AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Comparison of Measurement Methods for Black Carbon in Diesel Engine Exhaust
SANNA SAARIKOSKI, Samara Carbone, Matti Happonen, Antti Rostedt, Topi Ronkko, Jyrki Ristimäki, Jorma Keskinen, Risto Hillamo, Finnish Meteorological Institute
Abstract Number: 626 Working Group: Combustion
Abstract Black carbon (BC) is a by-product of both anthropogenic (e.g. fossil fuel) and natural incomplete burning (wild fires). Being a strong absorber of solar radiation it is a key component in global warming, and due to its health effects, an important factor of air pollution. Diesel engines are one anthropogenic source of BC. However, there is a gap of knowledge between the parameters required by the models and the current measurement results of diesel derived BC. The aim of this study was to compare three methods for measuring BC from diesel exhaust.
The measurements were performed in the emission laboratory of Wärtsilä Finland Oy in 2011. Medium speed diesel engine was tested with ultra-low sulphur diesel fuel. Eight engine load points were measured. Black carbon was measured with filter smoke number (FSN), multi-angle absorption photometer (MAAP) and soot particle aerosol mass spectrometer (SP-AMS). In addition to BC, particle size distributions were measured with two scanning mobility particle sizers and particle mass concentration with tapered element oscillating microbalance.
Black carbon concentrations in the diesel engine exhaust varied from 0.2 to 4.9 mg m-3 measured by the FSN. FSN measured BC from the undiluted exhaust whereas the MAAP and SP-AMS measured diluted emissions with the BC concentration ranging from 0.3 to 56 µg m-3. The BC concentrations from MAAP and SP-AMS correlated strongly with that from the FSN. However, BC concentrations from the SP-AMS were much lower than those from the FSN and MAAP. The dispersion of small and nonspherical particles in the aerodynamic lens inlet of the SP-AMS may cause particles to miss the laser vaporizer, and therefore they were not detected by the SP-AMS.
This work was supported by the the Cluster for Energy and Environment (CLEEN Ltd) Measurement, Monitoring and Environmental Assessment (MMEA) Work package 4.5.2.