MASS EMISSION RATES AND CHEMICAL CHARACTERIZATION OF PM 2.5 EMISSIONS FROM TWO MOTORCYCLES Deniz Karman and Colin Welburn Department of Civil and Environmental Engineering, Carleton University 1125 Colonel By Drive, K1S 5B6 Ottawa, Ontario, Canada Lisa A. Graham Environmental Technology Centre, Environment Canada 3439 River Road, K1A 0H3 Ottawa, Ontario, Canada 11TH CRC ON-ROAD VEHICLE EMISSIONS WORKSHOP San Diego, California March 26-28, 2001

Overview Considerations for PM2.5 sampling from vehicle exhaust Motorcycle emission measurement program Results & Discussion –PM2.5 Mass emission rates –Chemical characterization Comparison with diesel bus emissions Conclusions

Sample Collection Goals Dilute and cool the hot exhaust gases simulating the actual dilution process that occurs at the tailpipe or exhaust stack of a vehicle on the road Capture sufficient sample on a filter without causing changes in the physical and chemical composition of the particulate matter

Requirements of Dilution System Easily cleaned between tests. Useful for light duty gasoline and diesel vehicles and heavy duty diesel vehicles. Residence time appropriate for collecting primary particle emission samples Adequate conditioning of dilution air Provide complete mixing of dilution air and hot exhaust before samples are collected

Requirements of Dilution System Simulate as much as possible real world dilution process Present dilute samples to the collection media at a temperature and relative humidity consistent with ambient conditions. Must be able to collect multiple, simultaneous samples using different sample collection methods and different sample media.

ERMD Dilution System Located in cold temperature test cell to simulate all seasons (25 to -20 °C) Exhaust transfer line from vehicle to tunnel is heated and relatively straight to reduce PM loss. Constructed of flanged pipe segments for easy cleaning. All samples collected under iso-axial, isokinetic conditions.

Critical Flow Venturi - Constant Volume Sampler

Multiple PM 2.5 samples collected in parallel from 2 isokinetic sampling probes in dilution tunnel

Motorcycle testing 2 motorcycles: –Suzuki 750 –Honda gasoline fuels: –Summer Grade Commercial (SGC) –Low-sulfur (2 ppmw) 3 driving cycles – LA4, US06, NYCC

Collecting Sufficient Mass More repeats of a test, same filter is exposed longer –2 X LA4 ; first one cold start, followed by second one –3 X US06 –3 X NYCC

PM2.5 Sample Analysis Gravimetric  mg/mile Chemical –Organic / Elemental Carbon –Ion Analysis –Ammonia –Sulphur Dioxide

PM 2.5 Emission Rates

Results of Motorcycle Testing - Gravimetric Analysis High degree of uncertainty in PM emission rates (5-94% RSD). Uncertainty linked to low mass of PM collected on filters. Cold Start emission rates not significantly different from Hot Start emission rates US-06 and NYCC produce significantly higher emission rates compared to FTP

OC/EC Analysis Quartz Teflon Traditional Method Supplemental Method T 1 Q 3 Q 1 Q 2

Organic Carbon in PM corrected for filter adsorption

Organic/Elemental Carbon Analysis Need to correct for sampling “artefacts” Correction method critical for accurate results Number of invalidated tests directly linked to mass of sample collected. EC emission rates below detectable limits

Measured Sulphur (SO 4 and SO 2 ) vs. Fuel S

Sulphur Balance - Motorcycles Fuel sulphur consumed >> sulphur collected as SO 2 and PM-bound SO 4. Causes: –SO 2 by-pass? –Gaseous sulphur species not identified?.

PM 2.5 Emission Rates - Diesel Bus on CBD

Conclusions –PM2.5 mass emission rates from motorcycles are 1/1000 of emissions from bus - approaching limit of gravimetric method of measurement –the effect of aggressive driving cycles is noticeable –Motorcycle PM2.5 virtually all organic carbon Current work: –Particle size distribution with SMPS and ELPI, potential for observing effect of driving conditions on emission rate and size distribution

Acknowledgement Contributions from the following programs are gratefully acknowledged: PERD (Government of Canada Panel on Energy Research and Development) TSRI - Health Canada (Toxic Substances Research Initiative) NSERC -PGS (Natural Sciences and Engineering Research Council of Canada, Post Graduate Scholarships)