-3 theoretical stages are required

• Interfacial tension is moderate to high, although low interfacial tensions may also be economical

• A reduction in solvent usage is beneficial to the process economics

• The process requires a wide turndown as well as the ability to handle a range of S/F ratios



Column Selection CriteriaSCHEIBEL® Column

• Systems that require a large number of stages due to either theoretical stage requirements or low mass transfer rates

• Low volume applications in which a relatively small column is required

• Systems that process relatively easily, without a tendency to emulsify and/or flood




Column Selection CriteriaKARR® Reciprocation Plate Column

• Difficult systems that tend to emulsify and/or flood easily

• Systems in which the hydraulic behavior varies significantly through length of the column

• Sometimes requiring non-metallic internals, such as Teflon due to wetting characteristics or corrosive materials

• Fouling applications that may have tars formations and/or solids precipitation




3 Cornerstones of Successful Extraction Applications

Selection Based on:

• Sound thermodynamic principles• Sound economic principles

• Availability• Recoverability

• Sound environmental principles• Toxicity• Safety

Testing Based on:

• Actual feed stocks• Full process including

solvent recovery• Wide range of operating

conditions

Scale-Up Based on:

• Proven techniques• Proper safety factors

Successful Application

Proper Solvent Selection Meaningful

Pilot Tests

Accurate Scale-Up



Solvent Selection

• Literature – DECHEMA, Perry’s Chemical Engineers Handbook

• Internet search

• Understanding the chemistry of the process

• Experience – consulting with experts

• Laboratory Experiments:

1. Quickly screen solvents

2. Generate equilibrium data

3. Observe phase behavior



Liquid-Liquid Extraction Scale-Up

Theoretical scale-up is difficult due to

Complex processes occurring in an extractor• Coalescing / Wetting Characteristics• Interfacial and Drop Turbulence Effects• Axial and Radial Mixing• Tendency to Emulsify• Phase Ratio Variability and Density Gradients• Effects of Impurities or Solids• Mass Transfer Rate



Liquid-Liquid Extraction Scale-Up

Best method of design: Pilot testing followed by empirical scale-up



Pilot Plant Configuration

Determine type of column to be used based on process considerationsUse the same kind of equipment for the production unitDetermine diameter and height of pilot column based on experience

Table 1: Smallest Possible Column for Testing

Type of Column Diameter Height

Packed 3” to 4” 3’ to 6’ per Theoretical Stage (TS)

Tray ≥ 6” 4 to 5 Trays per TS

KARR® 1” 1’ to 3’ per TS

SCHEIBEL® 3” 3 to 6 Actual Stages per TS (Approx. 3” to 6”)




Continuous Extraction Pilot PlantArrangement

Hot Oil

Feed Solvent

Raffinate

Extract



KMPS Pilot Plant Services Group

KMPS maintains a pilot plant dedicated to extraction R & D and applications testing



Which Phase is Continuous?

Solvent is Heavy Phase

Primary Interface

FA + B

SC

RA

SolventDispersed

EB + C

Primary Interface

FA + B

SC

RA

SolventContinuous

EB + C

Solvent is Light Phase

F

S

E

R

Primary Interface

A + B

B + C

C

A

SolventDispersed

F

S

E

R

Primary Interface

A + B

C

A

SolventContinuous

B + C



Determining the Dispersed Phase

Flow Rate (Phase Ratio)• For Sieve Tray and Packed Columns – disperse the higher flowing phase

• For Agitated Columns – disperse lower flowing phase

Viscosity• For efficiency – disperse less viscous phase

• For capacity – disperse more viscous phase

Viscous drop

Diffusion rate inside the drop is inhibited by viscosity

Viscous continuous phase

Drop rise or fall will be inhibited




Surface Wetting• Want the continuous phase to preferentially wet the internals – this

minimizes coalescence and therefore maximizes interfacial area.

Importance of maintaining dropletsAssume – 30% holdup of dispersed phase in 1 M3 of solution

Droplets coalesce. Interfacial area lost.

Droplets retain shape. Maximizes interfacial area.

Droplet Diameter [m]

Droplet Volume [M3]

Number Droplets

Droplet SA [M2]

Interfacial Area [M2/M3]

100 0.3 7.16x1010 1.26x10-7 9022

300 0.3 2.65x109 1.13x10-6 2995

500 0.3 5.73x108 3.14x10-6 1796




Marangoni Effect• Coalescence is enhanced by mass transfer from

droplets continuous phase

A + B A + BC

A

A + B

C

C + B C + B

C

Mass Transfer Direction

Dispersed Continuous (d c)

• Droplets tend to coalesce

• Must be counteracted by additional energy

Continuous Dispersed (c d)

• Droplets tend to repel each other

• Less energy required to maintain dispersion



Interface Behavior

Emulsion band builds up at interface due to slow phase separation

Rag Layer

Rag Layer

Solids build up at the interface = Rag Layer



Rag Layer or Emulsion Band

Corrective Action1. Reverse Phases2. For Emulsion Band: slow down capacity or reduce agitation speed3. For Rag Layer: circulate liquid through an external filter

Filter

Feed



Entrainment

Entrainment refers to removing a small portion of one phase out of the wrong end of the column i.e. where the other phase exits. Entrainment is controlled by:

1.) Increased settling time inside the column2.) Coalescer inside the column3.) Coalescer external to the column

E

F

R

S

E

R

F

S

F

S

E

R

E

R

F

SOR OR1 2 3



Flooding

Flooding – the point where the upward or downward flow of the dispersed phase ceases and a second interface is formed in the columnFlooding can be caused by:

• Increased continuous phase flow rate which increases drag on droplets

Primary Interfacef

F1

S

E

R

Primary Interfacef

F2

S

E

R

SecondInterface

F2 > F1



Flooding

Flooding can be caused by:• Increased agitation speed which forms smaller droplets which cannot overcome

flow of the continuous phase• Decreased interfacial tension – forms smaller drops – same effect as increased

agitation

Primary Interfacef1

F1

S

E

R

Primary Interfacef2

F2

S

E

R

SecondInterface

f2 > f1



Pilot Plant Testing

Column Selection Based Upon:1. Process Criteria

2. Physical/Chemical Properties

3. Laboratory Work

4. Experience

Test Method5. Experimental Design

6. Step-by-Step Optimization



Agitated Column Testing

• Set-up column (multiple inlets)

• Select continuous and dispersed phases

• Select initial operating conditions(capacity – S/F – No. Stages)

• Operate at increasing agitation speed (flooding)

• Based on results, vary:

1. Continuous phase

2. S/F vs No. Stages

3. Capacity

4. Other Variables(temp, pH, etc.)



Static Column Testing

• Set-up column (multiple inlets)

• Select continuous and dispersed phases

• Select initial operating conditions(capacity – S/F – height)

• Operate 3 different capacities

• Based on results, vary:

1. Continuous phase

2. S/F vs Column Height

3. Other Variables(temp, pH, etc.)



Extractor Flow Patterns

Ideal Plug Flow Actual Flow

This “axial” or “back” mixing causes concentration gradients that decrease driving force and therefore increase HETS

Y

X

Y

X



Generalized Scale-up Procedure

Pilot Scalef1

Q1

D1

H1

Feed Rate

f2

Q2

Feed Rate

D2Basic Scale-up Relationships:

D2/D1 = K1(Q2/Q1 )^M1

H2/H1 = K2(D2/D1 )^M2

f2/f1 = K3(D2/D1)^M3

Where: K1, M1 = Capacity Scale-up Factors K2, M2 = Efficiency Scale-up Factors K3, M3 = Power Scale-up Factors



Application – SCHEIBEL® Column

• Extraction of nitrated organics from spent acid stream using an organic solvent

• Reduce nitrated organic compounds from 3.9% to less than 50 ppm

• S/F ratio fixed by process at 3.9

• Equilibrium data indicated that 4.5 theoretical stages required




SCHEIBEL® Column Pilot Plant SetupNitrated Organics Extraction


Hot Oil

Spent Acid Feed

MCB Solvent

Aqueous Raffinate

Organic Extract

Interface




SCHEIBEL® Column Nitrated Organics Extraction

Column designed based upon results from the pilot plant tests:

•Diameter = 14” (D1)

• Expanded Head Diameter = 20” (D2)

• Bed Height = 9’-6” (A)

• Overall Height = 16’-4” (B)A

D1

D2

B



Application 2 - Recovery of Carboxylic Acids from Fermentation Broth

Broth generated from cellulosic materials – approx. 5% acidsLLE Goal: To achieve >95% recovery (high purity) and minimize solvent usageEthyl acetate selected solvent – but emulsified easily

Preliminary Data in RDC ColumnsDifficult operation due to emulsification< 90% acid recovery High S/F ratio – 2.0

KARR® Column Required

70



Pilot KARR® Column for Carboxylic Acids 1” diameter x 12’ Plate Stack

71

Hot Oil

Whole Broth Feed Ethyl Acetate


Aqueous Out

(Raffinate)

Organic Out (Extract Phase)



Results from Extraction Testing

• Process successfully tested in KARR® Column and data generated for scale-up

• KARR® Column is the correct design for this process which failed in RDC column

• S/F ratio improved to 1.5 (client expected 2)• 96-97% recovery at room temperature and 98-99% recovery at 40-45 C• Complete system (LLE + distillations) designed, fabricated, and installed• LLE testing identified “unknown” component

72KARR® and SCHEIBEL® are registered trademarks of Koch-Glitsch, LP.



KARR® Column DesignCarboxylic Acid Extraction from Broth

• Diameter = 22” (D1)

• Expanded Ends Diameter = 44” (D2)

• Plate Stack = 38’-0” (A)

• Overall Height = 50’-6” (B)

A D1

D2

B



Application - Aromatic Purification by Fractional Liquid-Liquid Extraction

•Light tar feed with polar aromatics (product) and non-aromatic impurities

•>90% recovery; 1% impurities

•Polar solvent for aromatics

•Alkane for non-polar impurities

•Preliminary Data in RDC ColumnsMany extraction stagesHigh ratio of non-polar to polar solventSignificantly more non-polar solvent stages required

74



PFD - Pilot Plant Setup: Aromatic Purification by Fractional Extraction

75

Mixed Polar Solvent

Organic Feed

Non-Polar Solvent (Alkane)

Stage 77

Stage 65

Stage 53

Stage 42

Stage 99

Stage 0

Extract Raffinate



Fraction Extraction Test Variables

• 65-99 agitated stages• 12-34 stages above feed• 42-65 stages below feed• Capacity 21 – 25.5 m3/m2 hr

• Polar solvent to feed ranged between 0.5: 1 and 1.4 : 1• Non-polar solvent to feed ranged between 1.1:1 and 3:1• Agitation speed 400-850 RPM

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Aromatic PurificationFinal Results – Design Basis

Scale-up design:Diameter 1778 mm (70”)Height 65 Agitated stagesFeed Stage 13 from topPolar solvent: Feed 0.7: 1.0Non-Polar: Feed 1.8: 1.0Internals = Variable Impeller Diameters94% recovery with <1.0% impurities

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Alcohol Extraction from Acrylates

Extraction of methanol from an acrylate stream using water as the solvent

Reduce methanol from 2.5% to less than 0.1%

S/F ratio specified by client as 0.32 wt. basis

Equilibrium data: distribution coefficient generated by KMPS, with average value of 5.3

KARR® Column Pilot Plant SetupAlcohol Extraction from Acrylates

Hot Oil

Water Feed

Acrylate Feed (methyl or ethyl)

Extract(H2O + Alcohol)

Raffinate(Acrylate Phase)

Interface


KARR® Column

1” Dia. x 8’ Plate Stack

Variable Plate Spacing

Extraction Technology Groupwww.modularprocess.com



KARR® Column Pilot Plant Scale-upMethanol Extraction from Acrylate

• Diameter = 45” (D1)

• Expanded Head Diameter = 68” (D2)

• Plate Stack = 26’-0” (A)

• Overall Height = 36’-8” (B)

A D1

D2

B






Extraction Experience

KMPS has supplied over 300 commercial extraction columns

KMPS has also supplied hundreds of pilot scale extraction columns

We have tested more than 200 different processes in the pilot plant

QUESTIONS?