1.Palm Oil Refining

(1)

PEMURNIAN

MINYAK SAWIT

(2)

•

Pemurnian (

purification

) bertujuan

) bertujuan untuk

untuk

menghilangkan senyawa ikutan yang sering

disebut sebagai

impurities

(kotoran) dalam

minyak

•

Perubahan minyak kasar (

crude oil

) menjadi

minyak makan (

edible oil

)

•

Meliputi satu atau lebih proses berikut:

degumming

, netralisasi a

, netralisasi atau physical refining

tau physical refining,,

bleaching

, dan deodorisasi

, dan deodo

risasi

TUJUAN

(3)

•

Pemurnian (

purification

) bertujuan

) bertujuan untuk

untuk

menghilangkan senyawa ikutan yang sering

disebut sebagai

impurities

(kotoran) dalam

minyak

•

Perubahan minyak kasar (

crude oil

) menjadi

minyak makan (

edible oil

)

•

Meliputi satu atau lebih proses berikut:

degumming

, netralisasi a

, netralisasi atau physical refining

tau physical refining,,

bleaching

, dan deodorisasi

, dan deodo

risasi

TUJUAN

(4)

•

Proses ekstraksi minyak

Proses ekstraksi minyak menyebabkan

menyebabkan

sejumlah senyawa non

sejumlah senyawa non trigliserida terbawa

trigliserida terbawa

•

Meliputi: asam lemak, gliserida, fosfatida,

sterol, tokoferol, hidrokarbon, pigmen (klorofil,

karoten), fragmen protein.

•

Jenis minyak yang

Jenis minyak yang berbeda: kotoran berbeda

berbeda: kotoran berbeda

•

Contoh: minyak hewani, CPO dan PKO :

asam lemak bebas; minyak canola: klorofil

•

Kotoran tertentu dikehendaki seperti sterol

dan tokoferol

JENIS-JENIS IMPURITIES

(5)

•

Menghilangkan senyawa yang tidak

dikehendaki tertentu dengan meminimalkan

kerusakan trigliserida

•

kotoran yang dihilangkan: asam lemak

bebas, fosfatida, gum, dll

•

Proses pemurnian meliputi: bleaching

(penghilangan warna), deodorisasi

(penghilangan bau), refining (penghilangan

asam lemak bebas), degumming

(6)

Proses pemurnian

PROSES

PROSEDUR

KOTORAN YANG DIHILANGKAN

Degumming

H

3 PO

4 , H

2 0,

70-80



C

fosfolipid, trace metal, pigmen,

karbohidrat, protein

Netralisasi

NaOH (alkali

lain)

Asam lemak, fosfolipid, pigmen, trace

metal, senyawa bersulfur, oil-insoluble,

water soluble

Pencucian

H2O

Sabun

Drying

Na2SO

4 anhidrat Air

Bleaching

Bentonit,

adsorben lain

Pigmen, produk hasil oksidasi, trace

metal, senyawa bersulfur, trace of soap

Filtrasi

Spent of bleaching earth

Deodorisasi atau

Physical refining

Steam under

reduced pressure

Asam lemak, MG dan DG, produk

oksidasi, produk dekomposisi pigmen,

pestisida, trace of oil-insoluble

(7)

Proses pemurnian secara kimiawi (kiri) dan fisik (kanan)

Storage of crude oil

•

Degumming

•

Netralisasi

•

Washing

•

Drying

•

Bleaching

•

Filtration

Storage of

partly refined oil

•

Bleaching

•

Filtration

Storage of

•

Deodorization

•

Polishing

•

Cooling

•

Steam refining

•

Polishing

•

Cooling

(8)

By Product

PROSES

BY-PRODUCT

Degumming

Lesitin

Netralisasi

Pencucian

Asam lemak

Steam refining

Asam lemak, mono dan

digliserida

(9)

DEGUMMING

•

Pada proses ini minyak dipanaskan dengan

penambahan asam fosfat

•

Perlakuan ini dilakukan jika sebagian besar

senyawa berfosfor dapat terhidrasi dan

menggumpal/tidak larut

(10)

NETRALISASI

•

Netralisasi merupakan perlakuan dengan

alkali yang dilakukan pada kondisi tertentu

sehingga kehilangan minyak netral

(trigliserida) serendah mungkin

•

Pemurnian fisik (physical refining atau steam

refining) merupakan alternatif lain untuk

menghilangkan asam lemak bebas

(11)

BLEACHING

•

Terutama ditujukan untuk menjernihkan

•

Dilakukan dengan pemanasan minyak

(80-180



C) tetapi biasanya dilakukan antara 90-120



C.

•

Pada kondisi tanpa oksigen dengan

menggunakan adsorben

•

Adsorben dapat berupa bentonit, fuller’s earth,

karbon aktif, silika amorf

•

Tingkat penggunaan adsorben adalah 0.2-2.0%

dari berat minyak

•

Minyak sawit dapat dibleaching dengan

(12)

DEODORISASI ATAU PEMURNIAN FISIK

•

Merupakan langkah terakhir proses pemurnian

yang bertujuan mendapatkan minyak yang tidak

berbau dan daya simpan tinggi

•

Proses ini terutama bertujuan menghilangkan

produk hasil oksidasi yang berperan terhadap

bau minyak

•

Dilakukan dengan pemanasan suhu tinggi

(170-250



C) pada tekanan rendah dengan

menggunakan uap air

•

Penggunaan suhu yang tinggi (lebih dari 220



C

beresiko terhadap streomutasi yang biasa terjadi

pada asam linolenat

(13)

(14)

(15)

(16)

EKSTRAKSI MINYAK SAWIT KASAR

(CPO, CRUDE PALM OIL)

•

Beberapa tahapan ekstraksi minyak dari

tandan sawit adalah:

1. Sterilisasi

2. Pelepasan buah (

bunch stripping

)

3. Digesti

4. Ekstraksi minyak

(17)

Klarifikasi dan Purifikasi

•

CPO yang diekstrak mengandung air, padatan,

dan partikel-pertikel terlarut yang harus

dihilangkan

•

Partikel serat dipisahkan dari CPO dengan

melewatkan minyak pada penyaring bervibrasi.

•

Pasir dan kotoran dipisahkan dengan cara

pengendapan

•

Air dipisahkan dengan cara pengendapan atau

sentrifugasi dilanjutkan dengan pengeringan

(18)

(19)

(20)

Komponen Minor

•

Komponen minor dalam CPO adalah fosfolipid,

karbohidrat, trace metal, ALB, mono- dan

digliserida, sterol, pigmen karotenoid, tokoferol,

tokotrienol, produk hasil oksidasi, dan

komponen-komponen berbau

•

Pemurnian mengurangi komponen pengotor

yang dapat mempengaruhi mutu minyak akhir

dengan tetap mempertahankan tokoferol dan

tokotrienol

•

Proses pengolahan setelah ekstraksi adalah

pemurnian dan fraksinasi

(21)

Refining Crude Palm Oil:

Unit Processes

(22)

Refining Bleaching Deodorizing

of Palm Oil

(23)

Neutralizing, Bleaching, Deodorizing

of Palm Oil

(24)

A. PHYSICAL REFINING

•

Dilakukan dengan steam distillation pada

suhu tinggi dan kondisi vakum

•

Terdiri dari dua tahap utama, yaitu

(25)

1. Pretreatment

•

Dilakukan dengan proses degumming

menggunakan asam fosfat dilanjutkan

dengan bleaching

•

Bleaching dilakukan dengan proses adsorpsi

pada kondisi vakum, suhu 90-130C,

dilanjutkan dengan filtrasi

•

Pretreatment mengurangi kadar fosfolipid,

(26)

2. Degumming

•

Pretreatment refers to the initial degumming of

crude palm oil with concentrated phosphoric acid

and the subsequent adsorptive cleansing with

bleaching clay.

•

Crude palm oil is dosed with phosphoric acid (80

–

85% concentration) at a rate of 0.05–0.2% (of the

feed oil), heated to 90–110C, and given a residence

time of 15

–

30 min before passing to the bleacher

where bleaching earth is added as a slurry.

•

The earth required ranges from 0.8 to 2.0%,

(27)

The purpose of the phosphoric acid is to precipitate

the nonhydratable phosphatides while the function

of the earth is fourfold:

•

to adsorb the undesirable impurities such as

trace metals, moisture, insolubles, and part of

the carotenoids and other pigments

•

to reduce the oxidation products

•

to adsorb the phospholipids precipitated by

the phosphoric acid

•

to remove any excess phosphoric acid present

(28)

Removal of Phosphoric Acid

•

Complete removal of residual phosphoric acid

in the bleaching stage is also critical as any

‘‘slip through’’ can result in the rapid rise of

free fatty acid content and color of the final

RBD oil

•

As a further assurance, a suitable quantity of

calcium carbonate is often added after dosing

of the bleaching earth to the degummed oil,

to help neutralize the residual phosphoric

(29)

3. Bleaching

•

Bleaching is carried out under a vacuum of 20

–

25 mmHg and at a temperature of 95

–

110C with retention

time of 30

–

45 min

•

The slurry containing the oil and earth is then filtered to

recover a clear, light orange color pretreated oil

•

Usually a small amount of diatomaceous earth is used

to precoat the filter leaves to improve the filtration

process.

•

As a quality precaution, the filtered oil is polished

(30)

Loss of Oil

•

This is essential as the presence of spent earth

particles in the pretreated oil reduces the

oxidative stability of the final RBD oil

•

The spent bleaching earth from the filter

normally contains about 20

–

40% oil, and this

is the major source of oil loss in the refining

(31)

4. Deodorization

•

The pretreated oil is then ready for

deacidification and deodorization.

•

The pretreated oil is first deaerated followed

by heating to 240

–

270C in an external heat

exchanger before pumping into the

deodorizer, which is kept under a vacuum of

2 –

5 mm Hg

•

Superheated high-pressure steam is now

(32)

•

Temperatures above 270C are to be avoided to

minimize loss of neutral oil, tocopherols/tocotrienols,

and also the possibilities of isomerization and

undesirable thermochemical reactions

•

Under such conditions and with the help of stripping

steam, the free fatty acids, which were still present in

the pretreated oil, are distilled together with the

more volatile odoriferous and oxidation products

such as aldehydes and ketones, which otherwise

would impart undesirable odor and taste to the oil

•

At the same time, the residual carotenoids present

are also thermally decomposed, and the end result is

the production of a light-colored, bland RBD palm

(33)

Cooling after Deodorization

•

To maximize the recovery of thermal energy,

the hot deodorized oil is heat exchanged

against incoming pretreated oil to be cooled

down to a temperature of 120

–

150C

•

Further cooling is effected by water down to

55 –

65C prior to storage

•

Antioxidant and citric acid, if required, are

(34)

(35)

Desirable Quality of Pretreated and

RBD Palm Oil from the Factory

(36)

B. CHEMICAL REFINING

•

Also called caustic refining, chemical refining

involves three stages:

•

(1) gum conditioning and neutralization

•

(2) bleaching and filtration

(37)

•

Alkali refining sesuai untuk minyak dengan

kadar ALB tinggi

•

Kelemahan

alkali refining

: terjadi

penyabunan minyak netral menyebabkan

refining loss

•

Steam refining

: hanya menghilangkan ALB

sehingga refining loss rendah

•

Syarat minyak untuk

steam refining

: kadar

fosfatida rendah dan tidak sensitif panas

(38)

1. Gum Conditioning and

Neutralization

•

The crude oil is heated to a temperature of

80 –

90C. Phosphoric acid of 80

–

85%

concentration is then dosed in at a rate of

0.05 –

0.2% (of the feed oil)

•

This serves to precipitate the phospholipids

•

After this, the degummed oil is further

(39)

Neutralization

•

A caustic soda solution of about 4 N (or 20 Be´)

concentration with a calculated excess (based on free fatty

acid content of the crude oil) of about 20%

•

The reaction between caustic soda and the free fatty acids in

the degummed oil results in the formation of sodium soap,

which is readily removed by a centrifugal separator

•

The lighter phase discharged consists mainly of neutralized oil

containing 500–1000 mg/kg of soap and moisture while the

heavy phase is mainly soap, insoluble impurities, gums,

phosphatides, excess alkali, and a small quantity of oil loss

through emulsification

(40)

Washing

•

The neutralized palm oil (NPO) is then

washed with 10

–

20% hot water to remove

traces of soap still present

•

After another stage of centrifugal separation,

the washed oil is then dried under vacuum to

a moisture level below 0.05%.

(41)

2. Bleaching and Filtration

•

The neutralized palm oil is treated with

bleaching earth in a similar manner as that

described in physical refining

•

In this case, the earth also removes traces of

(42)

3. Deodorization

•

The neutralized and bleached oil is then channeled to the

deodorizer in a similar manner to that in the physical

refinery

•

The oil is subjected to distillation at a temperature of 240

–

260C and a vacuum of 2–5 mm Hg with direct steam

injection

•

Under such conditions, residual free fatty acids, volatile

oxidation products, and odoriferous materials are removed

together with thermal decomposition of carotenoids

•

The final product, called neutralized, bleached, and

deodorized (NBD) palm oil is then cooled down to 60C and

passed through polishing filter bags before pumping to the

storage tanks

Tek. Peng. Nabati 2 - Teti Estiasih - THP

(43)

Refining Factor

•

The efficiency of the refining process is

(44)

Desirable Quality of Freshly Produced Intermediate

and Final Products in Alkaline Refining of Palm Oil

(45)

FRAKSINASI

•

Trigliserida utama dalam minyak sawit adalah

oleodipalmitin dengan titik leleh 37C dan

palmitodiolein dengan titik leleh 19C

•

Tujuan fraksinasi adalah menghasilkan fraksi

olein yang cair (slip melting point 21.6C dan

cloud point 8.8C) dan fraksi padat stearin

•

Fraksi olein digunakan terutama untuk minyak

goreng dan minyak masak, sedangkan fraksi

stearin digunakan untuk, margarin, shortening,

dan minyak goreng

•

Fraksinasi dilakukan dengan dua proses yaitu

(46)

(47)

(48)

(49)

Dry Fractionation

•

Minyak dipanaskan pada suhu 70-75C untuk

melelehkan inti-inti kristal

•

Minyak panas tersebut dimasukkan ke

dalam crystallizer dan didinginkan pada

suhu 18-20C selama 4-8 jam

•

Proses ini menghasilkan minyak dalam

bentuk sluri

•

Fraksi padat dan cair dipisahkan dengan

(50)

Detergent Fractionation

•

Pada proses ini pemisahkan fraksi padat dan

cair dalam sluri dari crystallizer dilakukan

dengan mencampur sluri dengan deterjen

•

Deterjen yang digunakan natrium lauril sulfat

atau magnesium sulfat

•

Pada proses sentrifugasi fraksi olein yang lebih

ringan terpisah dari fraksi akueous yang

mengandung stearin

•

Fraksi olein kemudian dicuci dan dikeringkan,

sedangkan fraksi stearin direkoveri dari fraksi

akueous dan deterjen didaur ulang

(51)

Solvent Fractionation

•

This process is the most expensive because of solvent loss, solvent

recovery equipment, much lower temperature requirement, and

stringent safety features

•

The process involves the use of solvents such as hexane or acetone

•

The oil is first dissolved in the solvent followed by cooling to the

desired temperatures to obtain the desired crystals

•

The miscella containing the partially crystallized oil and solvent is

then filtered under vacuum suction in an enclosed drum filter

•

The olein miscella and stearin miscella are then separately

distilled to remove the solvent and recover the fractions

•

Yield of olein is about 80%

•

The solvent process nowadays is only viable in the production of

(52)

(53)

Second Fractionation/

Double Fractionation

•

Dilakukan untuk mendapatkan superolein

dengan titik leleh dan titik kabut rendah dan

bilangan iodin tinggi

•

Palm Mid Fraction (PMF) diperoleh sebagai

fraksi stearin dari fraksinasi kedua ini

(54)

Jenis Asam Minyak Sawit dan Fraksinya

Jenis Asam

Lemak

Refined

Palm Oil

RBD Palm

Olein

RBD Olein (Double

Fractionation)

RBD

Stearin

PMF

Laurat

0.2

0.1

0.3

0.1 Miristat

1.1

1.0

1.5

1.2 Palmitat

44.0

39.8

36.6

52.0

51.0 Palmitooleat

0.1

0.2

0 Stearat

4.5

4.4

4.0

4.9

5.6 Oleat

39.2

42.5

44.8

33.3

34.0 Linoleat

10.1

11.2

12.6

7.6

7.4 Lunolenat

0.4

0.2

0.1

0.1 Arakhidat

0.4

0.7

0.3

0.6 Jenuh

50.2

45.8

42.4

59.0

58.5 MUFA

39.2

42.5

44.8

33.3

34.0 PUFA

10.5

11.6

12.8

7.7

7.5

(55)

Krakteristik Minyak Sawit dan Fraksinya

Karakteristik

Refined

Palm Oil

RBD Palm

Olein

RBD Olein (Double

Fractionation)

RBD

Stearin

PMF

Bil. iodin

53.3

58.0

61.4

44

42.5 Slip melting

point (



C)

36.0

21.6

19.0 44-56

Solid Fat

Content (%)

5



C

62.2

51.1

67.2

10



C

50.3

37.0

16.7

61.2

76.1

15



C

35.2

19.2

5.0

53.1

66.2

20



C

23.2

5.9

3.1

43.4

52.1

25



C

13.7

33.9

21.9

30



C

8.5

27.0

18.3

(56)

QUALITY ASSURANCE

•

The two main quality problems associated

with palm oil are hydrolysis, leading to

formation of fatty acids, and oxidation,

leading to rancidity

(57)

Hydrolysis

•

The hydrolysis of palm oil is promoted by the

presence of free moisture and heat and also by

lipolytic enzymes endogenous to the plant tissue

•

This mode of deterioration occurs during the

bruising of fruits in the harvesting and

transportation of the FFB to the mill and also their

extended storage under unfavorable conditions

•

In the case of oil during storage, the hydrolysis is

attributed to a chemical reaction that is

autocatalytic ith poor cold stability

(58)

Hydrolysis

•

The presence of high FFA in crude palm oil is undesirable:

•

(1) reduces the yield of RBD palm oil through higher loss of

PFAD by-product

•

(2) reduces the capacity of refining

•

(3) results in poor bleachability of crude oil and poor stability in

the final product

•

Crude palm oil with high FFA content invariably also contains a

high amount of partial glycerides, especially diglycerides

•

Interactions between the diglycerides and the triglycerides often

lead to formation of eutectics resulting in poor crystal formation

during fractionation, difficulty in separation of olein and stearin

by filtration, and also in production of olein with poor cold

(59)

Oxidation

•

Oxidation of oils and fats is due to prolonged exposure

to air

•

Palm oil is relatively more stable to oxidative

deterioration than the polyunsaturated vegetable oils

•

In the presence of trace metals such as iron and copper,

excessive oxidation at the olefin bonds of the oleic and

linoleic acids can occur, resulting in rancidity

•

Highly oxidized crude palm oil is known to have poor

bleachability and thus requires more bleaching earth

and more severe refining conditions, and the final

product will likely be of poor stability

(60)

Quality Assurance Measures in

Plantation and Milling

•

Availability of goodquality crude palm oil is a

prerequisite for the production of good-quality

refined palm oil products

•

The criteria for good-quality crude palm oil are:

•

Low free fatty acid content

•

Low in oxidation characteristics

•

Good bleachability

•

Low in trace metals and insoluble impurities

•

Moisture content of about 0.15

–

0.20%

•

(61)

DOBI = Deterioration of Bleachability

Index

•

DOBI, which is defined as the ratio of the

uncorrected absorba

uncorrected absorbance values at

nce values at 446 nm to

446 nm to

that at 269 nm, was introduced as a quality

parameter to differentiate the refinability of

good- and poor-quality crude palm oil

•

The relation to quality is DOBI >3, good; 2.4

–

2.9, fair, and <2.3, poor

(62)

Quality Control

Type

Action

Raw material

Each and every delivery must be carefully

inspected to ensure that specifications are met

and that the shipment is free from contamination.

Good raw material is a prerequisite to

good-quality product

FFB handling

Minimize bruising and sterilize as soon as possible

(24 hr)

Sterilization

optimize conditions, avoid overheating, do not

mix boiler condensate with crude palm oil

Clarification

eliminate water and impurities; use hermetic

system

(63)

Quality Control

Type

Action

In-process

materials

Regular analyses of important quality parameters will

serve as a check that proper processing has been

achieved

Process control

Proper processing conditions (dosage of processing aids,

temperature, pressure/vacuum, flow rate, etc.) must

be closely adhered to and monitored to ensure the oil

is processed correctly and to minimize undesirable side

reactions. In order to assess process efficiency, the oil

losses through spent clay or soapstock (as in the case of

alkaline refining only) must also be monitored

Finished products

Regular checks on the finished products must be

carried out to ensure compliance to quality

specifications before the products are permitted for

discharge to storage or shipment

(64)

(65)

PENGGUNAAN MINYAK SAWIT

dan FRAKSINYA

•

Palm oil, palm olein, dan palm stearin

masing-masing bersifat semisolid, cair, dan

solid pada suhu 25



C

•

Karena sifat plastisnya yang luas, minyak

sawit digunakan secara luas dalam produk

pangan dari yang bersifat cair sampai

(66)

Penggunaan dalam Produk Pangan

•

Minyak goreng/masak

•

Shortening dan lemak masak

•

Vanaspati (vegetable ghee)

•

Margarin

•

Cocoa butter substitutes

•

Es krim

•

Coffee whitener

•

Lemak untuk bakery dan biskuit

•

Mie instan

•

Filled milk

(67)

Penggunaan untuk Non Pangan

•

Oleokimia (asam lemak, fatty alcohols, fatty

amines, gliserol, dan metil ester)

•

Deterjen dan surfaktan

•

Sabun

•

Lilin

•

Pelumas

•

Kosmetik

•

Pelapis kaleng

•

Bahan bakar diesel

(68)

(69)