FT Waxes –
the Next Generation of Candle Fuel
Helmut Gutberlet
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
2
We all want to have beautiful candles of all types.
Will we be able to make them all in future?
3
Introduction
Worldwide Wax Demand
1 million tons  2.2 billion pounds
Wax Demand in 1000 tons
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
2006
2011
Wax supply
2016
Wax shortage
2020
Estimated numbers
4
Introduction
Classification of Waxes
Polar
synthetic
waxes
5
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
6
Introduction
History of FT Process
Inventors of the
Fischer-Tropsch (FT)
process in 1925
Prof. Dr. Franz Fischer
1877 - 1947
Kaiser-Wilhelm
Institute for Coal
Research, Mülheim,
Germany
Dr. Hans Tropsch
1889 - 1935
7
Fischer-Tropsch Process
Some Hydrocarbon Molecules
C7H16
C24H50
n-alkane, linear
iso-alkane, branched
C12H24
cyclo-alkane
Remark: FT waxes do not contain cyclo-alkanes
8
Fischer-Tropsch Process
Reformer
FT Synthesis
(2n + 1) H2 + n CO → CnH(2n+2) + n H2O
CH4
Desulphurization
15 to 50 bar, 200 to 350 °C
H2O + CH4 → CO + 3 H2
Distillation
Waxes:
Low-melt, 30 °C, 86 °F
.
.
.
High-melt
Hydrogenation
115 °C, 239 °F
Supply forms
- liquid
- solid
9
Fischer-Tropsch Process
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
10
Fischer-Tropsch Process
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.
11
Fischer-Tropsch Process
Production Locations
Qatar
Bintulu
Sasolburg
existing production
12
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
13
FT Waxes – Structure and Properties
Crystals
no crystals
hot and liquid
hexagonal crystals
warm and soft
orthorhombic crystals
cold and hard
(melting point < 75 °C,167 °F)
hot
temperature
liquid solid
solid solid
congealing point
transition point
change of crystal type
cold
14
FT Waxes – Structure and Properties
View with Optical Microscope
Paraffin wax - crystal habit.
It crystallizes in the form of
needles.
FT wax - crystal habit.
It crystallizes in
lamellar form.
15
FT Waxes – Structure and Properties
View with Electron Microscope
100 µm
Paraffin wax crystals
30 µm
FT wax crystals
16
FT Waxes – Structure and Properties
Gas Chromatography (GC) – PW Fully 129/133 °F
10
9
n-alkane 75 %
iso-alkane 25 %
Paraffin wax
Fully 54/56 °C
8
Share in %
7
6
5
4
3
2
1
0
Number of C-Atoms
17
FT Waxes – Structure and Properties
Gas Chromatography (GC), FT Medium-melt Wax
10
9
n-alkane 93 %
FT medium-melt
iso-alkane 7 %
8
Share in %
7
6
5
4
3
2
1
0
Number of C-Atoms
18
FT Waxes – Structure and Properties
Gas Chromatography (GC), Micro Wax
10
9
n-alkane 17 %
Micro wax
iso-alkane 83 %
8
Share in %
7
6
5
4
3
2
1
0
Number of C-Atoms
19
FT Waxes – Structure and Properties
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
20
FT Waxes – Structure and Properties
Differential Scanning Calorimetry (DSC), Paraffin Wax
4
Paraffin wax
Fully 54/56 °C,129/133 °F
Heat Flow in mW/mg
3
2
1
0
10
20
30
40
50
60
70
80
90
-1
-2
-3
-4
Temperature in °C
Heating
Cooling
21
FT Waxes – Structure and Properties
Differential Scanning Calorimetry (DSC), FT Wax
4
FT medium-melt
Heat Flow in mW/mg
3
2
1
0
10
20
30
40
50
60
70
80
90
-1
-2
-3
-4
Temperature in °C
Heating
Cooling
22
FT Waxes – Structure and Properties
Oil Content
FT waxes (and paraffin waxes) can be subdivided into the
following categories:
Oil content
Fully refined wax
Semi refined wax
Scalewax
Slackwax
≤ 0.5 %
> 0.5 – 3 %
>3–6%
>6%
High oil content paraffinic slackwax,
non hydrotreated.
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
23
FT Waxes – Structure and Properties
Hardness, Penetration
200
180
FT medium-melt
140
Fully 56/58
120
Microwax
Penetration in 0.1 mm
160
100
80
FT high-melt
60
40
20
0
20
68 °F
25
30
35
Temperature in °C
40
45
113 °F
24
FT Waxes – Structure and Properties
Viscosity
FT medium-melt
Fully 56/58
Microwax
FT high-melt
16
Kin. Viscosity in mm²/s
14
12
10
8
6
4
2
0
70
158 °F
80
90
100
Temperature in °C
110
120
248 °F
25
FT Waxes – Structure and Properties
Comparison with Paraffin Wax and Micro Wax
FT Medium
Melt Wax
Paraffin
Wax
FT High
Melt Wax
Micro Wax
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
50 – 70 °C
40 – 70 °C
70 – 115 °C
55 – 90 °C
122 – 158 °F
104 – 158 °F
158 – 239 °F
131 – 194 °F
Oil content
0–4%
0–6%
0–2%
0–4%
Penetration @ 25 °C, 77 °F
10 – 40
12 – 100
< 10
10 – 40
[0.1 mm]
[0.1 mm]
[0.1 mm]
[0.1 mm]
3 – 4,5
3–8
7 – 12
11 – 25
mm²/s
mm²/s
mm²/s
mm²/s
Number of C atoms
Congealing point
Viscosity @ 100 °C, 212 °F
All waxes are hydrotreated. Food contact and pharmaceutical
grades of all waxes possible.
26
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
27
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
28
FT Waxes – Candle Application
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
29
FT Waxes – Candle Application
Candle Types and Production Methods
3) Candle types
4) Production methods
• Pillar candles
• Extrusion
• Jar candles
• Moulding
• Household candles
• Filling
• Votive candles
• Pressing
• Dinner candles
• Tealights
• etc.
• Drawing
• Dipping
All candles with Ø ≤ 10 cm  4’’
are possible (one wick).
30
FT Waxes – Candle Application
Machine Selection
Existing machines can be used.
Modification is not necessary.
e. g. pillar stamp press
e. g. pillar moulding
31
FT Waxes – Candle Application
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
32
FT Waxes – Candle Application
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
33
FT Waxes – Candle Application
No Dye
translucent
opaque
Fat
FT Wax
opaque
translucent
Paraffin Wax
Stearin
No dye
34
FT Waxes – Candle Application
Red Dye
Fat
FT Wax
Paraffin Wax
Stearin
Each sample coloured with the same dye and dye concentration
35
FT Waxes – Candle Application
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
36
FT Waxes – Candle Application
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
37
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
38
FT Waxes – Burning Characteristics
Melting of Wax
Infrared pictures of burning FT wax and paraffin wax candles
Paraffin wax
FT wax
Container candle, Ø = 60 mm
Sequence: 5 hours
FT wax
Paraffin wax
Paraffin wax
Pillar candle, Ø = 100 mm
Sequence: 8 hours
FT waxes and paraffin waxes show similar melting behaviour
39
FT Waxes – Burning Characteristics
Emission Comparison of Candle Fuels
2007
emission study
2013
new emission study
40
FT Waxes – Burning Characteristics
Emission Comparison of Candle Fuels
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
h = 24 mm
Sulphur is a good indicator of
paraffin wax purity. It should be < 20
ppm
Maxi light candle
Ø = 60 mm
41
FT Waxes – Burning Characteristics
Emission Comparison, Study 2013
90
Ranking value
80
70
60
50
Compounds tested:
PCDD/PCDF
PAH
Aldehydes
SO2
Particulate matter
40
30
20
Low ranking value is better,
it means less emissions.
10
0
Palm fat
Paraffin
2 ppm S
Paraffin
10 ppm S
Paraffin
40 ppm S
Paraffin
240 ppm S
FT wax
sulphur free
Stearin
Only the sample paraffin wax (240 ppm S) exceeds some air quality standards
42
Energy content in kWh/kg
FT Waxes – Burning Characteristics
Energy Content of Candle Fuels
14
12
10.95
10.95
Fat
Stearin
13.06
13.06
Paraffin wax
FT wax
10
8
6
4
2
0
FT wax and paraffin wax are pure hydrocarbons. The combustion
reaches highest emissions in form of heat and light.
43
Quotient (effectivity) [cd*h/g]
FT Waxes – Burning Characteristics
Emission of Light, Brightness of Candle Flames
FT wax / Paraffin wax
0,20
Beeswax
0,15
Fat
Stearin
0,10
0,05
0
0
2
4
6
8
10
12
14
Fuel consumption g/h
Beeswax
Stearin
Fat
FT wax / Paraffin wax
Trend line
Trend line
Trend line
Trend line
FT waxes have a highly effective light emission over a wide
range of fuel consumption rates
44
Overview
• Introduction
• Fischer Tropsch Process
• Structure and Properties of FT Wax
• FT Wax in Candle Application
• FT Wax Burning Characteristic
• Sustainability and Outlook
45
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
46
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
47
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
48
FT waxes will help to make beautiful candles
of all types also in future
49
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
50
Thank you for your Attention
51