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Best Practice of High-Quality Lecithin Production. From Miscella-Clarification to Lecithin-Powder

Barbara Harten– Application Sales Manager

PRACTICAL EXPERIENCE: OILSEEDS DEEP PROCESSING

TECHNOLOGIES (LECITHIN))

• Lecithin

• Water degumming

• Lecithin drying

• Crude oil clarification.

• Lecithin de-oiling

• Summary

Content

2 High Quality Lecithin Production

Basics of Lecithn

• Lecithin belongs to the phospholipids, one part of the molecule is hydrophilic the other part

hydrophobic

• Degumming =Removal of phospholipids (gums) from fats and oils

• Phospholipids are phosphorous containing organic substances

• The content of phospholipids are determined by analysing the phosphorous content in the oils and

fats

• Factor to convert phosphorous to phospholipids: 30

• Hydratable gums are removed by adding water

• The quantity of gums are depending on the extraction method of the oil from the seed;

only pressing leads to a low total gum content with high hydratable gum content

High quality lecithin production 3

Gly

ce

rol Fatty Acid

Fatty Acid

Fatty Acid P O O

O

O-

Phospatidyl choline (lecithine)

Composition of phospholipids

• Hydratable phospholipids

• Phosphatidyl choline (PC)

• Phosphatodyl inositol (PI)

• Non-hydratable phospholipids

(calcium, magnesium and iron salts)

• Phosphatitic acid (PA)

• Phosphatidyl etholamine (PE)

Remark: Simplified model, not all PA and PE are NHP

Soybean Oil Rapeseed Oil Sunflower Oil

Phosphor content [ppm] 400 - 1200 200 – 900 300 – 700

Phospholipids content [%] 1.0 – 2.9 0.5 – 2.3 0.8 – 1.8

Phospholipids

distribution

[%]

PC (MW 784) 47 27 29 – 52

PI (MW 861) 24 17 11 – 22

PE (MW 742) 20 17 17 – 26

PA (MW 699) 9 39 15 -30

High Quality Lecithin Production


• Market price of soybean meal –

300 – 500 US$ per ton

• Market price of dried lecithin –

600 – 1.200 US$ per ton

• Market price for lecithin granulate

– 2 – 10 US$ per kg

• Growing interest for lecithin

granulates / powder in food

industry

• Growing interestest in lecithin

from sunflower and rapeseed oil

0

500

1000

1500

2000

2500

3000

3500

Price in US$ per ton

Lecithin market

5

• Emulsifier for food products

• Bread

• Margarine

• Chocolate

• instant drinks

• Animal feed

• Emulsification, digestion and

binding of dust during production

• Fish Farming

• Non food applications / technical

applications

• Cosmetics

• Pesticides

• Paint industry etc.

• What is Lecithin used for

Lecithin Usage


• Target quality of Lecithin

• Light Color – influenced strongly by solids in

the crude oil

• Low content of solids

• Technical use:

< 0.3%

• Food products:

target < 0.1%

6

Water-Degumming

Pressing

Seed Beans

Animal feed

Press oil

clarification

Extraction Press-Cake

Wet-Gums

Oil

Meal

Lecithin-Drying

Refining

Crude-

Lecithin

Lecithin-Deoiling

Crude-Lecithin

Lecithin

Powder

Miscella-Clarification

Water degumming


Lecithin recovery process overview

Water Degumming


• Removes only hydratable phosphatides

• Wet gums can be dried in a lecithin dryer and sold

as lecithin

• Refining of degummed oils causes lower oil losses

• Pre-caution for soap-stock splitting for yield

improvement of the alkaline neutralisation

• Improve storage and transportation stability of the

oil

8

• Process achievements:

• Residual phosphatides:

non-hydratables + max. 0,1 % hydratables

• Oil loss: max. 35 % oil in dried gums

• Moisture:

< 0.5 % without vacuum drying

< 0.1 % with vacuum drying

Water Degumming


• Process parameters:

• Oil temperature: 75 - 90 °C

• Water addition:

corresponding to the phosphatide content

• Hydration time:

with high shear mixing not required

with static mixers min. 30 minutes

9

Loss formula for neutralization:

Total Loss= ffa + phosphatides+ moisture+ impurities+ 0,3 %

Loss=0,6 +1,25* Total Loss

Losses water degumming:

AI = 65 %= 35 % oil in gums

:

Loss calculation alkaline neutralisation


Typical quality for crude sunflower oil:

• ffa = 1 %

• P crude = 800 ppm= 2,4 %

• P water degummed= 100ppm=0,3 %

• Moisture = 0,2 %

• Impurities= 0,2 %

Neutralisation without water

degumming

Neutralization combined with water

degumming

TL = 1 +2,4+0,2+0,2 + 0,3= 4,3 %

Losses = 0.6+ 1,25 * 4,3 = 5,97 %

TL = 1 +0,3+0,2+0,2 + 0,3= 1,96 %

Losses = 3,05 %

Gum content in the gum discharge=

800 ppm P-100ppmP = 700 ppm P *

30 =2,1 % gums/35 %Oil content=

0,73 % oil loss + 2,1% gums =

Loss = 5,97 % Loss = 5,88 %

Loss calculation


Yield gain 0,09 %

Profit:

300 t/d = 100.000 t/a x 0.09 % x 800 € = 72,000 €/a

1000 t/d= 330.000 t/a x 0,09 % X 800 € = 237,600 €/a

Water-Degumming

Pressing

Seed Beans

Animal feed

Press oil

clarification


Wet-Gums

Oil

Meal

Lecithin-Drying

Refining

Crude-

Lecithin

Lecithin-De-oiling

Crude-Lecithin

Lecithin

Powder


Lecithin drying


Lecithin recovery Lecithin recovery process overview

Effective Lecithin drying is necessary for:

• Storage stability

• Transportation cost

Best Practice Lecithin Drying

Important Factors :

• Temperature (∆ t low)

• Solid content in the lecithin in the dryer

• Design of the dryer (horizontal/vertical)

• Oil content

• Purity of the condensate

• High flexibility in terms of throughput capacity

• Low residence time in the dryer ( approx. 1 min)

Lecithin Drying


• Horizontal dryer and conical backward design :

One floor installation Is used for products , which agglomerate

to hard particles

example: lecithin form rape or sunflower seed,

particles are draught back to the feed side with milder

temperature less burning of particles

cheaper installation (one floor) easy maintained

Wider range of throughput capacity

Gap between the rotor and inner shell can be adjusted as

set up for different types of lecithin

• Vertical dryer :

Can be used for soy bean lecithin as this lecithin does not

intent to built hard particles

Cheaper apparatus

Design of Lecithin Dryer Short Path distillation


Lecithin-Drying

High Quality Lecithin Production 15

Water-Degumming

Pressing

Seed Beans

Animal feed

Press oil

clarification


Wet-Gums

Oil

Meal

Lecithin-Drying

Refining

Crude-

Lecithin

Lecithin-Deoiling

Crude-Lecithin

Lecithin

Powder

Miscella-Clarification Oil

clarification



When it is needed to produce a high quality lecithin it is a condition that

the oil must be clarified before degumming. That means that all the

solid impurities must be removed prior the degumming process, like:

• Fibers

• Proteins

This can be mane in several ways:

1. Hydrozyclon

2. Crude oil filtration

3. Clarification of the crude oil with separators

4. Miscella clarification

Crude oil clarification / filtration


• Amount of Particles

• Particle Size

• Particle size is the main limit for the clarification / filtration technology

• Particle Size distribution analyse should be done

Influence Parameters on Clarification


5 µm – Limit of Crude Oil Clarification/Filtration

2 µm – Limit of Miscella Clarification

50 µm – Limit of Hydrocyclon 15 -

Miscela size distribution particles (Drey May13).pdf

Crude Oil Filtration


Crude oil

Filtrated oil Filter

cake

Filter aid

• Use of filter aid

• A second filter or big intermediate tanks necessary

• Big installation area

• Specific manpower for operation and filter cleaning

• Needs steam for blowing the filter

• Oil losses in the spent filter aid

• Reposition for the filtering clothes

• Disposal of the filter cake

Risk= filter leakage

• In case of filter leakage the separators for degumming will have erosion

problems

• Filter aid and particles from the crude oil will contaminate the gum discharge

Crude Oil Filtration


Crude oil clarification


Soya flakes

Meal

Clarified oil

Hexane

EXTRACTION DESSOLVENTIZING DESTILLATION CLARIFICATION

21


• Continuous process

• No significant oil losses

• Without additional effluent stream

• Solids can be added to the

meal or returned to extractor

• Equivalent result as filtration

(Hexane insoluble in dried

lecithin typically 0.05 to 0.1 %)

• Low space requirement of the

installation

• No additional manpower required

• No oil losses in the filter aid

Crude oil clarification

Crude oil Clarified oil

Impurities

22

Soya flakes

Meal Clarified oil

Hexane

EXTRACTION DESSOLVENTIZING DESTILLATION + CLARIFICATION

Miscella clarification




Inert gas panel N2

Miscella Clarified

miscella

Impurities Model used by:

24

• No oil losses due to integration in extraction process

• No effluents

• No filter aid

• More efficient than crude oil filtration

(typically < 0.05% hexane insoluble in the dried lecithin)

• Low space requirement of the installation

• Now additional manpower required

• Additional advantage:

• Keeps the hexane distillation clean

(no cleaning during the year)

• Keeps steam economy constant

(no increase of vapor pressure to compensate fouling)

• Lighter Color of lecithin (Most important for lecithin quality)



Water-Degumming

Pressing

Seed Beans

Animal feed

Press oil

clarification


Wet-Gums

Oil

Meal

Lecithin-Drying

Refining

Crude-

Lecithin

Lecithin-De-Oiling

Crude-Lecithin

Lecithin

Powder


Lecithin De-Oiling



Lecithin-De-Oiling and Powder Production



Main Process

Overview Lecithin De-Oiling

Storage and Pre-

treatment of crude

lecithin

De-oiling

Drying

Grinding

Packing

Distillation

Rectification

Vent washing

Side process

Utilities

Cooling/chiller

Nitrogen Generation

Instrument air

Grinding

Lecithin De-Oiling


De-oiled

Lecithin

Acetone

Lecithin

Acetone / Oil

Miscella

Decanter Decanter


De-Oiling

The de-oiling is done in a two stage counter current

extraction using decanter the removal the oil/acetone mixture from

the lecithin.

Extraction temperature : 25 °C

M

M M

M

M M

4

7 8

1

2

6

Aceton

1

2

3

4

7

8

By means of a decanter centrifuge the oil containing acetone phase

is separated, and pumped to a storage tank

the acetone /oil mixer to the acetone recovery

The lecithin discharge of the first decanter is mixed with “fresh “acetone

( from the acetone rectification) and conveyed to the second decanter,

the lecithin discharge is pumped to the lecithin grinding,

the oil acetone phase back the first decanter

Crude Lecithin is mixed with the

Acetone /traces of oil containing

discharge of the second decanter

3

3

5

8

6


Storage and Pre-Treatment the Dried Lecithin

• The intermediate storage capacity

should be big enough for 48-72 h

storage time, each vessel must be

equipped with heating and cooling

system plus effective agitator

• During the filling of the vessel,

hydrogen peroxide is mixed with the

lecithin for disinfection

• Storage temperature 60 °C


Granulation

• The de-oiled lecithin from the discharge of the

decanter needs to be grind to enlarge the surface

• Only from grinded lecithin acetone can be

removed


Drying

• The drying of the lecithin is

done in two steps .

• Due to hazardous area caused

by the acetone, the first drying

is under nitrogen atmosphere

• Drying temperature 80-100°C

• The acetone is condensed by

means of ammonia and

recovered

Trockner 2

Trockner 1

• In the second dryer the acetone content is below the explosion point therefor

regular air can be used .


Grinding

• In the next step, the dried granulates are grinded to

powder by a fine impact mill.

• Due to the high dust content this process stage

needs to be

nitrogen purged under hazardous area regulation

• The high energy input leads to a high increase of the

gas circulation temperature therefore a cooling

system needs to be foreseen

• To protect the mill a metal protector is

installed upfront to the mill


Packing

• Can be done in 25 kg plastic bags

• As the lecithin is hydroscope, the packing

area must fulfill following ambient:

- max. 25 °C temperature

- max. relative humidity of 50-60 °C


Distillation of Acetone from Oil

• The distillation of acetone from oil is done in

a two stage falling film evaporator

• The oil can be mixed to the crude oil

• The acetone is condensed and convey to the

rectification stage


Rectification

• For the reuse of the acetone in the in the lecithin

de-oiling stage the acetone need to be purified

from water

• Even the dried lectin still contains water, which

would accumulate in the recycled acetone

• Max. acceptable water contend of the acetone for

de-oiling : ca. 0,5%

• Therefore a rectification of acetone from water is

permitted .


Vent Washing

• The vent need to be washed to prevent the

environmental from acetone vapours

• .the vent washing is done in 2 stages, as the wash

water temperature is responsible for effective

washing

• The first washing is done with cooled process

water, the second stage with ice water


Cooling

Cooling is necessary for many stages of the de-oiling

process:

For the removal of the acetone of the first drying step

of the lecithin

Ice water (2 °C) ) for the vent washing, condensation,..

• Lecithin is used for a lot of application in the food and feed industry. As a side effect the

quality of the lecithin especially in case of food use comes more into focus.

• Water degumming is well known since many decades for yield improvement of the

edible oil refinery and for better storage stability of the oil

• The by-product of the water degumming = wet gums are a valuable product. For selling

the water needs to be removed by a lecithin dryer, which need to be designed for best

quality lecithin

• To get a lecithin after the dryer with light color the impurities upfront to the water

degumming needs to be removed by

filtration

clarification

GEA propose the miscella clarification as the clarification effect is the best and the

availability in the oil extraction distillation is higher

• The de-oiling of the dried lecithin is the next step in the lecithin treatment but is also

quite cost intensive. Therefore it is only feasible for higher capacities and or special

markets.

Summary


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