This document discusses air emissions monitoring methods for sulfur dioxide (SO2) at GlaxoSmithKline (GSK) in Ireland. It provides an overview of SO2 monitoring requirements and techniques. GSK currently uses non-dispersive infrared spectroscopy to continuously monitor SO2 emissions in compliance with EPA standards. Alternative techniques like fluorescence analysis and differential optical absorption spectroscopy are also described that could provide more sensitive or selective SO2 detection. In conclusion, GSK is meeting all regulatory standards but may consider updating methods in the future if standards change.

1. Air emissions monitoringAir emissions monitoring
- A case study with Glaxo Smith- A case study with Glaxo Smith
KlineKline.
Aim:
To evaluate the analytical methods for determining sulfursulfur
dioxidedioxide emissions.
What is the best approach for GKSB?
By: Matthew Harpur, Brian O’ Connell & Ian O’ Connor.By: Matthew Harpur, Brian O’ Connell & Ian O’ Connor.

2. The Biogeochemical Cycles in our Biosphere
 Ecosystems respond to
climate systems through
physical, biological &
chemical feedback
systems.
 Anthropogenic emissions
of SO2 alter the balance of
the sulfur cycle in our
biosphere.
 This has adverse effects
on human health and alters
the balance of the Earth-
atmosphere system;
Acid Air
Change in Earth’s
energy budget.
The Sulfur Cycle & the Environment.The Sulfur Cycle & the Environment.
SOSO22
SOSO4`4`
2-2-

3. The Environmental Impact ofThe Environmental Impact of
Anthropogenic SOAnthropogenic SO22 Emissions.Emissions.
 Anthropogenic sulfur emissionsAnthropogenic sulfur emissions to the
atmosphere are significant and can be larger in
magnitude than those from natural sources in
urban regions in the industrialised developed
world.
 Atmospheric sulfur compounds exists in aerosols –
condensed phase particles in stable suspension
with gases – e.g. hazes & smogshazes & smogs. Acidic aerosols
contain sulfate particles. Such aerosols adversely
impact on human health.
 Sulfate particles are derived from SO2 gas in air
scatter light and reduce amount of solar heat
reaching the Earth’s surface – add to ‘GlobalGlobal
Dimming’Dimming’ phenomenon.

4.  Monitoring of SO2 emissions is a fundamental aspect of an
environmental authorities air control policy.
 Primary inorganic pollutant gases play an important role in
atmospheric acidity. Sulfur dioxide is a primary inorganic gas
pollutant. It takes part in chemical reactions in the atmosphere and
produces secondary pollutants such as sulfate compounds in
particulate.
 These secondary pollutants formed in the atmosphere include acidic
sulfate aerosols.
The Environmental Impact ofThe Environmental Impact of
Anthropogenic SOAnthropogenic SO22 Emissions.Emissions.

5. GlaxoSmithKline (GSK)
 GSK is the second largest
pharmaceutical company in
the World.
 The company is a global
leader and a pioneer in all
elements of healthcare from
R&D and vaccines to all the
main therapeutic areas.
 The Cork facility was
established in Carrigaline in
1974 and employs over 400
people.
 The facility generates solid
waste from its production
processes which it deals with
on site.

6. Incineration at GSK
 There are three high
temperature toxic waste
incinerators at the site.
 The three units are designed to
burn solids,liquids and vapours
from chemical processes.
 The units operate at a
temperature of 1100 0
C and
there is 99.99% removal of the
toxic waste.
 By products of the incineration
include SO2.
 Each incinerator has a
continuous emission monitoring
system installed.
A schematic of the operations of a typical
incinerator
showing gaseous pollutant
formation.

7. Reasons For Continuous Monitoring
 Continuous emissions monitoring equipment is installed
for a number of reasons.
 Regulatory compliance.
 Monitoring of plant performance.
 Calculation of emissions inventories.
 Compilation of environmental impact assessments

8. Legislation
 The primary environmental legislation driving continuous
emission monitoring is the Integrated Pollution Prevention and
Control (IPPC) which is embodied in the IPPC directive of
1996.
 This requires all industrial operations covered by the directive
to obtain a permit from authorities within the country.
 The Permit is based on the concept of Best Available
Techniques (BAT) which is sometimes costly for plants to
adapt to BAT.
 The directive allows installations an eleven-year transition
period to achieve compliance beginning on the day that the
directive entered into force.

9. The EPA’s role
 GSK send the EPA quarterly reports of all continuous monitoring
data.
 An alternate to this is real time data gathering from industries by
direct computer link up.
 This is used in Germany however, the EPA feel that this would be
expensive and technically challenging to install for industries in
Ireland such as GSK.
 The EPA has a team that carry out spot checks on flue gas
monitoring, occasionally throughout the year to validate results.
 To date GSK have been in full compliance with EPA regulations
regarding SO2 emissions from the plant.
 The EPA consider their role in the future is unlikely to change unless
legislation is strengthened.

10. EPA Method of Analysis for SO2
 The EPA use a Horiba PG-
250 Portable Multi-gas
Analyzer when spot checks
are carried out at GSK
 The PG-250 is a portable
stack gas analyzer that can
simultaneously measure up
to five separate gas
components.
 The PG-250 uses non-
dispersive IR detection for
CO, SO2, and CO2.
 The performance of the PG-
250 has been tested and
verified under a number of
programs.
PG-250 portable stack
gas analyzer

11. Continuous Emission Monitoring Technologies
 Continuous emission
monitoring or automated
measuring systems can be
categorised into two types:
 Type 1: Extractive systems
 Type 2: In situ systems
 Extractive systems withdraw
flue gas continuously from
stack and transport it to the
analyser.
 In situ systems carry out most
of their operations in the stack.
 Point in situ carry out analysis
at a single point in the stack.
 Path monitors carry out
analysis usually over the entire
stack.
Extractive monitoring system
In situ monitoring
system.

12. Comparison of SO2 analysis techniques.
MonitoringMonitoring
SystemSystem
SystemSystem
DetailsDetails
AdvantagesAdvantages DisadvantagesDisadvantages
Simple non-dispersive
Infrared (NDIR)
Based on Beer
Lambert Law.
Low cost.
Reliable.
Suffers interferences
from CO2 and H2O
Luft Detector (NDIR) Works on same
basis as NDIR.
Reduces interference
associated with NDIR.
Susceptible to problems
associated with
vibration.
Fourier Transform IR
(FTIR)
Heart of the
system is the
interferometer.
Fast response time.
Fewer interferences
than IR.
Generates large
amounts of data.
Ultraviolet
Fluorescence (UV)
Based on the
absorption of
UV light.
Specific to SO2.
High Sensitivity &
selectivity
Quenching effect by
other molecules in the
sample gas.
Differential Optical
Absorption
Spectroscopy. (DOAS)
Based on Beer
Lambert Law.
Highly selective.
Extractive and in situ
Expensive to install &
high training demands.

13. Technique presently in use at GSK
 GSK are presently using a Perkin
– Elmer MCS 100 Multi
component Non –dispersive
infrared (NDIR) system for SO2
analysis.
 This is an extractive system.
 The principle of the method is
based on Beer lamberts law.
(A=ε x c x l).
 Many heteroatomic ( e.g.
SO2,CO2) gaseous molecules
absorb light in the IR region.
 In NDIR light is emitted from a
heated coil through a reference
cell and the sample cell.
MCS 100 Multi component Non –dispersive infrared (NDIR)
system for SO2 analysis.

14. Technique presently in use at GSK
 As the beam passes through
the sample cell the pollutant
molecule absorbs some light.
 The light energy entering the
cell will now have less energy.
 The energy difference is
detected by a solid state
detector.
 The ratio of the detector
signals from the cells gives the
light transmittance.
 This ratio can be related to the
pollutant gas concentration.
Courtesy of cascade-technologies, UK.
Typical IR spectrum

15. Limitations of NDIR
 A limitation of this method is
that gases that absorb light in
the same spectral region will
cause a positive affect.
 Water vapour and CO2 strongly
absorb in the IR region.
 At GSK these molecules are
removed by a scrubber,
decreasing interferences.
 Also, another solution to this
problem by using absorption
cells arranged in series.
 This is incorporated into
systems to enable accurate
A typical scrubber system
Scrubber

16. Luft Detector NDIR
 The Luft detector works on the
same basis as the simple NDIR.
 The reference cell and a sample
cell are arranged in series.
 The light energy is absorbed by
the SO2 causing the gas to heat
up.
 Differential heating caused by the
difference in IR light causes a
differential pressure between the
two cells.
 The pressure difference between
the two cells is detected by a flow
sensor.
Luft Detector with cells in parallel.

17. Luft Detector NDIR
 This dual beam analyser is a
standard method for analysis of
SO2 across Europe.
 It has received regulatory
approval in Germany.
 However, these detectors are
more susceptible problems
associated with vibration than
other detectors.
 The development of microflow
sensors has helped to
overcome this problem.
Luft detector unit.

18. Fourier Transform Infrared (FTIR)
Spectroscopy
 FT-IR is the preferred method of infrared spectroscopy and is growing in
popularity for the multi component analysis of stack gases.
 It produces a infrared spectrum with a unique combination of bands
corresponding to an individual species, creating a distinct fingerprint for the
sample.
Courtesy of Maine tech. UK.

19. What is FTIR?
 The heart of the system is the
interferometer in which the light from
the source is divided into two
beams.
 Beams pass through the sample cell
and then recombine resulting in a
signal.
 All information required to identify
and quantify the gases in the sample
is present in the interferogram.
 Interferogram signal is converted to
a frequency spectrum by a
mathematical technique called
Fourier Transformation.
A Typical Interferogram.

20. Advantages and Disadvantages of FTIR
 Advantages
 Analysers capable of measuring 50
determinants.
 Fewer interferences than IR
 Does not require frequent calibration.
 Typically have a range of 2.5 to 25 µm.
 Disadvantages
 Difficulty in obtaining a
representative background
 Generation of large amounts of
data from inferograms when
continuous emission monitoring
Real time FTIR analyzer: supplied by
Applitek, Venecoweg, 199810
Nazareth, Belguim.

21. Fluorescence spectroscopy is a powerful tool for the study
of chemical & photochemical species.
Absorption of UV radiation is followed by fluorescencefluorescence at
longer wavelengths.
Intensity of fluorescence is used to determine the
concentration of analyte.
Changes in concentration can be detected rapidly, changes in
fluorescence intensity within picoseconds can be detected.
Fluorescence signal is proportional to concentration and
therefore high sensitivity can be achieved.
Monitoring of Air using FluorescenceMonitoring of Air using Fluorescence

22. Sulfur dioxide molecules
absorb light at a specific
wavelength (214 nm) & emit
light at a longer wavelength.
Fluorescence occurs as
the molecules emit excess
energy and return to ground
state.
The distribution of wavelength
is dependent on intensity of
emitted energy. This is shown
in a fluorescence emission
spectrum.
SOSO22 Detection using Fluorescence.Detection using Fluorescence.

23. UV – Fluorescence detectors can be used in on-line monitoring systems.
Fluorescence is detected using a photomultiplier tube.
A hydrocarbon ‘scrubbing’ system removes interfering molecules prior to
measurement.
Air sample
intake
UV – Fluorescence SOUV – Fluorescence SO22
AnalyzerAnalyzer
Monitoring of SO2 using FluorescenceMonitoring of SO2 using Fluorescence
(as used by(as used by
Queensland AuthorityQueensland Authority
Austrailia).Austrailia).

24. Differential Optical Absorption
Spectroscopy - DOAS
 Applicable to extractive & in situ
systems
 Method principle is Beer-
Lambert Law.
 Light of different length is
transmitted across emission
stack.
 Light wavelength are selected
using – diode laser, photodiode
arrays or moving slits.
 Detector’s signal at wavelength
where no absorption occurs is
reference measurement.

25. DOAS – How it works
Courtesy of Enviro Tech. UK

26. DOAS - Extractive System features
 Measurement cell & heated
oven for the sample cell
 Heated sample line
including temperature
regulator
 Heated sample probe
including filter unit
 Sample pump to extract gas
via heated extraction line.
 Automatic calibration unit in
order to meet the
requirements from the local
environmental authorities.

27. Conclusions
 Glaxo Smith Kline have been fully compliant with
requirements with respect to SO2 emission to ambient
air.
 GSK use Non-dispersive Infrared technique for SO2
emission analysis.
 EPA use Non-dispersive Infrared technique for SO2
emission analysis as part of air emission compliance
programs.
 Alternative techniques are available, which include
analysis methods which are more sensitive and selective
with respect to SO2 detection.

28. Conclusions
 Fluorescence analysis includes techniques which use
detection methods such as Pulsed Fluorescence
Detectors (PFD) which are specific to SO2.
 Differential Optical Absorption Spectroscopy (DOAS) is
easily incorporated into stack systems that monitor for
multiple gas emissions.
 Under present legislation conditions including ‘Best
available techniques’ (BAT) there is no requirement for
change in SO2 analysis method at GSK.

29.  Ian McAuliffeIan McAuliffe
 Peter Webster
 Keith Golding
 Lynn Davies
 Robert McDowney
 Ruth Hopkins
Acknowledgements