solvent extractionsolvent retention. solvent extraction parameters. ... solvent. water effluent....

Solvent Extraction

AOCS Annual Meeting & ExpoOrlando, FL

May 2017

Oilseedmicrostructure

Oilseed microstructure

Typical Soybean Flake

Lets zoom in fora closer look


Oilseed Flake Cell Structure

0.38 mm Approx. 15 cells thick


Soybean Flake Cell Structure

0.38 mm

Lets zoom in further to view a single cell


25 μm

75 μm

Typical Soybean Cell


Protein Bodies

Cell Wall

Carbohydrates, Ash, etc.

Oil Bodies (0.2-0.5 μm diameter)

Typical Soybean Cell


Actual Soybean Cell

Protein Bodies

Cell Wall

Carbohydrates, Ash, etc.

Oil Bodies(0.2-0.5 μm diameter)

Yaklich/Murphy, USDA-ARS


Typical Oil BodyHuang, University of California

Triglycerides(blue)

Phospholipids(red)

Oleosin(yellow)

.2-.5 μm

Solvent ExtractionProcess

Seed Preparation Impact

The seed preparation process determines the portion of the cells whose walls are ruptured.

FLAKING – ruptures a portion of the cell walls

EXPANDING – ruptures a significant portion of the cell walls

PREPRESSING – ruptures a significant portion of the cell walls

Solvent Extraction Process

For cells with ruptured walls, oil is extracted quickly via:

LEACHING / WASHING

DIFFUSION / DIALYSIS

For cells with walls intact, oil is extracted slowly via:

Solvent Extraction Parameters

1. EXTRACTION CONTACT TIME2. NUMBER OF EXTRACTION STAGES 3. PARTICLE THICKNESS4. MISCELLA FLUX RATE 5. SURFACE MOISTURE6. TEMPERATURE7. SOLVENT RETENTION


Extraction contact time is the total time in which miscella immerses the material while descending down through the material layer.

1. Extraction Contact Time


Increasing the number of countercurrent extraction stages that approach equilibrium, shortens the total extraction time required.

It is important that each stage approaches equilibrium, and does not mix with adjacent stages to be effective.

Most commercial extractors have 6-12 extraction stages.

2. Number of Extraction Stages


Particle thickness determines the time required for the miscella in the cells to approach equilibrium with the surrounding miscella at each

extraction stage.

Seed type & material preparation have a significant impact:Soybean Expandates: 4 minutes/stage

Rapeseed Cake: 8 minutes/stage0.38 mm Soybean Flakes: 5 minutes/stage0.30 mm Soybean Flakes: 4 minutes/stage

The material preparation choice significantly impacts operating cost.

3. Particle Thickness


Miscella flux rate is the rate which miscella descends down through the material layer.

Critical in extractor design to minimize extraction stage mixing.

Material preparation has a big impact on the miscella flux rate:

Soybean Expandates: 41 m3/h/m2 or 1.4 m/min down through expandatesRapeseed Cake: 25 m3/h/m2 or 0.8 m/min down through cake0.38 mm Soybean Flakes: 19.5 m3/h/m2 or 0.6 m/min down through flakes0.30 mm Soybean Flakes: 12.5 m3/h/m2 or 0.4 m/min down through flakes

4. Miscella Flux Rate


A coating of surface moisture on the particles in the extractor impedes the ability for miscella to penetrate the coated

particles, preventing proper oil extraction.

Excess moisture in the air surrounding the flakes, expandates or cake conveyed to the extractor can condense on the surface of

the particles, causing a coating of surface moisture.

Proper preparation aspiration and conveyor insulation is critical for good extraction results.

5. Surface Moisture


The higher the extractor operating temperature, the faster the miscella diffuses through cell walls, and the faster the miscella in the cells approaches

equilibrium with the surrounding miscella.

When balancing extraction efficiency with safety and environmental concerns,

the extractor should ideally be operated just under the azeotropic solvent boiling temperature of 61-62°C.

6. Temperature


Solvent retention is the amount of weak miscellaleaving the extractor in the extracted solids.

The dripping time, material layer height, miscella flux rate, and supporting screen open area

all impact solvent retention.

Solvent retention is in the range of 26-30% in adequately sized extractors.

7. Solvent Retention


1. EXTRACTION CONTACT TIME2. NUMBER OF EXTRACTION STAGES 3. PARTICLE THICKNESS4. MISCELLA FLUX RATE 5. SURFACE MOISTURE6. TEMPERATURE7. SOLVENT RETENTION

Major Solvent ExtractorDesigns

Major Solvent Extractor Designs

Chain Conveyor Type

Crown Model III Extractor


Belt Conveyor Type

Desmet Ballestra LM™ Extractor


Rotary Compartment Type

Desmet Ballestra Reflex® Extractor


Linear Compartment Type

Lurgi Extractor


All of these major extractor designs can achieve similar oilextraction efficiency when adequately sized, fed a properly prepared product, and they are properly operated OPEX, CAPEX and maintenance requirements (reliability)

are the differentiating factors

Performance

MealDesolventizing

DT Unit Processes

Predesolventizing

Desolventizing

Toasting & Stripping

Steam Drying

DT Unit Processes

Predesolventizing

Purpose is to remove a minority of the solvent usingindirect steam heat to reducelive steam condensed into themeal and thereby save DC steam 10-20% of solvent removed 5766°C meal temperature 12% typical meal moisture

DT Unit Processes

Purpose is to remove the majority of the solvent using live steam 80-90% of solvent removedMostly direct steam latent heat Some added indirect steam heat 6699°C meal temperature 1220% meal moisture

Desolventizing

DT Unit Processes

Toasting & Stripping

Remove final traces of hexane Deactivate anti-nutritional factors Direct Steam Specific Heat Indirect Steam Heat 99-108°C Meal Temperature 2019% Meal Moisture 20-25 minutes (soybean)

DT Unit Processes

Steam Drying

Purpose is to both dry the meal to save DC steam, and to enable low pressure water vapor heat to be recovered in extraction Half of drying heat is from meal Half of drying heat is from trayWater vapor captured via

steam ejector for heat recovery

MealDrying & Cooling

DC Unit Processes

Meal drying

Meal cooling

DC Unit Processes

18-21% meal moisture in 102°C meal temperature in 13% typical meal

moisture out 63°C typical meal

temperature out 600 mm typical meal levelsMechanical gate level

control

Meal Drying

DC Unit Processes

13% meal moisture in 63°C meal temperature in 12.3% typical meal

moisture out 38°C typical meal

temperature out

Meal Cooling

Miscella Distillation


Approximately 94% of the solvent is evaporated in this process step using waste heat from the DT vent

Miscella composition entering is 20-30% oil & 70-80% solvent

Miscella composition exiting is 80-90% oil & 10-20% solvent

Critical heat recovery device

First Stage Solvent Evaporation


Second Stage Solvent Evaporation

Approximately 5% of the solvent is evaporated in this process step using fresh steamMiscella composition entering

is 80-90% oil & 10-20% solventMiscella composition exiting

is 96-97% oil & 3-4% solvent

2 Pr

ehea

ting

pass

es

Evap

orat

ion


Live Stream Stripping

Approximately 1% of the solvent is evaporated in this process step using fresh steamMiscella composition entering

is 96-97% oil & 3-4% solventMiscella composition exiting

is 99.995% oil & 0.005% solvent

Solvent Recovery

Atmospheric Vapor Condensation

Separation Tank

Atmospheric Condenser

Miscella Tank

First Stage Evaporator

MOS

Solvent Recovery

Extractor

DT

Vacuum Vapor CondensationO

il Stripper

Vacuum Condenser

Second Stage Evap.


Oil Dryer

Solvent Recovery

M.O

. StripperVacuum

Pre-Condenser

Solvent Recovery

Solvent / Water Separation

Vacuum Condenser Vacuum Pre-Condenser


Atmospheric Condenser

Solvent/Water Separator

solventwater effluent

Solvent Heating

Solvent Recovery

Solvent Heater(steam

heat)

Vacuum Precondenser

(waste stripper heat)

To Extractor

60°C

38°C

60°C

Condensate Preheater(condensate flash heat)

54°C

solvent

~99.95% solventis recovered andrecirculated tothe extractor

Mineral Oil System

From Sol vent RecoveryItem 20B/C

SOLVENT VAPORABSORBER

120

To Solvent RecoveryItem 32/34

To Solvent RecoveryItem 23A

Steam FromSteam And Condensate

To Steam And CondensateItem 46ATM

CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B

MINERAL OIL/MINERAL OIL

HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Final Vent Cooler

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Solvent Vapor Absorber

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Oil/Oil Heat Exchanger

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Mineral Oil Heater

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Mineral Oil Stripper

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Mineral Oil Cooler

Mineral Oil System



120





CWR


Vent T oA tmosphere

ATM

EXHAUSTVENT FAN

136

MINERAL OILCOOLER

181B


HEAT EXCHANGER

181A

MINERAL OILHEATER

121

MINERAL OILSTRIPPER

122

FINAL VENTCOOLER

20D

P122

TI20D

PI20D

TI20D

TT120

AT120

FA120

P120

PIP120

TIP120

LT120

LCVP120

PT120

PI136

PI120

FCV120

TI181B

TI181B

PI181B

TI181B

TI181A

PIP122

TIP122

LS122

PI122

FG122

PI121

TT121

ATM

TI121

PI122

TI122

TCV121

XV121

SC136

ATM

ATM

CWS

PI20D

TT120

TI20D

FT120

PSV122

PSV181B

FG20D

FT120

PSV181A

Solvent Vapor Absorber

Mineral Oil System

Thank you!

Tim KemperGlobal Operations Director,OFO Division

AOCS Annual Meeting & ExpoOrlando, FL

May 2017

Solvent ExtractionOilseed�microstructureOilseed microstructureOilseed microstructureOilseed microstructureOilseed microstructureOilseed microstructureOilseed microstructureOilseed microstructureSolvent Extraction�ProcessSeed Preparation ImpactSolvent Extraction ProcessSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersSolvent Extraction ParametersMajor Solvent Extractor�DesignsMajor Solvent Extractor DesignsMajor Solvent Extractor DesignsMajor Solvent Extractor DesignsMajor Solvent Extractor DesignsMajor Solvent Extractor DesignsMeal �DesolventizingDT Unit ProcessesDT Unit ProcessesDT Unit ProcessesDT Unit ProcessesDT Unit ProcessesMeal �Drying & CoolingDC Unit ProcessesDC Unit ProcessesDC Unit ProcessesMiscella DistillationMiscella DistillationMiscella DistillationMiscella DistillationMiscella DistillationSolvent RecoverySolvent RecoverySolvent RecoverySolvent RecoverySolvent RecoveryMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemMineral Oil SystemThank you!

solvent extractionsolvent retention. solvent extraction parameters. ... solvent. water effluent....

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