Browse Publications Technical Papers 1999-01-3338
1999-09-28

Best Available Technology for Emission Reduction of Small 4S-SI-Engines 1999-01-3338

1

Small off-road 4-stroke SI-engines have extraordinarily high pollutant emissions. These must be curtailed to comply with the new Swiss clean air act LRV 98. The Swiss environmental protection agency (BUWAL) investigated the state of the technology. The aim was a cleaner agricultural walk behind mower with a 10kW 4-stroke SI-engine. Two engine designs were compared: side-valve and OHV.
A commercially available 3-way catalytic converter system substantially curtailed emissions: In the ISO 8178 G test-cycle-average, HC was minimized to 8% and CO to 5% of raw emissions. At part load points, the residual emission was < 1%. Simultaneously, fuel consumption improved 10%. Using a special gasoline (Swiss standard SN 181 163), the aromatic hydrocarbons were curtailed, e.g. Benzene < 1%, and fuel consumption further improved. Those results were confirmed in field tests. The engine is approved for retrofitting. Disquieting are the high emissions of ultrafine particulates: the catalytic converter only minimizes the volatile but not the solid particulates.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Real-Time Measuring System for Engine Exhaust Solid Particle Number Emission - Performance and Vehicle Tests

2006-01-0865

View Details

TECHNICAL PAPER

Plasma-Catalysis for Diesel Exhaust Treatment: Current State of the Art

2001-01-0185

View Details

TECHNICAL PAPER

Characterization of Diesel Crankcase Emissions

770719

View Details

X