The Effects of the Catalytic Converter and Fuel Sulfur Level on Motor Vehicle Particulate Matter Emissions: Gasoline Vehicles
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- 作者：M. Matti Maricq ; Richard E. Chase ; Ning Xu ; and Diane H. Podsiadlik
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：January 15, 2002
- 年：2002
- 卷：36
- 期：2
- 页码：276 - 282
- 全文大小：250K
- 年卷期：v.36,no.2(January 15, 2002)
- ISSN：1520-5851
文摘
Scanning mobility and electrical low-pressure impactorparticle size measurements conducted during chassisdynamometer testing reveal that neither the catalytic converternor the fuel sulfur content has a significant effect ongasoline vehicle tailpipe particulate matter (PM) emissions.For current technology, port fuel injection, gasolineengines, particle number emissions are 
2 times higherfrom vehicles equipped with blank monoliths as comparedto active catalysts, insignificant in contrast to the 90+%removal of hydrocarbons. PM mass emission rates derivedfrom the size distributions are equal within the experimentaluncertainty of 50-100%. Gravimetric measurementsexhibit a 3-10-fold PM mass increase when the activecatalyst is omitted, which is attributed to gaseoushydrocarbons adsorbing onto the filter medium. Bothparticle number and gravimetric measurements show thatgasoline vehicle tailpipe PM emissions are independent(within 2 mg/mi) of fuel sulfur content over the 30-990 ppmconcentration range. Nuclei mode sulfate aerosol is notobserved in either test cell measurements or during windtunnel testing. For three-way catalyst equipped vehicles,the principal sulfur emission is SO2; however a sulfur balanceis not obtained over the drive cycle. Instead, sulfur isstored on the catalyst during moderate driving and thenpartially removed during high speed/load operation.
2 times higherfrom vehicles equipped with blank monoliths as comparedto active catalysts, insignificant in contrast to the 90+%removal of hydrocarbons. PM mass emission rates derivedfrom the size distributions are equal within the experimentaluncertainty of 50-100%. Gravimetric measurementsexhibit a 3-10-fold PM mass increase when the activecatalyst is omitted, which is attributed to gaseoushydrocarbons adsorbing onto the filter medium. Bothparticle number and gravimetric measurements show thatgasoline vehicle tailpipe PM emissions are independent(within 2 mg/mi) of fuel sulfur content over the 30-990 ppmconcentration range. Nuclei mode sulfate aerosol is notobserved in either test cell measurements or during windtunnel testing. For three-way catalyst equipped vehicles,the principal sulfur emission is SO2; however a sulfur balanceis not obtained over the drive cycle. Instead, sulfur isstored on the catalyst during moderate driving and thenpartially removed during high speed/load operation.