Scientific presentation at Pittcon Conference 2016, Atlanta, 8th of March by Gasera Ltd. http://www.gasera.fi/

1. March 2016
Ship Emissions Monitoring with Laser-based
Cantilever-enhanced Photoacoustic Detection
Dr. Jaakko Lehtinen, Client Partner, Gasera Ltd.
Pittcon 2016, 8.3.2016, 10:45 am
Gasera Ltd. Tykistökatu 4, 20520 Turku, Finland

2. - 2 -
Why to monitor ship emissions?
Ships using marine fuel oil
release SO2 emissions
Ships using marine dieseloil
release NO2 emissions
Biogas ships release unburnt
CH4
Both SO2 and NO2 are air
pollutants
CH4 is a greenhousegas
NIOSH Relative Exposure Limits:
SO2 2ppm,NO2 1 ppm
US NationalAmbientAir Quality
Standards limits:SO2 only 75
ppb, NOx only 53 ppb!

3. SO2 and NO2 emission control
areas
ECA (emission control area)
Sulphur emission control areas (SECA) include the Baltic Sea, the
North Sea, the North American ECA, including most of US and
Canadian coast and the US Caribbean ECA
Allowed SO2 emissions from ships are notably lower in SECAs
Similarly NECA for nitrogen emissions
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https://www.bbc-chartering.com/informations/news/archive/2014.html

4. Timeline for tighter regulation fuels
The new regulation for sulphur content in
fuel in ECAs is a relatively new topic
From January 2015 the maximum allowed
Sulphur content in fuel in ECAs has been
0.1%
The regulations are becoming global in near
future
Global limit for sulphur content in fuel will
decrease from 3.50% to 0.50% from 1
January 2020, subject to a feasibility review
to be completed no later than 2018
Also, new tighter regulations for nitrogen
dioxide emission have been effective since
the beginning of 2016
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http://www.aecm aritime.com/eca

5. Motivation for emissions monitoring
Shipping companies can save around $10000
per day per ship by using illegal highersulfur
level fuel
New regulations costaround $45 billion per
year to the shipping industry
The emissions of an individualship are not
directly monitored
The SO2 contentin fuel is mainly determined
by taking samples straightfrom the fuel tank
of the ship and sending them to analysis
The inspectionscan be random occasional
checks orbased on suspicion
The inspectionsare performed by authorities
The ships often have two differenttanks for
operation in different areas
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Emissions monitoring is required
to reliably ensure that the
regulations are being obeyed!

6. - 6 -
Problems with current technologies
Different gases are detected with different
technologies
SO2, UV-fluorescence
CO2, Infrared
NO2, Chemiluminescence
CH4, Infrared
Different analyzeris required for every gas
compound
Air monitoring station with multiple expensive
analyzersand costly maintenance -> therefore
the numberof stations is limited
Already single analyzersare expensive
Different technologieshave differentsources for
uncertainty
https://www.portoflosangeles.org/environment/air_quality.asp
Air monitoring stations in the Port of Los Angeles

7. - 7 -
Solution
Multi-gas analyzerwith high sensitivity is
required
High selectivity is required because of the
ambientair background
Sub-ppb detectionlimit is required for SO2
Proposedsolution is based on cantilever
enhanced photoacoustic laserspectroscopy
Enough sensitivity to use Mid-infrared (MIR)
region instead of UV for SO2
Pressure can be lowered for sufficient
selectivity
High resolution laserspectroscopy is needed
as the SO2 absorption linesare normally
buried understrongerabsorption lines of
water

8. Optical cantilever microphone
Cantilever sensor
Over 100 times greater physical movement can be
achieved compared to conventional microphone
membrane – cantilever has very low string constant
1 N/m
Highly linear response
Optical readout system
Contactless optical measurement based on laser
interferometry
Measures cantilever displacements smaller than
picometer (10-12
m)
Extremely wide dynamic measurement range
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9. - 9 -
Concept for SO2 and CO2
A combination of quantum cascade laser
(QCL) and diode laser is used in conjunction
with the photoacoustic cell
A narrow linewidth QCL is used to measure
SO2 absorptionlines in MIR region
CO2 is measured in the NIR region with a
tunable diode laser

10. - 10 -
Simulations for SO2
A QCL operating between
1340-1350 cm-1 was
chosen based on the
simulations
Possible absorption lines
for detection are in 1343-
1344 cm-1 and 1345-1346
cm-1 regions
The strongest absorption features of SO2 in infrared
region are between 1300 and 1400 cm-1

11. - 11 -
Simulations for CO2
For CO2, a standard diode
laser was used
CO2 lines are well separated
and 2nd harmonic simulations
are not necessary
Selectivity is easily achieved
as the concentrations are
typically above 400 ppm

12. - 12 -
Realization
Prototype analyzerpictured underthe hood

13. - 13 -
Measured spectra
Higher concentration CH4 sample
was used to confirm the range of
the laser source
CH4 has a simple absorption
pattern in this range
Coarse tuning of the wavelength is
done by altering temperature
Fine tuning is done by altering
current
Wavelength modulation is done
with current
Optimal temperature for maximal
power output in the desired range
was determined

14. - 14 -
Measured spectra
SO2 sample was measured when the optimal temperature of the
laser was determined
Spectrum of SO2 has more features in this region than CH4
Based on the spectrum, the optimal spectral line was chosen

15. - 15 -
Achieved performance
Application requirementis sub-ppb leveldetection limit
Achieveddetection limitwith photoacousticsetup was 0.5 ppb
Typicalconcentrationin the application is below 100 ppb
Highersensitivity enables the placing of the monitoring stations further away
from the seaways
The analyzerwill be further tested againstthe SO2 reference method (UV-
fluorescence)by Finnish MeteorologicalInstitute FMI
Response time,linearity,repeatability,drift, pressure,temperature
Gas compound Integration time Detection limit
SO2
1 s 3.2 ppb
60 s 0.5 ppb
Achieved detection limits:

16. - 16 -
Concept for implementing all the
necessary gas compounds
Simulated concept for all required gas
components
Two GASERA ONE analyzers working in
slave/master configuration
Simulations are based on the
measurements made with SO2
Also ammonia (greenhouse gas) from
Denox scrubbers can be included in two
analyzer configuration
Gas compound Integration time Detection limit
NO2 10 s 0.2 ppb
CH4 10 s 0.5 ppb

17. HyperGlobal
Part of a HyperGlobal consortium
GASERA
Finnish Meteorological Institute
VTT- Technical research centre of Finland
University of Oulu
Rikola Oy
Aeromon Oy
Mosaic Mill Oy
Avartek
Idea is to provide a solution for reliable
emissions monitoring
UAV and fixed measurement stations
Consortium is funded by Tekes – the
Finnish Funding Agency for Innovation
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18. Booth #1657
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