Real Time and In Situ Monitoring of the

Crystallization of Palm Oil-based Products

using Focused Beam Reflectance

Measurement (FBRM)

Elina Hishamuddin

Malaysian Palm Oil Board, Malaysia

OVERVIEW Introduction

Palm oil

Palm oil fractionation

Focused beam reflectance measurement (FBRM)

Materials and Methods Crystallization experiments

Compositional analyses

Results and Discussion Palm Oil Crystallization - Crystals population

Palm Oil Melting – Melting mechanisms

Palm Olein Crystallization - Crystal size distribution & Crystallisation mechanisms

Palm Olein Blend with Legume Seed Oil – effect of blending on crystallization mechanism

Conclusions

2

PALM OIL

• Palm oil – largest produced vegetable oil in the world,

>59.5 million tonnes in 2014. (Source: Oil World Annual 2014)

• Palm oil mainly consists of a multicomponent mixture of:

• Triacylglycerols (TAGs): 94%

• Diacylglycerols, monoacylglycerols and free fatty acids:

6%.

• Serves as feedstock for a variety of industries, i.e. food,

oleochemicals, biofuels etc.

• Palm-based food products range from cooking oils, salad

oils to margarines and shortenings and confectionery fats .

3

PALM OIL FRACTIONATION

• Dry fractionation : controlled partial crystallisation of oil from the melt and

filtration of crystallized slurry

• Crystallisation : driven by differences in the melting points of the TAGs &

operating temperature

• Quality of subproducts depend on the operating conditions during the

crystallization stage and crystal characteristics such as size, numbers and

shape have a profound effect on the filtration stage.

4

Palm Oil

Palm Olein Palm Stearin

Super

Olein

Palm Mid

Fraction Soft

Stearin

Super

Stearin

Most crystallization studies are performed on static systems – Differential Scanning Calorimetry (DSC), polarized light microscopy (PLM), X-ray diffraction (XRD) etc.

Static systems do not accurately reflect the actual industrial process. Dynamic systems are less studied due to fewer available monitoring devices.

Particle characteristic studies – image analysis, laser particle counters, particle size analyzers.

Most require sampling the material and in some cases dilution -> changes material in study

Focused beam reflectance measurement (FBRM) – non-destructive technique capable of monitoring particle characteristics on-line in real time.

5

MOTIVATION

FOCUSED BEAM REFLECTANCE

MEASUREMENT (FBRM)

6

In-situ measuring device

Real time tracking of particle size, population and events.

No sampling or dilution required

Particle size range : 0.8 – 1000 µm

Particle size in chord length

Measurement depends on crystal orientation

Source : Mettler Toledo

CRYSTALLIZATION METHODS

• Material : 700 mL oil

• 1 L Mettler Toledo LabMax Automatic Lab

Reactor with LASENTEC FBRM Model D600L

• Agitation speed: 50 rpm

• Isothermal Crystallization time:

– Palm oil : 2 hours

– Palm olein : 6 hours

– Blended oil : 5 hours

• Morphological analysis by polarised

light microscope

7

FBRM

COMPOSITIONAL ANALYSES

Fatty acids composition

• ISO 5508:1990

• GC-FID Conditions

– Column : DB-23, 60m L x 0.25

mm i.d., film thickness 0.25 µm

– Oven T : 185 °C

– Injector & detector T : 240 °C

– Carrier gas : He @ 0.8 mL/min

– Split ratio 1:100

Triacylglycerols composition

• AOCS Method Ce 5c-89

• HPLC-RID Conditions

– Column : Purospher RP-18, 4.6

mm i.d. x 250 mm L, 5 µm

particles, 2 connected in series

– Column & detector T : 35 ° C

– Acetone:Acetonitrile = 63.5:36.5

– Flowrate : 1 mL/min

8

HPLC-RID GC-FID

PALM OIL CRYSTALLIZATION

9

PALM OIL CRYSTALLIZATION

10

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0

10

20

30

40

50

60

70

80

0 100 200 300

To

tal p

art

icle

s (

cts

/s)

Oil

tem

pe

ratu

re (

oC

) /

Fil

ter

cake

yie

ld (

%)

Time (min)

Total particles

Oil temperature

Filter cake yield

Hishamuddin et al. (2011), J. Cryst. Growth, 335, 172-180

Crystal population of palm oil crystallized at 32 °C

PALM OIL MELTING

11

0

2000

4000

6000

8000

10000

12000

0

10

20

30

40

50

60

70

80

0 100 200 300 400 500 600

Part

icle

co

un

ts (

Cts

/s)

Tem

pera

ture

(°C

)

Time (min)

Toil Fine particles

0.8 - 5.5 mm

Coarse particles

>88 mm

24°C

30°C 36°C

44°C

Hishamuddin et al. (2011), J. Cryst. Growth, 335, 172-180

Melting mechanism of pre-crystallized palm oil from 24 to 46 °C

Deagglomeration Melting

12

PALM OLEIN CRYSTALLIZATION

PALM OLEIN CRYSTALLIZATION

13

0

1000

2000

3000

4000

5000

6000

7000

0 50 100 150 200 250 300 350

To

tal C

ou

nts

(#

/s)

Isothermal hold time (min)

Agglomeration

Primary

Nucleation

9 °C

13 °C

15 °C

Secondary

Nucleation

Crystal population of palm olein crystallized at 9, 13 and 15 °C

Hishamuddin et al. (2011), Eur. J. Lipid Sci., 113(S1): 1-46

PALM OLEIN CRYSTALLIZATION

14

0

50

100

150

200

250

300

350

1 10 100 1000

Co

un

t/C

han

nel (#

)

Chord Length (µm)

9 °C

13 °C

15 °C

Hishamuddin (2014). Palm Oil Dev., 61, 12-13 & 21-25.

Crystal size distribution of palm olein crystallized at 9, 13 and 15 °C

PALM OLEIN CRYSTALLIZATION

15

Fatty acid composition of palm olein crystallized at 9, 13 and 15 °C

13.3 12.1 11.8

39.4 42.5 43.3

47.2 45.3 44.9

56

57

58

59

60

61

62

63

64

65

0

10

20

30

40

50

60

9 11 13

Iod

ine

Va

lue

(IV

)

Pe

rce

nta

ge

(%

)

Temperature (°C)

PUFA SFA MUFA IV

IV : Iodine value

PUFA : polyunsaturated fatty acids

SFA : saturated fatty acids

MUFA : monounsaturated fatty acids

16

PALM OLEIN CRYSTALLIZATION

0

10

20

30

40

50

60

9 13 15

Pe

rce

nta

ge

(%

)

Temperature (°C)

SUS SUU UUU

Major triacylglycerol groups of palm olein crystallized at 9, 13 and 15 °C

SUS : monounsaturated SUU : diunsaturated UUU : triunsaturated

17

OIL BLEND CRYSTALLIZATION

OIL BLEND CRYSTALLIZATION

18

Crystals population of palm olein blended with winged bean seed oil at 13 °C

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 50 100 150 200 250 300 350

Tota

l co

un

ts (

#)

Time (min)

Primary nucleation

Secondary nucleation

Palm

Olein

2.5%

WBSO

5%

WBSO

OIL BLEND CRYSTALLIZATION

19

Crystal size distribution of palm olein blended with winged bean seed oil at 13 °C

0

50

100

150

200

250

300

350

1 10 100 1000

Co

un

t/C

ha

nn

el (#

)

Chord Length (µm)

Palm Olein2.5% WBSO5% WBSO

OIL BLEND CRYSTALLIZATION

Fatty acid Palm Olein WBSO 2.5% WBSO in

palm olein

5% WBSO in

palm olein

C16:0 39.74 5.59 31.77 31.21

C18:0 4.30 3.90 3.95 3.95

C18:1 42.53 31.88 45.60 45.27

C18:2 11.21 37.13 15.74 16.27

C18:3 0.22 1.37 0.48 0.51

C20:0 0.43 1.03 0.34 0.35

C20:1 - 3.41 0.25 0.32

C22:0 - 11.90 0.35 0.61

C24:0 - 2.52 - -

Iodine value 56.63 95.05 67.72 68.42

20

Fatty acid composition of palm olein blended with winged bean seed oil at 13 °C

CONCLUSIONS

FBRM is a useful tool to characterize crystallization of palm oil-based

products and oils and fats systems, in general.

FBRM provides valuable information such as population, size distribution

and mechanisms of particle formation/disappearance.

In situ and real time data – representative of actual process conditions.

By complementing FBRM data with an imaging technique and

compositional analysis, more information on crystallization behavior can

be deciphered.

Utilization of FBRM enables proper control and optimization of

crystallization conditions to ensure production of optimum crystal

characteristics.

21

23