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FT Waxes –

the Next Generation of Candle Fuel Helmut Gutberlet

2

Overview

• Introduction

• Fischer Tropsch Process

• Structure and Properties of FT Wax

• FT Wax in Candle Application

• FT Wax Burning Characteristic

• Sustainability and Outlook

3

We all want to have beautiful candles of all types.

Will we be able to make them all in future?

4

Introduction

Worldwide Wax Demand

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

2006 2011 2016 2020

Wax D

em

an

d i

n 1

000 t

on

s

Wax supply Wax shortageEstimated numbers

1 million tons 2.2 billion pounds

5

Introduction

Classification of Waxes

Polar

synthetic

waxes

6

Overview

• Introduction






7

Introduction

History of FT Process

Dr. Hans Tropsch

1889 - 1935

Prof. Dr. Franz Fischer

1877 - 1947

Inventors of the

Fischer-Tropsch (FT)

process in 1925

Kaiser-Wilhelm

Institute for Coal

Research, Mülheim,

Germany

8

Fischer-Tropsch Process

Some Hydrocarbon Molecules C24H50 n-alkane, linear

C7H16 iso-alkane, branched

C12H24 cyclo-alkane

Remark: FT waxes do not contain cyclo-alkanes

9


Desulphurization

Reformer

Distillation Hydrogenation

15 to 50 bar, 200 to 350 °C

H2O + CH4 → CO + 3 H2

(2n + 1) H2 + n CO → CnH(2n+2) + n H2O

Waxes:

Low-melt, 30 °C, 86 °F

.

.

.

High-melt

115 °C, 239 °F

FT Synthesis

CH4

Supply forms

- liquid

- solid

10


Feedstock Options

FT processes can be differentiated according to their feedstock

for synthesis gas production:

• Natural Gas – GTL, Gas to Liquid

• Coal – CTL, Coal to Liquid

• Biomass – BTL, Biomass to Liquid

11


Other Products

The FT process does not only make wax, it can produce a

variety of products:

• Diesel

• Naphtha

• Jet fuel

• Base oils

• Liquid paraffin

• etc.

12


Production Locations

Bintulu

Sasolburg

existing production

Qatar

13

Overview

• Introduction






14

FT Waxes – Structure and Properties

Crystals

orthorhombic crystals

cold and hard

hexagonal crystals

warm and soft

(melting point < 75 °C,167 °F)

congealing point

hot temperature cold

liquid solid solid solid

transition point

change of crystal type

no crystals

hot and liquid

15


View with Optical Microscope

Paraffin wax - crystal habit.

It crystallizes in the form of

needles.

FT wax - crystal habit.

It crystallizes in

lamellar form.

16


View with Electron Microscope

Paraffin wax crystals FT wax crystals

100 µm 30 µm

17


Gas Chromatography (GC) – PW Fully 129/133 °F

0

1

2

3

4

5

6

7

8

9

10

Sh

are

in

%

Number of C-Atoms

n-alkane 75 %

iso-alkane 25 %

Paraffin wax

Fully 54/56 °C

18


Gas Chromatography (GC), FT Medium-melt Wax

0

1

2

3

4

5

6

7

8

9

10

Sh

are

in

%

Number of C-Atoms

n-alkane 93 %

iso-alkane 7 %

FT medium-melt

19


Gas Chromatography (GC), Micro Wax

0

1

2

3

4

5

6

7

8

9

10

Sh

are

in

%

Number of C-Atoms

n-alkane 17 %

iso-alkane 83 %Micro wax

20


Congealing Points

FT waxes cover a wide range of melting and

congealing points:

from 30 to 115 °C, 86 to 239 °F

Terminology

FT medium-melt waxes:

50 to 70 °C, 122 to 158 °F

FT high-melt waxes:

70 to 115 °C, 158 to 239 °F

21


Differential Scanning Calorimetry (DSC), Paraffin Wax

-4

-3

-2

-1

0

1

2

3

4

10 20 30 40 50 60 70 80 90

Heat

Flo

w in

mW

/mg

Temperature in °C

Heating Cooling

Paraffin wax

Fully 54/56 °C,129/133 °F

22


Differential Scanning Calorimetry (DSC), FT Wax

-4

-3

-2

-1

0

1

2

3

4

10 20 30 40 50 60 70 80 90

Heat

Flo

w in

mW

/mg

Temperature in °C

Heating Cooling

FT medium-melt

23


Oil Content

The oily portion of FT wax is not identical to that of paraffin wax:

• The “oil” of FT wax contains mainly branched hydrocarbons

• The “oil” of paraffin wax contains mainly cyclic hydrocarbons

FT waxes (and paraffin waxes) can be subdivided into the

following categories:

Oil content

Fully refined wax ≤ 0.5 %

Semi refined wax > 0.5 – 3 %

Scalewax > 3 – 6 %

Slackwax > 6 %

High oil content paraffinic slackwax,

non hydrotreated.

24


Hardness, Penetration

0

20

40

60

80

100

120

140

160

180

200

20 25 30 35 40 45

Pen

etr

ati

on

in

0.1

mm

Temperature in °C

FT medium-melt

Fully 56/58

Microwax

FT high-melt

68 °F 113 °F

25


Viscosity

0

2

4

6

8

10

12

14

16

70 80 90 100 110 120

Kin

. V

isc

os

ity i

n m

m²/

s

Temperature in °C

FT medium-melt

Fully 56/58

Microwax

FT high-melt

158 °F 248 °F

26


Comparison with Paraffin Wax and Micro Wax

FT Medium

Melt Wax

Paraffin

Wax

FT High

Melt Wax

Micro Wax

Number of C atoms 20 – 45 20 – 45 20 – 110 20 – 75

n-alkane content 85 – 90 % 60 – 90 % 85 – 90 % 15 – 30 %

iso-alkane content 10 – 15 % 10 – 40 % 10 – 15 % 70 – 85 %

Aromatics 0 ppm 0 ppm 0 ppm 0 ppm

Sulphur 0 ppm ≤ 20 ppm 0 ppm ≤ 20 ppm

Congealing point 50 – 70 °C 122 – 158 °F

40 – 70 °C 104 – 158 °F

70 – 115 °C 158 – 239 °F

55 – 90 °C 131 – 194 °F

Oil content 0 – 4 % 0 – 6 % 0 – 2 % 0 – 4 %

Penetration @ 25 °C, 77 °F 10 – 40 [0.1 mm]

12 – 100 [0.1 mm]

< 10 [0.1 mm]

10 – 40 [0.1 mm]

Viscosity @ 100 °C, 212 °F 3 – 4,5 mm²/s

3 – 8 mm²/s

7 – 12 mm²/s

11 – 25 mm²/s

All waxes are hydrotreated. Food contact and pharmaceutical

grades of all waxes possible.

27

Overview

• Introduction






28

FT Waxes – Candle Application

General

FT waxes for candle production. What does that mean for

a manufacturer?

1) Supply forms

2) Storage

3) Candle types

4) Machines and production methods

5) Wicks

6) Colours and optical appearance

7) Fragrances

8) Other additives

29


Supply and Storage

1) Supply forms of FT wax

• Bulk liquid

• Slabs

• Pastilles

• Powder

2) Storage of FT wax

a) Liquid – standard tanks, stainless steel is not required,

carbon steel is sufficient. 20 °C (68 °F) above melting point

b) Solid – dry at room temperature, no direct sunlight

30


Candle Types and Production Methods

3) Candle types

• Pillar candles

• Jar candles

• Household candles

• Votive candles

• Dinner candles

• Tealights

• etc.

All candles with Ø ≤ 10 cm 4’’

are possible (one wick).

4) Production methods

• Extrusion

• Moulding

• Filling

• Pressing

• Drawing

• Dipping

31


Machine Selection

Existing machines can be used.

Modification is not necessary.

e. g. pillar stamp press

e. g. pillar moulding

32


Wick Selection

5) Proper wick selection is

the key for a good burning

candle

• FT waxes do not need new

wick types. All types of wicks

for paraffin wax are suitable

• Thickness of the wick might

be slightly thinner, because of

lower FT wax viscosity

• Wicks for FT wax need no

special chemical treatment

Standard wick for paraffin

wax is suitable

33


Colours and Optical Appearance

6) FT wax candles can be coloured with

standard candle colours (liquid and

solid)

• Dyes for through-colouring

• Pigments for overdipping with standard

overdipping waxes

• Lacquers for surface finishing

Optical appearance

• Transparency varies form translucent to

opaque (similar to paraffin waxes)

• Mottling effect is possible

• High gloss surface

34


No Dye

Fat

Paraffin Wax

FT Wax

Stearin

No dye

opaque

translucent

translucent

opaque

35


Red Dye

Fat

Paraffin Wax

FT Wax

Stearin

Each sample coloured with the same dye and dye concentration

36


Fragrance Selection

7) Fragrances for scented candles

• Fragrances that work well with

paraffin waxes can also be used with

FT waxes

• FT high-melt waxes can be used as

additive to improve oil binding

capability

• Fragrance intensity of “cold” and

“hot” FT wax candles are comparable

with paraffin wax candles

37


Other Additives

8) FT waxes are completely miscible with other materials

such as:

• paraffin waxes

• fats, e. g. soy fat, palm fat, tallow etc.

• fatty acids, e. g. stearin (vegetable and animal based)

• beeswax

• polymer waxes, e. g. PE-wax

• stabilizers Jet stream mixing

38

Overview

• Introduction






39

FT Waxes – Burning Characteristics

Melting of Wax

Infrared pictures of burning FT wax and paraffin wax candles

FT wax Paraffin wax Paraffin wax

Pillar candle, Ø = 100 mm

Sequence: 8 hours

Paraffin wax FT wax

Container candle, Ø = 60 mm

Sequence: 5 hours

FT waxes and paraffin waxes show similar melting behaviour

40


Emission Comparison of Candle Fuels

2007

emission study

2013

new emission study

41


Emission Comparison of Candle Fuels

Ø = 60 mm h

= 2

4 m

m

Maxi light candle

What was new in the 2013 study?

• Commissioned by Sasol Wax only

• FT wax tested

• Palm fat tested

• Paraffin waxes with different

sulphur concentrations were tested

Sulphur is a good indicator of

paraffin wax purity. It should be < 20

ppm

42


Emission Comparison, Study 2013

0

10

20

30

40

50

60

70

80

90

Palm fat Paraffin2 ppm S

Paraffin10 ppm S

Paraffin40 ppm S

Paraffin240 ppm S

FT waxsulphur free

Stearin

Ran

kin

g v

alu

e

Low ranking value is better,

it means less emissions.

Only the sample paraffin wax (240 ppm S) exceeds some air quality standards

Compounds tested:

PCDD/PCDF

PAH

Aldehydes

SO2

Particulate matter

43


Energy Content of Candle Fuels

FT wax and paraffin wax are pure hydrocarbons. The combustion

reaches highest emissions in form of heat and light.

10.95 10.95

13.06 13.06

0

2

4

6

8

10

12

14

Fat Stearin Paraffin wax FT wax

Energ

y c

onte

nt in

kW

h/k

g

44


Emission of Light, Brightness of Candle Flames

0

0,05

0,10

0,15

0,20

0 2 4 6 8 10 12 14 Fuel consumption g/h

Qu

otie

nt (e

ffe

ctivity)

[cd

*h/g

]

Beeswax Stearin Fat FT wax / Paraffin wax Trend line Trend line Trend line Trend line

Beeswax

Stearin Fat

FT wax / Paraffin wax

FT waxes have a highly effective light emission over a wide

range of fuel consumption rates

45

Overview

• Introduction






46

FT Waxes – Sustainability

Sustainability is a complex issue.

Merely looking at the topic of renewability

would be too simple

• Is a resource used up or not? All factors that speed up or slow

down this consumption need to be assessed

• Product quality is important when looking at sustainability

• Storage stability of FT waxes and long shelf life of FT wax

candles reduce waste in production and use

• FT waxes have particularly low emissions. FT waxes are

completely free of sulphur

• FT waxes are not in competition with food production

47

FT Waxes – Outlook

• FT waxes with properties good for candle making will be a

more significant part of the wax supply in future

• A world scale FT plant will be required every 7 to 10 years, at

the current rate of decline of paraffin wax supply

• Such a plant will introduce fully synthetic products with

constant properties as it is possible to make tailor-made cuts

at different melt-points from 50 to 100 °C (122 to 212 °F)

• FT waxes fulfil the growing tendency for improved purity in

consumer products

48

FT Waxes – Summary

FT waxes

• are synthetically produced pure hydrocarbons

• have properties very similar to paraffin waxes

• are suitable for making all candle types

• are suitable for all candle production methods

• can be blended with all candle fuels, colours and fragrances

• have good burning properties and lowest emissions

From a practical point of view FT waxes and paraffin

waxes are interchangeable for candle production

49

FT waxes will help to make beautiful candles

of all types also in future

50

Acknowledgements

Dr. Thorsten Butz

Dr. Hendrik Eberhard

Kerstin Knauer

Gary Kok

Uwe Kurras

Kai Lüdeke

Dr. Maik Malessa

Dr. Gernot Meyer

Dr. Mark Veit

Dr. Glenda Webber

51

Thank you for your Attention

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