Effect of oxygenates on exhaust emissions from two-stroke motorcycles.

The advantages of adding oxygenates to gasoline include their raising of the octane rating and their ability to reduce toxic compounds in the gasoline. A study of impacts of various oxygenates used in 50cc two-stroke motorcycle fuel was conducted, using the two most popular motorcycles in Taiwan, to determine the effect of oxygenates on exhaust emissions. Oxygenates used in the study were methanol, ethanol, benzene, methyl tert-butyl ether (MTBE) and isopropyl ether (IPE). Addition of oxygenates effectively reduced exhaust emissions. Of the oxygenates tested, with oxygenate content 7% by volume, MTBE was found to be the most suitable for reducing exhaust emissions. Results showed that total hydrocarbon (THC), CO, and NO(x) emissions decreased by 50%, 70%, and 60%, respectively, compared with emissions without any oxygenate added.