EXHAUST EMISSIONS OF DUAL FUEL SPARK IGNITION ENGINE FUELLED GASOLINE AND METHANOL

Today, more and more attention is paid to search for alternative fuels, which would be not only environmentally friendly, but also cost-competitive to petroleum fuels. In the recent years much attention is paid to investigations at adaptation of combustion engine to run on bio-fuels. Results of the investigations show, that methyl and ethyl alcohols could belong to one from the most promising and future bio-fuels, being a serious alternative to petroleum fuels. Interest in these fuels comprises such areas as exploration of raw materials to production of the alcohols, development of technology of their production, especially 2nd generation of ethyl alcohol, special fuelling and control systems, design changes of the engines fuelled with alcohols. In the present paper are shown test results of Fiat 1.3 Multipoint engine fuelled in dual fuel system with methanol and gasoline. In this engine one assembled prototype fuel supply system with duplex injectors on each cylinder, to injection of methanol and gasoline. Implemented system enables fuelling with gasoline only, with methanol only, or simultaneously with gasoline and methanol with any fraction of the methanol. Change of fuelling system and change of methanol fraction can be accomplished in course of engine operation. Performed investigations showed advantageous effect of the methanol on toxicity of exhaust gases. One confirmed reduction of emissions of hydrocarbons, nitrogen oxide and carbon dioxide. The biggest changes in the concentration occurred in case of fuelling with the methanol only, and amounted to: 2-3 times reduction of the THC, reduction of NO