Emissions – Cracking the Candle’s Code

Chemistry meets Cryptography

2nd World Candle Congress, Cancún, June 2007

by Dr. Michael Matthäi

2

Overview

General introduction

Ökometric study

Candle‟s code

Conclusion

3

Part 1: General Introduction

Enigmas are there to be cracked!

Code of the Quipu

of the Incas

Egyptian

hieroglyphics

4

The Aztec Calendar

The Cuetzpalin, lizard of the Aztec calendar, symbolises

a good day to work on reputation through action.

5

My Personal Involvement with an Enigma

for the last 3 Years

Pictograms vs. Hieroglyphics

6

The Candle & Science

"There is not a law under which

any part of this universe is

governed which does not come

into play and is touched upon in

these phenomena. There is no

better, there is no more open

door by which you can enter into

the study of natural philosophy

than by considering the physical

phenomena of a candle."

Michael Faraday, 1791 - 1867

7

Why are Candle Emissions being Focused on?

The consumer of today has the right to demand high quality products, the use of which do not present a hazard to people or the environment.

Global warming has created an increase in ecological awareness for all kinds of emissions.

Interest in indoor air quality has increased too

Unsubstantiated claims of sooting petroleum-based candles vs. non-sooting vegetable-based ones employed as marketing tools.

8

Candle Studies and Reports

All kinds of reports concerning candles, theircombustion and harmful substances related to

them have been gathered and classified:

more than 120 items since 1970

Extraction of relevant reports

concerning candle emissions during

combustion experiments in the lab:

24 international papers since 1988

9

Evaluated Reports (1988 – 2007)

24 international papers –

Is there a „Rosetta Stone‟

to „read‟ the Candle‟s Code

somewhere in them?

Rosetta Stonediscovered in 1799

Egyptian hieroglyphics

10

Part 2: The Ökometric Study

IGI

Sasol Wax

11

Collaborative Study

– The Illustrious Group of Code Crackers

NCA

AECM

12

Faced with an Enigma

“It may well be doubted

whether human ingenuity can

construct an enigma... which

human ingenuity may not, by

proper application, resolve.”

Edgar Allan Poe (1809 - 1849)

US short story author, editor, & poet

13

Purpose of the Study – to Crack the Candle’s Code

Aim to characterize candle

emissions for different materials

Evaluate results against exposure

limits for emitted chemicals

Particular matter, investigation of

particle size distribution

Investigate correlations between

visible and invisible emissions for

different candle materials (hourly

soot indexes)

14

Ökometric Offer

Ökometric

15

Evaluation – the Influence of Raw Materials

Beeswax

Paraffin Wax

Fats

Stearic Acid

16

Emission Components

Volatile organic

components

(VOC)

• Alkanes

• Benzene

• Aldehydes:

- Formaldehyde

- Acetaldehyde

- Acrolein

- Propionaldehyde

Gases

e. g. CO2

Burning

Semi / low volatile

organic components

• Dioxins/ Furans:

- PCDD

- PCDF

• PAH

Soot / Particulate matter

• Amount:

- mass

- soot index

• particle size:

- fine dust

• chemical characterisation

17

Money – Main Limitation of the Investigation

36,000 Euro

45,000 US$

A limited number of raw materials were tested

and only 2 of them were sooting systems.

Additives (e. g. fragrances, dyes…) were not

considered.

No detailed chemical analysis of soot

was undertaken.

18

Emission Concentrations

How little is 1 ng?

1 ng = 0.000000001 g

or

1 ng has the same ratio to 1 g

as

2 nickels (0.05 US$) to the weight of the Eiffel Tower

19

Comparison of the Raw Materials

All the raw materials examined

in the Ökometric study:

Emit the same group of

chemical substances.

Have emission quantities of

the same order of magnitude.

Have a comparable ratio on

a very low absolute level.

20

Scenario for Evaluation

Room volume = 5 m x 4 m x 2.5 m

= 50 m³ = 1766 ft³

5 m = 16.4„2.5

m =

8.2

„ 4 candles, Øtop = 63 mm

height = 90 mm

4 hours burning time

no air exchange!

21

Limit Values for the Calculation Scenario

AGW-values, TRGS 900: Work place limit values

MAK-values: Former maximum work place levels

TRK, TRGS: Former technical guidance values

MIK-values: Maximum immission concentrations

WHO-values: WHO air quality guideline for Europe

RfC: Inhalation reference concentration

STEL: Short-term Exposure Level

PEL: Permissible Exposure Level

LAI-values: LAI target value for air protection

IRK/ALOG: Guidance value

EU-values: European target values for ambient air

NIK / AgBB values: Lowest concentration of interest, committee for the health oriented evaluation of building products.

TRGS

22

Results of Evaluation

There are no general indoor air quality standards available for all the relevant emitted substances.

None of the considered air quality standards were exceeded, or even reached.

The sooting candles show increased emission rates in some cases, but are still within the limit values.

The emission increase for the sooting candles was not as high as expected.

23

Particulate Matter – Results from SEM

24

Particulate Matter

Energy-Dispersive X-ray Analysis (EDXA)

the raw material cannot be identified

from the diagram

25

Particulate Matter Results

No significant differences between the individual materials tested

SEM shows primary particles (spherical) – in accordance with the basic soot formation theory

Particles‟ growth through coagulation and agglomeration

The experimental conditions have a very strong influence on the size of the agglomerates.

The existing method to determine the particle size distribution is not suitable with the experimental set-up used.

26

Soot Index vs. Emission

There is a correlation between the visible and invisible

emissions.

No exact formula yet – but a marked tendency.

27

Our main Objective is the Production of Good Candles

All the raw materials

examined can be,

and are, used to

make good candles.

28

Part 3: The Candle’s Code

29

The Candle’s Code

24 international papers incl. the Ökometric study

Limited comparability, repeatability

Different methods

Missing information

(e. g. fuel flow, material, conditions)

Inconsistent evaluations, limits

National languages

Are uniform methods necessary?

30

Testing Matrix

Paraffin

WaxFat Stearin Beeswax Others

Pure Material X X X X X

Blends

Colours

Fragrances

Lacquers

Additives

31

The Candle’s Code

Rosetta Stone

The riddle of the candle‟s code

is hidden in „hieroglyphics‟

which need to be deciphered.

Evaluation of the 24 papers incl. the Ökometric study.

Which parameter can be used as our „Rosetta Stone‟?

32

Candle System

OH1nCOnO2

1n

2

3HC 2222n2n

OHnCOnO2

mn

2

3OHC 222m2nn

WickShape

Material

burning

condition

33

Example PAH: Distribution of the Results

*) not detectable

PAH

34

Example PAH:

Do the Results depend on the Candle’s Shape?

*) not detectable

35

Do the Results depend on the Wick?

The wick determines the fuel flow.

The fuel flow determines the flame

size.

The fuel flow determines the carbon

concentration in the flame.

The fuel flow influences sooting

behaviour.

36

Example PAH:

Do the Results depend on the Sooting Behaviour?

*) not detectable

37

Fuel Flow

What happens if a candle soots?

C-concentration in the flame is too high for complete combustion

Fragments of the candle material gather in the flame

The fragments both:

accumulate to greater visible pieces visible soot

react uncontrollably to a variety of different substances non visible emissions

The system is, then, out of control.

Conclusion: The occurrence of soot is also a clear sign for the presence of non visible emissions.

38

Fuel Flow vs. Emissions

The wick selection determines the fuel flow.

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

0 1 2 3 4 5 6 7 8 9 10 11 12

fuel flow V [g/h]

so

ot

ind

ex

/h

Vcrit1 (Material 1)

Vcrit2 (Material 2)

SI > 1/h: sooting candle

SI = 1/h: quality candle

39

The Candle’s Code

The fuel flow is our „Rosetta Stone‟. The fuel flow determines the:

burning time

brightness

flame size

emissions

non sooting

/ sooting

All future investigations must evaluate the results under consideration of the fuel flow.

g/hour

40

Part 4: Conclusion

Thesis:

The candle is a system.

All materials tested are suitable for

making good candles.

The key parameter for emissions is

the fuel flow.

41

Part 4: Conclusion

Thesis:

The critical fuel flow differentiates between

sooting and non sooting candles.

Below the critical fuel flow

the emissions are far lower

than air quality standards‟

limits.

Soot measurement is an

adequate quick check for

candle emissions too.

42

“Everything should be

made as simple as

possible, but not simpler.”Albert Einstein, 1879 - 1955

Formula for Success

High quality raw materials

+

Candle know-how (e. g. wick selection)

+

On going quality control (e. g. soot test)

=

Quality Candles

which pose no health threat

Candles have had, have, and will continue to have

a very positive image. Enjoy them.

44

The Temple of Ramses II with Seated Colossi of

Ramesses II at Abu SimbelDon’t Forget to be Proud of and Enjoy your Good

Products

45

Reference

I would like to thank the whole Sasol

Wax Candle Team for their support with

the preparation of this presentation.

Especially:

Helmut Gutberlet

and

Barbara Fertl

46

Thank you for your attention.